Long-term effects of three hypoglycaemic plants (Irvingia gabonensis, Urena lobata and Carica papaya) on the oxidative status of normal rabbits

Abstract

Medicinal plants have been recognized to have therapeutic effects and they may also have toxic side effects. Our previous studies have shown that Irvingia gabonensis, Urena lobata and Carica papaya, locally used in Nigeria to treat diabetes, possess long term hypoglycaemic and anti-obesity effects on normal rabbits. In this study, the long term effects of aqueous extracts of I. gabonensis bark, U. lobata root and C. papaya leaves on the oxidative status of normal rabbits were monitored at specific intervals in the serum for 24 weeks, and in the tissues. Oxidative status was determined by measuring activities of superoxide dismutase (SOD) and catalase (CAT), and the concentration of malondialdehyde (MDA). Significant (p<0.05) decreases were observed in some weeks in the serum MDA levels; also, liver and pancreatic MDA levels were significantly (p<0.05) lower for all treated rabbits. SOD and catalase activities in the serum and tissue of the rabbits treated with the medicinal plants were generally higher or statistical similar to control. Findings in this study showed that these hypoglycemic medicinal plants did not exert oxidative damage; in some instances, particularly in the pancreas, they were found to be protective against oxidative damage. KEYWORDS: Medicinal plants, Irvingia gabonensis, Urena lobata, Carica papaya, Hypoglycaemic plants, oxidative damage