Influence of dietary curcumin, capsaicin and garlic on the antioxidant status of red blood cells and the liver in high-fat-fed rats

BACKGROUND/OBJECTIVE:
An animal study was carried out to examine the beneficial influence of known hypolipidemic spice principles – curcumin and capsaicin – and the spice garlic on the antioxidant status of red blood cells and liver tissue in hyperlipidemic rats.

METHODS:
Rats were rendered hyperlipidemic by maintaining them on a high-fat (30%) diet for 8 weeks. Spice principles – curcumin (0.2%) or capsaicin (0.015%) – or garlic (2.0%) were included in the diets of separate animal groups. Erythrocytes isolated at the end of the study were analyzed for intracellular antioxidant molecules and antioxidant enzymes.

RESULTS:
Intracellular total thiols in the erythrocytes of high-fat-fed rats were depleted significantly (16%). Similarly, the intracellular glutathione content in erythrocytes was depleted in high-fat-fed rats (28%). The concentration of lipid peroxides in the erythrocytes (intracellular as well as membrane) induced by H(2)O(2) was significantly higher in the high-fat-fed group. Curcumin (0.2%) or capsaicin (0.015%) or garlic (2.0%) in the diet which produced the hypotriglyceridemic effect were also effective in reducing oxidant stress, which was indicated by a significant countering of the depleted intracellular antioxidants – total thiols and glutathione – and elevated lipid peroxides in erythrocytes. The elevated lipid peroxide in blood plasma due to the high-fat diet was also significantly countered by the spice treatments. The severely depleted hepatic glutathione in high-fat treatment was also effectively reversed by dietary curcumin, capsaicin and garlic.

CONCLUSIONS:
Thus, dietary hypolipidemic spices were effective in reducing the oxidant stress, which was indicated by countering the depleted antioxidant molecules and antioxidant enzymes in erythrocytes and liver, and decreasing the elevated lipid peroxide content.