Abstract

In view of alleged antidiabetic potential, effect of methanolic extract of Ocimum sanctumL. (Lamiaceae) roots on fasting blood sugar levels and serum biochemical analysis in streptozotocin-induced diabetic rats were investigated. The resulted extract had shown significant protection and lowered the blood glucose levels to normal in glucose tolerance test. In long term treatment of streptozotocin-induced diabetic rats, the degree of protection was determined by measuring blood glucose, triglycerides, total cholesterol and serum insulin levels. Phytochemical investigation of the roots resulted in the isolation of three new active constituents characterized as urs-12-en-3β,6β,20β-triol-28-oic acid (2), 1´´-menthyl-2-glucopyranosyloxybenzoate (4) and n-decanoyl-β-D-glucopyranosyl-(2a→1b)-β-D-glucopyranosyl-(2b→1c)-β-D-glucopyranosyl-(2c→1d)-β-D-glucopyranosyl-2d-2΄-hydroxybenzoate (5), along with known compounds of ursolic acid (1) and palmityl glucoside (3). The structures of the isolated compounds were established by proton nuclear magnetic resonance (1H-NMR), carbon-13 NMR (¹³C NMR), fast atom bombardment (FAB) mass, ¹H-¹H correlation spectroscopy (COSY) and heteronuclear multiple-bond correlation (HMBC) spectral techniques.

Key words: Ocimum sanctum L., roots, antidiabetic activity, phytoconstituents.