| Coreopsis tinctoria is a kind of compositae plants growing in the Kunlun Mountains alpine area at the altitude of above 3000 m.It is the only natural and wild alpine plant as famous as Saussurea involucrata in Xinjiang.The study found that C.tinctoria is rich in protein,polysaccharides,saponins,phenolics and other nutrients,and it has many nutraceutical properties,such as the reduction of blood pressure,blood sugar,blood lipid effects,and antioxidant,anti-inflammatory,antibacterial,anticoagulation activities,but the hepatoprotective effects of C.tinctoria has not been reported.Therefore,in this study,we used C.tinctoria flowers and buds as raw material and obtained the phenolics from them by 80% frozen acetone solvents.Then we performed the qualitative and quantitative analysis of the phenolic components by HPLC and evaluated the antioxidant activity of phenolic extracts by DPPH radical scavenging activity,ABTS radical scavenging activity,ferric ion reducing power and oxygen radical absorbance capacity(ORAC).And the hepatoprotective effect of phenolic extracts on acute liver injure induced by D-GalN/LPS was investigated in KM mice.The main results are as follows:(1)The contents of free,bound and total phenolics in C.tinctoria flowers were 125.427,3.896,129.323 mg GAE/g DW,respectively.The contents of free,bound and total phenolics in C.tinctoria buds were 99.197,6.483,105.700 mg GAE/g DW,respectively.Free phenolics is the main form of phenolics in C.tinctoria flowers and buds,and the contribution rate of bound phenolics in flowers was 2 times of that in buds.9 kinds of phenolic compounds were identified by HPLC,including 4 kinds of phenolic acids,4 kinds of flavonoids,and 1 kind of stilbenes.The free phenolics were mainly composed of chlorogenic acid,caffeic acid,vanillin,orientin,rutin,hyperoside,kaempferol and resveratrol,while hyperoside,rutin,orientin had a high content.The bound phenolics were mainly composed of protocatechuic acid,caffeic acid,vanillin,orientin,rutin and hyperoside,while hyperoside,caffeic acid had a high content.(2)The phenolic extracts of C.tinctoria flowers and buds were found to have antioxidant activity.The DPPH radical scavenging activities of the free,bound phenolics in C.tinctoria flowers with IC50 values were 20.308,25.520 ?g/mL,respectively;the DPPH radical scavenging activities of the free,bound phenolics in C.tinctoria buds with IC50 values were 23.207,24.194 ?g/mL,respectively.The ABTS radical scavenging activities of the free,bound phenolics in C.tinctoria flowers with IC50 values were 0.375,0.257 ?g/mL,respectively;the ABTS radical scavenging activities of the free,bound phenolics in C.tinctoria buds with IC50 values were 0.359,0.270 ?g/mL,respectively.The ferric ion reducing powers of the free,bound phenolics in C.tinctoria flowers with IC50 values were 62.689,41.214 ?g/mL,respectively;the ferric ion reducing powers of the free,bound phenolics in C.tinctoria buds with IC50 values were 67.544,48.447 ?g/mL,respectively.The ORAC values of the free,bound phenolics in C.tinctoria flowers were 1534.867,110.994 ?mol TE/g DW,respectively;the ORAC values of the free,bound phenolics in C.tinctoria flowers were 1394.666,268.896 ?mol TE/g DW,respectively.(3)The phenolic extracts of C.tinctoria flowers and buds were found to have effects on serum indexes of KM mice with acute liver injury induced by D-GalN/LPS.Compared with the model group,the level of serum AST,MDA was siginificantly decreased and the level of serum SOD,CAT,GSH was siginificantly increased after treatment with phenolic extracts of C.tinctoria flowers(150,600 mg/kg·d)or buds(150,600 mg/kg·d)(p<0.05);the level of serum ALT was siginificantly decreased after treatment with phenolic extracts of C.tinctoria flowers(150,600 mg/kg·d)or buds(600 mg/kg·d)(p<0.05).(4)The phenolic extracts of C.tinctoria flowers and buds were found to have effects on liver indexes of KM mice with acute liver injury induced by D-GalN/LPS.Compared with the model group,the level of liver ALT,AST,MDA was siginificantly decreased and the level of liver GSH was siginificantly increased after treatment with phenolic extracts of C.tinctoria flowers(150,600 mg/kg·d)or buds(150,600 mg/kg·d)(p<0.05);the level of liver SOD was siginificantly increased after treatment with phenolic extracts of C.tinctoria buds(600 mg/kg·d)(p<0.05);the level of liver CAT was siginificantly increased after treatment with phenolic extracts of C.tinctoria flowers(600 mg/kg·d)or buds(600 mg/kg·d)(p<0.05).(5)The phenolic extracts of C.tinctoria flowers and buds were found to have effects on the level of Nrf2,PPAR?,PPAR? mRNA and the expression of Nrf2,PPAR?,PPAR? protein of KM mice with acute liver injury induced by D-GalN/LPS.Compared with the model group,the level of Nrf2,PPAR? mRNA and the expression of PPAR? protein were siginificantly increased after treatment with phenolic extracts of C.tinctoria flowers(150 mg/kg·d)(p<0.05);the level of PPAR?,PPAR? mRNA and the expression of Nrf2,PPAR?,PPAR? protein were siginificantly increased after treatment with phenolic extracts of C.tinctoria buds(150 mg/kg·d)(p<0.05);the level of Nrf2,PPAR?,PPAR? mRNA and the expression of Nrf2,PPAR?,PPAR? protein were siginificantly increased after treatment with phenolic extracts of C.tinctoria flowers(600 mg/kg·d)or buds(600 mg/kg·d)(p<0.05).In conclusion,C.tinctoria flowers and buds were rich in phenolics,and had strong antioxidant activity.The phenolic extracts of C.tinctoria flowers and buds were found to have hepatoprotective effects on KM mice with acute liver injury induced by DGalN/LPS,and it might take effects through the activation of the Nrf2/ARE signaling pathway to inhibit oxidative stress response and the activation of the PPAR?,PPAR? signaling pathway to inhibit the inflammatory response. |
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