Vitamin E attenuates nicotine- and noise-induced reproductive impairment in male albino Wistar rats

Effect of perinatal nicotine exposure on oxidative stress and BDNF levels in the brain tissue of offspring rats: The protective role of Vitamin E

OBJECTIVE

Nicotine, a well-known neurotoxin, induces oxidative stress in fetal tissues, leading to organ damage and fetal growth retardation. This study aims to evaluate oxidative stress parameters in the brain tissue of rat offspring exposed to perinatal nicotine and assess vitamin E's protective effects.

METHODS

Twenty-five pregnant rats were administered 10 mg/L of nicotine and 300 mg/L of Vitamin E in drinking water starting from the first day of gestation. On gestational day 21, some offspring were euthanized to form the prenatal group. The remaining litters were born naturally, and dams received treatments via drinking water during gestation and lactation (6 weeks). After the lactation period, the pups were weaned and directly treated for an additional 9 weeks, resulting in an overall treatment duration of 15 weeks. Brain tissues were analyzed for MDA, GSH, TOS, TAS, OSI, BDNF, Caspase-3 activity, and histopathological changes.

RESULTS

The nicotine-exposed pups exhibited significantly reduced crown-rump length, body mass, and brain mass compared to controls. Nicotine exposure decreased BDNF, GSH, and TAS levels and increased MDA, TOS, and OSI levels. Histopathologically, the nicotine prenatal group showed a significantly higher number of heterochromatic nuclei in brain tissue. Caspase-3 activity did not show a significant increase in nicotine groups compared to the control. Vitamin E supplementation mitigated nicotine-induced brain damage in some measured parameters.

CONCLUSION

Perinatal nicotine exposure induces oxidative damage in the brain tissue of rat offspring, while vitamin E exerts a protective antioxidant effect, preventing nicotine-induced neurotoxicity. Furthermore, the significant reduction in BDNF levels and the increase in heterochromatic nuclei in the nicotine-exposed groups highlight the detrimental impact of nicotine on neurodevelopment, which can be effectively mitigated by vitamin E supplementation.

Impact of carbimazole combined with vitamin E on testicular injury induced by experimental hyperthyroidism in adult albino rats: oxidative/inflammatory/apoptotic pathways

Thyroid hormones play essential roles in spermatogenesis, but their effects on infertile males remain poorly understood. This study aimed to evaluate the impact of combining carbimazole (CBZ) with vitamin E (VE) on testicular injury induced by experimental hyperthyroidism in adult albino rats, focusing on oxidative, inflammatory, and apoptotic pathways. In this experimental study, 64 adult male albino Wistar rats were divided into eight groups: Group I (control-untreated), Group II (CBZ-control), Group III (VE-control), Group IV (CBZ + VE-control), Group V (levothyroxine-induced testicular injury), Group VI (levothyroxine + CBZ-treated), Group VII (levothyroxine + VE-treated), and Group VIII (levothyroxine + CBZ + VE-treated). The study was conducted in the Faculty of Medicine, Suez Canal University (Ismailia, Egypt). After cervical decapitation, both testes and epididymis were examined histopathologically and immunohistochemically. Significant differences were observed among groups concerning malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT; all P < 0.001). Polymerase chain reaction analysis showed significant differences in tumor necrosis factor-α (TNF- α ), interleukin-10 (IL-10), Bcl-2-associated X protein (BAX), B-cell lymphoma 2 protein (Bcl2), p53, Caspase-3, Caspase-8, Caspase-9, and nuclear factor-kappa B (NF- κ B) mRNA levels (all P < 0.001). Hyperthyroid group treated with CBZ alone (Group VI) exhibited testicular side effects, affecting seminiferous tubules and spermatogenesis. However, the Group VIII showed improved spermatogenesis and a decrease in testicular side effects. The addition of VE to the treatment of hyperthyroid rats with CBZ reduced testicular side effects and seminiferous tubular affection when potentially improving spermatogenesis. Further research is needed to elucidate the underlying mechanisms fully.

