Subacute dermal toxicity investigation of nanosilver on serum chemical biomarkers in male mice

Nanosilver is one of the most widely used nanomaterials due to its strong antimicrobial activity. Thus, because of increasing potential for exposure of human to nanosilver, there is an increasing concern about possible side effects of these nanoparticles. In this study, we tested the potential dermal toxicity of nanosilver bandage on serum chemical biomarkers in mice. In this study, 20 male BALB/c mice were randomly allocated into the treatment and control groups [n=10]. After general anesthesia and shaving the back of all animals in near the vertebral column, in the nanosilver group, a volume of 50microl of 10 microg/ml of nanosilver solution [40 nm], and in the control group the same amount of distilled water was added to the sterile bandage of mice, then the bandages were fixed on the skin surface with cloth glue. After 3 and 7 days, the bandages were opened and serum levels of blood urea nitrogen [BUN], creatinine [Cr], alanine aminotransferase [ALT] and aspartate aminotransferase [AST] were measured by using standard kits for two groups of mice. In treatment group, a significant increase in ALT, AST and BUN levels were observed compared with control group during experiment periods [p<0.05], but there wasn't a significant increase in Cr level in treatment group during experiment periods [p>0.05]. The present results indicated that the dermal absorption of 10 microg/ml nanosilver [40 nm] can lead to hepatotoxicity and renal toxicity in mice

Mechanism of the dysfunction of the bull spermatozoa treated with cadmium / 中华男科学杂志

<p><b>OBJECTIVE</b>Heavy metals such as cadmium (Cd) are widely distributed in the environment as industrial pollutants and characterized by their ability to affect the male reproductive system. The objective of the present study was to test the effect of Cd in the concentration range from 10 to 1000 micromol/L, in vitro, on the membrane and DNA integrity, motility, and ability of sperm to undergo acrosomal exocytosis in Holstein bull spermatozoa.</p><p><b>METHODS</b>Bull semen samples were processed for sperm analyses using semen-diluting fluid, PBS. Membrane integrity of the processed bull sperm was evaluated by lipoperoxidation (LPO) test. Gelatin digestion test was performed to determine the ability of bull spermatozoa to undergo acrosomal exocytosis. Single cell gel electrophoresis (SCGE) assay was performed to detect the DNA strand breaks and alkali labile damages in the individual cell.</p><p><b>RESULTS</b>We found a significant increase in the lipoperoxidation (LPO) indicating the deleterious effect of Cd on the sperm membrane integrity. This effect was prominent at the concentration of 1000 micromol/L Cd. There was a negative correlation between LPO rate and the percentage of motile spermatozoa (r = -0.94, P < 0.001). The gelatin digestion test indicated that Cd caused a decline in the percentage of acrosomal exocytosis of bull spermatozoa. A reverse correlation was also found between LPO rate and the percentage of halos (r = -0.97, P < 0.001). Data obtained from the comet assay revealed that Cd was capable of inducing DNA breaks in the sperm nuclei. Almost 93% of DNA damages were double-stranded breaks. The correlation between LPO rate and the percentage of DNA breaks was found to be 0.95 (P < 0.001).</p><p><b>CONCLUSION</b>Collectively, Cd induced membrane impairments, lowered motility, DNA breaks and a decreased rate in the acrosome reaction of bull spermatozoa, leading to sperm dysfunction. Entering Cd in the male gonads and seminal plasma may exert deleterious effects on the animal sperm cells.</p>

Anti-fertility effect of nicotine / 中华男科学杂志

In recent years, the quality of human sperm and its fertility potential have decreased dramatically. This may suggest that the quality of semen has deteriorated partly due to the effects of increasing toxic factors in the environment. Infertility remains a major problem in society, and recent data show that as many as one in four couples is trying to solve the problem. Male infertility accounts for 40% of infertility cases. Many environmental agents such as tobacco smoke and nicotine and genetic factors have been implicated in the poor sperm function and resultant infertility. The article is a review of the impacts of nicotine on human fertility potential. According to our results, nicotine is proved to be a potent pro-oxidant to the biological samples like spermatozoa population and is able to alter the fertility potential of man by inducing the membrane impairments, altering the GSH metabolism cycle, changing the sperm morphology and motility, and also inducing the DNA fragmentation. Antioxidant supplementation could reverse partially the negative effect of nicotine on sperm functions. However, further studies are necessary to illuminate the other dark sides of nicotinic infertility in human spermatozoa.