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Sebaugh, J. L. "Guidelines for accurate EC50/IC50 estimation." Pharmaceutical Statistics 10, no. 2 (March 2011): 128–34. http://dx.doi.org/10.1002/pst.426.
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Salazar, Carl, Ahmad M. El-Arabi, and Jacob J. Schmidt. "EC50 and IC50 Measurements of TRPM8 in Lipid Bilayers." Biophysical Journal 102, no. 3 (January 2012): 344a—345a. http://dx.doi.org/10.1016/j.bpj.2011.11.1887.
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Watcho, Pierre, Esther Ngadjui, Pepin Alango Nkeng-Efouet, Telesphore Benoît Nguelefack, and Albert Kamanyi. "Evaluation ofIn VitroUterotonic Activities of Fruit Extracts ofFicus asperifoliain Rats." Evidence-Based Complementary and Alternative Medicine 2011 (2011): 1–7. http://dx.doi.org/10.1093/ecam/nep221.
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The aim of the present study was to determine the uterotonic activities ofFicus asperifoliaand investigate its mechanism. The effects of aqueous and methanol extracts of the dried fruits ofF. asperifolia(0.05–1.60 mg mL−1) were evaluated on estrogenized isolated rat uterus in the presence and absence of atropine (1.73–55.27 nM), pyrilamine maleate (1.25 × 10−3to 40 × 10−3 M), indomethacin (0.06 × 10−5to 2.00 × 10−5 M) or hexamethonium (0.66 × 10−4to 21.43 × 10−4 M). Aqueous (EC50, 0.36 mg mL−1) and methanol (EC50, 0.22 mg mL−1) extracts as well as oxytocin (EC50, 0.02 nM), acetylcholine (EC50, 7.87 nM) and histamine (EC50, 0.76 nM) evoked concentration-dependent contractions of the uterus. Atropine, pyrilamine maleate and indomethacin concentration dependently blocked the response of the uterus to acetylcholine (IC50, 4.82 nM), histamine (IC50, 2.49 nM) and oxytocin (IC50, 0.07 nM), respectively, and to aqueous extract. Hexamethonium produced graded decreases in oxytocin-induced uterine contractions (IC50, 0.37 μM), but did not prevent the contractile effects of the aqueous extract (IC50, 9.88 μM). These results suggest thatF. asperifolia-induced uterotonic effect is related to the release of prostaglandins and contraction of the myometrial cells through muscarinic, oxytocic and H1histamine receptors. These data further give added value to the ethnic use ofF. asperifoliafor its abortificient and contraceptive properties.
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Umang Haribhai Gajjar, Niralee Kalpeshkumar Velhal, Hetvi Girdharbhai Parikh, Jayrajsinh Bhartbhai Parmar, Yash Bhut, and Viral Rupeshbhai Patel. "Evaluation of antioxidant activity of unpurified and purified datura seed." World Journal of Biology Pharmacy and Health Sciences 7, no. 1 (July 30, 2021): 030–35. http://dx.doi.org/10.30574/wjbphs.2021.7.1.0070.
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Aim: Evaluation of effect of shodhana process of datura seed (Datura stramonium) antioxidant activity. Methods: The datura was purified with two different processes viz. cow’s urine, and cow’s milk by Dolayantra method. Antioxidant activity was evaluated by in-vitro 1,1-Diphenyl-2-picryl hydrazyl (DPPH) radicals scavenging activity and Ferric reducing power ability (FRPA) assay. Result: cow urine purified datura (CUD) showed a significant effect in inhibiting DPPH, reaching up to 85.96% at concentration 1000 mcg/ml and its IC50 was 314.3 mcg/ml while Unpurified Datura Seed (UD) reaching up to 86.06% at concentration 1000 mcg/ml and its IC50 was 171.73 mcg/ml. The Cow Milk Purified Datura Seed (CMD) extract reach 69.72% at concentration 1000 mcg/ml and its IC50 value was 640. The IC50 value of Ascorbic acid was 23.35 mcg/ml. CUD showed a significant effect in reduction of ferric ion, reaching up to 85.59% reduction at concentration 1000 mcg/ml and its EC50 was 304.46 mcg/ml while UD reaching up to 86.11% at concentration 1000 mcg/ml and its EC50 was 280.28 mcg/ml. CMD extract reach 52.28% at concentration 1000 mcg/ml and its EC50 value was 1091.3mcg/ml.
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Hollande, F., J. P. Bali, and R. Magous. "Neurohormonal regulation of histamine synthesis in isolated rabbit fundic mucosal cells." American Journal of Physiology-Gastrointestinal and Liver Physiology 266, no. 3 (March 1, 1994): G395—G402. http://dx.doi.org/10.1152/ajpgi.1994.266.3.g395.
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In a population of rabbit fundic mucosal cells enriched in mucous and endocrine cells, gastrin and cholecystokinin octapeptide (CCK-8) were shown to increase dose-dependently histidine decarboxylase (HDC) activity with the same efficacy and high potencies [50% effective concentration (EC50) 0.389 +/- 0.041 and 0.275 +/- 0.011 nM, respectively], whereas pentagastrin was less potent (EC50 2.90 +/- 0.13 nM). L-365,260 and PD-135,666 inhibited gastrin- and CCK-8-stimulated HDC activity with a high potency [50% inhibitory concentration (IC50) 1.00 +/- 0.08 and 4.2 +/- 0.7 nM for gastrin-stimulated and 1.95 +/- 0.21 and 1.78 +/- 0.12 nM for CCK-8-stimulated HDC activity, respectively], whereas L-364,718 was 50 to 100 times less potent (EC50 100 +/- 2.5 and 91.2 +/- 3.1 nM, respectively on gastrin- and CCK-8-stimulated HDC activity). Carbachol also dose-dependently increased HDC activity (EC50 7.08 +/- 0.32 nM), and its effect was reversed by selective muscarinic-receptor antagonists with the following order of potency: pirenzepine (IC50 15.1 +/- 1.2 nM) > para-fluoro-hexahydro-siladifenidol (IC50 0.316 +/- 0.02 microM) > 11-2[(2-[(diethyl-amino)-methyl]-1-piperidinyl)acetyl]-5,11-dihydro-6H- pyrido[2,3-b][1,4]benzodiazepine-6-one (IC50 28.5 +/- 1.1 microM). Moreover, gastrin and carbachol were able to modify slightly but significantly both the Michaelis constant (Km) and the maximal velocity (Vmax) of HDC in the same way (18-20% reduction of the Km and 25-30% increase of the Vmax).(ABSTRACT TRUNCATED AT 250 WORDS)
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Zekovic, Zoran, Sasa Djurovic, and Branimir Pavlic. "Optimization of ultrasound-assisted extraction of polyphenolic compounds from coriander seeds using response surface methodology." Acta Periodica Technologica, no. 47 (2016): 249–63. http://dx.doi.org/10.2298/apt1647249z.
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Coriandrum sativum L. (coriander) seeds (CS) were used for preparation of extracts with high content of biologically active compounds. In order to optimize ultrasoundassisted extraction process, three levels and three variables of Box-Behnken experimental design (BBD) in combination with response surface methodology (RSM) were applied, yielding maximized total phenolics (TP) and flavonoids (TF) content and antioxidant activity (IC50 and EC50 values). Independent variables were temperature (40-80oC), extraction time (40-80 min) and ultrasonic power (96-216 W). Experimental results were fitted to a second-order polynomial model with multiple regression, while the analysis of variance (ANOVA) was employed to assess the model fitness and determine optimal conditions for TP (79.60oC, 49.20 min, 96.69 W), TF (79.40oC, 43.60 min, 216.00 W), IC50 (80.00oC, 60.40 min, 216.00 W) and EC50 (78.40oC, 68.60 min, 214.80 W). On the basis of the obtained mathematical models, three-dimensional surface plots were generated. The predicted values for TP, TF, IC50 and EC50 were: 382.68 mg GAE/100 g CS, 216 mg CE/100 g CS, 0.03764 mg/mL and 0.1425 mg/mL, respectively.
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Fidrianny, Irda, Veliana Virna, and Muhamad Insanu. "ANTIOXIDANT POTENTIAL OF DIFFERENT PARTS OF BOGOR PINEAPPLE (ANANAS COMOSUS [L.] MERR. VAR. QUEEN) CULTIVATED IN WEST JAVA-INDONESIA." Asian Journal of Pharmaceutical and Clinical Research 11, no. 1 (January 1, 2018): 129. http://dx.doi.org/10.22159/ajpcr.2017.v11i1.22022.
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Objective: The aims of this research were to observe antioxidant activities from different parts of Bogor pineapple (Ananas comosus [L.] Merr. Var. Queen) using two antioxidant testing methods which were 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) and correlation of total phenolic and flavonoid contents with their inhibitory concentration 50% (IC50) of DPPH and exhibitory concentration 50% (EC50) of FRAP.Methods: Each sample was extracted by reflux using different polarity solvents. Antioxidant activities were determined using DPPH and FRAP assays, total phenolic content (TPC) using Folin–Ciocalteu reagent, flavonoid content by Chang’s method, and correlation with their IC50 DPPH and EC50 FRAP were analyzed by Pearson’s method.Results: IC50 DPPH of various extracts of different parts of Bogor pineapple ranged from 0.13 to 68.17μg/ml. The ethyl acetate peel extract of Bogor pineapple presented the highest TPC (7.84 g GAE/100 g) while the highest total flavonoid content (10.84 g QE/100 g) was shown by ethyl acetate bract extract of Bogor pineapple. TPC in peel extract of Bogor pineapple had negative and significant correlation with their EC50 FRAP. The IC50 DPPH and EC50 FRAP of peel extract of Bogor pineapple showed positive and significant correlation.Conclusion: All different part extracts of Bogor pineapple (except n-hexane flesh extract, peel extract, and bract extract) were categorized as a very strong antioxidant by DPPH method. Phenolic compounds in peel extract of Bogor pineapple were the major contributor in antioxidant activities by FRAP method. DPPH and FRAP methods gave linear results in antioxidant activities of Bogor pineapple peel extract.
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Fidrianny, Irda, Veliana Virna, and Muhamad Insanu. "ANTIOXIDANT POTENTIAL OF DIFFERENT PARTS OF BOGOR PINEAPPLE (ANANAS COMOSUS [L.] MERR. VAR. QUEEN) CULTIVATED IN WEST JAVA-INDONESIA." Asian Journal of Pharmaceutical and Clinical Research 11, no. 1 (January 1, 2018): 129. http://dx.doi.org/10.22159/ajpcr.2018.v11i1.22022.
