Anti-inflammatory effects and molecular mechanisms of bioactive small molecule garlic polysaccharide

Front Nutr. 2023 Jan 9:9:1092873. doi: 10.3389/fnut.2022.1092873. eCollection 2022.

Abstract

Although garlic polysaccharides have been found to possess anti-inflammatory activities, anti-inflammatory study on small molecule water-soluble garlic polysaccharide (WSGP) is few. In this study, a novel WSGP with a molecular weight of 1853 Da was isolated by DEAE-52 and Sephadex G-100 column and the chemical composition was identified by monosaccharide composition and methylation analysis. Furthermore, the antioxidant effects of WSGP and the potential molecular mechanisms on LPS-induced inflammatory responses in RAW264.7 macrophage cells were investigated. The results showed that WSGP has strong antioxidant activity, such as DPPH, hydroxyl, superoxide anion, ABTS radical scavenging capacity, Fe2+ chelating ability and reducing power. Meanwhile, WSGP could considerably suppress the manufacturing of NO and the mRNA and protein expression degrees of IL-6, TNF-α, and IL-1β in LPS inspired RAW264.7 macrophages WSGP could significantly suppress the production of NO and the mRNA and protein expression levels of IL-1β, IL-6, and TNF-α in LPS stimulated RAW264.7 macrophage cells (p < 0.05). In addition, the phosphorylated IκB-α, p65, and STAT3 proteins were significantly increased in LPS-induced macrophages, while this trend was significantly reversed by WSGP treatment in a concentration-dependent manner (p < 0.05). Consequently, WSGP supplementation might reduce LPS-induced inflammatory responses by suppressing proinflammatory cytokines and NF-κB and STAT3 pathway activation. The finding of this research would give scientific guidelines for the judicious use of small molecular garlic polysaccharide in anti-inflammatory treatments.

Keywords: NF-κB; STAT3; anti-inflammatory; bioactive; molecular mechanisms; small molecule garlic polysaccharide.

Grants and funding

This research was funded by the major program of Summit Project, Guangdong Province High-level Hospital Construction Project of Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences [No. DFJH2020028], the Science and Technology Program of Guangzhou City [No. 201803010058], the Innovative and Entrepreneurial Research Team Program of Maoming City [No. 20202402], and Postdoctoral Special Science Foundation Subject [No. BS2021012].