Abstract
The present study reports the structural characteristics of 3 polysaccharide fractions(SPS-F1,SPS-F2 and SPS-F3)isolated and purified from squash.SPS-F1(molecular weight(Mw)=12.30 kDa)and SPS-F2(Mw=19.40 kDa)were likely to contain HG and RG-I domain of pectic polysaccharide,respectively.SPS-F2(Mw=270.4 kDa)was mainly composed of rhamnose,galactose and arabinose.The treatment with SPS decreased body weight gain,glucose and TG levels in type 2 diabetes rats.Besides,25 differential metabolites were identified based on urinary metabolomics analysis,which are crucial to the anti-diabetic effect of SPS.The regulation of nicotinamide N-oxide,histamine,cis-aconitate,citrate,L-malic acid,3-(3-hydroxyphenyl)propanoic acid and N-acetyl-L-aspartic acid were mainly associated with energy metabolism,gut microbiota and inflammation.Study of surface plasmon resonance revealed the binding kinetics with galectin-3(Gal-3)and fibroblast growth factor 2(FGF2).The KD values of SPS-F2 and SPS-F3 to Gal-3 were 4.97×10-3 and 1.48×10-3 mol/L,indicating a weak binding affinity.All 3 fractions showed moderate binding to FGF2 and the affinity was SPS-F3>SPS-F2>SPS-F1.Thus,the metabolomics and SPR approach were proved to be a promising tool in exploring the anti-diabetes effects of SPS and provided a deep understanding of the mechanisms.
基金项目
National Natural Science Foundation of China(32122069)
National Natural Science Foundation of China(31972191)
Beijing Outstanding Young Scientist Program(BJJWZYJH01201910011025)
National Institutes of Health Grants(DK111958)
National Institutes of Health Grants(AG062344)