Abstract
Many azo dye derivatives are used as food colorants which cause cytotoxic effects. In recent years, a new trend to use antioxidants to neutralise the suspected effects of food additives has evolved. The present study investigated the possible modulatory effect of melatonin in reducing the cytotoxicity induced by the food colour additive Orange Yellow S (OYS) in male rats (Rattus norvegicus). The levels of thiobarbituric acid-reactive substances (TBARS) in the plasma, the activities of superoxide dismutase (SOD) and catalase in the blood and liver, the lipid profile and glucose concentration in serum and the histological appearance of the liver were also evaluated. Rats weighing 200-250 g were divided into four groups of five rats each; control, OYS-treated group, melatonin-treated and melatonin-and OYS-treated group. The treated groups were repeatedly gavaged with either 2.5 mg/kg body weight (bw) of OYS, 10 mg/kg bw of melatonin or both for three weeks. The results revealed no significant changes in liver catalase activity and serum HDL. OYS produced cytotoxic effects, while oral melatonin administration was significantly reduced the cytotoxic effect induced by OYS. The results support the use of supplemental melatonin as a modulating antioxidant agent.