Effects Of Huanglianwan Extract On Activities Of Intestinal Disaccharidases In Diabetic Rats And The Determination Of Effective Components

Objective:The methods were established for separation and determination of the effective components contained in the extract of Huanglianwan(HLW), a prescriptions of traditional Chinese medicine. In addition, the anti-hyperglycaemic effect of HLW extract was investigated in diabetic rats induced by Streptozotocin (STZ) in order to provide experimental basis for clinical use in the treatment of diabetes mellitus.Methods:(l)The content of three alkaloids (namely berberine hydeochloride, Jatrorrhizine hydrochloride and coptisine) contained in HLW extract were determined by HPLC method.(2)The content of catalpol contained in HLW extract were determined by HPLC method.(3)The diabetic rats were induced by intraperitoneal injection of STZ. Then the diabetic rats were treated by two dose of HLW extract for4weeks. At the end of this experiment, all rats were killed, and the weight change, plasma glucose level and the activity of lactate dehydrogenase (LDH) were assayed. The plasma glucose levels were measured using glucose reagent kits. The activity of lactate dehydrogenase was measured using LDH kit reagent. (4)Liver samples were collected, and the content of liver glycogen were measured using liver glycogen reagent kit.(5)The intestinal mucosas of three intestinal sections were collected for the determination of disaccharidases activities. The amounts of protein in each intestinal section were measured using coomassie brilliant blue protein assay reagent kit. The activities of disaccharidases (sucrase, maltase, and lactase) were measured using disaccharidases (sucrase, maltase, and lactase) kit reagents.Results:(1)The average content of three alkaloids in HLW extract was3.88mg/g for jatrorrhizine hydrochloride,5.34mg/g for coptisine and36.19mg/g for berberine hydeochloride.(2)The average content of catalpol was12.94mg/g.(3)After the oral administration of two doses of HLW extract, the levels of plasma glucose in diabetic rats were significantly decreased by39.7±8.2%and26.5±8.5%, respectively. The activities of serum lactate dehydrogenase in diabetic rats were significantly decreased by23.17±1.82%and15.64±1.83%, respectively.(4)After the oral administration of two doses of HLW extract, the content of liver glycogen were significantly increased to29.65±4.95mg/g and20.32±4.44mg/g from15.16±3.52mg/g, respectively(5) Compared with diabetic group, the activities of maltase in the duodenum and jejunum of diabetic rats treated with high dose of HLW extract were decreased by (40.9±0.7)%and (16.7±2.3)%, respectively. The activities of lactase in these two intestinal sections were decreased by (33.2±4.2)%and (62.5±7.1)%, respectively. And the activities of sucrase in the duodenum of diabetic rats were decreased by (27.2±4.2)%.Conclusion:(1) Method developed for the assay of three alkaloids is accurate and reliable. And it can be used to simultaneously determine berberine hydeochloride, Jatrorrhizine hydrochloride and coptisine in HLW extract. It is proved to be suitable for the quality control of HLW extract.(2) Method developed for the assay of catalpol is accurate and reliable. And it can be used to determine the content of catalpol in HLW extract.(3) HLW extract can significantly lower the plasma glucose level of diabetic rats. And current findings suggest that HLW extract could exert hypoglycemic effect on diabetic rats induced by STZ partly via promoting glycogen synthesis and inhibiting the increased activities of intestinal disaccharidases.