Antihyperglycemic and Antioxidant Properties of Sida linifolia Juss. ex Cav. (Malvaceae) Hydroalcoholic Extract in ICR Mice

Background and Objective: Sida linifolia Juss. ex Cav. (Malvaceae) is a medicinal plant used in Togo for the treatment of diabetes mellitus. The present study was designed to investigate the antihyperglycemic and antioxidant effects of the hydroalcoholic extract of S. linifolia. Materials and Methods: Antihyperglycemic activity was measured by oral glucose tolerance tests in glucose-loaded ICR mice and on their basal blood glucose. The effect of S. linifolia extract was evaluated ex-vivo on glucose absorption using inverted intestinal sacs and skeletal muscle isolated from rats. Antioxidant activities were assessed in vitro by the DPPH free radical scavenging method, iron-reducing power and total antioxidant capacity. Phytochemical groups were characterized by classical chemical staining using appropriate reagents and quantified by spectrophotometric method. Results: Hydroalcoholic extract of S. linifolia significantly reduced hyperglycemia in mice 30 min after glucose overload at doses of 100, 200 and 400 mg/kg compared to control mice. However, the reduction in hyperglycemia was greater in mice treated with the highest dose (400 mg/kg) of the extract for 180 min (p<0.0001). The effect of the extract on the basal glycemia of mice was also evaluated, but it did not show a significant decrease (p>0.05) compared to the normoglycemic control. The ex-vivo tests demonstrated that the extract inhibited glucose membrane transport through the intestine and increased peripheral glucose use. The antioxidant tests indicated a dose-dependent antioxidant activity of the extract. Phytochemical analysis revealed the presence of major phytochemical groups in the extract. Conclusion: Sida linifolia whole plant extract exhibited significant antioxidant and antihyperglycemic properties probably attributed to its phenolic compounds. The use of this plant extract in the production of herbal medicines can help treat diabetes and its complications.