Effects and possible mechanisms of combined exposure to noise and carbon monoxide on male reproductive system in rats

Environmental hazards are an increasing concern due to the rapid pace of industrialization. Among these hazards, noise and carbon monoxide (CO) are common risk factors and have been shown to cause serious health problems. However, existing studies focused on the individual effects of noise and CO exposure and the combined effects of these two factors remain poorly understood. Our study aimed to examine the combined effects of noise and CO exposure on testicular function by constructing individual and combined exposure models. Our findings indicated that combined exposure to noise and CO was associated with a higher risk of testicular damage and male reproductive damage when compared to exposure alone. This was evidenced by poorer semen quality and more severe pathological damage to the testis. This combined exposure led to higher levels of oxidative stress and apoptosis in the testes, with bioinformatics analyses suggesting the signaling pathways involved in these responses. Specifically, activation of the P53 signaling pathway was found to contribute to the testicular damage caused by the combined exposure. Encouragingly, pterostilbene (PTE), a novel phytochemical, alleviated combined exposure-induced testicular damage by reducing oxidative stress and germ cell apoptosis. Overall, we identified joint reproductive toxicity resulting from the exposure to noise and CO, and found that PTE is a promising potential treatment for injuries caused by these factors. The cover image is based on the Research Article Effects and possible mechanisms of combined exposure to noise and carbon monoxide on male reproductive system in rats by Yingqing Li et al., https://doi.org/10.1002/tox.23927.

Comprehensive review on the positive and negative effects of various important regulators on male spermatogenesis and fertility

With the increasing global incidence of infertility, the influence of environmental factors, lifestyle habits, and nutrients on reproductive health has gradually attracted the attention of researchers. The quantity and quality of sperm play vital roles in male fertility, and both characteristics can be affected by external and internal factors. In this review, the potential role of genetic, environmental, and endocrine factors; nutrients and trace elements in male reproductive health, spermatozoa function, and fertility potency and the underlying mechanisms are considered to provide a theoretical basis for clinical treatment of infertility.

The combined effects of noise and vibration stress on sex hormone levels, fertility capacity, and the protective role of cinnamon extract in rats: an experimental study

Due to the high prevalence of noise and vibration exposure in most industries, this study aimed to investigate the effects of simultaneous exposure to noise and vibration on sex hormone levels and fertility capacity in rats, as well as the protective effects of the hydroalcoholic extract of cinnamon. In this experimental study, 64 adult male rats were randomly divided into 8 groups, control, noise (N), cinnamon (C), noise + cinnamon (NC), vibration (V), vibration + cinnamon (VC), noise + vibration (NV) and groups Noise + Vibration + Cinnamon (NVC). Groups C, NC, VC and NVC received a 75 mg/kg dose of cinnamon extract by gavage. The rats of groups N and NC, V and VC and NV and NVC were each exposed to noise at 100 dB (700-5700 Hz), vibration acceleration of 1 m/s² rms (frequency range of 4-8 Hz), and simultaneously exposed to vibration and noise for 8 hours continuously every night (23:00-7:00) for 50 consecutive nights. Next, a blood sample was taken from the lateral tail vein and the levels of LH, FSH and testosterone were measured with ELISA kits. Each male rat was caged with 3 female rats for one week. The pregnant rats were kept until all of the rat pups were born. Then the fertility capacity, the total number of births, the live births and the birth weight of the rat pups were analyzed with the software SPSS. In the N and NV groups, compared to the control group, a significant decrease in LH and testosterone levels, the number of births and the birth weight was observed (p < 0.05). A significant decrease in testosterone levels, number of births and birth weight was observed in Group V compared to the control group (p < 0.05). In addition, significant increases in LH, FSH and testosterone levels and in birth weight were observed in group C compared to the control group (p < 0.05). Significant increases in FSH and testosterone levels, birth weight, and the number of births were noted in the NVC group compared to the NV group (p < 0.05). Based on the results of this study, cinnamon extract could alleviate the destructive effects of noise and vibration (both individually and in combination) on levels of sex hormones (LH, FSH, and testosterone), the number of births, and birth weight.

Dietary Antioxidants in the Treatment of Male Infertility: Counteracting Oxidative Stress

Infertility affects about 15% of the population and male factors only are responsible for ~25-30% of cases of infertility. Currently, the etiology of suboptimal semen quality is poorly understood, and many environmental and genetic factors, including oxidative stress, have been implicated. Oxidative stress is an imbalance between the production of free radicals, or reactive oxygen species (ROS), and the capacity of the body to counteract their harmful effects through neutralization by antioxidants. The purpose of this review, by employing the joint expertise of international researchers specialized in nutrition and male fertility areas, is to update the knowledge about the reproductive consequences of excessive ROS concentrations and oxidative stress on the semen quality and Assisted Reproduction Techniques (ART) clinical outcomes, to discuss the role of antioxidants in fertility outcomes, and finally to discuss why foods and dietary patterns are more innocuous long term solution for ameliorating oxidative stress and therefore semen quality results and ART fertility outcomes. Since this is a narrative review and not a systematic/meta-analysis, the summarized information in the present study should be considered cautiously.