Explore Of The Anti-atherosclerosis Mechanism Of Kaempferol And Study Of It’s Pharmacokinetics

ObjectiveTo evaluate the effect of kaempferol on Atherosclerosis in highcholesterol fed rabbits and it’s mechanism; To observe it’s impact oninflammatory molecules such as E-selectin (E-sel), intercellular adhesionmolecule-1(ICAM-1) and vascular cell adhesionmolecule-1(VCAM-1) inrabbit aortas. To investigate the pharmacokinetics of kaempferol in rabbits.Methods1. Thirty male New Zealand white rabbits were randomly divided intofive groups, control group, model group, fenofibrate(12mg/kg) group andkaempferol groups(150mg/kg and30mg/kg). The rabbits were fed with anormal diet or a high cholesterol diet for10weeks. Weights,levels of bloodlipids, malonaldehyde (MDA) and superoxide dismutase(SOD)activity inserum were detected at the end of the sixth and tenth week. Aortic plaquesarea was determined by oil red O staining and aorta morphology changewas observed by HE staining after ten weeks.2. At the end of10thweek, Serum tumour-necrosis factor-alpha (TNF-α)and serum interleukin-1beta (IL-1β) were measured by ELISA. Westernblot and Immunohistochemical staining was employed to measure proteinexpression of E-sel, ICAM-1and VCAM-1. Gene expression of E-sel,ICAM-1and VCAM-1in aortas was determined by RT-PCR. 3. A HPLC method for determining plasma level of kaempferol wasestablished firstly,then6rabbits were injected of kaempferol solution(2.0mg·kg-1) and1mL blood samples from each one were collected at1,3,5,10,15,20,40,80,160,240min after injection. The plasma drug levelswere determined by HPLC, pharmacokinetic parameters was calculatedwith3p97software.Results1. Model rabbits fed with ten weeks of high-cholesterol diet developedsignificant progression of atherosclerosis. Compared with the control,lesion areas of aorta increased markedly in model group, while kaempferolrabbits had smaller aortic lesion area than model rabbits. At the week endof6and10, weights among all groups showed no difference, levels ofblood lipids of model group rabbits rised greatly compared with normalones, but those in kaempferol groups had lower blood lipids. Also, MDAand in serum of model rabbits rised up with SOD levels decreased greatly,while kaempferol group took the opposite with MDA decreased and SODrised up.2. TNF-α level, IL-1β level, Gene and protein expressions of E-sel,ICAM-1and VCAM-1in atherosclerotic aortas increased remarkably inmodel group. However, comparing to the model rabbits, levels of TNF-αand IL-1β decreased significantly. Also, gene and protein expressions ofE-sel, ICAM-1and VCAM-1in aortas decreased significantly with thetreatment of kaempferol for10weeks.3. The concentration curves based on drug-time post injection ofkaempferol in rabbits was presented by two-compartment model. The mainpharmacokinetic parameters were calculated as follows: T1/2α=(0.957±0.172)min;T1/2β=(6.409±1.584) min;AUC0â†'t=(75.969±5.804)(μg·min)/mL;CL=(0.034±0.003)mg/kg/min(μg/mL). Conclusion1. Kaempferol shows anti-atherosclerotic effect on high-cholesterolinduced rabbits and can ameliorate atherosclerosis greatly. The mechanismmay be correlated with lipids lowering, anti-oxidant and vascularinflammation alleivating.2. The effect of kaempferol on inflammation of vascular may bemediated by the regulation of gene and protein expression of inflammatorymolecules such as E-sel, ICAM-1and VCAM-1in atherosclerotic aortas.3. Metabolism of kaempferol in vivo is quick, the concentration of drugdecreases immediately after administration. More than95%of orignalkaempferol is eliminated within30mins.