Investigation of the effect of toluene on nitric oxide production and protective properties of resveratrol

Toluene is one of the most widely used organic solvents in the world. Toluene is used in industry and in various commercial products, including paints, paint thinners, varnishes, nail polish, and cleaning products. Toluene is also the most commonly abused inhaled solvent. Exposure to toluene occurs primarily through inhalation of vapors and sometimes through oral or dermal contact. Metabolism of toluene produces reactive oxygen species (ROS) or reactive nitrogen species (RNS). Resveratrol (3,5,4'-trihydroxystilbene) is a naturally occurring polyphenol in many plant species, particularly grapes, peanuts, and mulberries. Resveratrol has been shown to have numerous biological effects, including antioxidant, anti-inflammatory, anti-aging, anti-cancer, cardioprotective, and neuroprotective. Nitric oxide (NO), a diatomic free radical formed endogenously from L-arginine by the nitric oxide synthase (NOS) family of enzymes, is a highly reactive gas that can regulate multiple signaling pathways by reacting with various reagents. In mammals, there are three NOS isoforms: neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS). The purpose of the present study was to investigate the effect of toluene exposure on the production of free radical NO and the protective effect of resveratrol. For this purpose, 36 male Wistar albino rats weighing 250-350 grams were used. The rats were divided into two, control and experimental groups. Toluene at a dose of 900mg/kg and three different doses of resveratrol (5mg/kg, 10mg/kg, and 20mg/kg) were administered i.p. to the rats in the experimental groups for six days. Rats in the control group received physiological serum and 10% ethanol in the same manner. On the sixth day, the rats were dissected and liver and blood tissues were collected. NO levels and NOS activities in the collected liver tissue and serum were examined. Our result showed that toluene treatment increases the level of NO in the liver tissue and serum compared to the control groups. However, toluene and resveratrol-treated at different doses of 5mg/kg, 10mg/kg, and 20mg/kg significantly decreased NO level in the liver tissue compared to toluene-treated groups and control groups. NOS activities were affected by the effect of toluene and the highest activity was found in iNOS. However, a significant decrease in iNOS activity was observed after resveratrol administration.