Validation of Antidiabetic and Antihyperlipidemic Effects of 80% Methanolic Extract of the Lonchocarpus laxiflorus Leaves in Streptozotocin-Induced Diabetic Swiss Albino Mice

Abstract

Introduction. Diabetes mellitus (DM) is a chronic endocrine disorder that requires long-term treatment. In Ethiopian traditional medicine practice, plants have been provided with a vital role in fighting human and animal diseases since ancient times. The aqueous extract of Lonchocarpus laxiflorus (L. laxiflorus) leaves has been consumed for treating diabetes mellitus without confirming its safety and efficacy scientifically. This experiment aimed to evaluate the safety and antidiabetic efficacy of the leaf extract of L. laxiflorus in mice models. Methods. The crude extraction was conducted using a cold maceration technique and 80% methanol solvent. Normoglycemic, oral glucose-loaded, and streptozotocin-induced (STZ) diabetic models were employed. Male Swiss albino mice were randomly grouped into five categories( with six mice per group during normoglycemic, oral glucose-loadingtest as a negative control, positive control, and three treatment groups. In STZ-induced diabetic models, the groups include normal and diabetic negative control, diabetic positive control, and three diabetic treatment groups. The negative control groups received vehicles, the positive control received 5 mg/kg glibenclamide, and the treatment groups received the crude extract at 100, 200, and 400 mg/kg doses, respectively. Results. Up to 2000 mg/kg crude extract, neither signs of toxicity nor death were observed. In normoglycemic mice, there was a significant blood glucose reduction at 200 and 400 mg/kg doses starting from the 2nd h post-administration. The oral glucose load showed a significant antihyperglycemic effect at 200 and 400 mg/kg of the crude extract and glibenclamide. In STZ-induced diabetic models, the 200, 400 mg/kg crude extract, and glibenclamide showed a significant antidiabetic activity and enhancement of a good serum lipid profile. Conclusion. This study confirmed that the leaf of L. laxiflorus was safe and possesses antidiabetic and antidyslipidemic activities.