Phytochemical Analysis and Hypoglycemic Activity from Ethanolic Extract of Oroxylum indicum (L.) Leaves

Oroxylum indicum (L.) is an important medicinal plant used in traditional medicine. The objective of this study is to evaluate the phytochemical compounds and the anti-hyperglycemic potential of ethanolic extract of O. indicum leaves in oral glucose tolerance tests carried out with glucose-loaded mice. Preliminary findings revealed that O. indicum showed the presence of carotenoid, essential oil, triterpenoids in free and glycosid forms, tannins, flavonoids and anthraquinones. The composition of ethanolic extract of O. indicum leaves was investigated by using an HPLC/MS fingerprinting technique coupled with chemometric analysis. According to the exact mass measurements and MS/MS data, the results showed the identification of four flavonoids such as 5, 7 dihydro - 3 methoxyflavone (1); pinobanksin (2); baicalein (3); and chrysin (4). The triterpenoid betulinic acid (5) was identified as constituents of O. indicum for the first time.The effects of three different doses (50 mg/kg, 70 mg/kg, and 100 mg/kg body weight) of ethanolic extract were orally tolerated to body mice before the oral glucose tolerance. The result indicated that percentage of inhibition of ethanolic extract of O. indicum leaves at the dose of 100 mg/kg body weight in glucose-induced hyperglycemic mice was effectively similar to standard drug glibenclamide.