Effect of curcumin on hepatic heme oxygenase 1 expression in high fat diet fed rats: is there a triangular relationship?

High fat diet (HFD) is associated with oxidative stress induced fatty liver. Curcumin, an extract of Curcuma longa, has been shown to possess potent antioxidant and hypolipidemic properties. In this study, we investigated the effect of curcumin treatment on hepatic heme oxygenase-1 (HO-1) expression along with pro-oxidant-antioxidant status and lipid accumulation in rats fed an HFD. Male Sprague-Dawley rats were distributed among 4 groups: Group 1, which was fed the control diet (10% of total calories from fat); Group 2, which was fed the HFD (60% of total calories from fat); and groups 3 and 4, which received the HFD supplemented with curcumin and the control diet supplemented with curcumin (1 g/kg diet; w/w), respectively, for 16 weeks. HFD caused increases in hepatic lipid levels, production of reactive oxygen species, and lipid peroxidation. Further, HO-1 expression was significantly decreased. Histopathological examination showed hepatic fat accumulation and slight fibrotic changes. Curcumin treatment reduced hepatic lipids and oxidative stress parameters, and HO-1 expression was significantly increased. These findings suggest that increased HO-1 expression, along with suppressed oxidative stress as well as reduced hepatic fat accumulation and fibrotic changes, contribute to the beneficial effects of curcumin in attenuating the pathogenesis of fatty liver induced metabolic diseases.

Effect of dietary curcumin and capsaicin on testicular and hepatic oxidant-antioxidant status in rats fed a high-fat diet.

This study investigated the effects of curcumin and capsaicin on testicular and hepatic oxidant-antioxidant status in rats fed a high-fat diet (HFD). Male Sprague-Dawley rats were divided into 5 groups (8 rats per group). The control group was fed a normal control diet (standard laboratory chow), the HFD group was fed HFD (60% of total calories from fat), the HFD+CUR group received HFD supplemented with curcumin (1.5 g curcumin/kg HFD), the HFD+CAP group was given HFD supplemented with capsaicin (0.15 g capsaicin/kg HFD), and the HFD+CUR+CAP group received HFD supplemented with curcumin and capsaicin for 16 weeks. Hepatic and testicular thiobarbituric acid reactive substances (TBARS), reactive oxygen species (ROS), glutathione (GSH) levels, glutathione transferase activity, and Cu-Zn superoxide dismutase, glutathione peroxidase, and catalase protein expression and enzyme activities were measured. Protein expression was determined by Western blotting. GSH levels and antioxidant enzyme activities were measured with colorimetric methods. HFD slightly increased hepatic and testicular oxidative stress parameters. GSH levels did not change between groups. TBARS and ROS levels were significantly reduced in the HFD+CUR+CAP group compared with the HFD group. Liver and testis antioxidant enzyme activities and expression increased significantly with combined capsaicin and curcumin treatment. Curcumin and capsaicin treatment attenuated testicular and hepatic oxidative stress and enhanced the antioxidant defense system. The combination of capsaicin and curcumin with HFD seems to have some remarkable and beneficial effects on testicular oxidative damage in the fatty liver rat model.

The effect of dietary curcumin and capsaicin on hepatic fetuin-A expression and fat accumulation in rats fed on a high-fat diet.

Effects of curcumin (turmeric) and capsaicin (red pepper) on hepatic fat accumulation and fetuin-A expression in rats fed high-fat diet (HFD) is aimed to be investigated. Male Sprague-Dawley rats received HFD (60% of total calories from fat) and 0.15 g capsaicin/kg HFD and/or 1.5 g curcumin/kg HFD for 16 weeks. Hepatic AMPK, p-AMPK and fetuin-A expressions were determined by western blotting, liver lipid levels were measured with colorimetric methods and serum fetuin-A, insulin, leptin and adiponectin levels were detected using commercial ELISA kits. HFD increased hepatic lipid levels, fetuin-A expression and serum leptin, insülin and fetuin-A levels. Curcumin and capsaicin treatments significantly reduced hepatic fat accumulation and leptin levels; liver fetuin-A expression was decreased significantly by the curcumin treatment. Curcumin and capsaicin treatments attenuated hepatic fat accumulation and increased leptin levels related to inflammation. The suppression of hepatic fetuin-A expression is observed to be especially sensitive to curcumin.