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17β-Estradiol and Vitamin E Modulates Oxidative Stress-Induced Kidney Toxicity in Diabetic Ovariectomized Rat

Ulas, Mustafa, Cay, Mehmet
Biological trace element research 2011 v.144 no.1-3 pp. 821-831
alpha-tocopherol, antioxidants, beta-carotene, catalase, estradiol, glutathione, glutathione peroxidase, kidneys, lipid peroxidation, malondialdehyde, nephrotoxicity, ovariectomy, rats, superoxide dismutase, vitamin A
The aim of this study was to investigate the effects of vitamin E (alpha-tocopherol) and 17β-estradiol (E₂) supplementation on malondialdehyde (MDA), glutathione (GSH), vitamin A, beta carotene, selenium-dependent glutathione peroxidase (GSH-Px), zinc-dependent superoxide dismutase (SOD), and copper/zinc-dependent catalase (CAT) values in the kidney of ovariectomized (OVX) diabetic rats. Forty-two female rats were randomly divided into seven equal groups as follows: group I, control; group II, OVX; group III, OVX+E₂; group IV, OVX+E₂+alpha-tocopherol; group V, OVX+diabetic; group VI, OVX+diabetic+E₂; and group VII, OVX+diabetic+E₂+alpha-tocopherol. E₂ (40 μg kg⁻¹/day) and alpha-tocopherol (100 μg kg⁻¹/day) were given. Bilateral ovariectomy was performed in all groups except group I. After 4 weeks, antioxidant and MDA levels in the kidney for all groups were analyzed. GSH-Px, CAT, SOD, GSH levels, vitamin A, and beta carotene levels were decreased in OVX group compared to those in the control group but MDA level was elevated via ovariectomy. However, E₂ and E₂+alpha-tocopherol supplementations in OVX group was associated with an increase in the GSH-Px, GSH, CAT and Zn-SOD values, vitamin A, and beta carotene levels but a decrease in MDA levels in kidney. The MDA levels in the kidney of diabetic OVX rats were found higher than those in the control and OVX groups. However, GSH, GSH-Px, CAT, SOD, vitamin A, and beta carotene levels in kidney were lower in OVX diabetic rats. On the other hand, E₂ and E₂+alpha-tocopherol supplementations to OVX diabetic rats have caused an increase in GSH-Px, CAT and SOD, GSH, vitamin A, and beta carotene levels but a decrease in MDA levels. In conclusion, the E₂ and E₂+alpha-tocopherol supplementations to diabetic OVX and OVX rats may strengthen the antioxidant defense system by reducing lipid peroxidation, and therefore they may play a role in preventing renal disorders.