| Hyperlipidemia is one of the major diseases that endanger human health,recent studies have demonstrated that commercially available lipid-lowering drugs cause various side effects;therefore,searching for anti-hyperlipidaemic compounds with lower toxicity is a research hotspot.This study was designed to investigate whether the marine-derived compound,5-hydroxy-3-methoxy-5-methyl-4-butylfuran-2(5H)-one,setosphapyrone C and D have anti-hyperlipidaemic activity,and the potential underlying mechanism in vitro.In this study,we use RAW264.7 cells to simulate peripheral cells in the process of lipid metabolism vitro,and we use BRL cells to simulate liver cells.RAW264.7 cells were induced with 50 ug/mL oxidized low-density lipoprotein(ox-LDL)for 24h to make them foamable.MTT assay was used to determine the cytotoxicity of the compounds.In this study,liver X receptor(LXR)agonist and Fenofibrate were were used as positive drugs,Oil-red O staining,(total cholesterol)TC and(triglyceride)TG detection kits,and[3H]labeled cholesterol effluent efficiency were used to detect intracellular cholesterol effluent.The cholesterol efflux promoting mechanism of lipid-lowering was studied by western blotting(WB)and Real time-PCR(RT-PCR).Furthermore,the furanone,setosphapyrone C and D had weak cytotoxicity compared to the liver X receptor α(LXRα)agonist T0901317.the furanone significantly lowered ox-LDL-induced lipid accumulation(-50%)(P<0.01),and its triglyceride(TG)-lowering effect was greater than that of liver X receptor(LXR)agonist T0901317.Setosphapyrone C and D significantly enhanced[3H]-cholesterol efflux by～21.3%and 32.4%(P<0.05).In RAW 264.7 macrophages,we measured the mRNA levels of genes involved in fatty acid biosynthesis,elongation and desaturation via RT-PCR.LXRα agonist T0901317 significantly enhanced the mRNA expression of sterol regulatory element-binding protein-1c(SREBP-lc),functionality Appreciation Scale(FAS),acetyl coenzyme A carboxylase 1(ACC1),and type ⅠDiacylglycerol O-acyltransferase(DGAT1)compared to the vehicle(P<0.01 or P<0.05).Although the furanone significantly increased the mRNA levels of ACC1 and DGAT1 by～40%(P<0.05),but not as much as T0901317,especially for that of ACC1(P<0.05).Setosphapyrone D significantly promoted the mRNA expression of Dgat1(～56%,P<0.05),it showed no effect on the mRNA expression of SREBP-1c,FAS,and ACC 1.In addition,setosphapyrone C showed no influence on the levels of lipogenic genes in this study.In RAW 264.7 cells,the furanone increased the expression of ATP binding cassette A1(ABCA1)about threefold and 60%as compared to the vehicle and model,respectively,as determined by Western blot and immunocytochemistry.Furthermore,the furanone increased the protein levels of ATP binding cassette G1(ABCG1)and scavenger receptor,class B type 1(SR-B1)by～1.8-fold and 1.5-fold,respectively,compared with vehicle group(P<0.01).However,the effect of T0901317 and furanone on the expression of ABCG1 did not show any significant difference compared to the model group.Setosphapyrone C and D had minor effect on the mRNA expression of lipogenic genes and they enhanced the protein levels of ABCA1 and LXRa by 58%and 69%,and 60%and 70%(8μM).In BRL cells,setosphapyrone C and D significantly improved the protein levels of ABCA1 and ABCG1,setosphapyrone D significantly enhanced the protein expression of low-density lipoprotein.In summary,the furanone exhibited a weak cytotoxicity but had powerful TC-and TG-lowering effects most likely through targeting LXRa and Peroxisome proliferator-activated receptor alpha(PPARα).Setosphapyrone C and D with weak cytotoxicity exhibited effective lipid-lowering effect via enhancing LXRα/ABC pathways.These findings indicate that the furanone,setosphapyrone C and D has a potential application for the treatment of dyslipidaemia. |
PDF Full Text Request