Arsenic exposure and its implications in male fertility

Arsenic exposure is a global health concern. This toxic metalloid is ubiquitous in the environment and contaminates food and drinking water. Once ingested, it undergoes a complex metabolic process within the body, which contributes to its accumulation and reactivity. Arsenic toxicity stems from the induction of oxidative stress, inhibition of thiol-containing proteins, and mimicry of inorganic phosphates. Arsenic poisoning is associated with the development of reproductive disorders. In males, arsenic causes a reduction in testicular weight and alterations in steroidogenesis and spermatogenesis. Moreover, it reduces the number and quality of spermatozoa harvested from the cauda epididymis. The mitochondria are targets of arsenic toxicity because of the production of free radicals and their high content of cysteine-rich proteins and fatty acids. Mitochondrial dysfunction may contribute to reproductive disorders because this organelle is crucial for controlling testicular and epididymal events related to sperm production and maturation. All of these alterations mediated by arsenic exposure contribute to the failure of male reproductive competence by reducing gamete viability. This review describes the potential mechanisms of arsenic toxicity, its detrimental effects on male reproductive organs, and consequences on sperm fertility.(AU)

Draft genome sequence of Chryseobacterium limigenitum SUR2T (LMG 28734T) isolated from dehydrated sludge

The type strain SUR2 of the novel species Chryseobacterium limigenitum was isolated from a dehydrated sludge of the municipal sewage treatment plant in Dogoše near Maribor in Slovenia. The draft genome, with 60 contigs, 4,697,725 bp, 34.4% of G+C content, was obtained using the Illumina HiSeq 2500-1 platform. Joint Genome Institute Microbial Genome Annotation Pipeline (MGAP v.4) has identified 4322 protein-coding sequences including resistance genes against arsenic and other heavy metals. In addition, a subclass B3 metallo-β-lactamase, which confers resistance to penicillins, cephalosporins and carbapenems, was also present in the genome. The genome sequence provides important information regarding bioremediation potential and pathogenic properties of this newly identified species.(AU)

Isolation and characterization of arsenic resistant bacteria from wastewater

The present study proposed the isolation of arsenic resistant bacteria from wastewater. Only three bacterial isolates (MNZ1, MNZ4 and MNZ6) were able to grow in high concentrations of arsenic. The minimum inhibitory concentrations of arsenic against MNZ1, MNZ4 and MNZ6 were 300 mg/L, 300 mg/L and 370 mg/L respectively. The isolated strains showed maximum growth at 37 ºC and at 7.0 pH in control but in arsenite stress Luria Bertani broth the bacterial growth is lower than control. All strains were arsenite oxidizing. All strains were biochemically characterized and ribotyping (16S rRNA) was done for the purpose of identification which confirmed that MNZ1 was homologous to Enterobacter sp. while MNZ4 and MNZ6 showed their maximum homology with Klebsiella pneumoniae. The protein profiling of these strains showed in arsenic stressed and non stressed conditions, so no bands of induced proteins appeared in stressed conditions. The bacterial isolates can be exploited for bioremediation of arsenic containing wastes, since they seem to have the potential to oxidize the arsenite (more toxic) into arsenate (less toxic) form.

Antioxidant potential of Ocimum sanctum in arsenic induced nervous tissue damage

The present study aimed to assess the antioxidant potential of hydro-alcoholic extract of Ocimum sanctum leaves (HAEO) in Wistar rats intoxicated with arsenic. The experimental animals (n=75) were divided randomly into five groups of 15 rats each. Rats in group I received distilled water, whereas rats in groups II, III, IV and V received arsenic as sodium arsenate salt @ 25 ppm in drinking water daily for 45 days. In addition, rats from groups III, IV and V received HAEO @ 50, 100 and 200 mg/ kg body weight, respectively, once daily for a period of 45 days. Rats of group I and II acted as negative and positive controls, respectively. At the end of the experiment, all rats were sacrificed; blood and tissues were assayed for various biochemical indicators of oxidative stress. Cytopathological changes in brain and spinal cord tissues were studied in arsenic intoxicated animals. The free radical scavenging and intracellular antioxidant activities of HAEO were determined from its radical scavenging ability and antioxidant power assay. HAEO was found to inhibit lipid peroxidation in brain tissue in a dose dependent manner. Administration of HAEO @ 100 mg/kg body weight was found to be more effective in restoring action on discrete regions of the brain than dose rate of 50 and 200 mg. Non-significant effect of HAEO on blood and tissue arsenic concentrations was observed except...

Antioxidant potential of Ocimum sanctum in arsenic induced nervous tissue damage

The present study aimed to assess the antioxidant potential of hydro-alcoholic extract of Ocimum sanctum leaves (HAEO) in Wistar rats intoxicated with arsenic. The experimental animals (n=75) were divided randomly into five groups of 15 rats each. Rats in group I received distilled water, whereas rats in groups II, III, IV and V received arsenic as sodium arsenate salt @ 25 ppm in drinking water daily for 45 days. In addition, rats from groups III, IV and V received HAEO @ 50, 100 and 200 mg/ kg body weight, respectively, once daily for a period of 45 days. Rats of group I and II acted as negative and positive controls, respectively. At the end of the experiment, all rats were sacrificed; blood and tissues were assayed for various biochemical indicators of oxidative stress. Cytopathological changes in brain and spinal cord tissues were studied in arsenic intoxicated animals. The free radical scavenging and intracellular antioxidant activities of HAEO were determined from its radical scavenging ability and antioxidant power assay. HAEO was found to inhibit lipid peroxidation in brain tissue in a dose dependent manner. Administration of HAEO @ 100 mg/kg body weight was found to be more effective in restoring action on discrete regions of the brain than dose rate of 50 and 200 mg. Non-significant effect of HAEO on blood and tissue arsenic concentrations was observed except...(AU)