Academic literature on the topic 'Erythrea centaurium'

Medicines from plants are widely used in the complex treatment of different diseases every day. Therefore, theoretical and practical interest is the in-depth study of the herb of perspective plants like Centaurium erythraea Rafn. and Gentiana cruciata L. These plants have a long history of usage and interest of people. The aim of the study was to determine the content of amino acids in these plants. The amino acids composition and content in the herb of study species of the family Gentianaceae determined by the HPLC method. The results of the research revealed that the raw material of Centaurium erythraea Rafn. and Gentiana cruciata L. contains free and bound amino acids. Sixteen free and seventeen bound amino acids were identified in the herb of Centaurium erythraea Rafn. The herb of Gentiana cruciata L. contained thirteen free and fifteen bound amino acids. L-glutamic acid, L-arginine, L-aspartic acid, and L-cystine were predominant of Centaurium erythraea Rafn. herb. Amino acids L-lysine, L-serine, L-aspartic acid, and L-phenylalanine were present in the herb of Gentiana cruciata L. in the greatest amount. The metabolic processes in which these amino acids are involved connected to the medicinal properties of the study plants according to their use in official or nontraditional medicine.

Phototherapy has known a great evolution all the world and some medicinal plants are importance remedies of some diseases. Centaurium erythraea is one of the medicinal plants widely used in this field. In this study, we have evaluated the total polyphenolic and the flavonoid contents of the methanolic (ME) and aqueous (AqE) extracts of the plant Centaurium erythraea as well as its antioxidant activity using the DPPH (2'2-diphenylpicrylhydrazyl), β-carotene /linoleic acid bleaching and reducing power assays. The total polyphenolic content of the methanolic extract was 35,45± 0,041 μg AGE/mg extract and flavonoids was 6,65 ± 0,060 μg QE/mg. The total polyphenolic content of the aqueous extract was 54,27 ± 0,023 μg AGE/mg extract and flavonoids was 3,275 ± 0,003 μg QE/mg. The results of the DPPH test showed a powerful antioxidant activity with a very similar IC50 for the methanolic (IC50=0.232 ± 0.002mg/ml) and aqueous (0.208 ± 0.002mg/ml) extracts. The inhibitory activity of the tow extracts in the β-carotene/linoleic acid assay was (86.781 ± 0.17%) for the methanolic extract and (77.816 ± 0.69%) for the aqueous extract. ME has the higher reducing power (IC50 = 0.35 ± 0.066 mg / ml) compared to the AqE (IC50 = 1.31 ± 0.047 mg / ml). Keywords: Centaurium erythraea, antioxidant activity, polyphenols, DPPH scavenging, β-carotene, reducing power.

Somatic embryogenesis (SE) is a developmental process during which plant somatic cells, under suitable conditions, produce embryogenic cells that develop into somatic embryos (se). SE is the most important method for plant propagation in vitro, having both fundamental and applicative significance. SE can be induced from different tissues and organs, but when se are used as explants, the process is recognized as secondary or cyclic SE. We induced secondary SE in Centaurium erythraea by application of 2,4-dichlorophenoxyacetic acid (2,4-D) and N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU). A medium containing 0.1 mgL−1 2,4-D and 0.25 mgL−1 CPPU was optimal in terms of the number of primary SE explants forming se, the number of well-developed se per explant, and morphological appearance of the obtained se. These concentrations allowed SE to progress through three cycles, whereas at higher concentrations of 0.2 mgL−1 2,4-D and 0.5 mgL−1 CPPU, only two cycles were achieved. Histological analysis revealed that secondary se are formed both directly and indirectly. Secondary SE readily germinated and converted into plantlets. Induction of cyclic SE contributes to the conservation efforts of this endangered medicinal plant and expands the spectrum of in vitro developmental pathways described in centaury—an emerging model in developmental biology.

