S O p e n A c c e s s Journal of Targeted Drug Delivery J Target Drug Deliv Volume 3(1): 2019 1 RESEARCH ARTICLE Ecotoxicology-Nanotoxicology and Reactive Oxygen Species (ROS) Stress Combination of Free Radicals and Nanoparticles towards Antioxidant Defense Therapeutics Loutfy H Madkour* Chemistry Department, Faculty of Science and Arts, Al Baha University, Baljarashi 65635, Saudi Arabia. Abstract The mechanisms by which metalloids and xenobiotic metals (particularly arsenic, lead, cadmium, tin and mercury) induce their toxic efects have been investigated. The unifying factor in determining toxicity and carcinogenicity for the metals ions is the generation of reactive oxygen and nitrogen species (RONS). The toxic manifestations of the metals are primarily due to imbalance between pro-oxidant and antioxidant homeostasis that is termed as oxidative stress. Metal ions interferes with body functions: the hematopoietic system, (CNS), renal liver, kidneys, cardiovascular, pulmonary, gastrointestinal, hepatic and dermatologic systems, include damage to lipids, proteins, enzymes and DNA via the production of free radicals. The metal ions deplete glutathione and protein-bound sulfhydryl groups, resulting in the production of (ROS) as superoxide ion, hydrogen peroxide and hydroxyl radical ( 1 O 2, O 2 ●— , H 2 O 2 , ● OH, OH — ). Toxicities of heavy metals can be increased by defciencies of certain essential nutrients such as Ca, Fe, Zn, and Se. This review attempts a comprehensive account of recent developments in the research on heavy metals and NPs. Toxicity, cytotoxicity, genotoxicity, ecotoxicology, nanotoxicology and nanopathology particularly the role of oxidative stress/ free radicals in the toxic manifestation, an update about the recent strategies for the treatment with a possible benefcial role of counteractive antioxidant defense supplementation to achieve the optimum efects in physiological processes and future needs for the safe environment. Keywords: Heavy Metals Ions; Nanoparticles; Ecotoxicology; Oxidative Stress; Nanotoxicology; Free Radicals; Antioxidants Therapeutics. Introduction Heavy metal toxicity is an important consideration in medical workups, at very high levels, most heavy metals can cause health problems for which no cause or solution has been found. Heavy metals are continuously released into the terrestrial environment by natural sources and human activities, accumulate in the environment and subsequently contaminate the food chain. In our previous publication the toxic efective of heavy metals on cardiovascular pathophysiology and heart health function have been studied, discussed and reported [1]. Thirty fve metals pose a threat to human health, 23 of which are heavy metals [2]. Studies report various efects of heavy metals in drinking water [3, 4]. According to the International Agency for Research on Cancer (IARC), inorganic as and Cd are classifed as human carcinogens [5]. As is related to cancer risk and skin damage, Cd is linked to kidney damage and cancer. Other efects such as heart diseases and blood cholesterol from Sb, Anemia from Pb, kidney and liver damage from Hg, and gastrointestinal disorder from Cu are also reported [3, 4]. Among the heavy metals As, Cd, Pb, Cr, Cu, Hg and Ni are of major concern, mainly due to their presence at relatively high concentrations in drinking water and their efects on human health [4]. Among the heavy metals, As, Cd and Pb have extensively been studied for their public health efects [3, 4]. Protein synthesis can be disturbed at many levels of toxic metals at a variety of mechanisms either by afecting the nucleic acid metabolism of structure, or in the protein forming system itself. Toxic agents acting directly on ribosomes, RNA enzymes of Co-enzymes may also have a drastic infuence on protein synthesis. All biosynthetic processes can be disturbed in one way or another. Supply of safe drinking water is crucial to human life and safe drinking water should not impose a signifcant risk to humans [6]. Although a few heavy metals are essential for human health, an excess amount of these metals can have negative efects [3]. Heavy metals are released into the environment through natural process and anthropogenic activities. Some heavy metals, such as mercury and lead, may also enter the atmosphere due to trafc pollution and industrial activities, which can be deposited in soils around the reservoir and then enter the water along with the surface runof [7]. Heavy metals are particularly severe in their action among all the various toxic substances. The main anthropogenic sources of heavy metals are various industrial processes, mining, foundries, and smelters, combustion of fossil fuel and Correspondence to: Loutfy H Madkour, Chemistry Department, Faculty of Science and Arts, Al Baha University, Baljarashi 65635, Saudi Arabia, Tel. +966 533899075; fax: +966 77247272, Email: loutfy_madkour[AT]yahoo[DOT] com;lha.madkour[AT]gmail[DOT]com; Lmadkour[AT]bu[DOT]edu[DOT]sa, Received: Mar 05, 2019; Accepted: Mar 07, 2019; Published: Mar 11, 2019