Vitamin E improves testicular damage in streptozocin-induced diabetic rats, via increasing vascular endothelial growth factor and poly(ADP-ribose) polymerase-1

Abstract

The precise mechanism by which diabetes impairs spermatogenesis and testicular function is not exactly known. Vascular endothelial growth factor (VEGF) and poly(ADP-ribose) polymerase-1 (PARP-1) are important for germ cell homeostasis and repair of DNA respectively. The aim of this study was to investigate the correlation between diabetes-induced testicular damage and testicular VEGF and PARP-1 expression and the possible protective role of vitamin E supplementation. A total of 45 male Wistar albino rats were randomly divided into three groups: Group I (nondiabetic rats), Group II (streptozocin-induced diabetic rats) and Group III (streptozocin-induced diabetic rats treated orally with 0.4 mg/kg vitamin E). Five weeks later, testicular tissue was used for assessment of MDA concentration by colorimetry, histopathological examination and immunostaining for PARP-1 and VEGFIn diabetic rats, testicular weight, seminiferous tubule diameter and germinal epithelial thickness were decreased, basement membrane was thickened and Johnsen score decreased. Reduced VEGF and PARP-1 immunostaining were associated with decreased Johnsen score in diabetic rats. Vitamin E administration was protective against oxidative stress-associated damage evidenced by lower MDA levels, improved testicular weight, spermatogenesis and higher immunostaining for VEGF and PARP-1. Testicular VEGF and PARP-1 might therefore be helpful biomarkers for diabetic testicular damage. Administration of vitamin E may have a protective role against diabetes-induced testicular damage.

Quercetin Ameliorates Testicular Damage in Zucker Diabetic Fatty Rats through Its Antioxidant, Anti-Inflammatory and Anti-Apoptotic Properties

“…Alterations to testicular architecture are a common side effect of chronically elevated blood sugar or excessive accumulation of body fat. In accordance with our morphometric analysis in the untreated animals, previous reports observed that the induction of diabetes through medication or increased feed intake led to a reduced germ cell count and abnormalities to the spermatogenic series [22,23,29,30]. In particular, ZDF obese controls presented with a reduced cell layer with contracted and/or disarranged spermatogenic cells in the seminiferous tubules.…”

“…Correspondingly to our morphometric outcomes, a recent meta-analysis published by Zhong et al [8] referred to experimental studies observing a deterioration of the seminiferous epithelium, occurrence of cellular debris, and germ cell detachment from the testicular basal lamina in obese individuals. At the same time, DM has been often accompanied by testicular atrophy and reduction of seminiferous tubules, all of which imply potential spermatogenic deficits [22,30,31]. On the other hand, neither Vendramini et al [23] nor Mansour et al [32] observed any significant differences in the morphometric features amongst ZDF Lean and Obese rats.…”

Resveratrol supplementation improves DNA integrity and sperm parameters in streptozotocin–nicotinamide‐induced type 2 diabetic rats

“…The mentioned mechanism for this action is improvement in testicular weight, higher spermatogenesis rate and higher VEGF expression. They concluded that oral administration of vitamin E may have a protective role against diabetes‐induced testicular damage (Omar, Aly, & Badae, ).…”

Exogenous oestradiol benzoate induces male mice azoospermia through modulation of oxidative stress and testicular metabolic cooperation

“…endogenous Mda mainly results from lipid peroxidation of polyunsaturated fatty acids. Therefore, Mda is often used to assess the impairment of the cell membrane in response to oxidative species (29)(30)(31). The increase in Mda content of the eB-treated group indicated the impairment of the cellular membrane structure.…”