Confirmation towards establishing antidiabetic activity in heart wood of Pterocarpus marsupium and analysis of phytoconstituents

Abstract

The crude powder, ethanolic extract and aqueous, chloroform, hexane and n-butanol soluble fractions of ethanolic extract of heart wood of Pterocarpus marsupium (Family: Fabaceae) showed marked improvement on oral glucose tolerance post sucrose load in normal rats, and all these except aqueous fraction showed improvement on oral glucose tolerance post sucrose load on streptozotocin-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 when given to streptozotocin-induced diabetic rats at a dose of 100 mg/kg body weight for 10 consecutive days declined blood glucose, glycosylated hemoglobin (HbA1c) and increased their serum insulin levels. The ethanolic extract also showed marked improvement on oral glucose tolerance on high fat-low dosed streptozotocin-induced diabetic rats and neonatally streptozotocin 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 streptozotocin-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 at the moment 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 in heart wood of P. marsupium.