Effects of diet energy level and tomato powder consumption on antioxidant status in rats

Background and aims Evaluate the influence of tomato powder in diets differing in energy level on antioxidant status in blood and liver of rats. Methods Twenty-four adult male Wistar rats weighing 150–180 g were placed four groups (n=6). For 28 days, animals were fed a diet that was either hyper energetic or hypo energetic. Some diets were supplemented with tomato powder. Liver and blood were collected for analysis of antioxidant enzymes, non-enzymatic antioxidants, thiobarbituric acid reactive species, ubiquinol 9, α-tocopherol, lycopene and β-carotene. Data were analysed by two-way ANOVA. Results Food intake and thiobarbituric acid-reactive substances contents in liver and plasma were significantly decreased by tomato powder at both energy levels. After tomato powder supplementation, the hepatic levels of ubiquinol 9, α-tocopherol, lycopene and β-carotene were significantly enhanced. In plasma, only the contents of lycopene and β-carotene were enhanced. The erythrocytic and hepatic activities of catalase were lower, while those of glutathione peroxidase were higher after the ingestion of tomato powder. Total and reduced glutathione contents in liver showed lower levels in cafeteria-fed rats compared to the hypo energetic diet. Conclusions The data suggest that the lycopene and β-carotene component in the tomato power supplement might be beneficial for the prevention of oxidative damage in rats fed both types of energetic diets.