Background: Medicinal plants with biologically active components such as antioxidant and antidiabetic are useful sources of novel therapeutics. In Iran, traditionally believed that the aqueous extract of berberry fruit (Berberis integerima F.) improved health, especially in people with diabetes.

Objective: In this study, in vitro phytochemical and antioxidant activities of B. integerrima and B. vulgaris fruit aqueous extracts (BIFA and BVFA) were compared. Effects of more active species on fasting blood sugar (FBS), serum lipid, and malondialdehyde (MDA) were evaluated in alloxan-induced diabetic rats.

Methods: The phytochemical potential and antioxidant activity of these extracts were quantified in terms of total phenolic content and total reducing power, respectively. BIFA (500 mg/kg) and glibenclamide (2 mg/kg) were administered orally to alloxan-induced diabetic rats and FBS, body weight, lipid profile, and serum MDA were monitored at 0, 7, 14, and 21 days after induction of diabetes.

Results: BIFA showed the highest phenolic content (6.816 ± 0.132 mg/g of dry extract) and antioxidant activity (0.134 ± 0.022 EC₅₀ mg/mL). LD₅₀ of BIFA was found to be ˃2500 mg/kg. FBS, lipid profile, and serum MDA have been significantly reduced in BIFA-treated rats after 21 days versus diabetic control and glibenclamide-treated rats. Extract has significantly decreased FBS levels of rats from 138.1 ± 1.68 to 82.00 ± 4.02 mg/dL. Furthermore, body weight has significantly improved in treated groups.

Conclusion: The results indicate B. integerrima with high phytochemical and antioxidant activities, has the potential of suppressed hyperglycemia, hyperlipidemia and lipid peroxidation.