MOLYBDATE HUMAN REPRODUCTIVE SEMEN QUALITY

Exposure to metals, including essential and nonessential elements, is widespread and may be associated with altered semen quality. This study aimed to examine the association between urinary metal concentrations and semen quality in a Chinese population. We measured semen quality parameters (sperm concentration, count, motility, normal morphology, and abnormal head) and 13 metals [arsenic (As), cadmium (Cd), Cobalt (CO), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), molybdenum (Mo), mercury (Ho, nickel (Ni), selenium (Se), and zinc (Zn)] in the mine of 394 men front an infertility clinic. Multivariable logistic and linear regressions were used to assess the relationship between the creatinine-adjusted urinary metal concentrations and semen quality parameters. We found a significant trend for decreased odds ratios (ORs) for below-reference sperm count with increasing Se quartiles (p for trend = 0.04) and a significant trend for increased sperm percent abnormal head with increasing Ni quartiles (p for trend = 0.03). These associations persisted; even when considering multiple metals. Our results suggest that Ni exposure may be associated with deteriorated sperm morphology and that Se exposure may be associated with better semen quality. However, our findings warrant further studies in a larger and general population.

Zeng, Q., Feng, W., Zhou, B., Wang, Y. X., He, X. S., Yang, P., You, L., Yue, J., Li, Y. F., and Lu, W. Q.,Urinary Metal Concentrations in Relation to Semen Quality: A Cross-Sectional Study in China, Environmental Science & Technology, 2015, 49, 5052.

MOLYBDENUM DISULFIDE NANOPLATELETS NOT CYTOTOXIC

This study investigates the effects of tungsten disulfide nanotubes (WSNTs) and molybdenum disulfide nanoplatelets (MSNPs) on fibroblasts (NIH-3T3) and mesenchymal stem cells (MSCs) to determine safe dosages for potential biomedical applications.

MATERIALS & METHODS:

Cytotoxicity of MSNPs and WSNTs (5-300 mug/ml) on NIH-3T3 and MSCs was assessed at 6, 12 or 24 h. MSC differentiation to adipocytes and osteoblasts was assessed following treatment for 24 h.

RESULTS:

Only NIH-3T3 cells treated with MSNPs showed dose or time dependent increase in cytotoxicity. Differentiation markers of MSCs in treated groups were unaffected compared with untreated controls.

CONCLUSION:

MSNPs and WSNTs at concentrations less than 50 microg/ml are potentially safe for treatment of fibroblasts or MSCs for up to 24 h.

Rashkow, J. T., Talukdar, Y., Lalwani, G., and Sitharaman, B.,Interactions of 1D- and 2D-layered inorganic nanoparticles with fibroblasts and human mesenchymal stem cells, Nanomedicine (Lond), 2015, 10, 1693.

Genetic Toxicology

Molybdenum trioxide was not mutagenic in tests with Bacillus subtillis , [Kada et al., 1980], Salmonella typhimurium, [Zeiger et al., 1992; Milvy and Kay, 1978], and Escherichia coli , [Venitt and Levy, 1974].
Kada, T., Hirano, K. and Shirasu, Y., in : Chemical Mutagens: Principles and Methods for their Detection.
Zeiger, E., Anderson, B., Haworth, S., Lawlor, T. and Mortelmans, K., Environ. Mol. Mutagen, 1992, 19 (Suppl. 21), 2.
Milvy, P. and Kay, K., J. Tox. Environ. Health, 1978, 4, 31.
Venitt, S. and Levy, L.S., Nature,1974, 250, 493.

Increased frequencies of chromosomal aberrations were reported in peripheral blood lymphocytes of experimental animals and workers exposed to molybdenum, molybdenite, and molybdenum trioxide [Babaian et al., 1980].

Babaian, E.A., Bagramian, S.B., and Pogosian, A.S., Gig. Tr. Prof. Zabol., 1980, 9, 33.

