Effects of lutein or lutein in combination with vitamin C on mRNA expression and activity of antioxidant enzymes and status of the antioxidant system in SD rats

This study was conducted to investigate the effects of lutein alone or in combination with vitamin C on the antioxidant defense system in rats. A total of 18 eight-week-old male Sprague Dawley (SD) rats were randomly assigned to three groups for 4 weeks: control (CON), lutein (LUT, 50 mg lutein/kg BW) and lutein plus vitamin C (LVC, 50 mg lutein/kg BW+1,000 mg vitamin C/kg BW). No differences in body weight, relative live weight or plasma biochemical profiles were observed among treatment groups. In the hepatic antioxidant defense systems, the mRNA expression of superoxide dismutase (SOD) in the LUT and LVC groups was significantly (P<0.05) higher than that in the CON group, whereas the mRNA level of glutathione peroxidase (GPX), catalase (CAT) and glutathione S-transferase (GST) was not affected by the administration of antioxidants. SOD and GST activities in the LUT and LVC groups were significantly higher (P<0.05) than those in the CON group, whereas GPX, CAT and lipid peroxidation did not differ among groups. In addition, the LVC group showed a significant (P<0.05) increase in plasma and hepatic total antioxidant power (TAP) relative to the CON group. Overall, administration of lutein in combination with vitamin C improved the status of the total antioxidant defense system in SD rats.