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Objective: The aims of this research were to observe antioxidant activities from different parts of Bogor pineapple (Ananas comosus [L.] Merr. Var. Queen) using two antioxidant testing methods which were 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) and correlation of total phenolic and flavonoid contents with their inhibitory concentration 50% (IC50) of DPPH and exhibitory concentration 50% (EC50) of FRAP.Methods: Each sample was extracted by reflux using different polarity solvents. Antioxidant activities were determined using DPPH and FRAP assays, total phenolic content (TPC) using Folin–Ciocalteu reagent, flavonoid content by Chang’s method, and correlation with their IC50 DPPH and EC50 FRAP were analyzed by Pearson’s method.Results: IC50 DPPH of various extracts of different parts of Bogor pineapple ranged from 0.13 to 68.17μg/ml. The ethyl acetate peel extract of Bogor pineapple presented the highest TPC (7.84 g GAE/100 g) while the highest total flavonoid content (10.84 g QE/100 g) was shown by ethyl acetate bract extract of Bogor pineapple. TPC in peel extract of Bogor pineapple had negative and significant correlation with their EC50 FRAP. The IC50 DPPH and EC50 FRAP of peel extract of Bogor pineapple showed positive and significant correlation.Conclusion: All different part extracts of Bogor pineapple (except n-hexane flesh extract, peel extract, and bract extract) were categorized as a very strong antioxidant by DPPH method. Phenolic compounds in peel extract of Bogor pineapple were the major contributor in antioxidant activities by FRAP method. DPPH and FRAP methods gave linear results in antioxidant activities of Bogor pineapple peel extract.
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Huang, Ren-Qi, and Glenn H. Dillon. "Functional Characterization of GABAA Receptors in Neonatal Hypothalamic Brain Slice." Journal of Neurophysiology 88, no. 4 (October 1, 2002): 1655–63. http://dx.doi.org/10.1152/jn.2002.88.4.1655.
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The hypothalamus influences a number of autonomic functions. The activity of hypothalamic neurons is modulated in part by release of the inhibitory neurotransmitter GABA onto these neurons. GABAA receptors are formed from a number of distinct subunits, designated α, β, γ, δ, ε, and θ, many of which have multiple isoforms. Little data exist, however, on the functional characteristics of the GABAA receptors present on hypothalamic neurons. To gain insight into which GABAA receptor subunits are functionally expressed in the hypothalamus, we used an array of pharmacologic assessments. Whole cell recordings were made from thin hypothalamic slices obtained from 1- to 14-day-old rats. GABAA receptor-mediated currents were detected in all neurons tested and had an average EC50 of 20 ± 1.6 μM. Hypothalamic GABAA receptors were modulated by diazepam (EC50 = 0.060 μM), zolpidem (EC50 = 0.19 μM), loreclezole (EC50 = 4.4 μM), methyl-6,7-dimethoxy-4-ethyl-β-carboline (EC50= 7.7 μM), and 5α-pregnan-3α-hydroxy-20-one (3α-OH-DHP). Conversely, these receptors were inhibited by Zn2+ (IC50 = 70.5 μM), dehydroepiandrosterone sulfate (IC50 = 16.7 μM), and picrotoxin (IC50 = 2.6 μM). The α4/6-selective antagonist furosemide (10–1,000 μM) was ineffective in all hypothalamic neurons tested. The results of our pharmacological analysis suggest that hypothalamic neurons express functional GABAA receptor subtypes that incorporate α1 and/or α2 subunits, β2 and/or β3 subunits, and the γ2 subunit. Our results suggest receptors expressing α3–α6, β1, γ1, and δ, if present, represent a minor component of functional hypothalamic GABAA receptors.
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Luyao, Harmie, Hendrik Luesch, and Mylene Uy. "GPCR Pharmacological Profiling of Aaptamine from the Philippine Sponge Stylissa sp. Extends Its Therapeutic Potential for Noncommunicable Diseases." Molecules 26, no. 18 (September 16, 2021): 5618. http://dx.doi.org/10.3390/molecules26185618.
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We report the first isolation of the alkaloid aaptamine from the Philippine marine sponge Stylissa sp. Aaptamine possessed weak antiproliferative activity against HCT116 colon cancer cells and inhibited the proteasome in vitro at 50 µM. These activities may be functionally linked. Due to its known, more potent activity on certain G-protein coupled receptors (GPCRs), including α-adrenergic and δ-opioid receptors, the compound was profiled more broadly at sub-growth inhibitory concentrations against a panel of 168 GPCRs to potentially reveal additional targets and therapeutic opportunities. GPCRs represent the largest class of drug targets. The primary screen at 20 µM using the β-arrestin functional assay identified the antagonist, agonist, and potentiators of agonist activity of aaptamine. Dose-response analysis validated the α-adrenoreceptor antagonist activity of aaptamine (ADRA2C, IC50 11.9 µM) and revealed the even more potent antagonism of the β-adrenoreceptor (ADRB2, IC50 0.20 µM) and dopamine receptor D4 (DRD4, IC50 6.9 µM). Additionally, aaptamine showed agonist activity on selected chemokine receptors, by itself (CXCR7, EC50 6.2 µM; CCR1, EC50 11.8 µM) or as a potentiator of agonist activity (CXCR3, EC50 31.8 µM; CCR3, EC50 16.2 µM). These GPCRs play a critical role in the treatment of cardiovascular disease, diabetes, cancer, and neurological disorders. The results of this study may thus provide novel preventive and therapeutic strategies for noncommunicable diseases (NCDs).
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Fidrianny, Irda, Siti Winarsih, and Komar Ruslan. "PHYTOCHEMICAL CONTENT AND ANTIOXIDANT POTENTIAL OF DIFFERENT ORGANS OF EGGPLANT (SOLANUM MELONGENA L.) GROWN IN WEST JAVA-INDONESIA." Asian Journal of Pharmaceutical and Clinical Research 10, no. 8 (August 1, 2017): 144. http://dx.doi.org/10.22159/ajpcr.2017.v10i8.18584.
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Objectives: The goals of this research were to evaluate antioxidant potential from different organs of eggplant (Solanum melongena L.) using two antioxidant testing methods which were 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) and correlation of total phenolic and flavonoid content with their inhibitory concentration 50% (IC50) of DPPH, and exhibitory concentration 50% (EC50) of FRAP.Materials and Methods: Each sample was extracted by reflux using different polarity solvents. The extracts were evaporated using rotary evaporator. Antioxidant activities were tested using DPPH and FRAP assays, determination of total phenolic and flavonoid content were carried out by ultraviolet-visible spectrophotometry and correlation with their IC50 of DPPH and EC50 of FRAP capacities were analyzed by Pearson’s method.Results: The lowest IC50 of DPPH scavenging activity 1.14 μg/ml and the lowest EC50 of FRAP capacity 49.80 μg/ml was given by ethanolic leaves extract of eggplant. Ethanolic leaves extract of eggplant also presented the highest total phenolic content (TPC) (8.87 g gallic acid equivalent/100 g), while the highest total flavonoid content was shown by ethyl acetate leaves extract (24.50 g quercetin equivalent/100 g). There was a significantly negative correlation between TPC in leaves and fruit extracts of eggplant with their IC50 of DPPH and EC50 of FRAP.Conclusions: All different extracts of eggplant organs (except n-hexane stem extract) were categorized as a very strong antioxidant by DPPH method. Phenolic compounds in eggplant leaves and fruit extracts were the major contributor in antioxidant activities by DPPH and FRAP methods. DPPH and FRAP showed linear results in antioxidant activities of eggplant leaves, fruit and stem extracts.
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Lima, Julianeli T., Jackson R. G. S. Almeida, José Maria Barbosa-Filho, Temilce S. Assis, Marcelo S. Silva, Emídio V. L. da-Cunha, Raimundo Braz-Filhod, and Bagnólia A. Silva. "Spasmolytic Action of Diplotropin, a Furanoflavan from Diplotropis ferruginea Benth., Involves Calcium Blockade in Guinea-Pig Ileum." Zeitschrift für Naturforschung B 60, no. 10 (October 1, 2005): 1093–100. http://dx.doi.org/10.1515/znb-2005-1013.
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Diplotropis ferruginea Benth. (Fabaceae) is a tree popularly known in Northeastern Brazil as “sucupira-preta”. In the present work, the isolation, identification and pharmacological activity of a furanoflavan-type flavonoid (2,3-trans-3,4-trans)-3,4,5,8-tetramethoxy-(6,7,2”,3”)-furanoflavan, which received the trivial name diplotropin is reported. The structure was determined by means of spectroscopic techniques, especially EIMS and 1D and 2D NMR. Diplotropin (10−8 −3 · 10−4 M) inhibited the phasic contractions induced by both acetylcholine (IC50 = 4.6±0.8 · 10−5 M) and histamine (IC50 = 2.3±1.1 · 10−5 M) in guinea-pig ileum. Diplotropin relaxed the ileum pre-contracted with KCl (EC50 = 3.9±1.1 · 10−6 M), acetylcholine (EC50 = 3.7±1.6 · 10−6 M) and histamine (EC50 = 4.4±1.4 · 10−5 M) in a concentration-dependent manner. As the maintenance of tonic contraction induced by these contractile agents involves Ca2+ influx through voltage-dependent Ca2+ channels, it is suggestive that this relaxation may be due to the blockade of Ca2+ influx through those channels. This hypothesis was confirmed by the observation that diplotropin antagonized (pD’2 = 4.83±0.37) CaCl2 induced contractions in Ca2+-free depolarizing medium (IC50 = 1.5±0.8 · 10−5 M).
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Subhadhirasakul, Sanan, Niwat Keawpradub, Charuporn Promwong, and Supreeya Yuenyongsawad. "Free Radical Scavenging and Cytoprotective Activity of Salacia Euphlebia Merr." Natural Product Communications 3, no. 2 (February 2008): 1934578X0800300. http://dx.doi.org/10.1177/1934578x0800300220.
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The present study reports the antioxidant activity of Salacia euphlebia stem extract. To understand the antioxidant activity of this plant, four compounds were isolated and elucidated as vitexin, 15α-hydroxyfriedelan-3-one, siphulitol and mangiferin. Mangiferin showed high free radical scavenging activity (EC50 1.10 ± 0.18 μg/mL) in comparison with quercetin (EC50 1.35 ± 0.02 μg/mL), while vitexin (IC50 37.6 ± 1.1 μg/mL) showed a good cytoprotective effect compared with quercetin (IC50 76.1 ± 1.0 μg/mL). This is the first report of the activities and bioactive compounds of S. euphlebia. These results may scientifically explain the folk and alternative-medicine use of this plant in longevity formulas.
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Yang, Jian, Yongtian Zhao, Jun Wan, Mingfang Jiang, Hong Jin, Ke Tao, and Taiping Hou. "Synthesis and Biological Evaluation of Novel Benodanil-Heterocyclic Carboxamide Hybrids as a Potential Succinate Dehydrogenase Inhibitors." Molecules 25, no. 18 (September 18, 2020): 4291. http://dx.doi.org/10.3390/molecules25184291.
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In order to discover new antifungal agents, twenty novel benodanil-heterocyclic carboxamide hybrids were designed, synthesized, and characterized by 1H NMR and HRMS. In vitro, their antifungal activities against four phytopathogenic fungi were evaluated, as well as some of the target compounds at 50 mg/L demonstrated significant antifungal activities against Rhizoctonia solani. Especially, compounds 17 (EC50 = 6.32 mg/L) and 18 (EC50 = 6.06 mg/L) exhibited good antifungal activities against R. solani and were superior to the lead fungicide benodanil (a succinate dehydrogenase inhibitor, SDHI) (EC50 = 6.38 mg/L). Furthermore, scanning electron microscopy images showed that the mycelia on treated media with the addition of compound 17 grew abnormally as compared with the negative control with tenuous, wizened, and overlapping colonies, and compounds 17 (IC50 = 52.58 mg/L) and 18 (IC50 = 56.86 mg/L) showed better inhibition abilities against succinate dehydrogenase (SDH) than benodanil (IC50 = 62.02 mg/L). Molecular docking revealed that compound 17 fit in the gap composed of subunit B, C, and D of SDH. Furthermore, it was shown that the main interaction, one hydrogen bond interaction, was observed between compound 17 and the residue C/Trp-73. These studies suggested that compound 17 could act as a potential fungicide to be used for further optimization.
