Anticoagulant activity of sulfated polysaccharides and polyphenols extracted from marine algae

: The aim of this study was to evaluate the anticoagulant activity of five marine algae from Bejaia’s coast (Algeria). Higher contents of phenolic compounds were obtained with ethanol for Cystoseira humilis, Halopteris scoparia, Padina pavonica and Rhodomela confervoides (8.55±0.29, 7.84±0.47, 6.41±0.14 and 4.16±0.04 mg CE/g of dw, respectively). Whereas, for Sargassum vulgare, the extraction with acetone showed higher content (3.04±0.071 mg CE/g of dw).The determination of sugar content showed that acetone extract of the five seaweeds was the richest in sugar, this rate increasingly dropped in ethanol extract and the fractions A and B. The red algae Rhodomela confervoides showed a significant anticoagulant activity in ethanol extract and the fractions A, B and C, with an elongation up to 407.97±58.12 s in the fraction C, at a concentration of 10 mg/mL. An anticoagulant activity was observed in the fractions A, B and C of all the brown seaweeds. A procoagulant activity was observed in the fractions A, B of Cystoseira humilis and Sargassum vulgare as well as the fraction B of Padina pavonica with an indeterminate period, at 10 mg/mL.

Effects of a natural PTP1B inhibitor from Rhodomela confervoides on the amelioration of fatty acid-induced insulin resistance in hepatocytes and hyperglycaemia in STZ-induced diabetic rats

A natural bromophenol BPN was identified as a competitive PTP1B inhibitor both in vitro and in vivo.

CYC27 Synthetic Derivative of Bromophenol from Red Alga Rhodomela confervoides: Anti-Diabetic Effects of Sensitizing Insulin Signaling Pathways and Modulating RNA Splicing-Associated RBPs

RNA-binding proteins (RBPs) lie at the center of posttranscriptional regulation and the dysregulation of RBPs contributes to diabetes. Therefore, the modulation of RBPs is anticipated to become a potential therapeutic approach to diabetes. CYC27 is a synthetic derivative of marine bromophenol BDB, which is isolated from red alga Rhodomela confervoides. In this study, we found that CYC27 significantly lowered the blood glucose levels of diabetic BKS db mice. Moreover, CYC27 effectively ameliorated dyslipidemia in BKS db mice by reducing their total serum cholesterol (TC) and triglyceride (TG) levels. Furthermore, CYC27 was an insulin-sensitizing agent with increased insulin-stimulated phosphorylation of insulin receptors and relevant downstream factors. Finally, to systemically study the mechanisms of CYC27, label-free quantitative phosphoproteomic analysis was performed to investigate global changes in phosphorylation. Enriched GO annotation showed that most regulated phosphoproteins were related to RNA splicing and RNA processing. Enriched KEGG analysis showed that a spliceosome-associated pathway was the predominant pathway after CYC27 treatment. Protein-protein interaction (PPI) analysis showed that CYC27 modulated the process of mRNA splicing via phosphorylation of the relevant RBPs, including upregulated Cstf3 and Srrt. Our results suggested that CYC27 treatment exerted promising anti-diabetic effects by sensitizing the insulin signaling pathways and modulating RNA splicing-associated RBPs.