Reactive oxygen species production and antioxidant enzyme activity during epididymal sperm maturation in Corynorhinus mexicanus bats

Sperm Dysfunction in the Testes and Epididymides due to Overweight and Obesity Is Not Caused by Oxidative Stress

Obesity is a condition that has been linked to male infertility. The current hypothesis regarding the cause of infertility is that sperm are highly sensitive to reactive oxygen species (ROS) during spermatogenesis in the testes and transit through the epididymides, so the increase in ROS brought on by obesity could cause oxidative stress. The aim of this study was to evaluate whether the activity of the enzymes catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX) is capable of counteracting oxidative stress in sperm. The male Wistar rat was used as an overweight and obesity model, and analysis of fertility in these groups was carried out including the control group. Serum testosterone levels were determined, and the scrotal fat, testes, and epididymides were extracted. The epididymides were separated ini0 3 principal parts (caput, corpus, and cauda) before evaluating sperm viability, sperm morphology, damage to desoxyribonucleic acid of the sperm, and ROS production. The protein content and specific activity of the three enzymes mentioned above were evaluated. Results showed a gain in body weight and scrotal fat in the overweight and obese groups with decreased parameters for serum testosterone levels and sperm viability and morphology. Fertility was not greatly affected and no DNA integrity damage was found, although ROS in the epididymal sperm increased markedly and Raman spectroscopy showed a disulfide bridge collapse associated with DNA. The specific activities of CAT and GPX increased in the overweight and obesity groups, but those of SOD did not change. The amounts of proteins in the testes and epididymides decreased. These findings confirm that overweight and obesity decrease concentrations of free testosterone and seem to decrease protein content, causing poor sperm quality. Implications. An increase in scrotal fat in these conditions fosters an increase of ROS, but the increase of GPX and CAT activity seems to avoid oxidative stress increase in the sperm without damaging your DNA.

Effects of Environmental and Pathological Hypoxia on Male Fertility

Male infertility is a widespread health problem affecting approximately 6%-8% of the male population, and hypoxia may be a causative factor. In mammals, two types of hypoxia are known, including environmental and pathological hypoxia. Studies looking at the effects of hypoxia on male infertility have linked both types of hypoxia to poor sperm quality and pregnancy outcomes. Hypoxia damages testicular seminiferous tubule directly, leading to the disorder of seminiferous epithelium and shedding of spermatogenic cells. Hypoxia can also disrupt the balance between oxidative phosphorylation and glycolysis of spermatogenic cells, resulting in impaired self-renewal and differentiation of spermatogonia, and failure of meiosis. In addition, hypoxia disrupts the secretion of reproductive hormones, causing spermatogenic arrest and erectile dysfunction. The possible mechanisms involved in hypoxia on male reproductive toxicity mainly include excessive ROS mediated oxidative stress, HIF-1α mediated germ cell apoptosis and proliferation inhibition, systematic inflammation and epigenetic changes. In this review, we discuss the correlations between hypoxia and male infertility based on epidemiological, clinical and animal studies and enumerate the hypoxic factors causing male infertility in detail. Demonstration of the causal association between hypoxia and male infertility will provide more options for the treatment of male infertility.

Effect of Polygonum Multiflorum Thunb on liver fatty acid content in aging mice induced by D-galactose

Background

Polygonum Multiflorum Thunb(PMT) has multiple biological effects, such as anti-inflammatory, lipid-lowering, anti-aging and so on. Therefore, D-galactose-induced aging mice were used to study the effect of PMT on fatty acid metabolism and its underlying mechanism.

Methods

C57BL/6 male mice were randomly divided into normal group, aging model group, PMT intragastrical administration group (high, Medium, low); model group and PMT intragastrical administration group Daily intraperitoneal injection D-galactose 800 mg·ml^{− 1}·Kg^{− 1} to establish subacute aging model; PMT intragastrical administration group at the same time to intragastrical PMT extract (1 g·ml^{− 1}·Kg^{− 1}, 0.6 g·ml^{− 1}·Kg^{− 1}, 0.3 g·ml^{− 1}·Kg^{− 1}), normal group injection and intragastrical equivalent saline for 60 consecutive days. By detecting the oxidation index of liver to judge the efficacy of PMT, gas chromatography-mass spectrometry (GC-MS) analysis was used to quantitatively analyze the fatty acid content in liver.

Results

Finally, we found that PMT improved the enzyme activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in aging mice, and reduce the enzyme activity of malondialdehyde (MDA), aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The content of fatty acids such as C18:1, C18:2, C18:3 N3, C20:2 and C20:3 N3 decreased significantly in senescent mice (P < 0.05) as evidenced by GC-MS analysis, whereas, these fatty acids increased significantly after treatment of PMT (P < 0.05).

Conclusion

PMT improves the content of liver fatty acids in aging mice induced by D-galactose through, enhancing the activity of anti-oxidant enzymes.