| Hawthorn,which is widely distributed in China,has been widely used as foodstuffs or medicinal materials.Besides,hawthorn present anti-inflammatory,hypotensive,hypolipidemic,hepatoprotective and anticancer potential due to the nutrients of polysaccharides,vitamins,and especially polyphenols.The present study investigated the differential effects of polyphenols-enriched extracts from hawthorn fruit peels(HPP)and fleshes(HFP)against liver injury and dyslipidemia induced by high-fructose diet in mice.Healthy male Kunming mice(weight 18-22 g)were selected in this experiment.After one week for adaptation of laboratory environment,they were divided into four groups averagely with 8 mice each:in the normal group,mice were allowed tap water and administered intragastrically(ig,0.4 mL)with physiological saline once daily;in the model group,mice were allowed 30%high-fructose water and administered intragastrically(ig,0.4 mL)with physiological saline once daily;in polyphenols-treated groups,mice were allowed 30%high-fructose water and administered(ig,0.4 mL)with 400 mg·(kg·bw)-1 HPP and HFP once daily,respectively.After 8 weeks,the serum and liver were collected for detection by kits,western blot and histopathological observation to compare the effects of HPP and HFP.The main results were as follows:(1)HPP and HFP were extracted from hawthorn fruit with 80%aqueous ethanol,and the extraction yield was 18.58%and 9.96%(w/w),respectively.Total polyphenol contents of HPP and HFP were 311.53 mg GAE g'1 and 128.34 mg GAE·g-1,the total flavonoids contents of HPP and HFP were 212.31 mg RE g-1 and 61.11 mg RE g-1,respectively.Furthermore,the main polyphenols of HPP and HFP were identified and quantified by a validated HPLC-UV technique.HPP consisted of chlorogenic acid,epicatechin,rutin and hyperoside at the concentration of 24.47,166.42,62.45,and 7.54?g mg-1,respectively,while only 1.69 ?g·mg-1 chlorogenic acid,20.80 ?g·mg-1 epicatechin and 22.53 ?g·mg-1 rutin in HFP were identified.(2)The results of antioxidant experiments in vitro showed that every polyphenol,which was detected in HFP and HPP,had antioxidant activities and the scavenging activities of DPPH· and ABTS+·.Besides,the antioxidant capacities in the mixture of polyphenol standards were slightly lower than the extracts of hawthorn polyphenol.In addition,the antioxidant capaticies of HPP and HFP both presented dose-effect relationship,and HPP was proved to be the powerful antioxidant abilities to HFP.(3)The in vivo experiments showed that 30%high-fructose water induced liver injury in mice.Administration of HPP was better than HFP to alleviate liver injury and hepatocyte apoptosis,reflected by the reduction of enzymatic(ALT,AST and ALP)activities as well as the ratio of Bax/Bcl-2 in mice.Meanwhile,HPP was also more effective than HFP to mitigate liver inflammation and oxidative stress by inhibiting inflammatory cytokine(TNF-a,IL-1 and IL-6)release,and elevating antioxidant enzyme activities and PPARa expression,while reducing Nrf-2 and ARE expression in mice.These results together with the histopathological examination indicated that high fructose diet induced severe pathological damage which was mitigated better by the administration of HPP than HFP.(4)The polyphenols of hawthorn regulating dyslipidemia were mainly involved in the promotion of lipid transport and the reduction of fatty acid synthesis.HPP-treated mice showed the lower levels of TC,TG,LDL-C,VLDL-C,apo-B,and the higher levels of HDL-C and apo-Al than HFP-treated mice via reducing FAS express.Therefore,HPP had better effects for mitigating dyslipidemia than HFP.These results suggest that hawthorn fruit,especially its peel,is an excellent source of natural polyphenolic chemopreventive agents in the treatment of liver disorders and dyslipidemia.And this research provide the experimental basis for the research and development using hawthorn as the raw material to the health products mitigating liver injury and regulating dyslipidemia in the future. |
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