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

In the traditional system of medicine, Ayurveda, several spices and herbs a re thought to possess medicinal properties. Among the spices, turmeric rhiz omes (Curcuma longa. Linn.) are used as flavoring and coloring agents in th e Indian diet everyday. In this research, we studied the effect of turmeric and its active principle, curcumin, on diabetes mellitus in a rat model. A lloxan was used to induce diabetes. Administration of turmeric or curcumin to diabetic rats reduced the blood sugar, Hb and glycosylated hemoglobin le vels significantly. Turmeric and curcumin supplementation also reduced the oxidative stress encountered by the diabetic rats. This was demonstrated by the lower levels of TBARS (thiobarbituric acid reactive substances), which may have been due to the decreased influx of glucose into the polyol pathw ay leading to an increased NADPH/NADP ratio and elevated activity of the po tent antioxdiant enzyme GPx. Moreover, the activity of SDH (soorbitol dehyd rogenase), which catalyzes the conversion of sorbitol to fructose, was lowe red significantly on treatment with turmeric or curcumin. These results als o appeared to reveal that curcumin was more effective in attenuating diabet es mellitus related changes than turmeric.