Effects of Aerobic Exercises with Tryptophan Supplementation on Enzymatic Antioxidant Defense and Lipid Peroxidation in Brain Tissues of Elderly Rats Fed with High-Fat Diets

Oxidative stress is one of the effective mechanisms in neurodegeneration and aging process in central nerve system. The aim of this study was to investigate effects of aerobic exercises with tryptophan supplementation on enzymatic antioxidant defense and lipid peroxidation in brain tissues of elderly rats fed with high-fat diets.

In this experimental study, 36 elderly male Wistar rats (age of 18 months and mean weight of 500 g ±100) were randomly divided into five groups including normal food control, G1 (n = 6); high-fat food, G2 (n = 6); high-fat food and exercise, G3 (n = 8), high-fat food and supplement, G4 (n = 8); and high-fat food, exercise and supplement, G5 (n = 8). Aerobic interval training program was carried out on treadmill including three days per week at speeds of 12–26 m/min for eight weeks. Each rat in the supplemented groups (G4 and G5) was administrated with 100 mg of tryptophan supplement per kilogram of body weight daily via gavage. Serum levels of superoxide dismutase, malondialdehyde and lactate dehydrogenase were assessed using kits and enzyme-linked immunosorbent assay. Data were analyzed using independent t-test and MANOVA test at p < 0.05.

Results showed no significant differences between the two groups of normal and high-fat foods for the highlighted factors as well as interactive effects of exercise and supplementation for weight factor (p = 0.441), brain tissue weight (p = 0.78), ratio of brain tissue weight to total weight (p = 0.47), malondialdehyde (p = 0.13), superoxide dismutase (p = 0.55) with no significant differences. However, significant differences were observed for LDH (p = 0.05).

It seems that high-intensity interval training with tryptophan supplementation does not include effects on antioxidant system and lipid peroxidation in brain tissues of elderly rats.