ABSTRACT
The present study was undertaken to investigate the antidiabetic potential of tap roots of Potentilla fulgens in streptozotocin induced diabetic rat models. The crude powder, ethanolic, ethanolic: aqueous and aqueous extracts of tap roots were administered to normoglycemic- and streptozotocin (STZ)-induced diabetic rats in a single dose study. The ethanolic extract showed significant improvement in oral glucose tolerance and antihyperglycemic effect on sucrose loaded normal rats and STZ-induced diabetic rats. Of the isolated aqueous, n-butanol, chloroform and n-hexane soluble fractions of the active ethanolic extract of the roots, the aqueous fraction (100 mg/kg body weight) showed significant blood glucose lowering effect on STZ-induced diabetic rats. In a multiple dose study, aqueous fraction of ethanolic extract of P. fulgens roots significantly improved the body weight, percent glycated hemoglobin (%HbA1c), fasting blood glucose, oral glucose tolerance (OGTT), serum insulin, lipid profile, liver and kidney parameters in STZ-induced diabetic rats. The aqueous fraction also showed marked improvement in OGTT and serum insulin level in neonatal STZ-induced diabetic rats for 30 consecutive days. The aqueous fraction of the roots also inhibited the activity of alpha (α)-glucosidase enzyme in a dose dependent manner. In conclusion, the finding suggested that an aqueous fraction of tap roots of P. fulgens possessed potential antidiabetic activity.
ABSTRACT
The crude powder, ethanolic extract and aqueous, chloroform, hexane and n-butanol soluble fractions of ethanolic extract of heart wood of P. marsupium showed marked improvement on oral glucose tolerance post sucrose load in normal rats. All these fractions except aqueous fraction showed improvement on oral glucose tolerance post sucrose load on streptozotocin (STZ)-induced diabetic rats. The crude powder, ethanolic extract and hexane and n-butanol fractions showed marked decline in blood glucose level on STZ-induced diabetic rats. The ethanolic extract (100 mg/kg body weight) when given to STZ-induced diabetic rats for 10 consecutive days declined blood glucose, improved OGTT and increased their serum insulin levels. The ethanolic extract also showed marked improvement on oral glucose tolerance on high fat-low dosed STZ-induced diabetic rats and neonatally STZ treated rats. The ethanolic extract of P. marsupium also showed marked antidyslipidemic effects on high fat diet fed Syrian golden hamsters. Altered renal and hepatic function markers and serum insulin levels of high fat diet fed-low dosed STZ-treated diabetic rats were also found towards normalization when these animals were treated with ethanolic extract of P. marsupium for 28 consecutive days. The four out of five phenolic C-glycosides isolated from n-butanol fraction of ethanolic extract of P. marsupium enhanced glucose uptake by skeletal muscle cells (C2C12) in a dose dependent manner. It may primarily be concluded that phenolic-C-glycosides present in P. marsupium heart wood are the phytoconstituents responsible for the antihyperglycemic activity and validate the claim of antidiabetic activity of heart wood of P. marsupium.