Effect of Benzoα］pryene and Butylated Hydroxylanisole on Learning and Memory in Rats

Objective To investigate the neurotoxic effect of benzo［α］pryene (B［α］P) and protective effect of butylated hydroxyl anisole (BHA) on learning and memory in hippocampus of rats. Methods Ninety male SD rats were randomly divided into blank control group, solvent control group, B［α］P exposed group 〔（2 mg/（kg·d）〕, BHA group 〔50 mg/（kg·d）〕 and B［α］P+BHA combined group. Rats were given the appropriate dose oral treatment according to body mass and group (the same volume of saline and peanut oil were given to blank and solvent control group, respectively) for 90 d. After 90 d exposer, Morris water maze (MWM) was conducted to estimate rats’ learning and memory ability. The level of malonaldehyde (MDA), superoxide dismutase (SOD) activity, Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase activity andCa²⁺concentration were measured after rats were sacrificed and brain tissue were removed. Results Behavioral test results showed that the escape latency of B［α］P exposed group were significantly increased than other groups (P<0.05); however, the number of crossing platform (4.13±0.78) were decreased significant. The level of MDA 〔(2.46±0.39) nmol/mg prot.〕 and Ca²⁺concentration〔(146.3±16.68) nmol/L〕 in the B［α］P exposed group increased significant, while the activity ofNa⁺-K⁺-ATPase and SOD 〔(76.1±11.42) nmol/mg prot.〕 were significantly decreased. Compared with B［α］P group, each index in B［α］P+BHA combined group improved significantly (P<0.05), besides, there were no statistically difference when compared with solvent control group. Conclusion The neurotoxic effect of B［α］P may be related to the decrease of ATPase activity and the increase of Ca²⁺concentration in hippocampus, while BHA can prevent these damages.