Academic literature on the topic 'Sesuvioideae'

<b>Background and aims</b> – The genus <i>Trianthema</i> (Aizoaceae – Sesuvioideae) is poorly known. Identification of two well circumscribed subgenera is followed by a revision of <i>T.</i> subg. <i>Papularia</i>, presenting for the first time a list of all species identified as members of the subgenus. <b>Methods</b> – Normal practices of herbarium taxonomy have been applied to study all herbarium material available, mainly from AD, B, BRI, C, DNA, E, HBG, K, L, MO, UTB, WAG, and Z. <b>Key results</b> – Based on an extensive investigation into as many characters as possible, results permitted the identification of new character states, supporting the division of the genus <i>Trianthema</i> into the two subgenera, <i>Trianthema</i> and <i>Papularia</i>. In consequence, species limits can be reliably re-circumscribed, resulting in the recognition of 17 species in the latter subgenus, of which five are described as new here: <i>T. corallicola, T. mozambiquensis, T. pakistanensis, T. ufoensis</i>, and <i>T. vleiensis</i>. Raised to species rank are <i>T. clavata</i> and <i>T. corymbosa</i>, and emended and re-circumscribed are <i>T. crystallina, T. hereroensis, T. parvifolia, T. salsoloides, T. sanguinea, T. sedifolia, T. sheilae, T. transvaalensis</i>, and <i>T. triquetra</i>. Unaltered is the description of <i>T. argentina</i>, for which, however, the critical features are also described and figured in order to permit a sound identification of each species in <i>T.</i> subg. <i>Papularia</i>. Distribution patterns are discussed and possible evolutionary pathways are suggested on a morphological base.

The taxonomy of perennial Sesuvium species in Africa has been poorly investigated until now. Previously five perennial species of Sesuvium were recognised in Africa (S. congense, S. crithmoides, S. mesembryanthemoides, S. portulacastrum, and S. sesuvioides). Based on the differing number of stamens, S. ayresii is accepted here as being distinct from S. portulacastrum. Field observations in Angola also led the authors to conclude that S. crystallinum and S. mesembryanthemoides are conspecific with S. crithmoides. A new subspecies, Sesuvium portulacastrum subsp. persoonii, is described from West Africa (Cape Verde, Gambia, Guinea-Bissau, Mauritania, Senegal). The molecular phylogeny indicates the position of S. portulacastrum subsp. persoonii within the "American lineage" as a part of the Sesuvium portulacastrum complex which needs further studies. A diagnostic key and taxonomic notes are provided for the six perennial species of Sesuvium found in Africa and recognised by the authors (S. ayresii, S. congense, S. crithmoides, S. portulacastrum subsp. portulacastrum, S. portulacastrum subsp. persoonii, S. verrucosum and the facultatively short-lived S. sesuvioides). The distribution of S. crithmoides, previously considered to be endemic to Angola, is now confirmed for the seashores of Republic of Congo and DR Congo. The American species S. verrucosum is reported for the first time for Africa (the Macaronesian islands: Cape Verde and the Canaries). It is locally naturalised in Gran Canaria, being a potentially invasive species. These findings as well as new records of S. verrucosum from Asia and the Pacific Islands confirm its proneness to transcontinental introduction. Lectotypes of S. brevifolium, S. crithmoides, S. crystallinum and S. mesembryanthemoides are selected. The seed micromorphology and anatomy of the perennial African species is studied. Compared to the seeds of some annual African Sesuvium investigated earlier, those of perennial species are smooth or slightly alveolate. The aril is one-layered and parenchymatous in all species and usually tightly covers the seed. The aril detachments from the seed coat that form a white stripe near the cotyledon area easily distinguish S. verrucosum from other species under study.

The current study intended to investigate the role of new natural compounds derived from the Sesuvium sesuvioides plant in mitigating symptoms of diabetes and insulin resistance in the diabetic mice model. Anti-advanced glycation activity, insulin, and adiponectin were quantified by enzyme-linked immunosorbent assay (ELISA). Glucose uptake was performed using enzymatic fluorescence assay, and glycogen synthesis was measured using PAS staining. Gene and protein expression was assessed using real time PCR (RT-PCR), and immunoblotting and fluorescent microscopy, respectively. The new flavonoid glycoside eupalitin 3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside 1 isolated from S. sesuvioides exhibited anti-AGE activity by reducing human glycated albumin in liver cells. In a diabetic mouse model treated with compound 1, we observed improved glucose tolerance, increased adiponectin levels, and decreased insulin resistance. We also observed alleviated AGEs induced reduction in glucose uptake and restored glycogen synthesis in the compound 1-treated diabetic mice muscles. Exploring the molecular mechanism of action in skeletal muscle tissue of diabetic mice, we found that 1 reduced AGE-induced reactive oxygen species and the inflammatory gene in the muscle of diabetic mice. Additionally, 1 exhibited these effects by reducing the gene and protein expression of receptor for advanced glycation end products (RAGE) and inhibiting protein kinase C (PKC) delta activation. This further led us to demonstrate that compound 1 reduced serine phosphorylation of IRS-1, thereby restoring insulin sensitivity. We conclude that a new flavonoid glycoside from S. sesuvioides could be a therapeutic target for the treatment of symptoms of insulin resistance and diabetes.