Background

Nanoparticles have wide range of application while there are some reports regarding their probable effects on male reproductive system and spermatozoa.

Objective

The aim of this study was to evaluate the effect of different doses of silver nanoparticles (AgNPs) (70nm) on acrosome of rat spermatozoa and number of spermatogenic cells.

Materials and methods

In this experimental study, in experimental group, 32 male wistar rats (8 rats/group) received oral feeding AgNPs every 12 hr in one spermatogenesis period (48 days) by means of gavages in 25, 50 , 100 and 200 mg/kg concentration (experimental groups 1-4, respectively). The control group (8 rats) was treated on schedule with distilled water. Spermatozoa were stained by triple staining protocol for acrosome reaction. Histological evaluation on testis sections was performed using tissue processing and hematoxylin-eosin (H&E) staining.

Results

There was significant difference between the control group and the experimental group 1 for acrosome reaction (11.00±0.00 and 24.25±3.68, respectively, p=0.01). There was only significant reduction in spermatogonia cells in experimental group 4. Experimental groups 2, 3 and 4 showed a significant reduction in the number of primary spermatocytes and spermatids as well as spermatozoa. But there were no significant differences between different groups for Sertoli cell number and seminiferous tubule diameter.

Conclusion

It seems that Ag NPs have acute and significant effects on spermatogenesis and number of spermatogenic cells and also on acrosome reaction in sperm cells. More experimental investigations are necessary to elucidate better conclusion regarding the safety of nanoparticles on male reproduction system.

A double burden of malnutrition occurs when individuals, household members or communities experience both undernutrition and overweight. Here, we show geospatial estimates of overweight and wasting prevalence among children under 5 years of age in 105 low- and middle-income countries (LMICs) from 2000 to 2017 and aggregate these to policy-relevant administrative units. Wasting decreased overall across LMICs between 2000 and 2017, from 8.4% (62.3 (55.1-70.8) million) to 6.4% (58.3 (47.6-70.7) million), but is predicted to remain above the World Health Organization's Global Nutrition Target of <5% in over half of LMICs by 2025. Prevalence of overweight increased from 5.2% (30 (22.8-38.5) million) in 2000 to 6.0% (55.5 (44.8-67.9) million) children aged under 5 years in 2017. Areas most affected by double burden of malnutrition were located in Indonesia, Thailand, southeastern China, Botswana, Cameroon and central Nigeria. Our estimates provide a new perspective to researchers, policy makers and public health agencies in their efforts to address this global childhood syndemic.