Effect of Dietary Restriction on the Age-Dependent Changes in the Expression of Antioxidant Enzymes in Rat Liver

Abstract

The effects of aging and dietary restriction on the expression of several enzymes (superoxide dismutase, catalase and glutathione peroxidase) that are involved in free radical detoxification were studied in liver tissue from male Fischer F344 rats. The expression (i.e., activities and mRNA levels) of superoxide dismutase (Cu-Zn) and catalase decreased with age in liver. Dietary restriction (40% restriction of energy intake) increased the activities of superoxide dismutase (24 to 38%) and catalase (64 to 75%) in liver at 21 and 28 mo of age. Glutathione peroxidase activity in liver of diet-restricted rats was significantly higher (37%) at 28 mo of age than that of rats fed ad libitum. The age-related changes in the relative levels of mRNA for superoxide dismutase, catalase and glutathione peroxidase paralleled the changes in the activities of these enzymes in rats fed ad libitum or rats fed the restricted diet. Thus, the changes in the activities of superoxide dismutase, catalase and glutathione peroxidase with age and dietary restriction appear to arise from changes in the levels of mRNAs coding for these enzymes. Free radical damage, as measured by thiobarbituric acid-reactive material and lipofuscin accumulation, was lower in diet-restricted rats than in rats fed ad libitum.

Effects of Isorhamnetin, Rhamnetin, and Quercetin on the Concentrations of Cholesterol and Lipoperoxide in the Serum and Liver and on the Blood and Liver Antioxidative Enzyme Activities of Rats

“…As it is well known that SOD and catalase act antioxidatively in vivo, 26,32) the elevation of SOD activity in the rats fed with flavonoids may suggest that the ingested flavonoids acted antioxidatively through their action in elevating SOD activity. However, the reason for the lower activity of erythrocytes catalase, in contrast to the higher activity of SOD in the rats fed with the flavonoids, remains to be clarified.…”

“…The enzyme solution for determing the catalase activity was prepared according to the method of Rao et al 26 ) The liver tissue (a section from the left lobe, 0.6 g) was homogenized in 4 ml of a buffer containing 0.32 mol sucrose and I mmol EDTA per liter of IOmM Tris-HCI (pH 7.8) in a Teflon-glass homogenizer. The homogenate was centrifuged at 13,600 x g for 30 min at 4°C, and the supernatant obtained was used for the measurement of enzyme activities.…”

Sexual dimorphism in liver mitochondrial oxidative capacity is conserved under caloric restriction conditions

“…However, the different studies in the literature do not support a clear-cut pattern of CR-related changes in antioxidant defenses, with reports showing controversial effects on these activities (35,42). Differences in rodent model, strain, age of initiation, and duration of CR may be responsible for the differences between these studies.…”

Superoxide dismutase activities in long-lived Drosophila melanogaster females: chico 1 genotypes and dietary dilution

“…However, Rao et al (1990) observed that caloric restriction can attenuate the age dependent decrease of SOD activity. In general, caloric restriction has been observed to increase, decrease, or have no effect on antioxidant enzyme activity in rodents (Koizumi et al 1987;Laganiere and Yu 1989;Rao et al 1990;Feuers et al 1993;Luthala et al 1994).…”