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.

Identification of fungus-responsive cis-acting element in the promoter of Brassica juncea chitinase gene, BjCHI1.

Chitinases are a group of pathogenesis-related proteins. The Brassica juncea chitinase gene BjCHI1 is highly inducible by pathogenic fungal infection, suggesting that the promoter of BjCHI1 might contain specific cis-acting element responsive to fungal attack. To identify the fungus-responsive element in BjCHI1 promoter (BjC-P), a series of binary plant transformation vectors were constructed by fusing the BjC-P or its deletion-derivatives to ß-glucuronidase (GUS) reporter gene. Expression of the GUS reporter gene was systematically assayed by a transient gene expression system in Nicotiana benthamiana leaves treated with fungal elicitor Hexa-N-Acetyl-Chitohexaose, as well as in transgenic Arabidopsis plants inoculated with fungus Botrytis cinerea. The histochemical and quantitative GUS assays showed that the W-box-like element (GTAGTGACTCAT) in the region (-668 to -657) was necessary for the fungus-response, although there were another five W-box-like elements in BjC-P. In addition, gain-of-function analysis demonstrated that the fragment (-409 to -337) coupled to the W-box-like element was needed for full magnitude of the fungal induction. These results revealed the existence of a novel regulation mechanism of W-box-like element involved in plant pathogenic resistance, and will benefit the potential application of BjC-P in engineering crops.