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 K_D 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.

Globally, hyperuricemia is a growing health, social, and economic problem which could cause gout, chronic kidney diseases and other diseases. There are increasing evidences that a sensible diet makes sense to reduce the risk of hyperuricemia. This review aims to explore the metabolic mechanism of dietary factors and effects of dietary types associated with hyperuricemia. Recommendations for dietary modification to prevent hyperuricemia are as following: decreasing intake of animal organs, seafood, sugar-sweetened, and alcohol beverages is essential; choosing water or unsweetened tea and coffee instead of sweetened beverages is beneficial; and increasing intake of vegetables, reduced-fat dairy products, foods containing fiber, micronutrients and unsaturated fatty acids is helpful. In addition, consumption of fruits and legumes in moderation is advantageous, and low-fructose of fruits and low-purine of non-soy beans are recommended. Moreover, personalized diet needs to be emphasized for hyperuricemic patients accompanied with diverse metabolic diseases.