|ISSN No. 1606-7754 Vol.16 No.3 December 2008|
Anti-diabetic effect of Costus pictus leaves in normal and streptozotocin-induced diabetic rats
MA Jayasri1, S Gunasekaran2, A Radha1 and TL Mathew1
School of Biotechnology, Chemical & Biomedical Engineering, VIT University1; Diabetes Research Laboratory, Department of Physiology, Christian Medical College2, Vellore, India
Costus pictus D. Don, commonly known as ‘insulin plant’ is a member of Zingiberacea family and is used as a munching dietary supplement for the treatment of diabetes in Southern India. The present study was carried out to evaluate the antidiabetic effect of Costus pictus leaves in normal and streptozotocin-induced diabetic rats. The oral feeding of aqueous leaf solution of this plant in diabetic rats for 28 days at a dosage of 2gm/kg body weight exhibited a significant (p<0.001) reduction in fasting blood glucose level and a remarkable increase in serum insulin level. There was a significant reduction (p<0.001) in serum parameters like SGOT, SGPT, lipids, triglycerides, total cholesterol, urea, TBARS, and albumin in diabetic rats treated with leaf solution. The body weight of diabetic rats was restored to normal state when treated with the C. pictus. Morphometric analysis of C. pictus-treated rat pancreatic islets showed a significant (p<0.001) increase in the number and area of islets when compared with normal and diabetic control rats. Histopathology studies in liver and kidney of diabetic rats treated with aqueous solution did not show any marked difference from normal which revealed the non-toxic effect of this plant. Estimation of trace elements using particle induced X-ray emission analysis in the leaf was also determined to find the antidiabetic potential elements in this plant. Based on the above results it is evident that the leaves of C. pictus have antidiabetic effect and must be considered as a potential candidate for future studies on diabetes mellitus.
Keywords: Costus pictus D.Don, Insulin plant, Diabetes, Morphometric analysis, PIXE
Diabetes mellitus is a known metabolic disorder of varied etiology characterized by chronic hyperglycemia due to relative deficiency of insulin or its resistance. Diabetes is associated with disturbances of carbohydrate, fat and protein metabolism. Since oral hypoglycemic agents cause side effects, there is a growing interest in herbal remedies for the treatment of diabetes mellitus.1 Many plant preparations are used in folk medicine to manage diabetes mellitus. New oral hypoglycemic compounds from medicinal plants may provide a useful source for development of pharmaceutical entities or as a dietary adjunct to existing therapies.2,3 Herbal drugs are considered to be less toxic and more free from side-effects compared to synthetic drugs.4 Wide arrays of plant-derived active principles representing numerous chemical compounds have demonstrated activity consistent with their possible use in the treatment of NIDDM.5 Recently, a search for appropriate anti-hyperglycemic agents has focused on plants used in traditional medicine because natural products may be a better option than currently used drugs.6 The ethno- botanical information reports that about 800 plants possess anti-diabetic potential.7 Plants have always been an exemplary source of drugs and many of the currently available drugs were derived directly or indirectly from them.8
With this background, the present study was undertaken to examine the anti-diabetic activity of the fresh leaves of C. pictus in streptozotocin-induced diabetic rats. C. pictus D.Don commonly known as ‘spiral ginger’ ‘step ladder’ or ‘insulin plant’ is a member of Zingiberacea family and is a newly introduced plant in India; originated probably in Mexico. In India it is grown in gardens especially in the state of Kerala where the fresh raw leaves are eaten by diabetic people. It is used as a munching supplementary food for the treatment of diabetes. Toxicity studies and antidiabetic activity of methanolic extract of this plant has been reported previously.9,10 The aim of the present study was to evaluate the antidiabetic potential of fresh solution of C. pictus leaves in normal and streptozotocin-induced diabetic rats.