Genotoxicity linked to occupational exposure in uranium mine workers: Granzyme B and apoptotic changes

Redox mechanisms of environmental toxicants on male reproductive function

Humans and wildlife, including domesticated animals, are exposed to a myriad of environmental contaminants that are derived from various human activities, including agricultural, household, cosmetic, pharmaceutical, and industrial products. Excessive exposure to pesticides, heavy metals, and phthalates consequently causes the overproduction of reactive oxygen species. The equilibrium between reactive oxygen species and the antioxidant system is preserved to maintain cellular redox homeostasis. Mitochondria play a key role in cellular function and cell survival. Mitochondria are vulnerable to damage that can be provoked by environmental exposures. Once the mitochondrial metabolism is damaged, it interferes with energy metabolism and eventually causes the overproduction of free radicals. Furthermore, it also perceives inflammation signals to generate an inflammatory response, which is involved in pathophysiological mechanisms. A depleted antioxidant system provokes oxidative stress that triggers inflammation and regulates epigenetic function and apoptotic events. Apart from that, these chemicals influence steroidogenesis, deteriorate sperm quality, and damage male reproductive organs. It is strongly believed that redox signaling molecules are the key regulators that mediate reproductive toxicity. This review article aims to spotlight the redox toxicology of environmental chemicals on male reproduction function and its fertility prognosis. Furthermore, we shed light on the influence of redox signaling and metabolism in modulating the response of environmental toxins to reproductive function. Additionally, we emphasize the supporting evidence from diverse cellular and animal studies.

The Effect of Neonicotinoids Exposure on Oreochromis niloticus Histopathological Alterations and Genotoxicity

This study aimed to examine the side effects of selected neonicotinoids (Acetamiprid, Aceta, and Imidacloprid, Imid) on Oreochromis niloticus juveniles. The acute toxicity, Probit method, revealed an LC₅₀ of 195.81 and 150.76 ppm for Aceta/96 h and Imid/72 h respectively. The fish were divided into three groups that were exposed, for 21 days (n = 5/replicate), to 1/10 of the LC₅₀ of either neonicotinoids, however, the third was an unexposed control group. Results of erythrocytic micronucleus (MN), and nuclear abnormalities (NA) showed that Aceta and Imid exposure caused a significant (p < 0.05) increase in MN by ~ 2.2 and ~ 10 folds, respectively relative to control. NAs occurred at the order of kidney-shaped > budding > binucleated in Aceta, however, budding > binucleated > kidney-shaped was noticed in the Imid group. Histopathological changes in gills, liver, and muscles were observed significantly in both exposed groups with more severity in the Imid group. Collectively, Aceta and Imid have potential genotoxicity and histopathological alterations in O. niloticus.

The Adsorption Characteristics of Uranium(VI) from Aqueous Solution on Leonardite and Leonardite-Derived Humic Acid: A Comparative Study

The humic substance is a low-cost and effective adsorbent with abundant functional groups in remediating uranium (U) (VI)-contaminated water. In this research study, leonardite together with leonardite-derived humic acid (L-HA) was used to eliminate U(VI) from water under diverse temperatures (298, 308, and 318 K). L-HA showed a higher adsorption volume for U(VI) than leonardite. U adsorption was varied with pH and increased with temperature. The adsorption kinetics of L-HA had a higher determination coefficient (R²) for pseudo-second-order (R² > 0.993) and Elovich (R² > 0.987) models, indicating possible chemisorption-assisted adsorption. This was further supported with the activation energies (15.9 and 13.2 kJ/mol for leonardite and L-HA, respectively). Moreover, U(VI) equilibrium adsorption on leonardite was better depicted with the Freundlich model (R² > 0.970), suggesting heterogeneous U(VI) adsorption onto the leonardite surface. However, U(VI) adsorption onto L-HA followed the Langmuir equation (R² > 0.971), which implied the dominant role of monolayer adsorption in controlling the adsorption process. Thermodynamic parameters, including standard entropy change (ΔS⁰ > 0), Gibbs free energy (ΔG⁰ < 0), and standard enthalpy change (ΔH⁰ > 0), suggested a spontaneous and endothermal adsorption process. In addition, ionic species negatively affected U(VI) adsorption by leonardite and L-HA.