Structural characterization of polysaccharides after fermentation from Ganoderma lucidum and its antioxidant activity in HepG2 cells induced by H2O2

Yang Zhao; Qinyang Li; Minghui Wang; Yuhua Wang; Chunhong Piao; Hansong Yu; Junmei Liu; Zhuowei Li

doi:10.1016/j.fochx.2023.100682

Structural characterization of polysaccharides after fermentation from Ganoderma lucidum and its antioxidant activity in HepG2 cells induced by H₂O₂

Food Chem X. 2023 Apr 23:18:100682. doi: 10.1016/j.fochx.2023.100682. eCollection 2023 Jun 30.

Authors

Yang Zhao^{1

2}, Qinyang Li³, Minghui Wang¹, Yuhua Wang¹, Chunhong Piao¹, Hansong Yu¹, Junmei Liu¹, Zhuowei Li⁴

Affiliations

¹ College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, China.
² Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, China.
³ School of Life Science, Jilin University, Changchun 130012, China.
⁴ Changchun Vocational Institute of Technology, Changchun 130033, China.

Abstract

In this study, Lactiplantibacillus plantarum ATCC14917 was used to ferment Ganoderma lucidum spore powder. Two polysaccharides were purified from unfermented (GLP) and fermented (FGLP) Ganoderma lucidum spore powder. The chemical structure and antioxidant activity of the polysaccharides were studied. Finally, the effect of GLP and FGLP on the oxidative stress regulation pathway in HepG2 cells was explored. The results showed that the main structural characteristics of Ganoderma lucidum polysaccharides remained unchanged during the fermentation. However, the average molecular weight (M_w) of Ganoderma lucidum polysaccharides decreased from 1.12 × 10⁵ Da to 0.89 × 10⁵ Da. Besides this, the contents of mannose, galactose, and glucuronic acid increased, while the contents of xylose and glucose were decreased. In addition, the content of uronic acid was raised, and the apparent structure was changed from smooth and hard to porous and loose. In antioxidant studies, intracellular ROS and MDA contents in the oxidative stress model were decreased, and T-AOC content was increased under GLP and FGLP intervention. In the investigation of the regulation pathway, Nrf-1 gene expression was up-regulated, and Keap1 gene expression was down-regulated under GLP and FGLP intervention. The antioxidant genes NQO1 and NO-1 expressions were increased to activate the activities of antioxidant enzymes CAT, SOD and GSH-PA to resist oxidative stress. Compared with GLP, FGLP has a stronger regulatory role in this pathway, thus showing more potent antioxidant activity. This experiment is beneficial to the further utilization of Ganoderma lucidum spore powder.

Keywords: Antioxidant activity; Ganoderma lucidum; Polysaccharide; Structure.