Protective role of tetrahydrocurcumin on changes in the fatty acid composition in streptozotocin-nicotinamide induced type 2 diabetic rats

Curcumin is the most active component of turmeric. It is believed that curcumin is a potent antioxidant and anti-inflammatory agent. Tetrahydrocurcumin (THC), one of the major metabolites of curcumin, exhibits many of the same physiological and pharmacological activities as curcumin and in some systems may exert greater antioxidant activity than curcumin. The aim of this study was to evaluate the effect of THC on the blood glucose, plasma insulin and fatty acid composition of the total lipids in the liver, kidney and brain of control and streptozotocin (STZ)-nicotinamide diabetic rats. The analysis of fatty acids showed that there was a significant increase in the concentrations of palmitic acid (16:1), stearic acid (18:0) and oleic acid (18:1) in the liver, kidney and brain, whereas the concentrations of linolenic acid (18:3) and arachidonic acid (20:4) were significantly decreased. Oral administration of the THC (80 mg/kg body weight) for 45 days to diabetic rats decreased the concentrations of fatty acids, viz., palmitic, stearic, and oleic acid, whereas linolenic and arachidonic acid were elevated. These results suggest that THC exhibits antidiabetic and antihyperlipidemic effects in STZ-nicotinamide induced diabetic rats. It also prevents the fatty acid changes produced during diabetes. The antidiabetic and antihyperlipidemic effects of THC are more potent than those of curcumin at the same dose. The results of the present study indicate that THC showed an antihyperlipidemic effect in addition to its antidiabetic effect in type 2 diabetic rats.