Cytotoxicity of molybdenum trioxide nanoparticles
There is a lack of information about the impact of nanomaterials on human health and the environment. The purpose of the study was to assess a mouse spermatogonial stem cell line (C18—4from type A spermatogonia isolated from 6-day-old mouse testes) as a model to assess nanotoxicity in the male germline in vitro. The effects of different types of nanoparticles on these cells were evaluated. MoO3 nanoparticles (30 microm) were made in a pulsed plasma reactor which forms the particles in a gas-phase process. There was a concentration-dependent toxicity for all types of particle (MoO3 , CdO, Ag, Al) tested, whereas the corresponding soluble salts had no significant effect. Molybdenum trioxide MoO3 nanoparticles were the least toxic. This cell line provides a valuable model with which to assess the cytotoxicity of nanoparticles in the germ line in vitro. With respect to their mitochondrial function MoO3 nanoparticles had a toxic effect of cellulsar metabolic activity at concentrations of 50 microg/l and above: EC50 90 microg/l. By contrast sodium molybdate in aqueous solution at the same concentrations was hardly toxic (EC50 322 microg/ml). In the LDH leakage test sodium molybdate did not affect the integrity of the plasma membrane whereas a significant increase of LDH leakage was observed with molybdenum nanoparticles: EC50 5 microg/l.

Braydich-Stolle, L., Hussain, S., Schlager, J. J., and Hofmann, M. C., In vitro cytotoxicity of nanoparticles in mammalian germline stem cells, Toxicological Sciences, 2005, 88, 412-419.

The toxicity of (inter alia) MoO3 nanoparticles (30 and 150 nm) was investigated in an in vitro model derived from rat liver cells BRL 3A. The interest was the cellular response to nanosized particle exposure. For toxicity evaluations cellular morphology, mitochondrial function (MTTassay), membrane leakage of lactate dehydrogenase (LDH assay), reduced glutathione (GSH) levels, reactive oxygen species (ROS),and mitochondrial membrane potential (MMP) were assessed under control and exposed conditions (24 h exposure) and at MoO3 concentrations from 0 to 250 ug/l. For MoO3 exposure at concentrations up to 100 microg/l the results of the LDH leakage and MTT assays showedno cytotoxicity but showed a significant effect at 250 microg/l.. The results were summarised as EC50 values (i.e. the concentration of nanoparticles that increased LDH leakage to 50% or decreased MTT reduction by 50%: MTT: 172 ± 25 (30 nm),175 ± 26 (150 nm); LDH: 210 ± 30 (30 nm)and 250 ± 17 (150 nm). MoO3 was less toxic than Ag and CdO but more so than, Fe3O4, Al, MnO2 and W particles.

Hussain, S.M., Hess, K. L., Gearhart, J. M., Geiss, K. T., and Schlager, J. J., In vitro toxicity of nanoparticles in BRL 3A rat liver cells, Toxicology in Vitro, 2005, 19, 975-983.

Mutagenicity
The mutagenic effect of an industrial enterprise (tungsten and molybdenum factory) was studied in three stages. At the first stage, the putative impact of the industrial sewage of the factory was studied using three plant test systems: Crepis capillaris L., Tradescantia sp. clone 02, and Glycine max (L.) Merill. It was found that the sewage increased the mutation level by a factor of 11-45. At the second stage, the rate of mutation was studied in the native vegetation growing on solid waste piles of the enterprise. It exceeded the corresponding index of uncontaminated areas by a factor of 2.0-4.5. At the third stage, the rates of children with birth defects and miscarriages were studied in the vicinity of the enterprise. The rate of miscarriages proved to be higher than the value averaged over the autonomous republic by a factor of 2.4. No change in the rate of birth defects was detected

Reutova, N.V., Vorobyeva, T. I., and Reutova, T. V., Some approaches to evaluation of the mutagenic effect of industrial waste on the environment, Russian Journal of Genetics, 2005, 41, 608-612.