Characterization and Hypoglycemic Activity of a Rhamnan-Type Sulfated Polysaccharide Derivative

Abstract

Polysaccharide chromium (III) derivatives are gaining increasing attention in improving type 2 diabetes. In this study, the sulfated polysaccharide from Enteromorpha prolifera (SPE) with 4.8 kDa was prepared by specific enzymatic hydrolysis. The obtained SPE was used to prepare a rhamnan-type sulfated polysaccharide derivative (SPED). Results indicated that O-H, C=O, and S=O were effectively involved in the chelation of SPED (chromium content 20.26%). Acute (half lethal dose > 2.38 g/kg) and sub-acute toxicity showed that SPED had no damaging effects on mice. Anti-diabetic experiment demonstrated that SPED improved glucose metabolism. Moreover, SPED promoted the PI3K/PKB/GSK-3β signaling pathway by regulating mRNA expression of insulin receptors (IR), insulin receptor substrate 2 (IRS-2), phosphatidylinositol 3 kinase (PI3K), protein kinase B (PKB), and glycogen synthase kinase 3β (GSK-3β). In conclusion, the SPED might represent a novel marine-derived candidate against hyperglycemia, which may undergo further pharmaceutical development as a hypoglycemic agent.

Antihyperlipidemic and hepatoprotective properties of alkali- and enzyme-extractable polysaccharides by Dictyophora indusiata

“…According to a modified method previously described by reports, acute toxicity experiment was performed 42,43 . Forty-two male Kunming strain mice were divided into seven groups at random including one control group and six dosage groups.…”

Microalgae with Immunomodulatory Activities

“…PS have been shown to be good antiviral agents, health foods, antioxidants, anti-inflammatory, and immunomodulatory compounds, and they can also be used as lubricants for bone joints and drag-reducing substances for ships [62]. sPS from marine sources exhibited, in particular, immunomodulatory activities [2,[63][64][65][66][67][68][69], and are promising candidates for drug development. sSP have been found in several macroalgae and microalgae, in both marine and freshwater environments, such as in the green alga Monostroma nitidum [70], the red algae Gelidum corneum [67] and Gracilaria caudata [71], the diatom P. tricornutum [23], the dinoflagellate G. impudicum, the freshwater xanthophycea Tribonema sp.…”

Phosphatidylserine from Portunus trituberculatus Eggs Alleviates Insulin Resistance and Alters the Gut Microbiota in High-Fat-Diet-Fed Mice

“…In skeletal muscle, insulin receptor substrate (IRS) is activated by insulin stimulation through inhibition of phosphorylation at its serine site and elevation of phosphorylation at its tyrosine site [ 5 ]. Activated IRS polymerizes PI3K and triggers the phosphorylation of the p85 regulatory subunit [ 6 ]. The signal is subsequently transmitted downstream, leading to Akt phosphorylation and glucose transporter 4 (Glut4) translocation from the cytoplasm to the cytomembrane [ 6 , 7 ].…”

“…Activated IRS polymerizes PI3K and triggers the phosphorylation of the p85 regulatory subunit [ 6 ]. The signal is subsequently transmitted downstream, leading to Akt phosphorylation and glucose transporter 4 (Glut4) translocation from the cytoplasm to the cytomembrane [ 6 , 7 ]. Glut4 in the plasma membrane (m-Glut4) is the exclusive protein that transports glucose into cells [ 8 ].…”