Hypoglycemic effect of triterpenoid-rich extracts from Euryale ferox shell on normal and streptozotocin-diabetic mice

The antioxidant effects of the triterpenoid-rich extracts from euryale ferox shell (es) have been confirmed in vitro. this study examined whether the triterpenoid-rich extract from es eases human hyperglycemia and diabetes caused by metabolic disorders. normal and streptozocin (stz)-induced diabetic mice were used as controls for the four groups that received the triterpenoid-rich extracts of es suspended in distilled water orally at doses of 200, 300, 400, 500±2 mg/l. body weight, blood glucose and pancreatic tissue morphology were observed after 4 weeks. the expression of protein tyrosine phosphatase-1b (ptp1b) and insulin receptor substrate (irs-1) proteins, which are related to the regulation of glucose metabolism in vivo, were also investigated. compared with the model group (ld50 900±2 mg/l), it was found that the triterpenoid-rich extracts of es could regulate glucose metabolism (p<0.01) and cause body weight to return to normal levels (p<0.05). islet morphology recovered well, the expression of the negative regulation protein ptp1b gene was reduced and insulin receptor irs-1 protein expression was increased. these data prove that the triterpenoid-rich extracts from es have a therapeutic effect on diabetes by insulin resistance.