Comparative free radical scavenging and hypoglycemic activities of n-hexane, ethyl-acetate, and aqueous fractions of Azanza garckeana pulp

Background: The prevalence of diabetes mellitus is increasing on a global trend. The aim of the present study is to identify the most effective antioxidants and hypoglycemic fraction of Azanza garckeana. Methods: The fractions (n-hexane or ethyl-acetate or aqueous) of A. garckeana were administered to the alloxan-induced diabetic rats at doses of 100, 200, and 400 mg/kg for 15 days. Antioxidants activities were evaluated at concentrations of 62.5, 125, 250, and 500 µg/mL using the DPPH scavenging assay. Results: Results revealed that both the hexane, ethyl-acetate, and aqueous fractions exhibited hypoglycemic and antioxidants activities in a dose-dependent manner. The n-hexane fraction demonstrated highest percentage DPPH scavenging effect of 26.34±3.43, 38.44±4.35, 59.34±3.45, and 74.83±5.35 at 62.5, 125, 250, and 500 µg/mL respectively. The ethyl-acetate fraction demonstrated 19.33±2.98, 28.94±3.24, 47.34±2.90, and 57.82±4.54 respectively while the aqueous fraction exhibited the least activities of 12.45±23.45, 18.64±2.94, 27.94±3.89, and 39.43±3.89 at concentrations of 62.5, 125, 250, and 500 µg/mL respectively. In addition, the n-hexane fraction demonstrated the most significant hypoglycemic effect with the highest glucose reduction of 58.97 ±3.45 %, 63.86±5.35 %, and 66.51±4.35 %, ethyl acetate fraction demonstrated glucose reduction of 7.55±0.54%, 21.77±2.35 %, and 29.56±3.46 % while the aqueous fraction demonstrated the least hypoglycemic effect of 9.89±2.67 %, 18.09±3.45 %, and 18.87±3.24 at 100, 200 and 400 mg/kg bw respectively. Conclusion: The n-hexane fraction of Azanza garckeana extract could serve as a reservoir of bioactive agents that could be useful for the development of a new anti-diabetic agent