Preparation Of Triterpene Acids And Flavonoids From Eriobotrya Japonica Leaves And The Effects On Improving Metabolic Syndrome

Metabolic syndrome(MetS)has become a global challenge of public health and clinic,and its pathogenesis and treatment researches have become hot spots in this field.The development of new MetS therapeutics has become increasingly important,while some compounds from natural sources have showed good application prospects in this field.In this paper,a novel and efficient combination of separative technology was used to isolate and purify the triterpene acids and flavonoids from genuine Eriobotrya japonica leaves.The effects and mechanisms of these two kinds of active components on improving MetS were studied systematically in the present study by chemical oxidation model in vitro,cell model,mouse model and molecular docking simulation.The main achievements of this paper are listed as follows:(1)Effective separation between triterpene acid components and flavone components from the Eriobotrya japonica leaves can be realized by a new combination technology of ethanol extraction-adjusting ethanol concentration precipitation-alkaline activated carbon decolornzation-macroporous resin column chromatography-pH selective crystallization.The relative high purity of UA-isomers component(ursolic acid,89.42%;oleanolic acid,8.53%)and CA-isomers component(corosolic acid,74.74%;maslinic acid,18.31%)were obtained.Total triterpene acid component-ELTA(total triterpene acid content 94.32%)and total flavono id component-EJLF(total flavono id content 675.3 mg equivalent rutin/g)were prepared.Four triterpene acid monomers:UA,oleanolic acid(OA),CA and maslinic acid(MA)were also obtained.The pilot scale preparation of triterpene acid components from Eriobotrya japonica leaves were completed with a stable product quality.(2)Acute toxicity and subacute toxical experimental results showed that ELTA has good biosafety.ELTA(up to 3.00 g/kg bodyweight)produced neither mortality nor toxicity of the organs in ICR male or female mice,and produced no significant adverse reactions in hematology,clinical biochemistry,and histopathology.(3)The pharmacodynamic experiment results of chemical oxidation model in vitro,cell model and animal model showed that the triterpene acid and flavono id components could significantly improve the typical pathological conditions of MetS such as oxidative stress,insulin resistance,inflammation and dyslipidemia,thereby improving the MetS comprehensive ly.Based on the studies of molecular pharmacology and molecular docking,the potential mechanisms of Eriobotrya japonica leaves active components on lmproving MetS are as follows:ELTA and EJLF can enhance the anti-oxidative stress effect of Nrf2 pathway through activating PPAR-? or AMPK,and then decrease the level of ROS and thus improve the oxidative stress state;ELTA and EJLF can improve inflammatory state by inhibiting JNK,TACE,TNF-?,or by activating AMPK,PPAR-?;ELTA and EJLF can improve dyslipidemia through inhibiting 11?HSD-1 or activating AMPK,PPAR-?,FXR;ELTA and EJLF can improve insulin signaling and tissue glucose uptake by activating AMPK,PPAR-?,GK or inhibiting ?-glucosidase,TNF-?,PTP1B,and then imrove glucose tolerance,thereby improving IR status.In conclusion,the Eriobotrya japonica leaves active conponents may affect multiple signal pathways by interacting with multiple targets,thereby improving MetS comprehens-ively,and suggesting its good clinical application value in improving MetS.(4)ELTA and EJLF could efectively inhibit the damages of HSF cells induced byUVB.The results of molecular pharmacology and molecular docking showed that the Eriobotrya joponica leaves active components might act on Nrf2,MAPKs pathways by targeting multiple regulatory factors,and then exert its activity of inhibiting ultraviolet damage.It also confirmed the effects and mechanisms of ELTA and EJLF on inhibiting oxidative stress and inmlamlatioin.This paper provided anew,efficient combination of separation technology,by means of which the separation oftriterpene acid components with flavonoid comonents and the separation of UA-isomers component with CA-isomers component in Eriobotrya japonica leaves can be effectively exerted,and high purity of CA-isomers and UA-isomers components can be pilot-prepared.This combined technology has a good prospect for industrial applications.For the first time,the present study reported the pharmacodynamic evaluation,mechanism and molecular docking results of triterpenoid acid and flavone components from Eriobotrya japonica leaves to improve of MetS.It provides animportant basis for further studies on the structure-activity relationship and the development of new drugs im this field.