A Comparative Study on Effect of Dietary Selenium and Vitamin E on Some Antioxidant Enzyme Activities of Liver and Brain Tissues

Abstract

Since selenium and vitamin E have been increasingly recognized as an essential element in biology and medicine, current research activities in the field of human medicine and nutrition are devoted to the possibilities of using these antioxidants for the prevention or treatment of many diseases. The present study was aimed at investigating and comparing the effects of dietary antioxidants on glutathione reductase and glutathione peroxidase activities as well as free and protein-bound sulfhydryl contents of rat liver and brain tissues. For 12-14 wk, both sex of weanling rats were fed a standardized selenium-deficient and vitamin E-deficient diet, a selenium-excess diet, or a control diet. It is observed that glutathione reductase and glutathione peroxidase activities of both tissues of the rats fed with a selenium-deficient or excess diet were significantly lower than the values of the control group. It is also shown that free and bound sulfhydryl concentrations of these tissues of both experimental groups were significantly lower than the control group. The percentage of glutathione reductase and glutathione peroxidase activities of the deficient group with respect to the control were 50% and 47% in liver and 66% and 61% in the brain, respectively; while these values in excess group were 51% and 69% in liver and 55% and 80% in brain, respectively. Free sulfhydryl contents of the tissues in both experimental groups showed a parallel decrease. Furthermore, the decrease in protein-bound sulfhydryl values of brain tissues were more pronounced than the values found for liver. It seems that not only liver but also the brain is an important target organ to the alteration in antioxidant system through either a deficiency of both selenium and vitamin E or an excess of selenium alone in the diet.

Characterization of Selenoprotein M and Its Response to Selenium Deficiency in Chicken Brain

“…In general, antioxidant defense systems eliminate reactive oxygen species (ROS) or other radical species to prevent oxidative stress, which is defined as an alteration in the steadystate balance between oxidant and antioxidant agents. It has been shown that under Se-deficient status, the activity of some antioxidative enzymes, such as GPx and CAT, the first line of cellular defense against potential oxidative damage [29], might be inhibited in various tissues, such as liver and muscle in poults [4], plasma in mice [30], and liver and brain of rat [31]. Consistent with previous studies, we observed decreased GPx, CAT, and Se in the Se-deficient group.…”

The effects of di(2‐ethylhexyl)phthalate on rat liver in relation to selenium status

“…Marked decreases in TrxR1 activity (2.2‐fold) and GSH levels and an enhancement of LP were observed, also by the others (Turan et al . ; Erkhembayar et al . ).…”

The trace element content of top-soil and wild edible mushroom samples collected in Tuscany, Italy

“…The element can also bind to amino acids forming low molecular species. A diet rich in Se (Turan et al 2001) ensures protection against free oxygen reactive species in tissues. Ingested Se can also bind to other toxic elements, as As, Cd, and Hg preventing their noxious action (Falandysz 2008).…”