Tese de mestrado em Química, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, em 2018
O uso de plantas para fins medicinais tem, nos últimos anos, voltado a desempenhar um papel de elevada importância, devido às potencialidades que os compostos resultantes do metabolismo secundário apresentam para a saúde humana. Tendo como base esta realidade, iniciou-se este trabalho experimental, que se centrou no estudo de Centaurium erythraea. Começou-se, então, com o processo de decocção desta planta, o que permitiu a obtenção de um extrato aquoso. Este extrato foi posteriormente purificado através da precipitação de mucilagens com etanol, obtendo-se um sobrenadante constituído maioritariamente por compostos fenólicos (sobrenadante). Foi ainda purificado através da recolha de frações por HPLC-DAD, que permitiu obter uma fração rica em xantonas (fração III), tendo sido este último o método de purificação que apresentou melhores resultados. Tendo em conta que a maioria dos artigos disponíveis para consulta referem o metanol como solvente utilizado para a extração dos compostos, preparou-se também dois novos extratos recorrendo ao metanol e ao etanol, de forma a comparar o perfil cromatográfico com o extrato aquoso e perceber se os diferentes solventes resultariam na extração de diferentes compostos. Observou-se, então, que o perfil obtido através da análise por HPLC-DAD é bastante semelhante para os três extratos, sendo as maiores diferenças associadas à quantidade de compostos extraídos. Para além disso, fez-se a identificação dos compostos existentes na decocção de C. erythraea através de LC-MSn. O extrato aquoso desta planta é caracterizado, principalmente, pela presença de secoiridoides, como a swertiamarina, o gentiopicrósido e o swerósido, e de xantonas, como a di-hidroxi-dimetoxixantona e a di-hidroxi-tetrametoxixantona. Paralelamente, foi quantificada a composição fenólica de cada um dos extratos recorrendo-se ao método que tem como base a reação dos grupos fenólicos com o reagente de Folin-Ciocalteu, tendo-se obtido para o extrato aquoso 20 μg de fenóis/mg de extrato e para a fração III 16 μg de fenóis/mg de extrato, valores expressos em equivalentes de ácido gálico. Realizaram-se também estudos no âmbito da valorização farmacológica de C. erythraea, nomeadamente da sua capacidade antioxidante através da inibição da eliminação do radical DPPH, da lipoperoxidação e da captura do radical óxido nítrico. O extrato aquoso revelou, através do método do DPPH, uma percentagem de inibição de 25 %, para uma concentração de 50 μg/mL, e a fração III de 18 %. Para o ensaio da peroxidação lipídica, para uma concentração de 400 μg/mL, o extrato aquoso inibiu a lipoperoxidação em 32 % e entre os extratos orgânicos, que apresentaram valores inferiores ao do extrato aquoso, não foram encontradas diferenças significativas. Já no ensaio da inibição da captura de radicais de óxido nítrico, o extrato aquoso revelou um EC50 = 775 μg/mL e o extrato etanólico foi o que apesentou um melhor potencial antioxidante, com um EC50 = 565 μg/mL. Neste trabalho experimental, procedeu-se ainda ao estudo da atividade inibitória da acetilcolinesterase, através do método de Ellman, obtendo-se um valor de 54% no extrato aquoso, para uma concentração de 500 μg/mL, e de 60 % na fração III, para a mesma concentração. Estudou-se também a atividade inibitória da HMG-CoA redutase, para a qual o extrato aquoso revelou uma percentagem de inibição de 48 % e a fração III de 27 %, para uma concentração de 10 μg/mL. Fizeram-se ainda estudos com o intuito de se avaliar a capacidade antitumoral de C. erythraea em linhas células humanas do cancro do fígado (Hep-G2), concluindo-se que nenhum dos extratos estudados foi citotóxico e que a fração III foi aquele que apresentou um maior potencial antitumoral, com um IC50 = 1,04 mg/mL, enquanto o extrato aquoso apresentou um IC50 = 1,57 mg/mL. Mais ainda, em estudos preliminares, observou-se que a fração III induz alterações a nível proteico em células do hepatocarcinoma e que existe uma relação inversa entre a quantidade de DNA e a quantidade de proteína. Estudos adicionais poderão indicar em que proteínas ocorrem estas modificações e se poderão ter influência no tratamento do cancro. Em suma, com este trabalho experimental, é possível concluir que a extração dos compostos bioativos, com água ou com os solventes orgânicos estudados, é semelhante. Este facto revela-se bastante vantajoso, dado que permite compreender que o uso desta planta, sob a forma de “chá”, possibilita a ingestão de compostos fenólicos reportados na literatura como importantes para a saúde humana, quando extraídos com solventes orgânicos. Para além disso, o extrato aquoso demonstrou ser bastante promissor para a inibição da biossíntese do colesterol. Foi possível, ainda, chegar à conclusão que a fração rica em xantonas possui uma boa atividade biológica, podendo desempenhar um papel importante na Doença de Alzheimer ou para facilitar a digestão através do aumento dos movimentos peristálticos.
