In vitro fermentation of Gracilaria lemaneiformis sulfated polysaccharides and its agaro-oligosaccharides by human fecal inocula and its impact on microbiota.

The fermentation behaviour of sulfated polysaccharides (GLP) and their agaro-oligosaccharides (GLO) derived from Gracilaria lemaneiformis were examined. During in vitro fermentation, GLP and GLO increased the concentrations of short chain fatty acids (SCFAs) and modulated the composition and diversity of gut microorganisms compared with control groups. GLP increased the abundance of Bacteroidetes and decreased the abundance of Firmicutes, while GLO increased the abundance of Firmicutes and Actinobacteria. Moreover, the abundances of potential pathogenic bacteria were reduced. Molecular weight and intrinsic viscosity of GLP decreased significantly from 2.15 × 105 to 1.22 × 105 Da, 374.45-113.91 mL/g, respectively. Furthermore, GLP was degraded into smaller degree of polymerization of oligosaccharides, with no significant change observed in GLO. Overall, this study revealed GLP and GLO could be beneficial for gastrointestinal tract by producing SCFAs and modulating intestinal microbes, indicating GLP and GLO are potentially sources of prebiotics in functional foods.

Anti-obesity effect of total phenylpropanoid glycosides from Ligustrum robustum Blume in fatty diet-fed mice via up-regulating leptin.

ETHNOPHARMACOLOGICAL RELEVANCE: In Chinese folk medicine, the leaves of Ligustrum robustum Blume (LR) were commonly used in the treatment of obesity and hyperlipidemia. This study aimed to evaluate the anti-obesity effect and mechanisms of total phenylpropanoid glycosides from Ligustrum robustum Blume (LRTPG) in fatty diet-fed C57BL/6J mice. MATERIALS AND METHODS: C57BL/6J mice were divided randomly into 6 groups, i.e., control, model, positive (Orlistat 0.12g/kg), and LRTPG at three dosages (0.3, 0.6 or 1.2g/kg), respectively. Control mice were fed with standard diet; the others were fed with fatty diet. After 4 weeks׳ modeling, therapy mice were intragastrically administrated with positive drug or LRTPG for 5 weeks, respectively. Pharmacodynamic effects including body weight, fat weight, Lee׳s index, serum lipid levels, morphological changes and adipocyte area ratio were evaluated. The mechanisms were explored as the factors related to lipids metabolism in gene expressions by real-time PCR, and assured as the protein level of differential gene by Western blotting. RESULTS: The anti-obesity effects of LRTPG in all treated mice were shown as decreased body weight, fat mass, Lee׳s index, total cholesterol (TC) level, and adipocyte area. The mechanisms were demonstrated as elevated mRNA and protein levels of adipose leptin, and consequently decreasing mRNA of adipose acyl coenzyme A: diacylglycerol acyltransferase (DGAT) with increasing mRNA of hepatic cholesterol 7α-hydroxylase (CYP7A1), which led to inhibition of triglyceride (TG) synthesis and promotion of cholesterol catabolism. CONCLUSIONS: The anti-obesity effect of LRTPG in fatty diet-fed mice was related to the up-regulation of leptin, which may provide scientific evidence supporting the traditional usage of LR on obesity in China.