Zinc Oxide Nanoparticles: Therapeutic Benefits and Toxicological Hazards

Abstract

Despite the widespread application of zinc oxide nanoparticles in biomedicine, their use is still a controversial issue. Zinc oxide nanoparticles were reported to have therapeutic benefits. However, they were reported to have toxicological hazards as well. Several studies reported the antibacterial, anticancer, antioxidant, and immunomodulatory effects of zinc oxide nanoparticles. Additionally, zinc oxide nanoparticles were used in sunscreens. Furthermore, the ability to use zinc oxide nanoparticles as an adjuvant treatment to alleviate the toxic effects of chemotherapeutic drugs has been reported. However, zinc oxide nanoparticles were shown to induce toxic effects in different body organs and systems. The affected organs included liver, spleen, kidney, stomach, pancreas, heart and lung. In addition, zinc oxide nanoparticles were reported to adversely affect the neurological system, lymphatic system, hematological indices, sex hormones levels, and fetal development. The toxic effects of zinc oxide nanoparticles were based on their concentration, their dose, the route of their administration, and the time of exposure to those particles. Thus, it is crucial to assess their efficacy and safety to determine their toxicological risks and therapeutic benefits.

Zinc Oxide Nanoparticles Ameliorate Aluminum Chloride-Induced Hepato-Renal Oxidative Stress and Inflammation in Rats

“…Balanced cell survival and cell death were reported to be created through Zinc channels via controlling free and intracellular zinc movements [74]. Due to their unique properties, ZnO NPs being bioavailable, biocompatible with high solubility and may localize in many tissues for cellular cycle regulation and cellular homeostasis maintenance, as they were supposed to mimic biomolecules' activity [75]. Moreover, ZnO NPs exposure suppressed NF-κB activity and translocation of nuclear ion of NF-kB and p65 in LPS-induced RAW macrophages, together with decreased transcription of cellular proteins leading to inhibition of NF-κB, thereby suppressing IL-1β and TNF-α production [76].…”

Neuro-biochemical changes induced by zinc oxide nanoparticles

“…Ben-Slama et al (2015) reported that the brain histological picture of rats treated with ZnNPs (10 mg/kg) for 5 consecutive days did not cause significant histological impairments; but caused edema and vascular congestion. Elshama et al (2018) found that ZnNPs i.p. injection for prolonged time induced histopathological and ultrastructural changes in rat’s brains, depending on the dose and ROS generation.…”

“…Zinc oxide nanoparticles (ZnNPs) are widely used in food for medicinal purposes as Zn is a dietary supplement and food additive, which was applied to food packaging materials. Furthermore, ZnNPs are commonly used in medicine, because they used to be coated on dental implants because of their excellent antibacterial and antifungal abilities ( Elshama et al, 2018 ).…”

“…The use of ZnNPs became controversial in recent years while ZnNPs can easily pass through the cell membrane and interact with cellular macromolecules leading to therapeutic effects like oxidative stress that has been found to have caused cytotoxic effects on certain organs ( Elshama et al, 2018 ). Xiao et al, 2016 , Elshama et al, 2018 reported that, due to their high solubility, ZnNPs have toxic effects on certain tissues, leading to cytotoxicity, oxidative stress and mitochondrial dysfunction. Meanwhile, ZnNPs have been approved by the Food and Drug Administration as a new and potent anticancer therapy.…”

“…Therefore, both toxicological risks and therapeutic advantages for the use of ZnNPs in medicine are urgently required to be evaluated. In addition, it is necessary to determine whether their toxicity is reversible, and whether this toxicity depends on the concentration and period of particulate exposure ( Elshama et al, 2018 ). Consequently, the purpose of this study is to investigate the neuro-biochemical effects of ZnNPs on healthy mice's brain.…”