Effects of vitamin E on reproductive hormones and testis structure in chronic dioxin-treated mice

Abstract

The purpose of this study was to investigate the effects of vitamin E on reproductive hormones and testis structure in mice treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Five experimental groups of a combination of TCDD and vitamin E were designed as follows: 0 ng/kg/d and 0 mg/kg/d (control group), 100 ng/kg/d and 0 mg/kg/d (Group I), 100 ng/kg/d and 20 mg/kg/d (Group II), 100 ng/kg/d and 100 mg/kg/d (Group III), and 100 ng/kg/d and 500 mg/kg/d (Group IV) respectively. Vitamin E and TCDD were given by oral gavage for 7 weeks. The results demonstrated that TCDD decreased the levels of brain gonadotropin releasing hormone (GnRH), testis luteinizing hormone (LH) and follicle stimulating hormone (FSH), serum testosterone and testis spermatozoa number, and damaged testis structure. Vitamin E at 20 mg/kg alleviated the decrease of GnRH; vitamin E at 20, 100, and 500 mg/kg antagonized the decline of LH and FSH; vitamin E at 20 and 100 mg/kg reversed the decrease of testosterone and spermatozoa number; and vitamin E at 100 mg/kg decreased the damage of the testis structure caused by TCDD. The results indicate that vitamin E antagonizes the reproductive endocrine toxicity and alleviates the changes in testicular structure caused by TCDD.

Protective effects of Vitamin E on CCl4-induced testicular toxicity in male rats

“…VE supplementation resulted in remarkable restoration of the structural alterations in the testes as a result of CCl 4 treatment. This amelioration could be attributed to the capacity of VE to scavenge ROS and reduce the oxidative stress, as reported in the previous studies (41,42).…”

“…These results were in agreement with other studies having reported that VE stimulated LH and FSH release (17,24). In addition, VE antagonized the decline of LH and FSH, testosterone, and sperm number; and reduced testicular injury as a result of dioxin treatment (41).…”

Chemoprotective effects of kolaviron on ethylene glycol monoethyl ether-induced pituitary-thyroid axis toxicity in male rats

“…The decline in the testosterone concentration in the present study could be attributed to the decrease in 3b-HSD and 17b-HSD activities, diminution in pituitary LH synthesis and secretion as well as decreased prolactin concentration in EGEE-treated rats. Vitamin E protected against prolactin decrease in aroclor exposed rats (Murugesan et al, 2005a) and ameliorated 2,3,7,8-tetrachlorodibenzop-dioxin-induced decline of LH and testosterone concentrations in rats (Yin et al, 2012). The significant reversal to near normalcy observed in the activities of steroidogenic enzymes and in the concentrations of LH, prolactin and testosterone in rats co-treated with kolaviron or vitamin E indicates its chemoprevention against EGEE adverse effect on Leydig cells in the interstitial tissues and pituitary gland.…”

Histological study of adult male rat seminiferous tubules following triclosan administration and the possible protective role of pomegranate juice

“…Inhibition of complex 1 is known to disrupt mitochondrial respiration and stimulates the mitochondrial production of ROS. In addition, vitamin E is known to maintain the structural integrity of sperm [68,69]. Vitamin C is known to protect mitochondrial DNA against oxidative damage [67].…”