The effect of 17-beta-Estradiol on Malondialdehyde levels and Total Antioxidant Capacity in Serum and Breast Tissue of Rats, with and without Pretreatment with Tamoxifen
Subject Areas : Veterinary Clinical Pathology
Ali Mohammad Rezaeii
1
,
Mohammad Reza valilou
2
,
Zafar Gholinejad
3
1 - D.V.M. Student, Faculty of Veterinary Medicine, Urmia Branch, Islamic Azad University, Urmia, Iran.
2 - Department of Pathobiology, TaMS.C., Islamic Azad University, Tabriz, Iran.
3 - Assistant Professor, Department of Laboratory Medical Sciences, Urmia Branch, Islamic Azad University, Urmia, Iran.
Keywords: Estradiol, Malondialdehyde, Rat, Tamoxifen, Total Antioxidant Capacity,
Abstract :
Although the hormone estradiol clearly affects the process of carcinogenesis through binding to its receptors (alpha and beta), it is possible that part of its effects may be mediated through the induction of oxidative stress. In the present study, the effect of 17-beta estradiol on oxidative stress markers in rats (as an animal model) was investigated. For this purpose, sixteen rats were randomly divided into four equal groups. After acclimatization to the environment, in the pre-treatment phase, the rats in groups 1 and 2 received tamoxifen at a dose of 5 mg/kg daily for one week, while the rats in groups 3 and 4 received the same volume of distilled water. Subsequently, during the treatment phase, the rats in groups 2 and 3 received a single dose of estradiol at 0.2 mg/kg. Three days after the treatment phase, serum and mammary tissue samples were collected from all rats, and the levels of total antioxidant capacity (TAC) and serum malondialdehyde (MDA) were measured. The tissue samples were also subjected to histopathological evaluation. The results showed that neither estradiol nor tamoxifen induced pathological changes in the mammary tissue. Moreover, estradiol did not cause significant changes in the serum levels of malondialdehyde and total antioxidant capacity. However, tamoxifen caused a noticeable increase in both parameters, although the changes were not statistically significant. On the other hand, a significant correlation was observed between the levels of malondialdehyde and total antioxidant capacity (p<0.023). The findings of the present study do not support a short-term effect of estradiol in inducing oxidative stress, but at the same time, they do not rule out the potential role of tamoxifen in inducing oxidative stress.
