Protective Effects of Garcinia kola Stem Barks Aqueous Extract on Metabolic Disorders and Oxidative Stress in Dexamethasone-Induced Insulin Resistance in Rat

Aim: To evaluate how the aqueous extract of Garcinia kola (GK) stem bark impacted dexamethasone-induced insulin resistance in male rats. Method: This work was completed in 2020. A phytochemical screening of the extract was first carried out. Using acute and subacute studies (11 days), the effect of the extract was evaluated at 100 mg/kg and 200 mg/kg, on dexamethasone-induced hyperglycemic rats. Glycemia was measured before and after treatment in both studies, while histological examination for isolated liver, kidneys and pancreas was performed, body weight and some internal organs determined, and biochemical assays. for blood samples were performed only for the subacute study. Results and Conclusion : An examination of the plant's chemistry showed the presence of alkaloids, phenolic compounds, flavonoids, saponins, coumarins, anthocyanins, and anthraquinones. GK extract decreased the Area Under Curve induced by dexamethasone (DEXA) injection both in the acute and in the subacute test. The extract and glibenclamide decrease the alanine amino transferase activity induced by DEXA. In both the glibenclamide and extract groups, total protein levels increased. The uric acid level in all dexamethasone-treated rats remains elevated when compared to the normal control group. Superoxide dismutase activity increased in both groups treated with the extract or glibenclamide. DEXA induced islet hypertrophy in the pancreas, vascular congestion, cytolysis, and vacuolation of hepatocytes. The kidney presented leucocyte infiltration and a decrease in glomerular cell density. All those abnormalities were improved by the administration of glibenclamide or the extract of Garcinia kola.