Respiratory exposure to carbon black nanoparticles may induce testicular structure damage and lead to decreased sperm quality in mice

Environmental carbon black nanoparticles (CBNPs) can enter into various organs including testes through the respiratory tract. However, there are few studies describing reproductive toxicity of CBNPs after respiratory exposure. In this study, male KM mice were exposed to CBNPs in their natural breathing state. Four-, 8-, and 12-week-old mice were exposed to 0, 9, 18 and 27 mg/m³ of CBNPs for 4 weeks in order to examine the relationship between CBNP exposure and age. Eight-week-old mice were exposed to CBNPs at the same four concentrations for 1-4 weeks in order to examine the effects of CBNP exposure time. After CBNP exposure, testicular oxidative stress and inflammation increased significantly, and these effects varied with exposure time. Seminiferous tubule diameter (STD), seminiferous epithelium height (SEH), the number of spermatogenic and Leydig cells, sperm motility, and sperm speed decreased significantly, and these effects varied with exposure dose. Data analyses suggested that increased oxidative stress and inflammation in testes damaged testicular morphology, spermatogenesis, and testosterone secretion, and decreased sperm quality. Morphological damage to the testes was also closely related to decreased the sperm quantity. These findings are of significance for evaluating the reproductive toxicity of CBNPs.

Assessment of the effect of sodium hydrogen sulfide (hydrogen sulfide donor) on cisplatin-induced testicular toxicity in rats

Cisplatin (CIS) is an antineoplastic drug able to produce free radicals that are capable to induce various side effects in different tissues. Hydrogen sulfide (H₂S) has notable antioxidant, anti-apoptotic, and anti-inflammatory effects in different systems but its role in male reproductive system is not fully understood. In the present research, the effect of sodium hydrosulfide (NaHS) on cisplatin-induced testicular toxicity in male rats was studied. Thirty-two Sprague-Dawley rats were equally divided into 4 groups. The control group was treated with normal saline by intraperitoneal injection. The NaHS group received NaHS (200 μg/kg/day) intraperitoneally for 15 days. The CIS group received single dose of cisplatin (5 mg/kg) intraperitoneally, while the combination of CIS and NaHS was given to the CIS+ NaHS group. At the end of the study, body and testicular weights, plasma testosterone level, histological and morphometrical alterations, inflammation via IL-1β protein, lipid peroxidation, and activity of antioxidant enzymes (including glutathione peroxidase, superoxide dismutase, and catalase) of testicular tissue were evaluated. CIS injection revealed a significant decrease (p < 0.01) in body and testis weights, plasma testosterone concentration, diameter of seminiferous tubules, germinal epithelium thickness, the number of Sertoli cells, spermatogonia and spermatocyte, Johnsen's testicular score, and testicular antioxidant enzymes, whereas it caused a significant increase (p < 0.01) in lumen diameter of the seminiferous tubules, level of lipid peroxidation, and IL-1β protein expression when compared with the control group. NaHS administration to CIS-treated rats provided marked improvement (p < 0.05) in all biochemical, histological, and morphometrical changes induced by CIS. The beneficial effects of NaHS were mediated, at least partly, by its antioxidant and anti-inflammatory properties.

Recovery effect of pre-germinated brown rice on the changes of sperm quality, testicular structure and androgen receptor expression in a rat model of drug addiction

Drug addiction is reported to have adverse effects in male reproduction. Dextromethorphan (DXM) administration was used in this study as a model of addiction in rats, and various treatments including the use of pre-germinated brown rice (PGBR) were investigated for their effects on the changes of sperm quality, testicular structure and androgen receptor (AR) expressions in rats receiving DXM. The results demonstrated that these animals showed significant reduction in all parameters of sperm quality, an increase in abnormal testicular structure and decreased androgen receptor expression in spermatogenic, Sertoli and Leydig cells. However, different effects of the treatments applied in this study were observed with the greatest recovery effect from treatment with PGBR. Sperm motility and sperm concentration reverted to normal after treatment with PGBR for 60 days. Moreover, all parameters of testicular structure also returned to normal after 60 days of PGBR treatment, as well as AR expression in Sertoli and Leydig cells. Therefore, we have demonstrated that PGBR treatment can reverse the changes in sperm quality, testicular structure and AR expression in addicted animals and PGBR may be a novel therapeutic strategy for the treatment of drug addiction.