Effect of the insulin plant (Costus igneus) leaves on dexamethasone-induced hyperglycemia

Abstract

The present study was planned to evaluate the effect of the leaves of Costus igeus on dexamethasone-induced hyperglycemia in male Wistar rats. Four groups of male Wistar rats (n= 6) were treated with 10 mg/kg/day of dexamethasone subcutaneously for 20 days. From day 11 to day 20, different groups received 100, 250 or 500 mg/kg/day of powdered leaves of Costus igeus in distilled water orally or Glibenclamide 500 microg/kg orally. On the 20th day, after overnight fasting, a retro-orbital puncture was performed for obtaining blood samples to estimate the fasting blood glucose level, and the same procedure was followed on the other eye 1 hour after a glucose load of 2.5 g/kg orally for estimation of post-glucose load blood glucose levels. Fasting blood sugar and postglucose load blood sugar levels were raised in the group that received dexamethasone when compared to normal controls (P < 0.001), whereas 250 and 500 mg/kg powdered leaf of Costus igeus and Glibenclamide 500 microg/kg decreased the dexamethasone-induced hyperglycemia (P < 0.01). The leaves of Costus igeus reduced the fasting and postprandial blood sugar levels, bringing them towards normal, in dexamethasone-induced hyperglycemia in rats.