Efficacy of turmeric on blood sugar and polyol pathway in diabetic albino rats

In the traditional system ofmedicine, Ayurveda, several spices and herbsare thought to possess medicinal properties. Amongthe spices, turmeric rhizomes (Curcumalonga. Linn.) are used as flavoring and coloringagents in the Indian diet everyday. In this research,we studied the effect of turmeric and itsactive principle, curcumin, on diabetes mellitus in arat model. Alloxan was used to induce diabetes.Administration of turmeric or curcumin to diabeticrats reduced the blood sugar, Hb and glycosylatedhemoglobin levels significantly. Turmeric andcurcumin supplementation also reduced the oxidativestress encountered by the diabetic rats. This wasdemonstrated by the lower levels of TBARS (thiobarbituric acid reactive substances), which mayhave been due to the decreased influx of glucose intothe polyol pathway leading to an increased NADPH/NADPratio and elevated activity of the potent antioxdiantenzyme GPx. Moreover, the activity of SDH (soorbitol dehydrogenase), whichcatalyzes the conversion of sorbitol to fructose, waslowered significantly on treatment with turmeric orcurcumin. These results also appeared to reveal thatcurcumin was more effective in attenuating diabetesmellitus related changes than turmeric.