Buckwheat Quercetin Regulates Lipid Metabolism In Sprague Dawley Rats Through Chemerin And Its Mechanism

The high-calorie and high-fat modern Western dietary patterns in relieving people’s stress but also put a huge burden on the body,the prevalence of hyperlipidemia caused by a high-fat diet is increasing every year.To address this phenomenon,from the perspective of low-fat dietary patterns,the present study of the association between active substances in buckwheat and hyperlipidemia will provide new dietary guidelines for people with dyslipidemia.In this study,we investigated the effects and effective action dosages of buckwheat quercetin(QUE)on improvement of hyperlipidemia by establishing a rat model of hyperlipidemia,observed changes in the intestinal flora and bile acid composition,and investigated the mechanism of action through the chemokine(Chemerin),chemokine-like receptor 1(CMKLR1),Toll-like receptor 4(TLR4),and nuclear transcription factor-κB(NF-κB)pathways.Fifty-four 6-week-old male Sprague Dawley(SD)rats were selected and 45 rats were equally divided into 5 groups given high-fat chow,namely high-fat model group(MC),positive control group(PC),buckwheat quercetin low dose(QUE-L),medium dose(QUE-M)and high dose(QUE-H)groups.The blank control(NC)group of 9 was given normal chow and modeled for 5 weeks.After the success of the high-fat model,six groups of rats were administered by gavage for 5 weeks,the NC group and MC group rats were gavaged with equal amounts of sodium carboxymethylcellulose.PC group rats were gavaged with simvastatin 10 mg/kg,buckwheat QUE low,medium and high groups were gavaged with doses of 50 mg/kg,100mg/kg and 200 mg/kg,respectively.After the rats were dissected,the vital organs were weighed,the tissue of the left lobe of the liver was taken and sections were prepared for HE staining.Determination of lipid parameters including total cholesterol(TC),triglycerides(TG),high-density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol(LDL-C),alanine aminotransferase(ALT)and glutathione aminotransferase(AST)in rats;determination of Total superoxide dismutase(SOD),malondialdehyde(MDA),glutathione peroxidase(GSH-PX)and cholinesterase(CHE)levels in rats;Using microbial diversity sequencing and targeted metabolomics to detect intestinal flora and bile acid composition.The levels of Chemerin,CMKLR1,TLR4 and NF-κB in rats were measured by ELISA,real-time fluorescence quantitative PCR and protein blotting.The results of this experiment showed that buckwheat QUE was able to regulate dyslipidemia in hyperlipidemic rats,repair liver damage and reverse the imbalance in intestinal microecology,probably through the Chemein/NF-κB pathway,with the following experimental results:(1)QUE had significant effects on lipid levels and basal indices in rats with lipid metabolism disorders.After modeling,the lipid levels and ALT and AST levels in all groups were significantly higher than those in the blank group(P<0.05),indicating that the modeling of high-fat rats was successful.Body weight,Lee’s index,and liver index were significantly higher in the model group(P<0.05).Compared with the NC,QUE intervention significantly inhibited the increase in body weight,significantly reduced Lee’s index and liver index,showed a decreasing trend in serum and liver levels of TC,TG,LDL-C,ALT,and AST,and significantly increased HDL-C levels(P<0.05),improved the level of lipid changes and was positively correlated with QUE dose.(2)QUE was able to exert antioxidant stress injury and anti-liver injury effects.Compared with the model group,each QUE group up-regulated the serum levels of SOD and GSH-PX and reduced the levels of MDA and CHE,while increasing the SOD content in the liver,resulting in a significant decrease in MDA content(P<0.05),neat arrangement of hepatocytes,less inflammation in the liver lobules and smaller fat droplets in the liver.Among them,the QUE-H group had the best ability to repair liver damage.(3)QUE had a significant effect on the intestinal flora and bile acid composition of dyslipidemic rats.Compared with the model group,the alpha index of each QUE group was significantly adjusted back and the Beta diversity was increased.At the family level,the abundance of beneficial bacteria such as Christensenellaceae and the abundance of harmful bacteria such as [Eubacterium]＿coprostanoligenes＿group were elevated in the QUE groups,and secondary bile acids such as taurocholic,lithocholic and ursodeoxycholic acids were also significantly elevated,contributed to the normal functioning of the hepatic and intestinal circulation.(4)In the hypolipidemic study mechanism of QUE in hyperlipidemic rats,it was found that after the administration of QUE,there was a decreasing trend of Chemerin,CMKLR1,TLR4,and NF-κB m RNA expression in the liver of rats in each dose group(P<0.05),and at the same time,the expression of Chemerin,CMKLR1,TLR4,and NF-κB proteins were also decreased to different degrees,which in turn suggested that QUE might achieve the hypolipidemic effect by regulating the levels of the above factors.The results showed that QUE had good modulating effects on lipid metabolism-related by-products in serum and liver of high-fat model rats,improved intestinal micro-ecological imbalance,regulated bile acid content,down-regulated the expression levels of Chemerin receptors CMKLR1 and TLR4 in the liver,which in turn inhibited the activation of NF-κB pathway and contributed to the normal functioning of lipid metabolism.Dietary buckwheat QUE,through the Chemerin factor significantly regulates the condition of hyperlipidemia and helps to alleviate the occurrence of hyperlipidemic diseases.