Antihyperlipidemic effects of different molecular weight sulfated polysaccharides from Ulva pertusa (Chlorophyta).

Ulvan, a sulfated polysaccharide from Ulva pertusa, was degraded to yield two low molecular weight fractions U1 and U2. The molecular weights of ulvan and its fractions were determined and varied from 151.6 to 28.2 kDa. They were fed to rats on a hypercholesterolemic diet for 21 days to evaluate and compare the antihyperlipidemic actions. Ulvan-based diet significantly lowered the levels of serum total cholesterol (-45.2%, P<0.05) and low density lipoprotein cholesterol (LDL-cholesterol, -54.1%, P<0.05). While U1- and U2-based diets significantly elevated the levels of serum high density lipoprotein cholesterol (HDL-cholesterol, +22.0% for U1, not significant; +61.0% for U2; P<0.05) and reduced triglyceride (TG, -82.4% for U1, -77.7% for U2; P<0.05) in rats as compared to control diet. In addition, consumptions of various ulvans significantly increased fecal bile acid excrement. The results indicated that ulvans with different molecular weights exhibited diverse effects on lipid metabolism. The high molecular weight ulvan was effective in serum total and LDL-cholesterol, whereas low molecular weight fractions were in TG and HDL-cholesterol. The fractions were considered to be more beneficial to hyperlipidemia associated with diabetes over ulvan.

Optimum extraction of polysaccharides from Ulva pertusa established by ortho gonal test / 中成药

AIM: To optimize and establish the extraction techn ology of water-soluble polysaccharides from Ulva pertusa. TLC was employed to determine the mainly neutral sugars in the Ulvan. METHODS: The orthogonal test was employed to test the effects of th e four factors including volume of water, temperature of extraction, time of ext raction and pH of water on the yield and total carbohydrate contents of water-s oluble polysaccharides from Ulva pertusa and optimize the extraction technol ogy. Five groups of parallel tests were carried out by the optimum parameters es tablished and the sugar constituents of products were analyzed by TLC. RESULTS: Temperature of extraction and time of extraction have sign ificant effects on the extraction yield of water-soluble polysaccharides from Ulva pertu sa, but, for total carbohydrate content, only temperature of extraction was a significant factor. The mainly neutral sugars were composed of rhamnose, xylose and glucose. CONCLUSION: The optimum extraction technology was A 1B 3C 3D 3 when the yield and total carbohydrate content were considered as preferential pa rameters.