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Huang, Huey-Chun, Hsiao-Fen Wang, Kuang-Hway Yih, Long-Zen Chang, and Tsong-Min Chang. "The Dual Antimelanogenic and Antioxidant Activities of the Essential Oil Extracted from the Leaves ofAcorus macrospadiceus(Yamamoto) F. N. Wei et Y. K. Li." Evidence-Based Complementary and Alternative Medicine 2012 (2012): 1–10. http://dx.doi.org/10.1155/2012/781280.
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The antimelanogenic and antioxidant activities of the essential oil extracted from the leaves ofAcorus macrospadiceus(Yamamoto) F. N. Wei et Y. K. Li have never been explored. The essential oil effectively inhibited mushroom tyrosinase activity (EC50= 1.57 mg/mL) and B16F10 tyrosinase activity (IC50= 1.01 mg/mL), decreased the melanin content (EC50= 1.04 mg/mL), and depleted the cellular level of the reactive oxygen species (ROS) (EC50= 1.87 mg/mL). The essential oil effectively scavenged 2,2-diphenyl-1-picryl-hydrazyl (DPPH) (EC50= 0.121 mg/mL) and 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) ABTS+radicals (EC50= 0.122 mg/mL). It also exhibited an apparent reducing power (EC50= 0.021 mg/mL) and metal-ion chelating activity (EC50= 0.029 mg/mL). The chemical constituents of the essential oil are ethers (55.73%), ketones (19.57%), monoterpenes (7.82%), alcohols (3.85%), esters (3.77%), sesquiterpenes (3.72%), and aromatic compounds (2.85%). The results confirm thatA. macrospadiceusessential oil is a natural antioxidant and inhibitor of melanogenesis.
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Sukrasno, Sukrasno, Slamet Tuty, and Irda Fidrianny. "ANTIOXIDANT EVALUATION AND PHYTOCHEMICAL CONTENT OF VARIOUS RICE BRAN EXTRACTS OF THREE VARIETIES RICE FROM SEMARANG-CENTRAL JAVA, INDONESIA." Asian Journal of Pharmaceutical and Clinical Research 10, no. 6 (June 1, 2017): 377. http://dx.doi.org/10.22159/ajpcr.2017.v10i6.16565.
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Objectives: The objectives of this research were to evaluate antioxidant activity from different polarities rice bran extract of three varieties of rice using two methods of antioxidant testing which were FRAP (Ferric Reducing Antioxidant Power) and DPPH (2,2-diphenyl-1-picrylhydrazyl), and correlation of total phenolic, flavonoid and carotenoid content with their EC50 of FRAP and IC50 of DPPH antioxidant activities. Methods: Extraction was conducted by reflux using different polarity solvents. The extracts were evaporated using rotary evaporator. Determination of total phenolic, flavonoid and carotenoid content, antioxidant activities using FRAP and DPPH assays were performed by UV-visible spectrophotometry and its correlation with EC50 of FRAP capacities and IC50 of DPPH scavenging activities were analyzed by Pearson’s method. Results: Ethanolic rice bran extract of black rice showed the lowest EC50 of FRAP capacity 64.35 µg/ml and IC50 of DPPH scavenging activity 23.92 µg/ml. The highest phenolic content, flavonoid content and carotenoid content were also given by ethanolic rice bran extract of black rice. There were significantly negative correlation between total phenolic content and carotenoid content in rice bran extract of red rice and black rice with their IC50 of DPPH. Conclusions: All of rice bran extracts (except n-hexane rice bran extract of black rice and ethanolic rice bran extract of white rice) were very strong antioxidant, by DPPH assay. Phenolic and carotenoid compounds in rice bran extracts of red rice and black rice were the major contributor in antioxidant activity by DPPH assay. Rice bran extracts of black rice had linear results by FRAP and DPPH assays.
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Rajput, Sajid Ali, Munazza Raza Mirza, and M. Iqbal Choudhary. "Bergenin protects pancreatic beta cells against cytokine-induced apoptosis in INS-1E cells." PLOS ONE 15, no. 12 (December 21, 2020): e0241349. http://dx.doi.org/10.1371/journal.pone.0241349.
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Beta cell apoptosis induced by proinflammatory cytokines is one of the hallmarks of diabetes. Small molecules which can inhibit the cytokine-induced apoptosis could lead to new drug candidates that can be used in combination with existing therapeutic interventions against diabetes. The current study evaluated several effects of bergenin, an isocoumarin derivative, in beta cells in the presence of cytokines. These included (i) increase in beta cell viability (by measuring cellular ATP levels) (ii) suppression of beta cell apoptosis (by measuring caspase activity), (iii) improvement in beta cell function (by measuring glucose-stimulated insulin secretion), and (iv) improvement of beta cells mitochondrial physiological functions. The experiments were carried out using rat beta INS-1E cell line in the presence or absence of bergenin and a cocktail of proinflammatory cytokines (interleukin-1beta, tumor necrosis factor-alpha, and interferon- gamma) for 48 hr. Bergenin significantly inhibited beta cell apoptosis, as inferred from the reduction in the caspase-3 activity (IC50 = 7.29 ± 2.45 μM), and concurrently increased cellular ATP Levels (EC50 = 1.97 ± 0.47 μM). Bergenin also significantly enhanced insulin secretion (EC50 = 6.73 ± 2.15 μM) in INS-1E cells, presumably because of the decreased nitric oxide production (IC50 = 6.82 ± 2.83 μM). Bergenin restored mitochondrial membrane potential (EC50 = 2.27 ± 0.83 μM), decreased ROS production (IC50 = 14.63 ± 3.18 μM), and improved mitochondrial dehydrogenase activity (EC50 = 1.39 ± 0.62 μM). This study shows for the first time that bergenin protected beta cells from cytokine-induced apoptosis and restored insulin secretory function by virtue of its anti-inflammatory, antioxidant and anti-apoptotic properties. To sum up, the above mentioned data highlight bergenin as a promising anti-apoptotic agent in the context of diabetes.
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Hassan, Sherif T. S., Miroslava Šudomová, Kateřina Berchová-Bímová, Karel Šmejkal, and Javier Echeverría. "Psoromic Acid, a Lichen-Derived Molecule, Inhibits the Replication of HSV-1 and HSV-2, and Inactivates HSV-1 DNA Polymerase: Shedding Light on Antiherpetic Properties." Molecules 24, no. 16 (August 11, 2019): 2912. http://dx.doi.org/10.3390/molecules24162912.
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Psoromic acid (PA), a bioactive lichen-derived compound, was investigated for its inhibitory properties against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), along with the inhibitory effect on HSV-1 DNA polymerase, which is a key enzyme that plays an essential role in HSV-1 replication cycle. PA was found to notably inhibit HSV-1 replication (50% inhibitory concentration (IC50): 1.9 μM; selectivity index (SI): 163.2) compared with the standard drug acyclovir (ACV) (IC50: 2.6 μM; SI: 119.2). The combination of PA with ACV has led to potent inhibitory activity against HSV-1 replication (IC50: 1.1 µM; SI: 281.8) compared with that of ACV. Moreover, PA displayed equivalent inhibitory action against HSV-2 replication (50% effective concentration (EC50): 2.7 μM; SI: 114.8) compared with that of ACV (EC50: 2.8 μM; SI: 110.7). The inhibition potency of PA in combination with ACV against HSV-2 replication was also detected (EC50: 1.8 µM; SI: 172.2). Further, PA was observed to effectively inhibit HSV-1 DNA polymerase (as a non-nucleoside inhibitor) with respect to dTTP incorporation in a competitive inhibition mode (half maximal inhibitory concentration (IC50): 0.7 μM; inhibition constant (Ki): 0.3 μM) compared with reference drugs aphidicolin (IC50: 0.8 μM; Ki: 0.4 μM) and ACV triphosphate (ACV-TP) (IC50: 0.9 μM; Ki: 0.5 μM). It is noteworthy that the mechanism by which PA-induced anti-HSV-1 activity was related to its inhibitory action against HSV-1 DNA polymerase. Furthermore, the outcomes of in vitro experiments were authenticated using molecular docking analyses, as the molecular interactions of PA with the active sites of HSV-1 DNA polymerase and HSV-2 protease (an essential enzyme required for HSV-2 replication) were revealed. Since this is a first report on the above-mentioned properties, we can conclude that PA might be a future drug for the treatment of HSV infections as well as a promising lead molecule for further anti-HSV drug design.
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Putri, Dewi Kumala, Berna Elya, and Nuraini Puspitasari. "FRACTIONATION OF THE N-HEXANE EXTRACT OF GARCINIA BANCANA MIQ. (MANGGIS HUTAN) LEAVES AND ITS ANTIOXIDANT ACTIVITY BASED ON 1,1-DIPHENYL-2- PICRYLHYDRAZYL AND FERRIC REDUCING ANTIOXIDANT POWER ASSAYS." International Journal of Applied Pharmaceutics 10, no. 1 (December 20, 2018): 407. http://dx.doi.org/10.22159/ijap.2018.v10s1.90.
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Objective: To assess the antioxidant activity from another part of the plant, in this study, leaf extracts in n-hexane were fractionated.Methods: Ten fractions were obtained and tested in vitro for antioxidant activity using two methods, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferricreducing antioxidant power (FRAP), to identify the most active fraction.Results: The IC50 of the most active fraction was 36.24 μg/mL using the DPPH method, and the EC50 was 39.54 μg/mL using the FRAP method. Themost active fraction was also shown to contain terpenoids.Conclusion: The most active fraction of an n-hexane extract of the leaves of Gacinia bancana Miq., which was tested by both DPPH and FRAP methodshad antioxidant activities with IC50 and EC50 values of 36.2482 μg/mL and 39.5442 μg/mL, respectively. Phytochemical screening showed that activefraction contains terpenoids.
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Kenmoku, Hiromichi, Hiroyuki Tada, Megumi Oogushi, Tomoyuki Esumi, Hironobu Takahashi, Masaaki Noji, Takeshi Sassa, Masao Toyota, and Yoshinori Asakawa. "Seed Dormancy Breaking Diterpenoids from the Liverwort Plagiochila sciophila and their Differentiation Inducing Activity in Human Promyelocytic Leukemia HL-60 Cells." Natural Product Communications 9, no. 7 (July 2014): 1934578X1400900. http://dx.doi.org/10.1177/1934578x1400900708.
