Unraveling the Antidiabetic Effect of Alternantera brasiliana (L.) Kuntze: A Combined in Vitro and in Vivo Approach

Abstract

Background of the study: This study established the antidiabetic efficacy of Alternantera brasiliana in vitro and in vivo, identified the most active fraction and profiled the chemical constituents of the most active fraction. Methodology: The leaf of A. brasiliana was air-dried, pulverized and extracted with methanol and evaluated for its α-amylase activity at different concentrations using in vitro method. The in vivo antidiabetic activity of the extract and glibenclamide was evaluated in glucose loaded and streptozotocin-induced diabetic rats using various doses, while the most active partitioned fraction was identified using glucose loaded method followed by identification of its chemical constituents through GC-MS analysis. Results: The extract elicited good α-amylase inhibitory potential with IC50= 0.45 mg/mL. Also, the 50 mg/kg dose demonstrated the highest percentage blood glucose level reduction and significantly (P > 0.05) comparable to glibenclamide (5 mg/kg) from 0.5 to 4 h. The streptozotocin-induced antidiabetic assay showed that the 50 mg/kg demonstrated better activity than glibenclamide (5 mg/kg) and was significantly comparable on days 10 and 14. The aqueous methanol fraction was the most active fraction with 53% blood glucose level reduction at 4 h. The secondary metabolite profiling identified 30 chemical compounds whereby 1H-Indole-2-carboxylic acid, 6-(4-ethoxyphenyl)-3-methyl-4-oxo-4,5,6,7-tetrahydro-, isopropyl ester, Benzo[h]quinoline, 2,4-dimethyl-, thymol and 13,5-trioxane as the major constituents. Conclusion: The antidiabetic activity demonstrated by the A. brasiliana extract established its antidiabetic efficacy