ABSTRACT
Objective: This study investigated into the ef-fect of lycopene on expression of APP, bax and bcl-2 in hippocampal CA1 region of rats with hyperlipidemia. Methods: By total cholesterol (TC) and body weight, 48 adult male SD rats were randomized into six groups, a normal control group, fed with basic feed; a high-fat model group, fed with high-fat feed; a positive drug control group, fed with high-fat feed and administrated with fluvastatin sodium at a dose of 10 mg?kg?bw-1?d-1 by gastric perfusion; and lycopene groups at three dose levels, fed with high-fat feed and administrated with lycopene at doses of 11, 22 and 44 mg?kg?bw-1?d-1 respec-tively also by gastric perfusion. Caudal venous blood samples of rats in all groups were taken at week 0, week 1 and week 3 after the experiment started so as to assay TC, TG, LDL-C and HDL-C; at the end of the experiment, rat brains were taken and sections of the hippocampal CA1 re-gion were prepared. Expression of APP, bax and bcl-2 in the CA1 region was determined by im-munohistochemical methods and morphologi-cal examination was carried out. Results: One week after fed with high-fat feed, models of hy-perlipidemia rats were established; at the end of experiment, hippocampal APP and bax expres-sion was enhanced while bcl-2 expression was significantly weakened (p<0.05); to rats with hyperlipidemia, both lycopene and fluvastatin sodium could reduce TC, TG and LDL-C, inhibit expression of hippocampal APP and bax and promote expression of bcl-2 (p<0.05). Conclu- sion: Lycopene down-regulates the expression of bax and up-regulates that of bcl-2 mainly by reducing serum TC and LDL-C and weakening expression of APP in the hippocampal CA1 re-gion of rats with hyperlipidemia, thereby main-taining normal morphology of hippocampal neurons and facilitating the protection of the brain.