Advances in Chemical Science Volume 1 Issue 1, December 2012 www.seipub.org/acs/ 1 Protective Effects of Solanum Macrocarpon against Air Pollution-Induced Oxidative Stress in Rats: Toxicological and Histopathological Studies Protective Effects of Solanum Macrocarpon against Oxidative Stress Abass A. Olajire 1* and Lukman Azeez 2 1* Industrial and Environmental Chemistry Unit, Department of Pure and Applied Chemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria 2 Department of Chemical Sciences, Fountain University, Osogbo, Nigeria Author for all Correspondence: olajireaa@yahoo.com (Olajire, A. A) Abstract Our study investigated the potential ability of Solanum macrocarpon (African eggplant), used as nutritional supplements, in alleviating toxicity induced by urban air pollution exposure. Male albino Wistar rats were exposed for 63 days either to urban air pollution without treatment (A); oral supplementation with Solanum macrocarpon given at 36 and 75 mg/kg body weight (BW), representing C and D respectively and exposed to air pollution; oral supplementation with Solanum macrocarpon given at 75 mg/kg BW after exposure to air pollution (B); or kept in animal house without exposure to air pollution (E). The exposure of rats to air pollution without treatment promoted oxidative stress with a significant increase in levels of cellular marker enzymes: alanine amino transferase (ALT) and aspatate amino transferase (AST) in serum and homogenates of the exposed animals. Histopathological changes observed show various pathological lesions in all of these tissues except heart caused by exposure to air pollutants. Oral supplementation with Solanum macrocarpon at 75 mg/kg body weight during exposure was able to halt the damage-inducing free radicals produced by air pollutants by reducing the levels of these enzymes leakages in animals. The histopathological findings also confirmed the potential protective effects of Solanum macrocarpon against toxicity induced by exposure to air pollution. Keywords Air Pollution; Exposure; Rats; Solanum macrocarpon; Toxicological Studies Introduction Urban atmospheric air pollution is considered a significant challenge to environmental health because it is associated with numerous adverse effects on human health ranging from respiratory and cardiovascular diseases to reproduction problems, cancers and increased morbidity and mortality (Lewtas, 2007; Yang and Omaye, 2009). Gaseous (CO, SO2, NO2, O3) and particulate air pollutants activate inflammatory cells to release oxidants such as superoxide anion, hydrogen peroxide, and hydroxyl radicals among other free radicals (Oyarzún et al., 2005; Rom, 2011). Among gaseous pollutants, carbon monoxide (CO) has been described as one of the main pollutants responsible for the development of cardiovascular diseases (Lodovici and Bigagli, 2011). Data from animal models supported a deleterious effect of air nitrogen dioxide such as its capacity to impair the function of alveolar macrophages and epithelial cells, thereby increasing the risk of lung infections such as influenza, which can predispose to causative bacterial agents of pneumonia such as pneumococcus. Prolonged exposure to higher levels of ambient air pollution has been reported to predispose individuals to pneumonia (Frampton et al., 2002; Neupane et al., 2010). Volatile compounds, such as benzene, in urban air pollution can induce DNA oxidation and carbon tetrachloride has been shown to damage liver, kidney, lung and intestine (Karthikeyan et al., 2006; Edewor et al., 2007). It has been found that concentrated particulate matter and ozone produce an inflammatory response on exposure to human lungs (Shrey et al., 2011). The general consensus does indicate that the mechanism of air pollution-induced health effects involves an inflammation related