The methanol extract of the whole plant of Eclipta prostrata and one of its isolated compounds, eclalbasaponin II were administered to alloxan-induced diabetic rats for 28 and 7 consecutive days, respectively. During the study, a potent antidiabetic activity was observed. Blood sugar was significantly (p < 0.001) reduced by E. prostrata extract (300 mg/kg) and eclalbasaponin II (10 mg/kg), as compared to untreated diabetic rats. Analyses of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) showed no significant (p < 0.001) hepatotoxicity by E. prostrata extractive in alloxan-induced diabetic rats when compared to the diabetic control rats.