| AIMIn order to further develop and utilize medicinal and edible homologous plant resources,the effective polar part of purslane was taken as the research object to investigate its anti-atherosclerosis mechanism from the reverse transport pathway of cholesterol.Meanwhile,the biological activities of purslane in antibacterial,whitening,anti-sensitization and hypoglycemic aspects were determined.MethodsExperiment 1:Preparation of different polarity parts of purslane extract,using oxidized low density lipoprotein(ox-LDL)to induce Raw264.7 mononuclear macrophage foamization,establish atherosclerotic foam cell model.The contents of Total cholesterol(TC)and Free cholesterol(FC)in the cleavage supernatant of cells in each group were detected,and the polar solvent extract with the best lipid-lowering effect of purslane was screened.Minimal inhibitory concentration(MIC)and minimal bactericidal concentration(MBC)of purslane extracts were determined to evaluate their antibacterial activities against five kinds of common tested bacteria.The effects of purslane extract on the activity inhibition rates of hyaluronidase,tyrosinase and α-glucosidase were determined,and the antibacterial,whitening,anti-allergy and hypoglycemic effects of purslane extract were evaluated.Experiment 2:The proliferation activity difference of Raw264.7 derived foam cells induced by ox-LDL in each group was measured by MTT method.The modeling concentration of ox-LDL and the concentration of Portulaca olerslane extract were determined,and the safety of the extract was evaluated.The distribution of lipid in cells was observed by oil red "O" staining,and the effect of purslane extract on adenosine triphosphate binding cassettetransporter A1(ABCA1)was observed by Western-blot.Adenosine triphosphate binding cassette transporter G1(ABCG1)and scavenger receptor B Cluster of differentiation 36(Cluster of differentiation 36)Effects of CD36,Macrophage Scavenger Receptor 1(MSR1)and class B on the expression of reverse cholesterol transport RCT related proteins.Experiment 3:SD rats were fed a high-fat diet and carotid artery balloon injury to form atherosclerotic plaques,and then gavaged an alcohol extract of purslane.He and Masson staining were used to evaluate the morphological changes of the strong arteries of the model rats.Serum lipid factors were detected by the kit,and the difference in the expression of cholesterol retrotransportin was detected by Western-blot.The ventricular structural changes were detected by cardiac ultrasound.ResultsExperiment 1:The alcohol extracts of purslane with different concentrations had inhibitory effects on 5 kinds of common tested bacteria,and the MIC/MBC value of Candida albicans was 50/200 mg-mL-1,which showed the best inhibitory effect.When the concentration of the alcohol extract of Portulaca oleracea was 20 mg·mL-1,the in vitro inhibition rate of hyaluronidase was 89.66%.In the selected range,the inhibitory rate of the alcohol extract was directly proportional to the concentration of the alcohol extract.When the concentration of the alcohol extract was 20 mg·mL-1,the inhibitory rate of the whitening index tyrosinase was as high as 76.71%,which was 1.25 times of the inhibitory effect of the positive drug arbutin at the same concentration.The inhibitory rate of 200 mg·mL-1 purslane extract on α-glucosidase reached 49%,and its inhibitory effect was close to that of acarbose.Experiment 2:In different polar parts of purslane extract,alcohol extract could significantly reduce the content of TC/FC and reduce the lipid deposition in foamy RAW264.7 cells,and the lipid lowering effect was the best.The alcohol extract of purslane promoted the expression of ABCG1 and ABCA1,inhibited the expression of CD36 and MSR1,reduced the lipid accumulation in foam cells,promoted the positive feedback of RCT,accelerated the decomposition and excretion of lipids,and delayed the formation and aggravation of atherosclerosis.Experiment 3:Portulaca oleracea extract could increase the serum HDL level of atherosclerosis model rats,and significantly inhibit the contents of negative indexes of lipid metabolism such as TG,TC,FC and LDL.The protein expression of ABCA1 was significantly decreased(p<0.05),the expression of MSR1 protein was significantly increased;The alcohol extract of purslane can improve the thickening of the media of carotid artery and the blockage of the lumen,increase the collagen fiber in the plaque,and then increase the stability of the plaque,and alleviate the atherosclerosis of the rat.The alcohol extract of purslane can improve the indexes of FS,EF2,LVESV and LVEDV,improve the level of cardiac hypertrophy and delay the disease process in model rats.Conclusion(1)The alcohol extract of purslane can maintain the balance of lipid metabolism and prevent atherosclerosis and other cardiovascular diseases by affecting the positive feedback of reverse cholesterol transport(RCT).(2)The alcohol extract of purslane can regulate lipid metabolism in and out of cells,protect the shape of elastic vessels and ventricular structure,strengthen the stability of atherosclerotic plaque,and improve ventricular remodeling.(3)Purslane can serve as a safe,no stimulation,and biological activities availability strong wild plant resources,widely used in skin disease treatment and health care food,anti-allergic whitening cosmetics,and other fields,the activity is expected to be developed into a sugar,lipid-lowering efficacy of health care products,whitening,anti-allergic effect of skin care products as well as natural bacteriostatic agent. |
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