Abstract

The purpose of this study is to evaluate the capacity of lycopene against diabetes-induced oxidative

damage in Wistar rats. Thirty Wistar rats of both sexes, twenty-five of which were diabetic, were used.

Diabetes was induced by a single intraperitoneal injection of streptozotocin (STZ) 60 mg/kg body weight

and it was confirmed by the elevated blood glucose ≥200 mg/dl after three days. The rats were divided

randomly into groups 1 to 6, each containing 5 rats. Group 1 (Normal control) and Group 2 (Diabetic

control) rats were administered 0.5 ml of olive oil; Groups 3, 4, and 5 rats were respectively

administered 10, 20 and 40 mg/kg body weight of lycopene, while Group 6 rats were administered 2

mg/kg body weight of Glibenclamide. All administrations were done orally and once daily for twentyeight

days. At the end of the treatment, serum levels of antioxidant enzymes, cortisol and

malondialdehyde (MDA) were determined. Administration of graded doses of lycopene to diabetic

animals significantly (P<0.05) decreased the blood glucose concentration after four weeks of treatment

when compared to diabetic untreated animals. Serum levels of cortisol and MDA (index of oxidative

stress) were reduced while there were up-regulated activities of serum endogenous enzymes

(superoxide dismutase, catalase and glutathione peroxidase) in diabetic animals treated with all doses

of lycopene when compared with diabetic untreated animals. Overall, lycopene attenuated the

biomedical alterations in STZ-induced diabetic Wistar rats. Lycopene therefore possesses antioxidant

activity at the doses tested in this study.