Abstract

Urena lobata is one of the medicinal plants used to treat diabetes in Nigeria. Its hypoglycaemic and anti-diabetic activities have been demonstrated. This study was designed to evaluate the long term effects of daily oral administration of aqueous extracts of U. lobata roots in normal rabbits. Parameters such as body weight, blood glucose and liver function tests were monitored at specific intervals in the serum for 24 weeks, and in the tissue. U. lobata significantly (P<0.05) reduced the body weight and fasting blood sugar of treated rabbits. Indicators of cholestasis, alkaline phosphatase and γ-glutamyl transferase, as well as serum direct bilirubin concentration, were initially significantly (P<0.05) increased, these parameters returned to the levels of control before the 10th week of monitoring and tissue enzymes were not depleted, suggesting that the initial toxic response was not sustained. Markers of hepatocyte injury; alanine transaminase and aspartate transaminase, were initially slightly elevated but subsequently returned to control levels. U. lobata root had no significant effects on serum total proteins, albumin and globulins. Regulation of dose and frequency of consumption of U. lobata extracts may reduce its toxic side effects.

Key words: Urena lobata, hypoglycaemic/anti-diabetic, liver function tests, medicinal plants, toxicity.