High fat diet and high polyphenols beverages effects in enzymatic and non-enzymatic antioxidant activity

High fat diets have been implicated in the generation of reactive oxygen species (ROS). Polyphenols from grapes may reduce ROS and restore oxidative balance. The aim of this study is to investigate the antioxidant properties of high polyphenols beverages associated with a high fat diet in enzymatic and non-enzymatic antioxidant activity.

Fifty female rats were divided into five groups: a) control group (CG) - control diet (4% fat); b) high fat diet group (HFD) - high fat diet (20% fat); c) grape juice group (GJ) - grape juice (15 ml/day) + high fat diet; d) red wine group (RW) - red wine (10 ml/day) + high fat diet; and e) resveratrol solution group (RS) - resveratrol solution (15 ml/day) + high fat diet. Eight weeks later, the superoxide dismutase, catalase and glutathione peroxidase activities were measured. Superoxide dismutase activity was assayed by measuring the inhibition of adrenaline auto-oxidation, catalase by the decrease rate in hydrogen peroxide and glutathione peroxidase by monitoring the oxidation of nicotinamide adenine dinucleotide phosphate. Non-enzymatic antioxidant activity was assessed by oxygen radical absorbance capacity and DDPH (free radical sequestration 2,2-diphenyl-1-picryhydracil) method in the animal's plasma.

GC and GJ presented the lowest glutathione peroxidase activity, pointing to a possible protective effect of grape juice against high levels of ROS (p < 0.05). RW increased catalase activity when compared to the RS (p <0 .05). Superoxide dismutase activity and non-enzymatic antioxidant plasma activity were similar in all groups.

Grape juice showed to be the most effective in minimizing the deleterious effects of a high fat diet. Resveratrol did not present any benefit and red wine possibly shows a harmful effect due to ethanol content.