Résumé
OBJECTIVE:To investigate the effect and mechanism of Allii macrostemonis bulbus on blood lipid levels in hyperlipidemia model rats,and to provide reference for clinical use of Allii macrostemonis bulbus to reduce blood lipid. METHODS:A total of 10 normal rats were included in normal control group and given common diet. Other 50 rats were given hyperlipid diet to induce hyperlipidemia rat model. 40 model rats were randomly divided into model group(hyperlipid diet),Allii macrostemonis bulbus low-dose,medium-dose and high-dose groups(0.83,1.67,2.50 g/kg,fed by hyperlipid diet which containing 10%Allii macrostemonis bulbus 8.3,16.7,25.0 g/kg,fill with hyperlipid feed in patients with insufficient food intake). After fed for 45 d,the contents of TC,TG,LDL-C and HDL-C in serum of rats were detected. Liver,spleen,renal and cardiac indexes of rats were calculated. mRNA expression of low density lipoprotein receptor(LDLR)and liver X-receptor α(LXRα)were detected in liver tissue of rats. RESULTS:Compared with normal control group,the contents of TC and LDL-C in serum and liver index of rats were increased significantly in model group,while the content of HDL-C in serum and mRNA expressions of LDLR and LXR α in liver tissue were decreased significantly,with statistical significance(P<0.01). Compared with model group,the contents of TC and LDL-C in serum were decreased significantly in Allii macrostemonis bulbus groups,while the content of HDL-C was increased significantly. mRNA expressions of LDLR and LXR α in liver tissue were increased significantly in Allii macrostemonis bulbus medium-dose and high-dose groups,while liver and spleen indexes were decreased significantly,with statistical significance(P<0.05 or P<0.01). CONCLUSIONS:Allii macrostemonis bulbus shows good blood-lipid lowering effect,the mechanism of which may be associated with up-regulating mRNA expressions of LDLR and LXRα in liver tissue.
Résumé
Objective:Apoptosis inhibitor 6(Api6),also known as AIM(Apoptosis Inhibitor expressed by Macrophage)or SP?(Soluble Protein alpha),is a newly defined member of the group B scavenger receptor cysteine-rich(SRCR)superfamily.Previous studies have suggested its important roles in immune system regulation,but the involvement of Api6 in lipid metabolism is seldomly studied.Methods:The aim of this study was to define the expression pattern of Api6 in lipid loading and inflammatory macrophages.The human monocyte/macrophage lineage THP-1 cells and murine Raw264.7 macrophages were incubated in the presence of 100 ?g/ml oxidized low-density lipoprotein(oxLDL)alone,LDL plus 200 ng/ml lipopolysaccharide(LPS)and LPS alone.Results:Foam cell formation after treatment was evidenced by oil red O staining.Real-time PCR results showed that after LPS or oxLDL treatment,the mRNA levels of Scavenger receptor SRA were increased 6-fold,2.5-fold and 6-fold,44-fold in Raw264.7 cells and THP-1 cellls respectively,but the expression of Api6 in Raw264.7 did not change.The mRNA levels of Api6 increased 2.7-fold after LPS and oxLDL treatment in THP-1 cells.Conclusion:The expression levels of Api6 in these macrophages were highly related to the presence of nuclear receptor liver X receptor(LXR)isoform LXR?.This study revealed that due to the lack of LXR? isoform,the basic expression level of Api6 was low in Raw264.7 macrophages,that makes it an ideal cell line for further study related to pathophysiological function of Api6 in lipid metabolism.