The effects of physical exercise, caloric diet restriction and antioxidant supplementation on the aging process in rats

Document Type : Original Article

Authors

1 Physiology, Pharmacology Department. Faculty of Medicine, Alexandria University, Egypt

2 Drug Toxicology Department, Faculty of Medicine, Alexandria University, Egypt

3 Medical Biochemistry Department, Faculty of Medicine, Alexandria University, Egypt

Abstract

The objective of the present study was to assess the effects of age, physical exercise,
caloric diet restriction (CR), and vitamin E supplementation on some markers of
oxidative stress, DNA damage, apoptosis and liver function in different age groups of
rats. The present study included 120 male “Wistar rats”, divided into 3 age groups;
12, 18 and 24 months old. Each group was further subdivided into 4 subgroups; 10
rats each. The first subgroup as a control, the second underwent exercise training, the
third was kept on CR and the last was supplemented with vitamin E. The measured
biochemical parameters included; serum malondialdehyde (MDA), as well as % DNA
fragmentation levels, the active caspase-3 concentration and the monoamine oxidase-
β (MAO-β) enzyme activity in the brain of all studied rats. In addition, hepatic
superoxide dismutase (SOD) and NADPH- cytochrome c reductase enzyme activities
were assessed. The results of this study showed that; the aging process was
associated with significantly increased serum MDA, decreased hepatic SOD activity,
increased brain DNA fragmentation and caspase-3 activation as well as decreased
cytochrome c reductase activity of liver. However, exercise, CR, and vitamin E
supplementation caused a significant decrease in serum MDA and increase in hepatic
cytochrome c reductase activity in old group. In addition, exercise could increase
SOD and lower caspase-3 in old rats, while CR had no significant effect on both of
them. Neither age nor any of the used intervention trials had an effect on brain MAO-
β activity. It is suggested that the age-induced oxidative stress, DNA damage and
improper hepatic metabolism could be partially attenuated by exercise, CR, and/or
vitamin E supplementation. All these beneficial effects might be mostly effective in
older age.

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