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To obtain the structural diversity of bioactive compounds similar to cotylenins and fusicoccins that modulate 14-3-3 protein-protein interactions in eukaryotes, screening tests were carried out using the lettuce seed dormancy breaking-assay. An acetone extract of the liverwort Plagiochila sciophila exhibited significant activity against the seeds in the presence of the plant hormone abscisic acid. Activity-guided fractionation of the extract afforded the isolation of seven novel fusicoccane-type diterpenoids, named fusicosciophins A-E (1–5), 8-deacetyl (6) and 9-deacetyl fusicosciophin E (7). Their structures were determined by spectroscopic methods and X-ray crystallographic analyses. All the pure isolated compounds (1–7) exhibited moderate lettuce seed dormancy breaking activity. In addition, the differentiation-inducing activity and cytotoxicity of these isolates, together with fusicoccin A (FC-A) and all- trans retinoic acid (ATRA), were evaluated in human promyelocytic leukemia HL-60 cells and human mouth epidermal carcinoma KB cells, respectively. Fusicosciophins (2 and 4) and FC-A exhibited moderate differentiation-inducing activity (EC50 31.2~59.1μM) compared with ATRA (EC50 0.3μM), while 2, 4 and ATRA exhibited higher selectivity indices (IC50/EC50 >3.38~667) than FC-A (IC50/EC50 1.05). This is the first report on the isolation of fusicoccane-type diterpenoids from liverworts having seed dormancy breaking activity and differentiation-inducing activity in mammal cells.
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Aleem, Ambreen, Khalid Hussain Janbaz, Imran Imran, Muqeet Wahid, Sumbal Bibi, Khurram Afzal, and Muhammad Hassham Hassan Bin Asad. "Antiplatelet Aggregation, Cardiotonic, Anti-Inflammatory, Antioxidant, and Calcium Channel Antagonistic Potentials of Nepeta ruderalis Buch." BioMed Research International 2020 (June 1, 2020): 1–9. http://dx.doi.org/10.1155/2020/2096947.
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The objective of this study was to authenticate the ethnobotanical claims of the Nepeta ruderalis Buch.-Ham. (N. ruderalis) extract in the traditional system of medicine. Crude extract was prepared via a simple maceration process. DPPH free radical scavenging and carrageenan-induced rat paw edema models were used to monitor antioxidant and anti-inflammatory responses of the N. ruderalis extract. Furthermore, it was tested for antiplatelet aggregation, cardioprotective, and calcium channel antagonistic activities via standard documented protocols. The N. ruderalis extract exhibited 80.82% antioxidant activity (IC50=207.51±4.36 μg) while the anti-inflammatory response was significant (p<0.05 to p<0.01) at 50 mg/kg (45.58%) and 100 mg/kg (60.90%) doses. Moreover, it was found to inhibit platelet aggregation (IC50=1.06 and 0.91 mg/mL) and, in addition, to increase the force of contraction at the concentration of 3.0-10 mg/mL with a decrease in the heart rate on isolated paired atria (EC50=11.78 mg/mL). Relaxant activity was observed on the isolated rabbit jejunum (EC50=0.96 mg/mL) and trachea (EC50=0.89 mg/mL). However, in a cumulative way, an 80-millimolar potassium-induced contraction was evaluated (EC50=1.31 mg/mL). The N. ruderalis extract exhibited antioxidant, anti-inflammatory, platelet aggregating, cardiotonic, and calcium channel antagonistic activities, therefore proving scientifically its effectiveness in the traditional system of medicine.
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Yang, Wei-Min, Ji-Kai Liu, Lin Hu, Ze-Jun Dong, Wan-Lin Wu, and Zhi-He Chen. "Antioxidant Properties of Natural p-Terphenyl Derivatives from the Mushroom Thelephora ganbajun." Zeitschrift für Naturforschung C 59, no. 5-6 (June 1, 2004): 359–62. http://dx.doi.org/10.1515/znc-2004-5-612.
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The antioxidant activity in vitro of three poly(phenylacetyloxy)-substituted 1,1′:4′,1″-ter-phenyl compounds from the edible mushroom Thelephora ganbajun were investigated. The IC50 values of compounds 1-3 for lipid peroxidation in rat liver homogenate were 400, 48, 54 μᴍ, respectively. Compounds 1-3 increased superoxide dismutase (SOD) activity with EC50 values of 182, 74, 204 μᴍ. They were also assessed on the DPPH (1,1-diphenyl-2-picryl- hydrazyl) radical scavenging activity with EC50 values of 49, 1233, 55 μᴍ.
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Souness, J. E., and L. C. Scott. "Stereospecificity of rolipram actions on eosinophil cyclic AMP-specific phosphodiesterase." Biochemical Journal 291, no. 2 (April 15, 1993): 389–95. http://dx.doi.org/10.1042/bj2910389.
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The stereospecificity of rolipram inhibition of particulate cyclic AMP-specific phosphodiesterase (PDE IV) from guinea-pig eosinophils has been investigated. (-)-Rolipram (IC50 = 0.22 +/- 0.08 microM) was 2.5-fold more potent than (+)-rolipram (IC50 = 0.58 +/- 0.05 microM) in inhibiting membrane-bound PDE IV. Solubilization of PDE IV with deoxycholate (0.5%) and NaCl (100 mM) increased rolipram stereospecificity [IC50 (-)-rolipram = 0.020 +/- 0.002 microM; IC50 (+)-rolipram = 0.33 +/- 0.07 microM]. Partial purification of this solubilized PDE IV by DEAE-trisacryl anion-exchange chromatography reduced the enantiomeric potency difference compared with the pre-chromatographed activity, with (-)-rolipram (IC50 = 0.20 +/- 0.02 microM) being only 2.9-fold more potent than (+)-rolipram (IC50 = 0.57 +/- 0.14 microM). Vanadate-glutathione complex (V-GSH) stimulated membrane-bound PDE IV activity and increased the potency of (-)-rolipram (IC50 = 0.014 +/- 0.006 microM) but not (+)-rolipram (IC50 = 0.32 +/- 0.07 microM). In intact eosinophils, (-)-rolipram (EC50 = 0.19 +/- 0.02 microM) was 10-fold more potent than (+)-rolipram (EC50 = 1.87 +/- 0.09 microM) in enhancing isoprenaline (10 microM)-stimulated cyclic AMP accumulation. Strong correlations were demonstrated for displacement of [3H]rolipram binding to brain membranes by several PDE inhibitors and their inhibition of solubilized PDE IV (r = 0.98, P < 0.001, n = 7) and stimulation of cyclic AMP accumulation in intact cells (r = 0.98, P < 0.001, n = 6). Rolipram was a relatively weak inhibitor of partially purified pig aortic PDE IV and only slight stereospecificity was exhibited [IC50 (-)-rolipram = 1.47 +/- 0.09 microM; IC50 (+)-rolipram = 2.73 +/- 0.38 microM]. The results indicate the presence of a partially concealed stereospecific site (Sr) on eosinophil PDE IV possibly similar to the high-affinity rolipram-binding site in brain through which rolipram can potently inhibit enzyme activity. This site, which apparently is not present on partially purified pig aortic PDE IV, is concealed in freshly prepared eosinophil membranes but is exposed by solubilization or V-GSH treatment and is important in regulating intracellular cyclic AMP accumulation in intact cells.
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Wangensteen, Helle, Huong Cam Thi Dang, Shaikh Jamal Uddin, Mahiuddin Alamgir, and Karl Egil Malterud. "Antioxidant and Antimicrobial Effects of the Mangrove Tree Heritiera fomes." Natural Product Communications 4, no. 3 (March 2009): 1934578X0900400. http://dx.doi.org/10.1177/1934578x0900400311.
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Heritiera fomes is a mangrove tree which is widely distributed in the Sundarbans mangrove forest, Bangladesh. In this study, the EtOH extract of stem bark from H. fomes was shown to be rich in procyanidins. Trimeric, pentameric and hexameric procyanidins were identified in addition to highly polymeric material (average degree of polymerization 18-24). Bioactivity studies showed high DPPH radical scavenging and 15-lipoxygenase (15-LO) inhibiting activities of the bark extracts (EC50 = 19.4 ± 1.7 and IC50 = 22 ± 1 μg/mL, respectively) which could be ascribed to its high content of procyanidins. The procyanidins were also assayed as DPPH scavengers and 15-LO inhibitors, with EC50 and IC50 values in the range of 8-15 and 10-15 μg/mL, respectively. The bark extracts showed antibacterial activities against K. rhizophilia, S. aureus, B. subtilis and P. aeruginosa, as well. No toxicity was observed in the brine shrimp assay.
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LaBella, Frank S., and Gary Queen. "General anesthetics inhibit cytochrome P450 monooxygenases and arachidonic acid metabolism." Canadian Journal of Physiology and Pharmacology 71, no. 1 (January 1, 1993): 48–53. http://dx.doi.org/10.1139/y93-007.
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Identification of a specific biomolecular target appropriately sensitive to a wide array of anesthetics has been elusive. At concentrations close to their respective ED50's for anesthesia in man or other species, 18 compounds, differing in potencies up to 66 000 fold, inhibited cytochrome P450 mediated metabolism of aminopyrine, a synthetic substrate, and arachidonic acid (AA), an endogenous substrate, in isolated liver microsomes. There was a highly significant correlation for both substrates between the absolute concentrations required for anesthesia (EC50) and for inhibition of P450 activity (Ki or IC50). The mean Ki/EC50 ratio was 0.97 for inhibition of aminopyrine demethylase. The mean IC50/EC50 ratios were 0.42 and 0.64 for inhibition of two AA-derived products and 2.8 for a third; a mean ratio of 1.4 for inhibition of overall AA metabolism suggests interaction of general anesthetics with a composite of P450 isozymes. The universal cytochrome P450 monooxygenases, in conjunction with other lipid oxygenases (cyclooxygenases and lipoxygenases) participate in the second messenger AA cascade. In nerve cells the sensitivity of these enzymes to hydrophobic neurodepressant drugs may underlie the state of general anesthesia: reversible disruption of intracellular and intercellular signalling without impairment of enzymes vital to cell respiration.Key words: anesthetics, general anesthesia, cytochrome P450, arachidonic acid, liver microsomes.
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ARAÚJO, Éverton José Ferreira de, Layana Karine Farias LIMA, Oskar Almeida SILVA, Luís Mário REZENDE JÚNIOR, Stanley Juan Chavez GUTIERREZ, Fernando Aécio de Amorim CARVALHO, Francisco das Chagas Alves LIMA, Cláudia PESSOA, Rivelilson Mendes de FREITAS, and Paulo Michel Pinheiro FERREIRA. "In vitro antioxidant, antitumor and leishmanicidal activity of riparin A, an analog of the Amazon alkamides from Aniba riparia (Lauraceae)." Acta Amazonica 46, no. 3 (September 2016): 309–14. http://dx.doi.org/10.1590/1809-4392201505436.
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ABSTRACT Aniba riparia (Lauraceae) is an important medicinal plant found in the Amazon region and presents alkaloids of the type alkamide known as riparins. Riparin A is structurally represented as the fundamental core of all Amazon riparins. This work aimed to assess the in vitro antioxidant, antitumor and antileishmanial effects of riparin A. Riparin A presented weak antioxidant capacity by tecniques of DPPH• (EC50 of 296.2 μg mL-1) and ABTS•+ (EC50 of 450.1 μg mL-1), showed moderate activity against colon carcinoma (HCT-116: IC50 of 21.7 μg mL-1) and leishmanicidal activity on promastigotes of L. amazonensis (IC50 of 307.0 ± 79.6, 193.7 ± 44.3 and 81.8 ± 11.2 μg mL-1, respectively, after 24, 48 and 72 h of incubation). Then, in addition to its structural simplicity, riparin A revealed promising biological activities and remarkable in vitro leishmanicidal action, an important result in epidemiological point of view to control leishmaniasis in Brazil, including in the Amazon region.
