Environmental Toxicants and Male Reproductive Toxicity: Oxidation-Reduction Potential as a New Marker of Oxidative Stress in Infertile Men

Understanding heavy metal toxicity: Implications on human health, marine ecosystems and bioremediation strategies

Heavy metals are constituents of the natural environment and are of great importance to both natural and artificial processes. But in recent times the indiscriminate use of heavy metals especially for human purposes has caused an imbalance in natural geochemical cycles. This imbalance has caused contamination of heavy metals into natural resources and such as soil and a marine ecosystem. Long exposure and higher accumulation of given heavy metals are known to impose detrimental and even lethal effects on humans. Conventional remediation techniques of heavy metals provide good results but have negative side effects on surrounding environment. The role played by microbes in bioremediation of heavy metals is well reported in the literature and understanding the role of molecules in the process of metal accumulation its reduction and transformation into less hazardous state, has myriads of biotechnological implications for bioremediation of metal-contaminated sites. The current review presents the implications of heavy metals on human health and marine ecosystems, conventional methods of heavy metal removal and their side effects on the environment. Bioremediation approaches have been discussed as well in this review, proving to be a more sustainable and eco-friendly approach towards remediation of heavy metals.

Arsenic-Induced Sex Hormone Disruption: An Insight into Male Infertility

Arsenic (As) is one of the most potent natural as well as anthropogenic metalloid toxicants that have various implications in the everyday life of humans. It is found in several chemical forms such as inorganic salt, organic salt, and arsine (gaseous form). Although it is mostly released via natural causes, there are many ways through which humans come in contact with As. Drinking water contamination by As is one of the major health concerns in various parts of the world. Arsenic exposure has the ability to induce adverse health effects including reproductive problems. Globally, around 15% of the couples are affected with infertility, of which about 20-30% are attributed to the male factor. Arsenic affects the normal development and function of sperm cells, tissue organization of the gonads, and also the sex hormone parameters. Stress induction is one of the implications of As exposure. Excessive stress leads to the release of glucocorticoids, which impact the oxidative balance in the body leading to overproduction of reactive oxygen species (ROS). This may in turn result in oxidative stress (OS) ultimately interfering with normal sperm and hormonal parameters. This study deals with As-induced OS and its association with sex hormone disruption as well as its effect on sperm and semen quality.

The therapeutic effects of Prunella vulgaris against fluoride-induced oxidative damage by using the metabolomics method

Fluoride is considered as one of the most ubiquitous environmental pollutants. Numerous studies have linked reactive oxygen species (ROS)-dependent oxidative damage with fluoride intoxication, which could be prevented by antioxidants. However, the metabolomic changes induced by ROS disruptions in fluoride intoxication are yet unknown. The present study aimed to provide novel mechanistic insights into the fluoride-induced oxidative damage and to investigate the potential protective effects of ethanolic extract of Prunella vulgaris (natural antioxidant, PV) against fluoride-induced oxidative damage. The serum biochemical indicators related to fluoride-induced oxidative damage, such as lipid peroxidation parameter, inflammation and marker enzymes in the liver increased significantly in the fluoride-treated group, while antioxidant enzymes were decreased. However, PV treatment restored the level of these biochemical indicators, indicating satisfactory antioxidant, anti-inflammatory, and hepatoprotective potential of PV. The metabolomics analysis in the serum was performed by liquid chromatography-mass spectroscopy, whereas the fluoride treatment caused severe metabolic disorders in rats, which could be improved by PV. The differential metabolites screened by multivariate analysis after fluoride and PV treatment, were organic acids, fatty acids, and lipids. These differential metabolites represented disorders of glyoxylate and dicarboxylate metabolism and the citrate cycle (TCA) according to metabolic pathway analysis in fluoride treatment rats. Interestingly, the result of metabolic pathway analysis of post-treatment with PV was consistent with that of fluoride treatment, indicating that the energy metabolism plays a major role in the progress of fluoride-induced oxidative damage, as well as the therapeutic effect of PV. These findings provided a theoretical basis for understanding the mechanism underlying metabolic disorders of fluoride toxicity and the effect of PV.