Hypoglycaemic effect of Berberis vulgaris L. in normal and streptozotocin-induced diabetic rats.

OBJECTIVE To achieve a primary pharmacological screening contained in the aqueous extract of Berberis vulgaris (B. vulgaris) and to examine the hypoglycaemic effect and biochemical parameters of aqueous and saponins extract on groups of rats rendered diabetic by injection of streptozotocin. METHODS The phytochemical tests to detect the presence of different compounds were based on the visual observation of color change or formation of precipitate after the addition of specific reagents. Diabetes was induced in rats by intraperitoneal (i.p.) injection of streptozotocin (STZ) at a dose of 65 mg/kg bw. The fasting blood glucose levels were estimated by glucose oxidase-peroxidase reactive strips (Dextrostix, Bayer Diagnostics). Blood samples were taken by cutting the tip of the tail. Serum cholesterol and serum triglycerides were estimated by enzymatic DHBS colorimetric method. RESULTS Administration of 62.5 and 25.0 mg/kg of saponins and aqueous extract respectively in normal rats group shows a significant hypoglycemic activity (32.33% and 40.17% respectively) during the first week. However, diabetic group treated with saponin extract produced a maximum fall of 73.1% and 76.03% at day 1 and day 21 compared to the diabetics control. Also, blood glucose levels of the diabetic rats treated with aqueous extract showed decrease of 78.79% on the first day and the effect remains roughly constant during 3 week. Both extracts also declined significantly biochemical parameters (20.77%-49.00%). The control in the loss of body weight was observed in treated diabetic rats as compared to diabetic controls. CONCLUSIONS These results demonstrated significant antidiabetic effects and showed that serum cholesterol and serum triglycerides levels were decreased, significantly, consequently this plant might be of value in diabetes treatment.