Hepatoprotective effects of peach gum polysaccharides against alcoholic liver injury: moderation of oxidative stress and promotion of lipid metabolism

Abstract

Natural polysaccharides extracted from plants have received increasing attention due to their rich bioactivity. In our study, peach gum polysaccharides (PGPs) were extracted by water extraction-alcohol precipitation method. PGPs are typical pyranose polysaccharides with a mean molecular weight of 3.68 × 10⁶ g/mol. The antioxidant activity and hepatoprotective capacity of PGPs were studied. In vitro, assays showed that PGPs scavenged DPPH, OH, and O₂^- in a dose-dependent manner. PGPs exhibited antioxidative properties against alcohol-induced HL7702 cells, as evidenced by the normalization of MDA, SOD, ROS, and GSH levels. To further elucidate the hepatoprotective mechanism of PGPs, we carried out in vivo experiments in male mice. PGPs exerted hepatoprotective effects in alcohol liver disease (ALD) mice by exerting antioxidant effects, decreasing the inflammatory response and modulating lipid metabolism. In addition, metabolomic analysis indicated that PGPs mainly regulate D-glutamine and D-glutamate metabolism, alanine, aspartate and glutamate metabolism, and arginine biosynthesis to promote hepatic metabolism and maintain body functions. Overall, this study revealed that the hepatoprotective mechanism of PGPs against ALD might be associated with the regulation of oxidative stress and lipid metabolism.

Keywords: alcoholic liver damage; antioxidant activity; metabolomic; peach gum polysaccharides; structural analysis.

FIGURE 1

Preliminarily explored the protective mechanism of PGPs against ALD.

FIGURE 2

Scheme for the study of the protective mechanism of PGPs against alcoholic liver injury.

FIGURE 3

Characterization of PGPs. (A) Monosaccharide composition of standard. (B) Monosaccharide composition of PGPs. (C) FT-IR spectra. (D) UV-Vis spectra. (E) AFM images of PGPs.

FIGURE 4

In vitro antioxidant capacity of PGPs.

FIGURE 5

Protective effect of PGPs on alcohol-induced HL7702 cells. (A) Viability of HL7702 cells cultured with PGPs for 24 h. (B) Viability of HL7702 cells cultured with different concentrations of alcohol for 12 h. (C) GSH contents. (D) MDA contents. (E) SOD contents. (F) ROS contents. ** and *** indicate P < 0.01 and P < 0.001, respectively, for Group M compared with group CG. #, ##, and ### indicate P < 0.05, P < 0.01, and P < 0.001, respectively, for group PGPs compared with group M.

FIGURE 6

Serum levels of AST (A), ALT (B), and γ-GGT (C). Morphological observation of the liver in alcohol-induced mice. (D) H&E staining. (E) Oil red staining. *** indicate P < 0.001, respectively, for Group M compared with group CG. #, ##, and ### indicate P < 0.05, P < 0.01, and P < 0.001, respectively, for group PGPs compared with group M.

FIGURE 7

Effects of PGPs on biochemical constituents in mouse livers. (A) TG contents. (B) ADH contents. (C) ALDH contents. (D) GSH contents. (E) MDA contents. (F) SOD contents. (G) CAT contents. * and *** indicate P < 0.05 and P < 0.001, respectively, for Group M compared with group CG. #, ##, and ### indicate P < 0.05, P < 0.01, and P < 0.001, respectively, for group PGPs compared with group M.

FIGURE 8

Effects of PGPs on biochemical constituents in mouse livers. (A) TNF-α contents. (B) IL-6 contents. (C) LPS contents. *** indicate P < 0.001, for Group M compared with group CG. ### indicate P < 0.001, for group PGPs compared with group M.

FIGURE 9

Multivariate statistical analysis and pathway analysis of metabolomics. OPLS-DA scores plot of M vs. 800 in positive (A) and negative (B). Permutation tests of M vs. 800 in positive (C) and negative (D). Volcano plot of M vs. 800 (E) and CG vs. M (F). (G) Heatmap of differential metabolites. (H) Bubble plots for pathway analysis.