Structural characterization and hepatoprotective activity of exopolysaccharide from Bacillus velezensisSN‐1

Abstract

BACKGROUND: Exopolysaccharide biopolymers produced by microorganisms are crucial to the environment. They contribute to areas such as the health and bionanotechnology sectors, food and cosmetic industries as gelling agents, and environmental sector as flocculants owing to their biodegradability and non-toxic nature. The current study aimed to isolate the fraction of released exopolysaccharide (rEPS) by Bacillus velezensis SN-1 from Chinese Da-Jiang. RESULTS:The weighted average molecular weight of the major isolated component, rEPS-2, was 202 kDa, and its monosaccharide composition included mannose, glucose, and galactose at a molar ratio of 0.38:0.30:0.32. Further, the rEPS-2 was characterized using methylation analysis and one-dimensional/two-dimensional nuclear magnetic resonance (1D/2D NMR) spectroscopy. In vivo hepatoprotective effects indicated that rEPS-2 could alleviate carbon tetrachloride (CCl 4 )-induced liver injury in mice by lowering the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and the malondialdehyde (MDA) levels. Furthermore, rEPS-2 can increase the expression of antioxidant genes HO-1, GCLC and NQO1 in the Nrf2/ARE signaling pathway, thereby increasing the activity of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and reduced catalase (CAT) in liver cells. Furthermore, the rEPS-2 can be used and modulate the gut microbiota of mice with liver injury caused by CCl 4 .CONCLUSIONS: These results suggest that rEPS-2 has promising potential to serve as hepatoprotective agents.

A Novel Polysaccharide Separated from Panax Notoginseng Residue Ameliorates Restraint Stress‐ and Lipopolysaccharide‐induced Enteritis in Mice

“…However, PNP‐20 significantly increased the expression of SOD2 in the intestinal tissue in LPS‐ and RS‐treated mice (Figure 10). Previous reports demonstrate that polysaccharides composed of Man, Glc and Gal can ameliorate intestinal flora disorder in vivo and in vitro by improving antioxidant genes’ expression via the activation of nuclear erythroid 2‐related factor 2 signaling pathway, [37] thereby increasing the activity of SOD [38] . Current data suggest that PNP‐20 reduces LPS and RS‐induced oxidative stress probably related to the increases in SOD activity and decreases in reactive oxygen species.…”

Lactic Acid Bacteria-Derived Exopolysaccharides Mitigate the Oxidative Response via the NRF2-KEAP1 Pathway in PC12 Cells

“…Based on our findings, there is a regulatory effect of L-EPSs on TOS and TAS levels in PC-12 cells induced by OS with H 2 O 2 . It has been stated in the literature that L-EPS provides balance between TOS and TAS levels, thanks to mechanisms of action such as free radical scavenging [55], metal chelation [56], lipid peroxidation [57], electron or hydrogen donation (to ROS) [58], antioxidant stimulant, and enzyme detoxification activities [59]. This view was supported by our findings in a previous study, which implied that our L-EPSs exhibited antioxidant activities (hydroxyl and superoxide anion scavenging activity, metal ion chelating activity, and lipid peroxidation activity) [35].…”

Functional features of the exopolysaccharide extracts produced by Lactiplantibacillus strains isolated from table olives

“…30 Recently, Cao et al (2023) also noticed that EPS crude extract obtained from Bacillus velezensis SN-1 increased the expression of antioxidant genes HO-1 in mice's liver through the Nrf2/ARE signalling pathway. 31…”