Effect of butylated hydroxytoluene on passive avoidance learning in male rats

Butylated hydroxytoluene (BHT; 2, 6-di-tert-butyl-p-cresol) is one of the extensively used antioxidants in the food industry. It is used in low-fat foods, fish products, packaging materials, paraffin, and mineral oils. BHT is also widely used in combination with other antioxidants such as BHA, propyl gallate, and citric acid for the stabilization of oils and high-fat foods. On the other hand, some investigators have reported that BHT has psychotic effects. Therefore, the aim of the present study was to investigate the effect of BHT on learning and memory in a model of passive avoidance learning in male rats. Twenty-eight male rats weighting 180-260 g were used. Animals were divided into 4 groups: 1- control group (received sesame oil with the same volume as experimental groups); -2 experimental 1 (received BHT 25 mg/kg/day); 3- experimental 2 (received BHT 100 mg/kg/day) 4- experimental 3 (received BHT 150 mg/kg/day). BHT was administered by oral intake for 15 days. Learning and memory were assessed by a passive avoidance shuttle-box. Data were analyzed by one way ANOVA and Tucky's post-hoc test. The level of significant was set at P<0.05. Our data showed that BHT at the doses of 25, 100 and 150 mg/kg/day significantly decreased the time spent in light compared to the control group. According to our results, BHT impairs learning and memory in passive avoidance learning.