rhapontin and Fatty-Liver

Rhapontin was purified from a methanol extract from the roots of Rheum undulatum, and rhapontigenin was produced by an enzymatic transformation of rhapontin. Rats were fed a high-cholesterol diet to induce hyperlipidemia, followed by oral treatment with rhapontin or rhapontigenin (1-5 mg/kg/day). Rhapontin and rhapontigenin treatment resulted in a significant (p<0.05) dose-dependent decrease in the serum lipid level, while the high-density lipoprotein cholesterol level increased slightly compared with the experimental control. Furthermore, rhapontin and rhapontigenin treatment improved the pathological characteristics of the degenerating fatty liver in high-cholesterol diet-induced hyperlipidemic rats dose-dependently. Aspartate aminotransferase and alanine aminotransferase levels in rhapontin- and rhapontigenin-treated hyperlipidemic rats were not significantly different from those in the control. These results indicate that rhapontin and rhapontigenin can be used as potent antihyperlipidemic agents.

Topics: Animals; Cholesterol; Fatty Liver; Hyperlipidemias; Hypolipidemic Agents; Plant Extracts; Rats; Rats, Sprague-Dawley; Rheum; Stilbenes; Triglycerides

We isolated several stilbene compounds including rhaponticin (3',5-dihydroxy-4'-methoxystilbene 3- O-beta- D-glucopyranoside) from extracts of rhubarb rhizomes. These compounds showed significant hypoglycemic effects in streptozotocin (STZ)-induced type 1 diabetic rats and mice. In this study, we investigated the effect of rhaponticin on glucose utilization, lipid metabolism, and liver and heart function in a KK/Ay type 2 diabetic mouse model. The results showed that oral administration of rhaponticin (125 mg/kg) significantly reduced blood glucose levels and improved oral glucose tolerance of KK/Ay diabetic mice. Elevated plasma triglyceride (TG), low density lipoprotein (LDL), cholesterol (CHO), non-esterified free fatty acids (NEFA), and insulin levels were also markedly attenuated. Serum enzymatic activities of lactate dehydrogenase (LDH), creatine kinase (CK), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) in the rhaponticin-treated group significantly decreased in comparison to the untreated model group. Livers of rhaponticin-treated mice had relatively normal cellular size and decreased fibrosis and steatosis. In addition, rhaponticin administration caused a remarkable increase in the hepatic glycogen content and a significant reduction in the hepatic triglyceride content. These results indicate that rhaponticin has a noticeable antidiabetic effect and could be potentially used as a new agent to treat type 2 diabetes mellitus and its complications.

Topics: Animals; Blood Glucose; Cholesterol; Diabetes Mellitus, Experimental; Enzymes; Fatty Acids, Nonesterified; Fatty Liver; Glucose Tolerance Test; Glycogen; Hypoglycemic Agents; Insulin; Lipids; Lipoproteins, LDL; Liver; Mice; Rheum; Rhizome; Stilbenes; Triglycerides