In the present study, 50 – 400 mg/kg of body weight/day of 50% ethanol extract of the fresh leaves of Morinda Lucida
Benth. (MLE) was investigated for its hypoglycemic and antidiabetic effects in adult normal and alloxan-induced diabetic male rats for 7 days. Acute oral toxicity study of MLE at the limit dose of 2000 mg/kg of body weight using Up-and-Down Procedure on statistical program, AOT425Pgm, was also conducted. Results showed that MLE significantly (p<0.05) lowered the fasting blood glucose (FBG) in both normal and alloxan-induced diabetic rats in dose related fashion, and its effect was higher (p<0.001) than that of tolbutamide (Tolb.). Results suggest that MLE could be mediating its hypoglycemic effect via enhanced peripheral glucose utilization. Also, acute oral toxicity result showed MLE to be non-lethal at 2000 mg/kg of body weight. These results suggest that MLE could be relatively safe on acute exposure when administered to suspected diabetic patients.