Untargeted serum and liver metabolomics analyses reveal the gastroprotective effect of polysaccharide from Evodiae fructus on ethanol-induced gastric ulcer in mice.

This study aimed at investigating the gastroprotective effect of Evodiae fructus polysaccharide (EFP) against ethanol-induced gastric ulcer in mice. Biochemical indexes along with untargeted serum and liver metabolomics were determined. Results showed that pre-treatment of EFP alleviated ethanol-induced gastric ulcer in mice. EFP lessened oxidative stress and inflammation levels of stomachs, showing as increments of SOD and GSH-Px activities, GSH content and IL-10 level, and reductions of MDA and IL-6 levels. Meanwhile, EFP activated the Keap1/Nrf2/HO-1 signaling pathway through increasing Nrf2 and HO-1 protein expressions, and decreasing Keap1 protein expression. Serum and liver metabolomics analyses indicated that 10 metabolic potential biomarkers were identified among normal control, ulcer control and 200 mg/kg·bw of EFP groups, which were related to 5 enriched metabolic pathways including vitamin B6 metabolism, nicotinate and nicotinamide metabolism, pentose phosphate pathway, bile secretion and ascorbate and aldarate metabolism. Further pearson's correlation analysis indicated that there were some positive and negative correlations between the biomarkers and the biochemical indexes. It could be concluded that the gastroprotection of EFP might be related to anti-oxidative stress, anti-inflammation, activation of Keap1/Nrf2/HO-1 signaling pathway and alteration of metabolic pathways. This study supports the potential application of EFP in preventing ethanol-induced gastric ulcer.

Physicochemical property and antioxidant activity of polysaccharide from the seed cakes of Camellia oleifera Abel.

Seed cake refers to the food by-product of Camellia oleifera Abel, and its insufficient utilization can cause serious environment pollution and resource waste. This study aimed to investigate antioxidant activities of the polysaccharide from the seed cakes of Camellia oleifera Abel (COCP) in vitro and in vivo. The physicochemical property of COCP was also determined. COCP was characterized to be an acidic glycoprotein and mainly consisted of rhamnose (Rha), arabinose (Ara), galactose (Gal), glucose (Glc), xylose (Xyl), mannose (Man), and galacturonic acid (Gal-UA). COCP exhibited the polysaccharide's characteristic absorption in the Fourier transform infrared (FT-IR) spectroscopy and showed as sheet-like structures with a smooth surface under the scanning electron microscope (SEM). COCP exerted good scavenging activities on ABTS, DPPH, and OH radicals, with IC50 values of 2.94, 2.24, and 5.09 mg/ml, respectively. COCP treatment improved learning and memory abilities of D-galactose-induced aging mice. Significant decreases were found in the levels of alanine transaminase (ALT), aspartate aminotransferase (AST), creatinine (CRE), blood urea nitrogen (BUN), creatine kinase (CK), and lactate dehydrogenase (LDH) in serum, as aging mice were supplemented with COCP. Aging mice showed obviously higher malondialdehyde (MDA) contents and lower superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in serum, brain, liver, kidney, and heart. The phenomena were noticeably reversed when mice were treated with COCP. Results indicated that COCP exerted excellent antioxidant activities in vitro and in vivo, which support its potential application as a natural antioxidant in food and medicine industries.

Physicochemical properties, antioxidant activities and α-glucosidase inhibitory effects of polysaccharides from Evodiae fructus extracted by different solvents.

In this study, polysaccharides from Evodiae fructus were extracted by water, 0.5 M HCl, 0.5 M NaOH, water + 0.5 M HCl and water + 0.5 M NaOH, which were named as ERP-W, ERP-AC, ERP-AK, ERP-W-AC and ERP-W-AK, respectively. Their physicochemical properties, antioxidant activities and α-glucosidase inhibitory effects were investigated and compared. Physico-chemical analysis showed that they were acidic heteropolysaccharides, which had α- and ß-configurations. ERP-W, ERP-AK and ERP-W-AK were mainly composed of Rha, Ara, Gal, Glc and Gal-UA, while ERP-AC and ERP-W-AC were dominantly made up of Rha, Gal and Gal-UA. ERP-AK had the highest yield (24.5%) and the best thermal stability, ERP-AC and ERP-W-AC showed better homogeneity and lower molecular weight (83.6 and 41.6 kDa), and ERP-W possessed the highest neutral sugar content (50.7%) and molecular weight. Biological evaluation indicated that ERP-W, ERP-AK and ERP-W-AK had relatively stronger antioxidant activities, including ABTS, DPPH, OH and O2- radicals scavenging activities, Fe2+ chelating ability and α-glucosidase inhibitory effects. Moreover, these actions were considerably related to their physicochemical properties especially monosaccharide composition and molecular weight. Therefore, polysaccharides extracted by water and alkaline solvents from Evodiae fructus could be developed as promising natural antioxidants and α-glucosidase inhibitors in the food and medicine industries.