Anti-diabetic activity of methanol leaf extract of Costus pictus D.DON in alloxan-induced diabetic rats

The methanol extract of Costus pictus (C. pictus) D.DON (Family: Zingiberaceae) leaf was investigated for its anti-diabetic effect in Wistar Albino rats. Diabetes was induced in Albino rats by administration of single doses of alloxan monohydrate (120 mg/kg, i.p.). The methanol extract of C. pictus (MECP) at a dose of 120 mg/kg, p.o. was administered as single dose per day to diabetes-induced rats for a period of 21 days. The effect of MECP leaf extract on blood glucose, plasma insulin, serum lipid profile [cholesterol, triglycerides, phospholipids, very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL)], serum enzymes [serum glutamate oxaloacetate transaminases (SGOT), serum glutamate pyruvate transaminases (SGPT), alkaline phosphatase (ALP)], total protein, and liver glycogen were measured in the diabetic rats. Histopathological studies of liver, pancreas and kidney were also carried out. MECP elicited significant (p < 0.001) reductions of blood glucose, lipid parameters except HDL, and serum enzymes and significantly (p < 0.001) increased HDL level. MECP also caused significant (p < 0.001) increases in plasma insulin levels in the diabetic rats. Furthermore, MECP significantly (p < 0.05), (p < 0.001) increased total protein and liver glycogen in diabetic rats. Histopathological observations revealed that leaf is non-toxic and regenerates the toxic effect of alloxan. From the above results, it is concluded that MECP possesses significant anti-diabetic effects in alloxan-induced diabetic rats.