Studies On Effects And Mechanism Of Chinese Medicine For Inhibiting Lipid Accumulation In Macrophage Foam Cell

BackgroundCardiovascular disease, currently the leading cause of death and illness in developed countries and our country, will become the prominent health problem worldwide. Atherosclerosis(AS), as the pathology basis of cardiovascular disease, constitutes the single most important contributor factor.Macrophages, as participant of innate immunity, uptake oxidized low-density lipoprotein and form of macrophage foam cells which were regarded as the initiation of atherosclerosis. Macrophages, as participants of acquired immunity, also collaborate extensively with lymphocytes through cell-cell and cytokine-mediated interactions to coordinate the evolution of inflammatory response that cause plaque disruption and myocardial infarction. The reason of "Why Atherosclerosis happened?" is elusive, however, the lipid is one of the most important factors that induce and promote inflammation in AS. LDL, which may be modified by oxidation, is a major cause of injury to the endothelium and leads to AS. When LDL particles become trapped in an artery, they can undergo progressive oxidation and be internalized by macrophages. The internalization leads to the formation of foam cells, which can be observed in condition of both high lipid level and no-high lipid level. Macrophages also have essential functions in all phages of atherosclerosis, from development of the fatty streak to processes that ultimately contribute to plaque rupture and myocardial infarction. The lipid-laden macrophage foam cell is considered to be a target for therapeutic intervention. New approaches for inhibiting lipid accumulation and inflammation response in macrophage may be of therapeutic value in preventing coronary artery disease.As intracellular cholesterol level increase, the main mechanism is not sufficient to maintain cholesterol homeostasis in the face of continued cholesterol uptake. Macrophages participate in the reverse cholesterol transport function, which is mediated mainly by HDLs, and export excess sterols to the liver for biliary excretion. ABCA1 has an important function in reverse cholesterol transport by mediating export of cholesterol fromperipheral cells to HDL and acts in concert to reduce free cholesterol levels and protect cells from its cytotoxic effects.There are many clinical experience of Traditional Chinese Medicine in treating CAD. AS is viewed as blood stasis caused by Yang-deficiency in TCM and should be treated by "Yiqihuoxue, benefiting vital energy and activating blood circulation" . Regulating the balance of mechanism of the human body is regarded as the most important way to health condition in TCM. So effects of Chinese Medicine for inhibiting lipid accumulation in macrophage foam cell could be an important potential way for anti-AS.Purposes1. Developing a screening flat to observe effects of the potential effective Chinese medicine for inhibiting lipid accumulation in macrophage foam cells.2. Exploring the potential mechanisms of the screened effective Chinese medicine for inhibiting lipid accumulation in macrophage foam cells.Methods and Results1 Extraction, separation and identification of LDLThrough the method of density gradient centrifuge at 70kr/min for 3 hours(twice), LDL were decanted from human plasma.Through the method of gelose and SDS-PAGE electrophoresis, extracted LDL wereidentified. The results show high purity of LDL.LDL were induced to ox-LDL by cuprum, the degree of oxidation was measuredby the method of TBA, and the result showed that LDL were induced to ox-LDL;the content of protein were measured by the method of BCA, were 2. 725 mg/mg,4.040 mg/mg, 1.583 mg/mg; total cholesterol content was 6.624 mmol/L.2 Maintenance and culture of THP-1 cellsTHP-1 cells were obtained from Shanghai Institute for Biological Science, China science academe. THP-1 cells were cultured in serum 1640 medium supplemented with 10% FBS at 37℃ in 5% CO₂. The cells were induced to differentiate into macrophage foam cells by incubation in medium with PMA and ox-LDL.3 Cholesterol content of THP-1 macrophage-derived foam cells observed and determined by image processing and analysis systemMethod: With the model of foam cells through depositing the oxidized low-density lipoprotein(ox-L DL)into THP-1 macrophage-derived foam cells, the foam cells were stained with red 0 oil and hematoxyllin, and were effected by medicine(Probucol, Angelica archangelica oil, Angelica archangelica, Sichuan lovage, Salvia miltiorrhiza, Total glucosides of Paeony, Astragalus Polysaccharoses, and Astragalus Polysaccharoses combined with total glucosides of Paeony). The rates of areas of cholesterol ester stained with red 0 oil contrasted with areas of THP-1 cell were observed and determined by image processing and analysis system.