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Matalińska, Joanna, Piotr F. J. Lipiński, Agnieszka Kotlarz, Piotr Kosson, Adriana Muchowska, and Jolanta Dyniewicz. "Evaluation of Receptor Affinity, Analgesic Activity and Cytotoxicity of a Hybrid Peptide, AWL3020." International Journal of Peptide Research and Therapeutics 26, no. 4 (February 19, 2020): 2603–17. http://dx.doi.org/10.1007/s10989-020-10051-5.
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Abstract In the present contribution we report design, synthesis and evaluation of receptor affinity, analgesic activity and cytotoxicity of a hybrid peptide, AWL3020. The peptide includes two pharmacophores, one of δ-opioid receptor (δOR) agonists and one of neurokinin-1 receptor (NK1R) antagonists. The design was motivated by the desire to obtain a compound with strong analgesic action and potential additional antiproliferative action. The compound displays high δOR affinity (IC50 = 29.5 nM). On the other hand, it has only poor affinity for the NK1R (IC50 = 70.28 μM). The substance shows good analgesic action which is however weaker than that of morphine. Regarding the effect on proliferation, the compound exhibits no pro-proliferative action in the assayed range. In higher concentrations, it has also cytotoxic activity. This effect is however not selective. The strongest effect of AWL3020 was found for melanoma MeW164 cell line (EC50 = 46.27 μM in reduction of cell numbers after a few days of incubation; EC50 = 37.78 μM in MTT assay).
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Yang, Wei-Min, Ji-Kai Liu, Xiang-Dong Qin, Wan-Lin Wu, and Zhi-He Chen. "Antioxidant Activities of Three Dihydrochalcone Glucosides from Leaves of Lithocarpus pachyphyllus." Zeitschrift für Naturforschung C 59, no. 7-8 (August 1, 2004): 481–84. http://dx.doi.org/10.1515/znc-2004-7-805.
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AbstractIn vitro antioxidant activities of three sweet dihydrochalcone glucosides from the leaves of Lithocarpus pachyphyllus (Kurz) Rehd. (Fagaceae), trilobatin 2″-acetate (1), phloridzin (2) and trilobatin (3), were investigated. The IC50 (50% inhibitory concentration) values for compounds 1-3 of lipid peroxidation in rat liver homogenate were 261, 28, 88 μm, respectively. Compounds 1-3 increased superoxide dismutase (SOD) activity with EC50 (50% effective concentration) values of 575, 167, 128 μm, and glutathione peroxidase (GSH-Px) activity with EC50 values of 717, 347, 129 μm, respectively, and showed only weak DPPH (1,1- diphenyl-2-picrylhydrazyl) radical scavenging activity
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Varghese, Christapher Parayil, Christina Ambrose, Veerasamy R, Pea Nai Hui, and Chen Siang May. "Antioxidant Activity of Hydroalcoholic Extract of Labisa Pumila var. Alata, an Indigenous Plant of Malaysia." International Journal of Pharmaceutical Sciences and Nanotechnology 4, no. 2 (August 31, 2011): 1418–22. http://dx.doi.org/10.37285/ijpsn.2011.4.2.8.
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This study was carried out to investigate the antioxidant potential of crude extracts of Labisa pumila var. Alata, a small herbaceous under shrub widely available in Malaysia. In this study, antioxidant activity was evaluated by diphenyl picryl hydrazine (DPPH) free radical assay and FRAP assay methods. In the DPPH free radical assay, different concentrations of the extract (5, 10, 25, 50 and 75 μg/ml in ethanol) were prepared and mixed with DPPH ethanol solution. After incubation, a photometric assay was performed and values were plotted. The IC50 values were calculated by a linear regression of plots and compared with IC50 of ascorbic acid as the standard antioxidant. In the FRAP assay, different concentrations of extract (20, 40, 60, 80 and 100 μg/ml) were prepared and the reducing power was estimated by a photometric assay and values were plotted. The EC50 values were calculated by a linear regression of plots and compared with the EC50 of ascorbic acid as a standard reducing agent. The study revealed that the crude extract possesses antioxidant activity.
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Liu, Hongmei, Jiguang Huang, Sifan Yang, Jialin Li, and Lijuan Zhou. "Chemical Composition, Algicidal, Antimicrobial, and Antioxidant Activities of the Essential Oils of Taiwania flousiana Gaussen." Molecules 25, no. 4 (February 20, 2020): 967. http://dx.doi.org/10.3390/molecules25040967.
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Taiwania flousiana (T. flousiana) Gaussen is a precious wood in the family Taxodiaceae. This study investigated the chemical components of the essential oil from the stem bark of T. flousiana and its algicidal, antifungal, and antioxidant properties. Sixty-nine compounds representing 89.70% of the stem bark essential oil were identified by GC-MS. The essential oil showed strong anti-algae, anti-bacteria, and anti-fungus activities against the tested species, and antioxidant activities. The IC50 values of the essential oil against chlorophyll a, chlorophyll b, and the total chlorophyll of Spirogyra communis (a species of algae), 24–96 h after the treatment, ranged from 31.77 to 84.92 μg/mL, while the IC50 values of butachlor ranged from 40.24 to 58.09 μg/mL. Ultrastructure changes revealed by the transmission electron microscopy indicated that the main algicidal action sites were the chloroplast and cell wall. The essential oil showed antifungal activities on Rhizoctonia solani (EC50 = 287.94 μg/mL) and Colletotrichum gloeosporioiles (EC50 = 378.90 μg/mL). It also showed bactericidal activities on Ralstonia solanacearum and Staphylococcus aureus, with zones of inhibition (ZOIs) being 18.66 and 16.75 mm, respectively at 40 μg/disk. Additionally, the essential oil possessed antioxidant activity estimated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) method (IC50 = 33.51 μg/mL; IC50 value of the positive control ascorbic acid was 7.98 μg/mL). Thus, the essential oil of this plant might be used as a possible source of natural bioactive molecules in agrochemical industry as well as in food and cosmetic industries.
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Zimmermann, U., B. Fluehmann, W. Born, JA Fischer, and R. Muff. "Coexistence of novel amylin-binding sites with calcitonin receptors in human breast carcinoma MCF-7 cells." Journal of Endocrinology 155, no. 3 (December 1, 1997): 423–31. http://dx.doi.org/10.1677/joe.0.1550423.
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Amylin, calcitonin (CT) and calcitonin gene-related peptide (CGRP) share limited structural homology including amino-terminal ring structures linked by a disulfide bridge and amidated carboxy-termini. Here, we have compared [125I]Bolton-Hunter-[Lys1] rat amylin ([125I]amylin) binding and the stimulation of cyclic AMP accumulation by human (h) amylin, hCT and hCGRP-I in the human breast carcinoma cell lines MCF-7 and T47D, which predominantly express hCT1a and hCT1b receptor isoforms (hCTR1a, hCTR1b) at a similar total number of hCT-binding sites. In MCF-7 cells, half-maximal inhibition (IC50) of [125I]amylin binding by human amylin was observed at 3.6 +/- 0.8 nM (n = 6). hCT and hCGRP-I displaced [125I]amylin binding with 22 and 66 times higher IC50. [125I]hCT binding was inhibited by hCT with an IC50 of 8.1 +/- 1.9 nM (n = 5), and human amylin and hCGRP-I were over 100 times less potent. In T47D cells, on the other hand, specific binding of [125I]amylin was not observed, but hCT inhibited [125I]hCT binding with an IC50 of 3.2 +/- 0.4 nM (n = 3), and human amylin and hCGRP-I had over 200 times higher IC50. In MCF-7 cells, half-maximal stimulation (EC50) of cyclic AMP accumulation by human amylin, hCT and hCGRP-I occurred at 1.4 +/- 0.2, 1.7 +/- 0.4 and 6.3 +/- 1.3 nM respectively. In T47D cells, the EC50 of hCT was 0.32 +/- 0.02 nM (n = 3), and 30- and 1900-fold higher with human amylin and hCGRP-I. In conclusion, the expression of hCTR1a and hCTR1b and [125I]hCT binding were indistinguishable in MCF-7 and T47D cells. Yet, [125I]amylin binding was only recognized in MCF-7 cells, consistent with a distinct amylin receptor.
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Arachchige, Sirimal Premakumara Galbada, Walimuni Prabhashini Kaushalya Mendis Abeysekera, and Wanigasekera Daya Ratnasooriya. "Antiamylase, Anticholinesterases, Antiglycation, and Glycation Reversing Potential of Bark and Leaf of Ceylon Cinnamon (Cinnamomum zeylanicum Blume) In Vitro." Evidence-Based Complementary and Alternative Medicine 2017 (2017): 1–13. http://dx.doi.org/10.1155/2017/5076029.
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Ethanol (95%) and dichloromethane : methanol (DCM : M, 1 : 1 v/v) bark extracts (BEs) and leaf extracts (LEs) of authenticated Ceylon cinnamon (CC) were studied for antiamylase, antiglucosidase, anticholinesterases, and antiglycation and glycation reversing potential in bovine serum albumin- (BSA-) glucose and BSA-methylglyoxal models in vitro. Further, total proanthocyanidins (TP) were quantified. Results showed significant differences (p<0.05) between bark and leaf extracts for the studied biological activities (except antiglucosidase) and TP. BEs showed significantly high (p<0.05) activities for antiamylase (IC50: 214±2–215±10 μg/mL), antibutyrylcholinesterase (IC50: 26.62±1.66–36.09±0.83 μg/mL), and glycation reversing in BSA-glucose model (EC50: 94.33±1.81–107.16±3.95 μg/mL) compared to LEs. In contrast, glycation reversing in BSA-methylglyoxal (EC50: ethanol: 122.15±6.01 μg/mL) and antiglycation in both BSA-glucose (IC50: ethanol: 15.22±0.47 μg/mL) and BSA-methylglyoxal models (IC50: DCM : M: 278.29±8.55 μg/mL) were significantly high (p<0.05) in leaf. Compared to the reference drugs used some of the biological activities were significantly (p<0.05) high (BEs: BChE inhibition and ethanol leaf: BSA-glucose mediated antiglycation), some were comparable (BEs: BSA-glucose mediated antiglycation), and some were moderate (BEs and LEs: antiamylase, AChE inhibition, and BSA-MGO mediated antiglycation; DCM : M leaf: BSA-glucose mediated antiglycation). TP were significantly high (p<0.05) in BEs compared to LEs (BEs and LEs: 1097.90±73.01–1381.53±45.93 and 309.52±2.81–434.24±14.12 mg cyanidin equivalents/g extract, resp.). In conclusion, both bark and leaf of CC possess antidiabetic properties and thus may be useful in managing diabetes and its complications.
