Study On The Active Components With Antihyperlipidemic Effect From Vaccinium Dunalianum

Objective: Vaccinium dunalianum Wight is a plant of the genus Vaccinium in the Ericaceae family.The buds of V.dunalianum are used as tea substitute in the Yi settlement of the Yunnan Province,China.It had the role of regulating metabolic diseases.Although studies have reported its effect on regulating blood lipids,there are only a few studies on its effective substances and mechanisms,especially its effectiveness in diet-induced hyperlipidemia.Therefore,the purpose of this study was to elucidate the therapeutic effect,pharmacodynamic material basis and mechanism of V.dunalianum buds on diet-induced hyperlipidemia.Methods: A high-fat diet-induced hyperlipidemic Sprague-Dawley(SD)rat model was established.Rats were gavaged with different doses of aqueous extract of V.dunalianum(VDW)for 8 weeks and their blood and organ samples were collected at the end of the trial.The antihyperlipidemic effect of VDW on SD rats was evaluated based on the biochemical indices and histopathological outcomes.To further clarify the pharmacoactive components,liquid chromatography–mass spectrometry(LC-MS)was used to determine the main components in VDW.The compounds were separated and purified using sequential chromatographic methods and determined using high-resolution mass spectroscopy and nuclear magnetic resonance spectroscopy.6′-O-caffeoyl-arbutin,as the main component of VDW,was also evaluated its antihyperlipidemic activity using an approach similar to that used for VDW.The potential targets of V.dunalianum Wight in lowering blood lipids were screened out using network pharmacology,and the selected targets were docked with arbutin derivatives.The expression of related target proteins was determined using western blotting to illustrate the antihyperlipidemic mechanisms of VDW and6′-O-caffeoyl-arbutin.Results: VDW reduced triglyceride,total cholesterol,low-density lipoprotein,alanine transaminase,and aspartate transaminase levels in the serum of modeled rats,and increased high-density lipoprotein levels.There was an improvement in steatoses,and lipid droplet accumulation decreased after VDW intervention.LC-MS revealed that VDW mainly contained arbutin and chlorogenic acid derivatives.Sixteen compounds were isolated and identified.Compounds 1–7 were arbutin derivatives,compounds 8–11 were chlorogenic acid derivatives,compound 12 was a flavonoid,compounds 13-14 were phenylpropionic acids,and compounds 15–16 were benzene derivatives.6′-O-caffeoyl-arbutin was the main compound of VDW.The content in the original medicine is about 8.5 %.It showed obvious antihyperlipidemic effect with low hepatic damage at different doses.PTGS2,ADH1 C,and MAOB were screened out using network pharmacology and they showed strong correlations with arbutin derivatives through molecular docking in lowering blood lipid.Results from WB showed that VDW and 6′-O-caffeoyl-arbutin could regulate blood lipid levels by reducing the protein expression of PTGS2,ADH1 C,and MAOB.Conclusions: V.dunalianum buds mainly contained arbutin derivatives in which6′-O-caffeoyl-arbutin was the main component.VDW and 6′-O-caffeoyl-arbutin could regulate blood lipid levels in the high-fat diet-induced rat model of hyperlipidemia without damaging their vital organs,and play a role by reducing the protein expression of PTGS2,ADH1 C,and MAOB.The findings of this study lay a foundation for the further development of V.dunalianum and 6′-O-caffeoyl-arbutin as health supplements or drugs for the management of hyperlipidemia.