Antihyperglycemic, antioxidant, and organ protective effects of Schumanniophyton magnificum stem bark aqueous extract in dexamethasone-induced insulin resistance rats

Abstract

This study aimed to evaluate the effect of Schumanniophyton magnificum stem bark aqueous extract in dexamethasone-induced insulin-resistant male rats. Firstly, a phytochemical screening of the aqueous extract was carried out. Thereafter, using acute and subacute studies (11 days), the effect of the extract (200 mg/kg and 400 mg/kg) was evaluated on dexamethasone-induced hyperglycemic rats. Glycemia was measured before and after treatment in both studies. Histological examinations for isolated liver, kidneys, and pancreas were performed, body and the weight of some internal organs was determined. The biochemical assay in the blood samples was performed only for the subacute study. Phytochemical analysis revealed that the extract contains phenolic compounds, flavonoids, anthocyanins, saponins, gallic tannins, coumarins, and anthraquinones. In both studies, Schumanniophyton magnificum stem bark aqueous extract reduced the glucose blood Area under the Curve produced by dexamethasone injection. The extract, as well as glibenclamide significantly lowered the dexamethasone-induced increase in transaminases activities and uric acid concentration. Superoxide dismutase activity increased in all extract and glibenclamide groups compared to the dexamethasone group. The extract effect on the glutathione concentration was dose-dependent (p < 0.05 and p < 0.001 respectively). The histology of organs from rats treated with dexamethasone revealed hepatic cytolysis, leukocyte infiltration, and islet hypotrophy. The extract nd glibenclamide-treated groups had fewer or no anomalies observed with dexamethasone administration. Aqueous extract of S. magnificum stem bark protects against dexamethasone-induced pancreatic and hepatorenal abnormalities, probably due to the antioxidant properties of the chemical groups present in this extract.