The use of plants for medicinal purposes has, in recent years, returned to play a very important role, due to the potential that the compounds resulting from the secondary metabolism present for human health. Based on this reality, we began this experimental work that focused on the study of Centaurium erythraea. This work started with the decoction process of this plant, which allowed to obtain an aqueous extract. The extract was then purified by the precipitation of mucilages with ethanol, obtaining a supernatant constituted mainly by phenolic compounds (supernatant). It was also purified by the collection of fractions by HPLC-DAD, which allowed to obtain a fraction rich in xanthones (fraction III), the latter being the purification method that presented better results. Taking into account that most of the articles available refer to methanol as the solvent used for the extraction of the compounds, two new extracts were also prepared using methanol and ethanol, in order to compare the chromatographic profile with the aqueous extract and to understand if the different solvents would result in the extraction of different compounds. It was then verified that the profile obtained by HPLC-DAD analysis is very similar for the three extracts, the largest differences being associated with the amount of extracted compounds. In addition, the compounds in the decoction of C. erythraea were identified by LC-MSn. The aqueous extract of this plant is characterized, mainly, by the presence of secoiridoids, such as swtertiamarin, gentiopicroside and sweroside, and xanthones, such as di-hydroxy-dimethoxyxanthone and di-hydroxy-tetramethoxyxanthone. At the same time, the phenolic composition of each extract was quantified using the method based on the reaction of the phenolic groups with the Folin-Ciocalteu reagent, obtaining for the aqueous extract and for fraction III 20 μg of phenols/mg of extract and 16 μg of phenols/mg of extract, respectively, values expressed as gallic acid equivalents. Studies have also been carried out in the field of pharmacological valorization of C. erythraea, namely its antioxidant capacity by inhibiting the elimination of the DPPH radical, lipoperoxidation and the capture of the nitric oxide radical. The aqueous extract revealed by the DPPH method an inhibition percentage of 25 % at a concentration of 50 μg/mL and fraction III of 18 %. In the lipid peroxidation assay, at a concentration of 400 μg/mL, the aqueous extract inhibited lipoperoxidation in 32 % and, among the organic extracts, which presented lower values than the aqueous extract, no significant differences were found. For the nitric oxide radical capture inhibition test, the aqueous extract showed an EC50 = 775 μg/mL and the ethanolic extract showed the highest antioxidant potential with an EC50 = 565 μg/mL. In this experimental work the acetylcholinesterase inhibitory activity was also studied by the Ellman method, obtaining a value of 54 % in the aqueous extract, at a concentration of 500 μg/mL, and of 60 % in fraction III, for the same concentration. The inhibitory activity of HMG-CoA redutase was also studied and for this study the aqueous extract showed an inhibition percentage of 48 % and fraction III percentage of 27 %, for a concentration of 10 μg / mL. Further studies were conducted to evaluate the antitumor capacity of C. erythraea in human liver cancer cell lines (Hep-G2), concluding that none of the extracts studied were cytotoxic and that fraction III was the one that presented a higher antitumor potential, with an IC50 = 1,04 mg/mL, while the aqueous extract had an IC50 = 1,57 mg/mL. Moreover, in preliminary studies, it was found that fraction III induces changes at the protein level in hepatocarcinoma cells and that there is an inverse relation between the amount of DNA and the amount of protein. Further studies may indicate in which proteins these modifications occur and whether they may influence the treatment of cancer. In summary, with this experimental work, it is possible to conclude that by using water or by using the organic solvents studied, the extraction of the bioactive compounds is similar. This conclusion is very beneficial, since it allows us to understand that the use of this plant under "tea" form enables the ingestion of phenolic compounds reported in the literature as important for human health, when extracted with organic solvents. Moreover, the aqueous extract has been shown to be very promising for inhibition of cholesterol biosynthesis. It was also possible to conclude that the xanthone-rich fraction has a good biological activity and may play an important role in Alzheimer's disease or to facilitate digestion by increasing peristaltic movements.