Physicochemical characteristics, acute and subacute toxicity of cashew nut shell oil in Wistar rats

Abstract

This study investigated the physicochemical characteristics of cashew nut shell oil (CNSO) as well as its acute and subacute toxicity in rats. In acute toxicity test, the CNSO was orally administered up to 3 g/kg in a single dose and thereafter toxicity signs and mortality rates were observed in the rats within 24 h. In subacute toxicity study, the experimental rats were placed into four (4) groups of 12 rats each. Group I served as control, while groups II, III and IV received daily 20, 40, 60 mg/kg of CNSO respectively for 14 days. The chemical properties of CNSO revealed iodine number (126), acid value (13.80) and saponification number (52). The peroxide value and free fatty acid were 2.80 and 6.90 respectively. The acute toxicity (LD50) of CNSO was 1000 mg/kg. A dose dependent significant decrease (p<0.05) was recorded in body weight, red blood cell (RBC), packed cell volume (PCV), haemoglobin (Hb) and platelet count in CNSO treated groups when compared to the control rats. Furthermore, white blood cell (WBC), lymphocytes, bilirubin, alkaline phosphatase (ALP), aspartate transaminase (AST), alanine transaminase (ALT), total cholesterol, triglycerides, electrolytes (Cl−, K+, Na+ and HCO3−), urea and creatinine concentrations significantly (p < 0.05) increased in the CNSO treated groups. CNSO dose-dependently decreased antioxidant enzymes (glutathione, superoxide dismutase and catalase). This study suggests that CNSO has the potentials to induce oxidative stress, cause hepato-renal toxicity and therefore may be unsafe for human and animal consumption. However, CNSO may be used in paint and plastic industries based on its physicochemical characteristics.