Chronic Maternal Tobacco Smoke Exposure and/or Alpha-Lipoic Acid Treatment Causes Long-Term Deterioration of Testis and Sexual Behavior in Adult Male Rats

Background: Tobacco use during pregnancy is known to have several negative effects on the offspring's reproductive health in the long term. The use of alpha-lipoic acid (ALA) as a dietary supplement during pregnancy has increased greatly in recent years and has been known to have positive effects on various pregnancy outcomes including miscarriage, diabetic embryopathy, preterm delivery, and congenital malformations.

Aim: To evaluate the effects of tobacco smoke exposure (TSE) on sexual behavior, reproductive parameters, and testicles in adult male rats and to reveal the possible role of ALA administration on these parameters.

Methods: Pregnant rats (n = 7 per group) were treated with tobacco smoke (TS), ALA (20 mg/kg), and TS + ALA for a total of 11 weeks. The following parameters were compared with 8 control rats: puberty parameters, sexual behavior; levels of serum gonadotropins and testosterone, total antioxidant status, and total oxidant status; the expression of the apoptotic protease-activating factor-1 and caspase 9 mRNA levels in the testis; and assessment of immunohistochemistry and terminal deoxynucleotidyl transferase dUTP nick end labeling assay of testis.

Main outcome measure: Sexual behavior, changes in puberty parameters, and hormonal and genetic alterations were the outcomes analyzed in this study.

Results: Maternal TSE caused a significant decrease in the number of intromissions compared to the control group. Similarly, ALA decreased erectile function in sexual behavior by decreasing the number of intromissions and intromission ratio in the ALA group compared to the control group. In addition, TSE and ALA treatment caused an impairment of some consummatory sexual behaviors. Also, in parallel with this inhibitory effect, the age of pubertal onset was significantly delayed in the TS + ALA group compared to other groups. Also, histopathological changes in testicular tissue, oxidative stress markers, apoptotic index, and mRNA levels of apoptosis-related genes increased in all treatment groups.

Clinical implications: The use of ALA and/or tobacco products during pregnancy may adversely affect the reproductive health of male newborns in the long term.

Strengths & limitations: To the best of our knowledge, this study is the first to show the effects of maternal ALA treatment and/or TSE on the sexual behavior and reproductive parameters in male rats; however, the study is based on an animal model, and the present findings partially reflect the characteristics of human sexual behavior.

Conclusion: Maternal TSE and/or ALA treatment may impair sexual behavior in adulthood in male rats because of testicular damage caused by oxidative stress during gonadal development. Yardimci A, Akkoc RF, Tektemur A, et al. Chronic Maternal Tobacco Smoke Exposure and/or Alpha-Lipoic Acid Treatment Causes Long-Term Deterioration of Testis and Sexual Behavior in Adult Male Rats. J Sex Med 2020;XX:XXX-XXX.

Keywords: Alpha-Lipoic Acid; Maternal Tobacco Smoke Exposure; Offspring; Puberty Onset; Sexual Behavior.