Zinc-Enriched Yeast May Improve Spermatogenesis by Regulating Steroid Production and Antioxidant Levels in Mice

Zinc (Zn) is an essential nutrient for the human body. This nutrient is involved in numerous physiological functions and plays an important role in spermatogenesis. Zn-enriched yeast (ZnY) is considered a Zn supplement with high bioavailability and is widely used as a functional food. However, the effect of ZnY on male reproductive function remains unclear. This study aimed to investigate the beneficial effects of ZnY on the treatment of male spermatogenesis disorders. The spermatogenic dysfunctional mice were established by using cyclophosphamide (CP). CP was administered in saline at a dose of 50 mg/kg bw/day for 5 days by intraperitoneal injection (i.p.). Then, ZnY was orally supplemented at the dose levels of 2, 4, and 8 mg Zn/kg bw/day for 30 days. CP significantly decreased the sperm density and viability, testicular marker enzymes, serum testosterone, follicular stimulating hormone (FSH), and luteinizing hormone (LH). ZnY supplementation significantly improved these sperm parameters and hormone levels. Additionally, ZnY decreased the CP-induced lipid peroxidation and increased the glutathione levels. Moreover, ZnY increased the gene expression of anti-apoptotic proteins and steroid synthetase in mouse testes. The low-dose ZnY supplementation has a better effect on improving spermatogenesis, while the other two groups are less beneficial roles possibly due to excessive Zn intake. The present results suggest that appropriate ZnY can act as an accessory factor to improve steroid production and antioxidant levels in spermatogenic dysfunction mice.

Effect of phthalates exposure during perinatal period on hormonal profile in Mexican males during their first months of life

Phthalates affect development of male reproductive system acting as an antiandrogenic agents. We sought to explore if perinatal exposure to phthalates could alter male hormone levels in humans during the first months of life. A cohort of 83 pregnant women and their male infants were studied. Five phthalate metabolites were measured in the mother's urine during the first, second, and third trimesters of pregnancy and during the first, third, and sixth months of life in the infants. Luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone and inhibin B were analyzed. Association between phthalate exposure and hormone variation was assessed using regression models for longitudinal data. Mono-butyl phthalate reduced FSH concentration (ß = -0.0012 international units [IU]/L, p < 0.01), mono-ethylhexyl phthalate reduced inhibin B (ß = -0.0094 pg/mL, p = 0.02), monoethyl phthalate reduced testosterone (ß = -0.0071 ng/L, p = 0.07), mono-ocytl phthalate reduced LH (ß = -0.0041 IU/L, p = 0.13). No effects were observed for exposure to mono-methyl phthalate. Our results are consistent with the findings in animal and human studies. Special precaution should be taken when measuring phthalate exposure in susceptible populations such as pregnant women and infants.

Organophosphate pesticide exposure, hormone levels, and interaction with PON1 polymorphisms in male adolescents

OBJECTIVE

To examine the association between urinary metabolites of organophosphate (OP) pesticides and serum concentrations of thyroid and reproductive hormones in male adolescents and to assess the potential effect of interactions between OP pesticides and paraoxonase 1 (PON1) polymorphisms on hormone levels.

METHODS

Study subjects (N = 117) were male 16- to 17-year-olds from the Environment and Childhood (INMA)-Granada cohort in Spain. Concentrations of 3,5,6-trichloro-2-pyridinol (TCPy), a metabolite of chlorpyrifos/chlorpyrifos-methyl, 2-isopropyl-6-methyl-4-pyrimidinol (IMPy), a metabolite of diazinon, and diethylthiophosphate (DETP) and diethyldithiophosphate (DEDTP), non-specific metabolites of OP pesticides, were measured in a spot urine sample from each subject and adjusted for creatinine. Levels of reproductive hormones (total testosterone [TT], estradiol [E₂], dehydroepiandrosterone sulfate [DHEAS], sex hormone binding globulin [SHBG], luteinizing hormone [LH], follicle stimulating hormone [FSH], anti-Müllerian hormone [AMH], insulin growth factor 1 [IGF-1], and prolactin), thyroid hormones (free thyroxine [FT4], total triiodothyronine [TT3], and thyroid stimulating hormone [TSH]), and PON1 Q192R and L55M polymorphisms were determined in blood drawn during the same clinical visit.

RESULTS

Multiple linear regression models showed that detectable levels of TCPy were associated with an increase in DHEAS and decreases in E₂, FSH, and AMH; detectable IMPy with increases in E₂, DHEAS, FSH, AMH, and prolactin and decreases in SHBG and LH; and detectable DETP with marginally-significant increases in TT and TT3 and decreases in FSH, AMH, and prolactin. The effect of IMPy and DETP on DHEAS and TT levels, respectively, was higher in subjects that carried the PON1 55MM genotype, while the effect of TCPy, IMPy, and DETP on thyroid hormone levels was higher in PON1 192QR/RR or 55MM genotype carriers.

CONCLUSIONS

In male adolescents, non-occupational exposure to OP pesticides was associated with several changes in reproductive and thyroid hormone levels, and the magnitude of some associations was greater in adolescents genetically more susceptible to OP pesticide exposure who carry the PON1 55MM genotype.