Studies On Protective Effect Of Lycopene On Models Of Hyperlipidemia Rats

Objects: This study investigated into the effect of lycopene on expression of APP, bax and bcl-2 in hippocampal CA1 region of rats with hyperlipidemia and studied on protective effect of lycopene on models of hyperlipidemia rats.Methods: By total cholesterol (TC) and body weight, 64 adult male SD rats were randomized into eight 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 4.4, 11, 22, 44 and 110mg·kg·bw^-1·d^-1 respectively 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 measured RBC parameters: including HGB,RBC,HCT,MCV,RDW-CV.; at the end of the experiment, rat brains were taken and sections of the hippocampal CA1 region were prepared. Expression of APP, bax and bcl-2 in the CA1 region was determined by immunohistochemical methods and morphological examination was carried out.Results:1. The model group rats, serum TC, TG, LDL-C by 1.31 mmol/L, 0.42mmol/L, 0.39mmol/L rose to 6.44mmol/L, 0.88mmol/L, 1.66mmol/L (p <0.05); 3 weeks high fat diet feeding, serum TC, TG, LDL-C were increased to 19.40mmol/L, 2.29mmol/L, 2.95mmol/L (p <0.05). By HE staining, in observations under high power lenses, the rats in Model group of the number of hippocampal pyramid cells decreased; the neurons were disorderedly arranged and were mostly stained deeply and triangular with degeneration and karyopyknosis.2. After lycopene and fluvastatin sodium administered the rats of serum TC, TG and LDL-C level than those in model group decreased, with 44mg kg bw^-1.d^-1.serum lycopene TC, TG, LDL-C levels were reduced to 4.49mmol/L, 0.62mmol/L, 0.73mmol/L (p <0.05). Experimental period of high fat diet serum HDL-C and the normal group decreased (p<0.05). Lycopene 11,22,44 mg.kg.bw^-1.d^-1 group and the effect of fluvastatin sodium had large amounts of hippocampal pyramid cells arranged tightly and regularly , clear profiles and distinct demarcation between surrounding tissue; the nuclei were blue and the cytoplasm was light red; in shape, size and arrangement, neurons of all groups were approximately normal.3. Experimental results show that the late detection of red blood cells. The hemoglobin (HGB), red blood cell count (RBC), hematocrit (HCT) were decreased in group B rats. MCV, RDW coefficient of variation (RDW-CV) increase (p<0.05) in group B rats. Different doses of lycopene on hypercholesterolemia rats above the level of red blood cell parameters show different regulatory role, with 44 mg·kg·bw^-1·d^-1 dose being the best and there is no significant difference (p> 0.05) between the normal control groups.4. At the end of experiment, hippocampal APP and bax expression 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).Conclusions: 1. Animal models were established with reference to the method adopted by Deepa et al. the rats in group models of the number of hippocampal pyramid cells decreased by feeding high-fat three weeks; the neurons were disorderedly arranged and were mostly stained deeply and triangular with degeneration and karyopyknosis. Lycopene have significant regulatory role to the hyperlipidemia rats of serum lipids .Lycopene 11, 22, 44 mg.kg.bw^-1.d^-1 group and fluvastatin sodium hippocampal CA1 area in rats no changes in morphology.2. The rats in lycopene Degeneration were minor in 4.4,110mg.kg.bw^-1.d^-1 groups .The rats in lycopene 11,22,44 mg.kg.bw^-1.d^-1 groups and fluvastatin sodium, large amounts of hippocampal pyramid cells arranged tightly and regularly , clear profiles and distinct demarcation between surrounding tissue; the nuclei were blue and the cytoplasm was light red; in shape, size and arrangement, neurons of all groups were approximately normal. Lycopene can maintain morphological normality of hippocampal neurons of hyperlipidemia rats.3. 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 region of rats with hyperlipidemia, thereby maintaining normal morphology of hippocampal neurons and facilitating the protection of the brain.