Effect of Zinc oxide nanoparticles (ZnO-NPs) on weights of some reproductive organs and sperm abnormalities in the tail of epididymis of albino mice

Increasing use of zinc oxide nanoparticles (ZnONPs) in many products may lead to damage of different organ tissues. Therefore, this study was conducted to identify the effect of ZnO-NPs on testicular, epididymal and some accessory glands weights as well as spermatic abnormalities in the epidydimal tail of male albino mice. Animals were orally administrated by 0.1 ml of 100 and 200 mg/kg ZnO-NPs for 7 and 14 days respectively for each concentration. The control group was orally gavaged with 0.1 ml of distilled water. Statistical analysis of the results showed a significant decrease (P≤0.05) in the average body weights of animals after 7 and 14 days of exposure to each treatment compared to the control and the weight of the same animal before treatment. Losing of body weight was increased by elevation the concentration and the duration of exposure. Whereas, the weight of testes and epididymis (head and tail) showed a significant decrease (P≤0.05) with both concentration and duration of exposure compared to the control, with more decreasing in the weight with high concentration and long duration of exposure. The average weight of seminal vesicle and prostate was significantly increased (P≤0.05) with both concentration and duration of exposure compared to control group. The percentage of sperm abnormalities was significantly (P≤0.05) increased with 100 and 200 mg/kg ZnO-NPs for 7 and 14 days of exposure compared to the control. The high concentration of ZnO-NPs and long duration of exposure resulted in more severe changes in the percentage of sperm abnormalities in the epididymis tail. Thus, we can conclude that increasing concentrations of ZnO-NPs and durations of exposure leads to negative effects on the male reproductive efficiency of albino mice. Key word: ZnO-NPs, male reproductive system, testes, epididymis, sperm quality, prostate, seminal vesicles. INTRODUCTION Nanoparticles (NPs) are very small, one-dimensional particles that vary in size from 1 to 100 nm[1]. Recently, they had great attention because of their unique characteristics that are useful in many medical and industrial applications [2]. Estimates show that 260,000-309,000 metric tons of nanoparticles were produced globally in 2010. [3] Other estimates predicts that, between 2014 – 2019, global consumption of NPs will increase from 225,060 to 58500 metric [4]. Zinc oxide nanoparticles (ZnO-NPs) represent the third most used nanoparticles, and their global annual production ranges from 550 and 33400 tons [5,6]. Zinc oxide nanoparticles are used in many products, including sun screens, biological sensors, food additives, dyes, rubber industry and electronic material [7]. It is expected that Zinc oxide nanoparticles will reach the environment and affect the nature of its living beings Reproductive system is one of the most important systems in living beings, which aims into genital reproduction and conservation of species. This system is affected by different ZnONPs, as many recent studies showed that of ZnO-NPs accumulate in different tissues, including brain and testis, which means that these nanoparticles can easily diffuse through blood brain and blood testes barriers. [9,10] Most NPs have toxic effect on spermatogenesis, [11] due to their small size which allows them to occupy higher surface area, compared to larger particles, and hence affecting specific physical and chemical proprieties, example chemical reactions, durability and high conduction ability. This small size allows NPs to penetrate cytoplasmic membrane and interfere with important cellular functions. Many reports have shown that NPs have more toxic effect than other larger part materials, due to their high reaction potential. Discussions previously concentrated on the positive aspects of ZnO-NPs, however, recently, more studies are dealing with their toxic effect. Yet, information about lines and toxicity of ZnO-NPs in environment is still limited. [13] That’s why it is very important to spot the light on ZnO-NPs-related problems and identifying their toxic effects on male albino mouse’ reproductive system secondary to oral ingestion of ZnO-NPs, and hence this study was conducted, in order to know the effect of ZnO-NPs on some reproductive organs (testes, epididymis, seminal vesicle and prostate) weight and sperm abnormalities in male of albino mice. MATERIALS AND METHODS The study was conducted on 30 male albino mice, with weights ranging from 30 – 35 g. They were divided on five groups, each one contains 6 animals. The first group was a control that ingested with distilled water. The second group was ingested with 100 mg/kg ZnO-NPs for 7 days, the third group was ingested with 100 mg/kg ZnO-NPs for 14 days, the fourth group was ingested with 200 mg/kg ZnO-NPs for 7 days, and the fifth group was ingested with 200 mg/kg ZnO-NPs for 14 days. Zinc oxide nanoparticles were prepared as the stored solution. All animals were exposed to normal laboratory conditions of temperature, light, air, and were provided with water and mice pelleted diet ad libitum. The concentration of 100 mg/kg ZnO-NPs was prepared by dissolving 325 mg of ZnO-NPs in 13 mL of distilled water and dissolving 650 mg ZnO NPs in 13 ml of distilled water to prepare a concentration of 200 mg/kg. The using Zinc oxide nanoparticles in this study were produced by Zhenghzou Dongyao nanomaterial company, and their characteristics were as follows: particle purity of 99.99%, mean particle size of 50 nm in diameter, have cube shaped and was a white powder form. The purity of the powder was tested by Energy Dispersive x-ray spectroscopy (SDX) device in AL-Nahrin University, faculty of science, physics department, electron microscopy lab. , which showed purity of 100% (Fig. 1). While the shape and size of the particles were determined by Transmission Electron Microscopy, in AL-Nahrin University, faculty of medicine. The results were almost identical to company descriptions (Fig. 2). Figure (1) shows the purity of ZnO NPs powder by using SDX device . Majida Jumaah Radhi et al /J. Pharm. Sci. & Res. Vol. 11(1), 2019, 243-246