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Diez-Iriepa, Daniel, Beatriz Chamorro, Marta Talaván, Mourad Chioua, Isabel Iriepa, Dimitra Hadjipavlou-Litina, Francisco López-Muñoz, José Marco-Contelles, and María Jesús Oset-Gasque. "Homo-Tris-Nitrones Derived from α-Phenyl-N-tert-butylnitrone: Synthesis, Neuroprotection and Antioxidant Properties." International Journal of Molecular Sciences 21, no. 21 (October 26, 2020): 7949. http://dx.doi.org/10.3390/ijms21217949.
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Herein we report the synthesis, antioxidant and neuroprotective power of homo-tris-nitrones (HTN) 1-3, designed on the hypothesis that the incorporation of a third nitrone motif into our previously identified homo-bis-nitrone 6 (HBN6) would result in an improved and stronger neuroprotection. The neuroprotection of HTNs 1-3, measured against oligomycin A/rotenone, showed that HTN2 was the best neuroprotective agent at a lower dose (EC50 = 51.63 ± 4.32 μM), being similar in EC50 and maximal activity to α-phenyl-N-tert-butylnitrone (PBN) and less potent than any of HBNs 4-6. The results of neuroprotection in an in vitro oxygen glucose deprivation model showed that HTN2 was the most powerful (EC50 = 87.57 ± 3.87 μM), at lower dose, but 50-fold higher than its analogous HBN5, and ≈1.7-fold less potent than PBN. HTN3 had a very good antinecrotic (IC50 = 3.47 ± 0.57 μM), antiapoptotic, and antioxidant (EC50 = 6.77 ± 1.35 μM) profile, very similar to that of its analogous HBN6. In spite of these results, and still being attractive neuroprotective agents, HTNs 2 and 3 do not have better neuroprotective properties than HBN6, but clearly exceed that of PBN.
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Guglani, Anchala, H. K. Pandey, Rajeshwar K. K. Arya, and Madhu Bala. "In Vitro Antioxidant Activity, Total Phenolic, Flavonoid and Tannin Contents in the Ajuga Bracteosa Wall. Ex Benth, Grown at Middle Hill Climatic Condition of Western Himalayas." Defence Life Science Journal 5, no. 3 (July 22, 2020): 198–203. http://dx.doi.org/10.14429/dlsj.5.15388.
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The antioxidant activity of aqueous and alcoholic extracts of different plant parts viz, leaves, flower, stem and root of Ajuga bracteosa was investigated against various in-vitro antioxidant assays. The total phenolic, flavonoid and tannin contents also estimated. The results revealed the significant antioxidant potential and variation in the IC50, EC50 and phytochemical contents among all the plant parts. The aqueous extract of leaves exhibited significantly (P<0.05) highest antioxidant activity on 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acixd), 2,2-diphenyl-1-picryl hydrazyl, and potassium ferricyanide reducing power assay, with IC50 values of 0.2707±0.0008, 0.4409±0.0020, and EC50 value 0.3413±0.0030 mg/mL, respectively, followed by the other parts of the plant. The leaves extract also possess the highest total phenolics, flavonoid and tannin contents among all the parts. Similarly, the aqueous extract is better than the alcoholic extract of different parts as far as phytochemical contents and antioxidant activity concerned. The present study revealed that the aqueous extract of leaves had the highest antioxidant potential, which correlated with the high level of total phenolic fl flavonoid, and tannin contents. Therefore, higher the phytochemical contents, higher will be the antioxidant potential.
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Grabkowska-Drużyc, Magdalena, Graciela Andrei, Dominique Schols, Robert Snoeck, and Dorota Piotrowska. "Isoxazolidine Conjugates of N3-Substituted 6-Bromoquinazolinones—Synthesis, Anti-Varizella-Zoster Virus, and Anti-Cytomegalovirus Activity." Molecules 23, no. 8 (July 28, 2018): 1889. http://dx.doi.org/10.3390/molecules23081889.
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1,3-Dipolar cycloaddition of N-methyl C-(diethoxyphosphoryl) nitrone to N3-substituted 6-bromo-2-vinyl-3H-quinazolin-4-ones gave (3-diethoxyphosphoryl) isoxazolidines substituted at C5 with quinazolinones modified at N3. All isoxazolidine cycloadducts were screened for antiviral activity against a broad spectrum of DNA and RNA viruses. Several isoxazolidines inhibited the replication of both thymidine kinase wild-type and deficient (TK+ and TK−) varicella-zoster virus strains at EC50 in the 5.4–13.6 μΜ range, as well as human cytomegalovirus (EC50 = 8.9–12.5 μΜ). Isoxazolidines trans-11b, trans-11c, trans-11e, trans-11f/cis-11f, trans-11g, trans-11h, and trans-11i/cis-11i exhibited moderate cytostatic activity towards the human lymphocyte cell line CEM (IC50 = 9.6–17 μM).
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Nuñez, Wilder J., Raomír Quispe, Norma J. Ramos, Américo J. Castro, and Gloria Gordillo. "ACTIVIDAD ANTIOXIDANTE Y ANTIENZIMÁTICA IN VITRO Y ANTINFLAMATORIA IN VIVO DEL EXTRACTO HIDROALCOHÓLICO DE Caesalpinia spinosa “TARA”." Ciencia e Investigación 19, no. 1 (August 2, 2017): 35–42. http://dx.doi.org/10.15381/ci.v19i1.13626.
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Se tuvo como objetivo explorar los potenciales antioxidante, antienzimático y antiinflamatorio del extracto hidroalcohólico de vainas de Caesalpinia spinosa “tara”. La actividad antioxidante se determinó por neutralización de los radicales 1,1-difenil-2-picril-hidrazilo (DPPH•+) y del ácido 2,2’-azinobis (3-etilbenzotiazolin)-6-sulfónico (ABTS•+). La actividad antienzimática se evaluó por inhibición de las enzimas colagenasa y elastasa. La actividad antiinflamatoria se determinó por el método de inducción de edema plantar en ratas por λ-carragenina. Se emplearon 30 ratas albinas de cepa Holtzman, con peso promedio de 200 ± 20 g, distribuidas al azar en cinco grupos de seis, un control con suero fisiológico, un grupo con el estándar farmacológico indometacina y los grupos de intervención con el extracto hidroalcohólico en dosis de 50, 100 y 250 mg/kg, respectivamente. El extracto mostró actividad antioxidante en los métodos DPPH (EC50 = 4,52 µg/mL ) y ABTS•+ (EC50 = 14,48 µg/mL), mayor que la del patrón de referencia trolox EC50 = 5,04 µg/mL y EC50 = 17,04 µg/mL, respectivamente. En la actividad antienzimática, el extracto presentó mayor potencial de inhibición de la enzima colagenasa (IC50 = 196,752 µg/mL) respecto al control positivo galato de epigalocatequina (EGCG) (IC50 = 216,99 µg/mL), sin presentar actividad significativa para la inhibición de la enzima elastasa. En la actividad antiinflamatoria con el extracto de 250 mg/kg la inflamación disminuyó en 44,854% a la sexta hora, sin embargo, a la misma hora la indometacina de 5 mg/kg disminuyó 48,267%; los extractos de 100 y 50 mg/g también disminuyeron el edema pero en menor proporción que el estándar. A los valores obtenidos se aplicó el análisis de varianza (ANOVA) seguido de la prueba de Dunnet, con nivel de confianza del 95% (p≤0,05), mostrando diferencias significativas en las medias de cada extracto en el transcurso de las horas. Se concluye que el extracto hidroalcohólico de la vainas de Caesalpinia spinosa “tara”, presenta actividad antioxidante, antienzimática, antiinflamatoria.
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Tang, Weimin, and Mary Jo Wildey. "Development of a Colorimetric Method for Functional Chloride Channel Assay." Journal of Biomolecular Screening 9, no. 7 (October 2004): 607–13. http://dx.doi.org/10.1177/1087057104266740.
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Anion channels play significant physiological roles in humans and animals. However, the effort of screening for anion channel modulators was limited by the available assay technologies. This report discusses the development of a cell-based functional chloride channel assay using iodine as the chloride channel functional indicator. Iodine concentrations were measured with modified Sandell-Kolthoff reaction using colorimetric detection. The assay was rapid and quantitative. When WSS-1 cells were activated by γ-aminobutyric acid (GABA) in the condition that γ-aminobutyric acid type A receptor (GABAA receptor) conducted outwardly rectifying chloride channel function, the EC50 of GABA was 7.69 μM. IC50 swere 0.53 μM for bicuculline and 3.1 μM for picrotoxin, respectively, in the presence of 10 μM GABA. When Capan-1 cells were activated by forskolin, the EC50 was 0.14 μM. The assay can also be applied to inwardly rectifying anion channels as exemplified by GABAA channel with an EC50 of 294 μM. Thus, the assay is universal and reliable and can be used for anion channel high-throughput screening.
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Mogana, R., K. Teng-Jin, and C. Wiart. "The Medicinal Timber Canarium patentinervium Miq. (Burseraceae Kunth.) Is an Anti-Inflammatory Bioresource of Dual Inhibitors of Cyclooxygenase (COX) and 5-Lipoxygenase (5-LOX)." ISRN Biotechnology 2013 (October 1, 2013): 1–8. http://dx.doi.org/10.5402/2013/986361.
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The barks and leaves extracts of Canarium patentinervium Miq. (Burseraceae Kunth.) were investigated for cyclooxygenase (COX) and 5-lipoxygenase (LOX) inhibition via in vitro models. The corresponding antioxidative power of the plant extract was also tested via nonenzyme and enzyme in vitro assays. The ethanolic extract of leaves inhibited the enzymatic activity of 5-LOX, COX-1, and COX-2 with IC50 equal to 49.66±0.02 μg/mL, 0.60±0.01 μg/mL, and 1.07±0.01 μg/mL, respectively, with selective COX-2 activity noted in ethanolic extract of barks with COX-1/COX-2 ratio of 1.22. The ethanol extract of barks confronted oxidation in the ABTS, DPPH, and FRAP assay with EC50 values equal to 0.93±0.01 μg/mL, 2.33±0.02 μg/mL, and 67.00±0.32 μg/mL, respectively, while the ethanol extract of leaves confronted oxidation in β-carotene bleaching assay and superoxide dismutase (SOD) assay with EC50 value of 6.04±0.02 μg/mL and IC50 value of 3.05±0.01 μg/mL. The ethanol extract acts as a dual inhibitor of LOX and COX enzymes with potent antioxidant capacity. The clinical significance of these data is quite clear that they support a role for Canarium patentinervium Miq. (Burseraceae Kunth.) as a source of lead compounds in the management of inflammatory diseases.
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Geneste, Clara C., and Andrew J. Massey. "Cell Density Affects the Detection of Chk1 Target Engagement by the Selective Inhibitor V158411." SLAS DISCOVERY: Advancing the Science of Drug Discovery 23, no. 2 (October 19, 2017): 144–53. http://dx.doi.org/10.1177/2472555217738534.
