The influence of age and gender on antioxidant enzyme activities in humans and laboratory animals.

Antioxidative/oxidative balance is one of the important factors for homeostasis. Antioxidative systems which protect from peroxidative damage are supposed to be under the influence of steroid hormones. The implications of this influence are age and gender as well as tissue dependent alterations in antioxidative enzyme activities. Apart from hormonal influence, antioxidative enzymes require the presence of microelements in their active centers as well as concerted action of non enzymatic antioxidants which support enzymes in their scavenging action. The aim of this review is to analyze and compare existing knowledge about the changes in activity of antioxidant enzymes in human and animal females and males of different age. Evidence as regards participation of oxidative stress in senescence are specific diseases which, to some extent, are gender dependent and appear more frequently in males or females. Several experiments in laboratory animals revealed that changes in enzyme activities are reflected in histopathological pictures of cells. The alterations observed during perimenopausal period provide with additional evidence of the participation of steroid hormones in the regulation of antioxidative system activity. Moreover, estrogens themselves exhibit antioxidative activity which is receptor independent. In conclusion, apart from genetic-related influences, also diet and style of life may have an impact on the antioxidative system which requires appropriate supplementation in microelements and vitamins for its effective function of scavenging excess of free radicals.

Comparison of antioxidant defence parameters in colostrum and milk between Berrichon du Cher ewes and Uhrusk ewes.

The aim of the study was to evaluate the profile of antioxidant parameters in ewes' colostrum and milk in relation to breed during 5 d post partum. Total antioxidant capacity (TAC) was analysed and the activity of the enzymic antioxidants, glutathione peroxidase (GSH-Px) and glutathione transferase (GSH-Tr), as well as the concentration of the non-enzymic antioxidants, vitamin C, vitamin A and beta-carotene, were measured. Samples were collected from healthy animals belonging to two ewe breeds: Berrichon du Cher (n=15) and Uhrusk (n=15) kept in the Podlasie Province (Poland). Colostrum was sampled directly after parturition, as well as after 12, 24 and 48 h later and milk was sampled 5 d after parturition. Colostrum and milk for the evaluation of all parameters except for vitamin A and beta-carotene were centrifuged, and the supernatant was used for further analysis. Spectrophotometric methods were used for biochemical measurements. The results showed dynamic changes of antioxidative parameters within the time period examined. TAC values and GSH-Px activity increased significantly during the experiment. GSH-Tr activity showed a similar tendency in Uhrusk ewes but an opposite relationship in Berrichon du Cher. Concentrations of examined vitamins followed the increasing trends noticed in the activities of antioxidative enzymes. Moreover, differences between breeds in the evaluated parameters were detected; these differences were not unequivocal however. The results are also a source of not previously published physiological antioxidant profile in colostrum and milk of ewes over the post-partum period.