Study On Screening Of Anti-T2DM Active Ingredients From Traditional Chinese Medicine Based On Oxidative Stress

Oxidative stress constitutes the primary mechanism leading to insulin resitance（IR）,which is the major reason for type 2 diabetes mellitus（T2DM）.The damage caused by oxidative stress to the cell and body can be alleviated by antioxidation.China is a country with the largest number of diabetic patients,and chinese medicinal materials are abundant,but their development and utilization are not thorough enough.Therefor,it’s great significance to sceen more natural compounds that can cure T2DM from chinese medicinal materials.Firstly,compound fom 8 natural plants were extracted by orthogonal expirement,respectively,and their contents were determined by high performance liquid chromatography（HPLC）,the methodology was investigated.In conclusion,the optimal extraction metod of picroside I was 20 times of 95%ethanol reflux extraction for 1.5 h,and the extraction yield（EY）was 0.511%.The isoliquiritin was ultrasonically extracted by 11 times the amount of 80%methanol for 1.5 h,the EY was 0.072%.Dihydrotanshinone I was extracted at 60°C with 25times of methanol:dichloromethane（8:2）with ultrasonic,the extraction content is 15.255μg/g.10 times the amount of 80%ethanol,reflux extraction at 50°C for 2 h to get 2.135%magnolol.Curcumol was extracted by ultrasonic with 25 times of distilled water at 50°C,and the EY is 0.232%.The EY of obacunone was 0.127%after ultrasonic extraction with 25 times of 70%methanol for 45 min.15 times the amount of methanol was used to reflux extracted plantagoside for 2 h,the EY was 0.055%.The EY of polydatin was 1.665%with ultrasonic extraction of 20 times 70%methanol at 50°C.The extraction method meets the experimental quantitative requirements.Then,the antioxidant activities（DPPH·method,ABTS·⁺method,reducibility determination,OH·elimination method）of the 8 compounds were determined in vitro,and the inhibitory activities ofα-amylase andα-glucoside were studied simultaneously.The results showed that the scavenging rate of picroside I,magnolol,dihydrotanshinone I,plantagoside and polydactin in experiments were stronger than that of the positive control Vc,inhibitory ability was stronger than that of acarbose,while isoliquiritin strong effects were shown in the reducing ability assay and two inhibition experiments,all of these indicating that the 6 compounds have strong antioxidant activity and enzyme inhibition ability.Finally,on the IR cell model（IR-HepG2）,8 compounds along with anthocyanins and myricetin were further screened in vitro.MTT method was used to investigate the effect of each compound on the activity of IR-Hep G2 cells at different concentrations,and the glucose consumption in the DMEM,the content of free radical metabolites malonic dialdehyde（MDA）and the activity of superoxide dismutase（SOD）in IR-Hep G2 cells were evaluated to determine the effect of 10 natural compounds on IR.Results show that 80μg.m L^-1 of each compound had little effect on IR-Hep G2 cell activity,so 80μg.m L^-1 was selected as the investigational concentration of each compound in IR-Hep G2.Picroside I,isoliquiritin,dihydrotanshinone I,magnolol,plantagoside,polydactin,anthocyanin and myricetin has obvious improvement effect on all indexes,among which,picroside I and plantagoside have the most significant effects,which are equivalent to the positive control rosiglitazone.Therefore,eight natural compounds can modulate oxidative stress,thereby improving IR and ultimately T2DM.