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Understanding drug target engagement and the relationship to downstream pharmacology is critical for drug discovery. Here we have evaluated target engagement of Chk1 by the small-molecule inhibitor V158411 using two different target engagement methods (autophosphorylation and cellular thermal shift assay [CETSA]). Target engagement measured by these methods was subsequently related to Chk1 inhibitor–dependent pharmacology. Inhibition of autophosphorylation was a robust method for measuring V158411 Chk1 target engagement. In comparison, while target engagement determined using CETSA appeared robust, the V158411 CETSA target engagement EC50 values were 43- and 19-fold greater than the autophosphorylation IC50 values. This difference was attributed to the higher cell density in the CETSA assay configuration. pChk1 (S296) IC50 values determined using the CETSA assay conditions were 54- and 33-fold greater than those determined under standard conditions and were equivalent to the CETSA EC50 values. Cellular conditions, especially cell density, influenced the target engagement of V158411 for Chk1. The effects of high cell density on apparent compound target engagement potency should be evaluated when using target engagement assays that necessitate high cell densities (such as the CETSA conditions used in this study). In such cases, the subsequent relation of these data to downstream pharmacological changes should therefore be interpreted with care.
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Prinz, C., D. R. Scott, D. Hurwitz, H. F. Helander, and G. Sachs. "Gastrin effects on isolated rat enterochromaffin-like cells in primary culture." American Journal of Physiology-Gastrointestinal and Liver Physiology 267, no. 4 (October 1, 1994): G663—G675. http://dx.doi.org/10.1152/ajpgi.1994.267.4.g663.
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The hormone gastrin stimulates acid secretion by releasing histamine from gastric enterochromaffin-like (ECL) cells and induces ECL cell proliferation in vivo. This study uses a > 90% pure ECL cell preparation in culture to compare gastrin effects on histamine release, histidine decarboxylase (HDC) activity, and DNA synthesis. Gastrin and the cholecystokinin octapeptide (CCK-8, nonsulfated) induced histamine release from ECL cells (24-96 h of primary culture) within 5 min of incubation [concentration eliciting 50% of maximal response (EC50), 4 and 2 x 10(-11) M, respectively]. The CCK-B antagonist L-365,260 inhibited this effect [concentration inhibiting 50% of maximal response (IC50), 2 x 10(-8) M], whereas the CCK-A antagonist L-364,718 (10(-8) M) and the tyrosine kinase inhibitor genistein (10(-4) M) had no effect. Histamine release was associated with a biphasic elevation of intracellular Ca2+. Gastrin stimulated HDC activity two- to threefold after 60 min of incubation (EC50, 10(-10) M). Gastrin also increased DNA synthesis in ECL cells, with an EC50 of 1.7 x 10(-12) M as measured by the incorporation of 5-bromo-2'-deoxyuridine (BrdU). Positive nuclear immunostaining increased two- to threefold in up to 20% of ECL cells after 48-96 h of incubation. This effect was inhibited by L-365,260 (IC50, 5 x 10(-9) M) and by genistein (10(-4) M) but was not altered by L-364,718 (10(-8) M). The antisecretory drugs omeprazole, lansoprazole, and pantoprazole did not affect BrdU incorporation in isolated ECL cells. In conclusion, acute and chronic gastrin effects on the ECL cell are mediated via CCK-B receptors but differ in apparent receptor affinity and signal transduction pathways.
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Fukushima, Kazuyuki, Yoshikuni Tabata, Yoichi Imaizumi, Naohiro Kohmura, Michiko Sugawara, Kohei Sawada, Kazuto Yamazaki, and Masashi Ito. "Characterization of Human Hippocampal Neural Stem/Progenitor Cells and Their Application to Physiologically Relevant Assays for Multiple Ionotropic Glutamate Receptors." Journal of Biomolecular Screening 19, no. 8 (June 30, 2014): 1174–84. http://dx.doi.org/10.1177/1087057114541149.
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The hippocampus is an important brain region that is involved in neurological disorders such as Alzheimer disease, schizophrenia, and epilepsy. Ionotropic glutamate receptors—namely, N-methyl-D-aspartate (NMDA) receptors (NMDARs), α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors (AMPARs), and kainic acid (KA) receptors (KARs)—are well known to be involved in these diseases by mediating long-term potentiation, excitotoxicity, or both. To predict the therapeutic efficacy and neuronal toxicity of drug candidates acting on these receptors, physiologically relevant systems for assaying brain region–specific human neural cells are necessary. Here, we characterized the functional differentiation of human fetal hippocampus–derived neural stem/progenitor cells—namely, HIP-009 cells. Calcium rise assay demonstrated that, after a 4-week differentiation, the cells responded to NMDA (EC50 = 7.5 ± 0.4 µM; n = 4), AMPA (EC50 = 2.5 ± 0.1 µM; n = 3), or KA (EC50 = 33.5 ± 1.1 µM; n = 3) in a concentration-dependent manner. An AMPA-evoked calcium rise was observed in the absence of the desensitization inhibitor cyclothiazide. In addition, the calcium rise induced by these agonists was inhibited by antagonists for each receptor—namely, MK-801 for NMDA stimulation (IC50 = 0.6 ± 0.1 µM; n = 4) and NBQX for AMPA and KA stimulation (IC50 = 0.7 ± 0.1 and 0.7 ± 0.03 µM, respectively; n = 3). The gene expression profile of differentiated HIP-009 cells was distinct from that of undifferentiated cells and closely resembled that of the human adult hippocampus. Our results show that HIP-009 cells are a unique tool for obtaining human hippocampal neural cells and are applicable to systems for assay of ionotropic glutamate receptors as a physiologically relevant in vitro model.
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Suleiman, Mohamed H. A., and Ali A. Ateeg. "Antimicrobial and Antioxidant Activities of Different Extracts from Different Parts of Zilla spinosa (L.) Prantl." Evidence-Based Complementary and Alternative Medicine 2020 (December 3, 2020): 1–10. http://dx.doi.org/10.1155/2020/6690433.
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Zilla spinosa is commonly used in traditional medicine to treat gastrointestinal disorders and diabetes. In this study, aqueous ethanol (AE) and aqueous methanol (AM) extracts from aerial parts and roots of Z. spinosa were investigated. The total phenolic (TPC) and flavonoid (TFC) contents and antioxidant capacities in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, hydrogen peroxide (H2O2), and ferric reducing antioxidant power (FRAP) assays were determined, and the correlations among the results were assessed using Pearson’s correlation. The antimicrobial activity was assessed through agar disc diffusion and broth microdilution assays. Phytochemical screening showed that Z. spinosa extracts had alkaloids, glycosides, saponins, triterpenoids, phenols, and flavonoids in different abundances. The aerial part-AE extract contained low TPC (30.17 ± 4.24 mg GAE/g) and TFC (7.40 ± 1.02 mg QE/g) and displayed significant antioxidant capacity in the DPPH (IC50 = 52.17 ± 7.30 μg/mL), H2O2 (91.22 ± 2.60 μg/mL), and FRAP (EC50 = 98.70 ± 2.21 μg/mL) assays. By contrast, the root-AM extract contained high amounts of TPC (87.72 ± 7.75 mg GAE/g) and TFC (25.60 ± 1.57 mg QE/g). It showed significantly high antioxidant activity with IC50 values of 12.33 ± 1.88 μg/mL in the DPPH and 39.37 ± 2.59 μg/mL in the H2O2 assays, as well as reducing power capacity with an EC50 value of 20.82 ± 1.14 μg/mL in the FRAP assay. Both TPC and TFC were exhibited negative correlations ( p < 0.01 ) with the IC50 and EC50 values obtained in the applied antioxidant assays. The aerial part-AM extract showed the highest inhibitory activity against Staphylococcus aureus (26.5 ± 0.20 mm), followed by Shigella flexneri (19.4 ± 0.40 mm) and Proteus mirabilis (17.7 ± 0.49 mm). S. aureus was the most affected microorganism with a minimum inhibitory concentration of 128 μg/mL against the aerial part-AM extract. Interestingly, all evaluated extracts showed potent antifungal activity against Candida albicans. However, aerial part-AM was the most effective, with an inhibition zone of 12.6 ± 0.17 mm. The results concluded that Z. spinosa possesses different phytochemicals displaying significant antioxidant and antimicrobial activities, thus lending credence to its use in traditional medicine.
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Benarba, Bachir, Okba Ibnou Nafaa Mendas, and Setti Righi. "Phytochemical analysis, antioxidant and anti-Candida albicans activities of Annona cherimola Mill. fruit pulp." North African Journal of Food and Nutrition Research 2, no. 4 (November 25, 2018): 121–30. http://dx.doi.org/10.51745/najfnr.2.4.121-130.
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Aims: The main objectives of the present study were to characterize the phytochemical profile of Annona cherimola Mill, to assess its antioxidant characteristics and its antifungal activity against Candida albicans. Methods and Material: Aqueous decoction, aqueous infusion, aqueous maceration, and methanolic maceration were screened for the presence of phytochemicals and to quantify content of phenolics, tannins, and flavonoids. Furthermore, antioxidant activity was assessed using DPPH and FRAP assays, as well the assessment of antifungal activity for the different extracts. Results: Results showed that phenols, tannins, flavonoids, and saponins were present in the four extracts. The aqueous maceration extract presented the highest total phenolic content (3.687 mg GAE/g of extract). Decoction extract showed the lowest phenolic content 2.504 mg GAE/g. Besides, infusion showed the most important total flavonoids content (2.567mg CE/g). The most relevant total antioxidant activity was found for decoction (lowest IC50 12.61 mg/ml AAE). The aqueous maceration exhibited the less antioxidant activity (IC50= 21.98 mg/ml AAE). The best scavenging activity was observed for decoction (IC50=7.27 mg/mL). All the extracts showed a reducing capacity. Infusion exhibited the best reducing power (EC50 = 11.29 mg/mL), compared to decoction (EC50 = 39.32 mg/mL). Regarding antifungal activity, at 100 and 200 µg/mL, decoction and methanolic maceration resulted in 6 and 9 mm inhibition zone, respectively. In addition, at higher doses (800 and 2000 µg/mL), inhibition zone increased in a dose dependent manner for all the extracts. Conclusions: Annona cherimola Mill. could be an important source of bioactive molecules with antioxidant and antifungal activities. Keywords: Annona cherimola Mill., phytochemical screening, flavonoids, antioxidant, Candida albicans.
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Bushfield, M., A. Savage, N. J. Morris, and M. D. Houslay. "A mnemonical or negative-co-operativity model for the activation of adenylate cyclase by a common G-protein-coupled calcitonin-gene-related neuropeptide (CGRP)/amylin receptor." Biochemical Journal 293, no. 1 (July 1, 1993): 229–36. http://dx.doi.org/10.1042/bj2930229.
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Both amylin and calcitonin-gene-related neuropeptide (CGRP) activated adenylate cyclase activity in hepatocyte membranes around 5-fold in a dose-dependent fashion, with EC50 values of 120 +/- 14 and 0.3 +/- 0.14 nM respectively. Whereas amylin exhibited normal activation kinetics (Hill coefficient, h approximately 1), CGRP showed kinetics indicative of either multiple sites/receptor species having different affinities for this ligand or a single receptor species exhibiting apparent negative co-operativity (h approximately 0.21). The CGRP antagonist CGRP-(8-37)-peptide inhibited adenylate cyclase stimulated by EC50 concentrations of either amylin or CGRP. Inhibition by CGRP-(8-37) was selective in that markedly lower concentrations were required to block the action of amylin (IC50 = 3 +/- 1 nM) compared with that of CGRP itself (IC50 = 120 +/- 11 nM). Dose-effect data for inhibition of CGRP action by CGRP-(8-37) showed normal saturation kinetics (h approximately 1), whereas CGRP-(8-37) inhibited amylin-stimulated adenylate cyclase activity in a fashion which was indicative of either multiple sites or apparent negative co-operativity (h approximately 0.24). Observed changes in the kinetics of inhibition by CGRP-(8-37) of CGRP, but not amylin-stimulated adenylate cyclase, at concentrations of agonists below their EC50 values militated against a model of two distinct populations of non-interacting receptors each able to bind both amylin and CGRP. A kinetic model is proposed whereby a single receptor, capable of being activated by both CGRP and amylin, obeys either a mnemonical kinetic mechanism or one of negative co-operativity with respect to CGRP but not to amylin. The relative merits of these two models are discussed together with a proposal suggesting that the activation of adenylate cyclase by various G-protein-linked receptors may be described by a mnemonical model mechanism.
