A Preliminary Study On The Effect And Mechanism Of The Traditional South African Drug Sutherlandia Frutescens On The Glucose And Lipid Metabolism Of Zebrafish

Diabetes has become the third killer of human health,and its mortality and morbidity is increasing year by year.In this study,type Ⅱ diabetes zebrafish model were established by morden science and technology.It hoped that the study will explore the effect and mechanism of Sutherlandia frutescens(L.)R.Br.(Fabaceae)on zebrafish model.Firstly,we extracted the Sutherlandia frutescens with ultrapure water and 80%ethanol.The HPLC method was successfully developed for quantitative determination of D-pinitiol.Followed by the use of infrared spectroscopy,nuclear magnetic resonance and liquid chromatography-mass spectrometry for structural confirmation.The final confirmation of the extract which contained a large amount of D-pinitol at 92mg/g.Secondly,we made research on toxicity of the two extracts,the positive control drug metformin hydrochloride,and the standard control drug D-pinitol.Zebrafish larvae(embryo)with 24 hours post fertilization were treated with these drugs.The morphological effect,cardiotoxicity,mortality rate and hatching rate were observed and recorded everyday during experiment.We found the toxicity of S.fru-OH was stronger than S.fru-H2O in zebrafish.The acute toxicity dose of S.fru-OH was above 50μg/ml,while S.fru-H2O was above 300μg/ml.Morphological abnormalities including edema of the periphery and/or abdomen,hemorrhage,abnormal body shape,large yolk sac,and motility reduction were been observed in S.fru-OH and S.fru-H2O developmental toxicity assay.The pharmacokinetic study of S.fru-OH and S.fru-H2O provided a theoretical basis for revealing the mechanism of drug action.Thirdly,zebrafish larvae with 96h post fertilization were treated with 100μM cAMP and 1μM DEX.After 48h treatment,we obtained the zebrafish larvae type diabetes mellitus model with overexpression of PEPCK gene and depressed expression of insulin receptor gene.The results showed that S.fru treatment could cause regulation of multiple target genes including PEPCK,GLUT2,GP,G6Pase,GYS1,PFKFB3,INSa,INSRa,INSRb.Through the regulation of glucose and lipid metabolism related genes,influence the insulin-mediated signal transduction pathway,increase liver uptake of glucose,promote liver glycogen synthesis,and cure insulin resistance.In particular,the effect of ethanolic extract on GLUT2,GP,GYS1,INSR and PEPCK genes was better than that of aqueous extract.Metformin is the mostwidely recognized type Ⅱ diabetes drugs on the market,But it can not improve the expression of GLUT2,nor reduce the expression of GP.In conclusion,type Ⅱ diabetes zebrafish model have proved that Sutherlandia frutescens has good hypoglycemic effect,which laid the foundation for the development of new anti diabetic drugs,provide the basis for the screen and the use of of natural drugs.