Efficacy of some plant extracts in regulating corticosteroid-induced hyperglycaemia in mice

Abstract

In an attempt to find the possible regulation of steroid diabetes by plant extracts, relative efficacy of Inula racemosa (root), Gymnema sylvestre (leaf), Boerhaavia diffusa (root) and Ocimum sanctum (leaf) extracts (400, 600, 150 and 500mg/kg. b. wt./day, respectively, for 15 days) in the regulation of dexamethasone-induced hyperglycaemia was studied in mice. Simultaneously, levels of thyroid hormones (thyroxine and triiodothyronine) were estimated by radio-immunoassay (RIA), to reveal the possible mediation of the effects of the plant extracts through thyroid hormones. While the administration of dexamethasone (1 mg/kg b.wt.) induced hyperglycaemia in mice, at least two plant extracts (out of the four) from Inula racemosa and Gymnema sylvestre, were able to ameliorate the drug induced hyperglycaemia by 24 and 15%, respectively. These effects were comparable to the standard corticosteroid-inhibiting drug, ketoconazole (Keto-Zole™). The lack of increase in hepatic lipid peroxidation and decrease in superoxide dismutase or catalase activity suggest the potential use of these plant extracts in the regulation of corticosteroid-induced hyperglycaemia.