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Honemann, Christian W., Gregor W. Nietgen, Tobias Podranski, Carrie K. Chan, and Marcel E. Durieux. "Influence of Volatile Anesthetics on Thromboxane A2Signaling." Anesthesiology 88, no. 2 (February 1, 1998): 440–51. http://dx.doi.org/10.1097/00000542-199802000-00023.
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Background Thromboxane A2 (TXA2) is a member of the prostaglandin family; activation of its receptor induces several important effects, including platelet aggregation and smooth muscle contraction. Because volatile anesthetics interfere with aggregation and contraction, the authors investigated effects of halothane, isoflurane, and sevoflurane on TXA2 signaling in an isolated receptor model. Methods mRNA encoding TXA2 receptors was prepared in vitro and expressed in Xenopus oocytes. The effects of halothane, isoflurane, and sevoflurane on Ca2+-activated Cl- currents induced by the TXA2 agonist U-46619 and on those induced by intracellular injection of inositol 1-4-5 trisphosphate or guanosine 5'-O-(2-thiodiphosphate) were measured using the voltage-clamp technique. Results Expressed TXA2 receptors were functional (half maximal effect concentration [EC50], 3.2 x 10(-7) +/- 1.1 x 10(-7) M; Hill coefficient (h), 0.8 +/- 0.2). Halothane and isoflurane inhibition of TXA2 signaling was reversible and concentration dependent (halothane half maximal inhibitory concentration [IC50], 0.46 +/- 0.04 mM; h, 1.6 +/- 0.21; isoflurane IC50, 0.69 +/- 0.12 mM; h, 1.3 +/- 0.27). 0.56 mM halothane (1%) right-shifted the U-46619 concentration-response relationship by two orders of magnitude (EC50, 1 x 10[-5] M). That h and maximal effect (Emax) were unchanged indicates that halothane acts in a competitive manner. In contrast, isoflurane acted noncompetitively, decreasing Emax by 30% (h and EC50 were unchanged). Both halothane and isoflurane had no effect on intracellular signaling pathways. Sevoflurane (0-1.3 mM) did not affect TXA2 signaling. Conclusions Both halothane and isoflurane inhibit TXA2 signaling at the membrane receptor, but by different mechanisms. This suggests that the effects of these anesthetics on TXA2 signaling are evoked at different locations of the receptor protein: halothane probably acts at the ligand binding site and isoflurane at an allosteric site.
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Henrion, D., I. Laher, A. Klaasen, and J. A. Bevan. "Myogenic tone of rabbit facial vein and posterior cerebral artery is influenced by changes in extracellular sodium." American Journal of Physiology-Heart and Circulatory Physiology 266, no. 2 (February 1, 1994): H377—H383. http://dx.doi.org/10.1152/ajpheart.1994.266.2.h377.
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We examined the effect of small changes in extracellular Na+ concentration ([Na+]e) on myogenic tone (MT) in isometrically mounted ring segments of the rabbit facial vein and in pressurized cannulated posterior cerebral artery segments. Decreasing [Na+]e from 150 to 120 mM in the vein increased MT by 24%, and raising [Na+]e to 165 mM attenuated it by 30%. In pressurized posterior cerebral arteries, decreasing [Na+]e to 120 mM reduced the intraluminal diameter by 12%, whereas increasing [Na+]e to 165 mM increased it by 17%. MT was inhibited by amiloride [50% inhibitory concentration (IC50) = 17 +/- 6 microM], an inhibitor of Na(+)-H+ exchange. Diisothiocyanatostilbene sulfonic acid, a Na(+)-Cl(-)-HCO3- cotransporter blocker, inhibited MT with an IC50 of 4.4 +/- 0.65 microM. Ouabain increased MT [50% effective concentration (EC50) = 0.10 +/- 0.04 microM] as did the reintroduction of HCO3- (EC50 5.0 +/- 1.5 mM). Our study suggests that MT in the rabbit posterior cerebral artery and rabbit facial vein is modulated by changes in [Na+]e. This effect is independent of the method used to register changes in wall force. The sensitivity of the tone to changes in [Na+]e and the independence of vessel diameter at different pressures at various [Na+]e may reflect changes in the sensitivity of smooth muscle stretch or mechanoreceptors to [Na+]e.
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Keating, Alison V., Jessica Soto, Claire Forbes, Min Zhao, Duncan Q. M. Craig, and Catherine Tuleu. "Multi-Methodological Quantitative Taste Assessment of Anti-Tuberculosis Drugs to Support the Development of Palatable Paediatric Dosage Forms." Pharmaceutics 12, no. 4 (April 17, 2020): 369. http://dx.doi.org/10.3390/pharmaceutics12040369.
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The unpalatability of antituberculosis drugs is often cited as a major cause of non-adherence in children, yet limited quantitative taste assessment data are available. The aim of this research was to quantify the bitterness of isoniazid, rifampicin, pyrazinamide, and ethambutol dihydrochloride using two in vivo (a human taste panel and a rat brief-access taste aversion (BATA) model) and one in vitro (sensor) method. The response of the Insent TS-5000Z electronic tongue was compared to the in vivo drug concentration found to elicit and suppress half the maximum taste response (EC50 in human and IC50 in rats). Using dose-relevant concentrations, an overarching rank order of bitterness was derived (rifampicin > ethambutol > pyrazinamid~isoniazid). In vitro, only ethambutol exhibited a linear response for all sensors/concentrations. Based on the EC50/IC50 generated, a ‘taste index’ was proposed to allow for anticipation of the likelihood of taste issues in practice, taking in account the saturability in the saliva and therapeutic doses; ethambutol and isoniazid were found to be the worst tasting using this measure. The study presents the first quantitative taste analysis of these life-saving drugs and has allowed for a comparison of three methods of obtaining such data. Such information allows the operator to identify and prioritise the drugs requiring taste masking to produce palatable formulations.
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Teng, B. Q., J. R. Grider, and K. S. Murthy. "Identification of a VIP-specific receptor in guinea pig tenia coli." American Journal of Physiology-Gastrointestinal and Liver Physiology 281, no. 3 (September 1, 2001): G718—G725. http://dx.doi.org/10.1152/ajpgi.2001.281.3.g718.
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Vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase-activating peptide (PACAP) interact with VPAC2 receptors in rabbit and guinea pig (GP) gastric muscle but with functionally distinct VIP and PACAP receptors in GP tenia coli. This study examined whether selectivity for VIP was determined by two residues (40, 41) in the extracellular domain that differ in the VIP receptors of GP gastric and tenial muscle. A mutant rat VPAC2 receptor (L40F, L41F), and two chimeric receptors in which the NH2-terminal domain of rat VPAC2 receptor was replaced with that of GP gastric (chimeric-G) or tenia coli (chimeric-T) VIP receptors, were constructed and expressed in COS-1 cells. VIP and PACAP bound with equal affinity to wild-type and mutant rat VPAC2 receptors and to chimeric-G receptor (IC50: VIP 0.3 ± 0.1 to 1.5 ± 0.4 nM, PACAP 0.4 ± 0.1 to 2.5 ± 0.1 nM) and stimulated cAMP with equal potency (EC50: VIP 13 ± 5 to 48 ± 8 nM, PACAP 8 ± 3 to 31 ± 14 nM). VIP bound with high affinity also to chimeric-T receptor (IC50: 0.5 ± 0.1 nM) and stimulated cAMP with high potency (EC50: 3 ± 1 nM). In contrast, PACAP exhibited >1,000-fold less affinity for binding or potency for stimulating cAMP. We conclude that GP tenia coli express a VIP-specific receptor and that selectivity is determined by a pair of extracellular phenylalanine residues.
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Jones, Jeremy C., Erik W. Settles, Curtis R. Brandt, and Stacey Schultz-Cherry. "Identification of the Minimal Active Sequence of an Anti-Influenza Virus Peptide." Antimicrobial Agents and Chemotherapy 55, no. 4 (January 10, 2011): 1810–13. http://dx.doi.org/10.1128/aac.01428-10.
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ABSTRACTThe antiviral peptide, entry blocker (EB), inhibits influenza virus replication by preventing attachment to cells. Here, we identified the minimal and optimal EB sequence that retained antiviral activity with a 50% inhibitory concentration (IC50) and 50% effective concentration (EC50) similar to those of the full-length EB peptide and several truncated variants that possessed up to 10-fold lower IC50s. These data have implications for improving the antiviral efficacy of EB-derived peptides while decreasing production costs and easing synthesis.
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Feriha, Bensafiddine, Asseli Brahim, Mahfoudi Reguia, Djeridane Amar, and Yousfi Mohamed. "High Antioxidant Capacities and Anti-inflammatory Effects of Hammada elegans Botsch. Extracts: An in vitro Assessment." Current Enzyme Inhibition 15, no. 1 (April 26, 2019): 55–68. http://dx.doi.org/10.2174/1573408015666190225151916.
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Introduction: Plants supply traditional Algerian medicines for the treatment of antiinflammatory effect. The reasons for the use of traditional treatments were that pure compounds obtained were also effective in reducing the toxicities of toxic agents or other drugs. Methods: In this study, we explore the phytochemical composition and the phenolic content by indirect method to evaluate the antioxidants and the anti-inflammatory capacities of twelve extracts from three plants. Results: Results: The total phenolic content ranged from 0.168 ± 0.020 to 4.166 ± 0.124 mg per gram of dry weight. Phytochemical screening revealed that tannins, C-heterosides, O-reduced heterosides and reducing compounds are the most common chemical groups. The highest antiradical activity was achieved with methanolic extract of Hammada elegans (EC50 = 0.551 ± 0.171mg/mL). However, the acetonic extract of Hammada elegans represents the most important reducing activity (EC50 = 0.747 ± 0.004mg/mL). Moreover, this extract also displays the highest chelating ferrous ions effect (EC50 = 5.749 ± 0.009 mg/mL) while the hydromethanolic extract of Cleome arabica has the best antilipoperoxidative effect (EC50 = 0.031 ± 0.000mg/mL). Furthermore, all extracts inhibit the activity of lipooxygenase and cyclooxygenase with IC50 values less than 19.210 ± 0.297 mg/mL. Therefore, the acetonic extract of Hammada elegans appears to be twice greater than that of standard inhibitors. Conclusion: The fractionation of the acetonic extract of Hammada elegans has given a potent bioactive compound which seems to have potential therapeutic possibilities for the prevention of the inflammatory effects.