Structural characterization of a pectic polysaccharide from laoshan green tea and its inhibitory effects on the production of NO, TNF-α and IL-6

Abstract

A novel pectic polysaccharide, named GTPS3-1, was isolated and purified from Laoshan green tea polysaccharide (GTPS) through DEAE Sepharose Fast Flow and Sephacryl S-300 columns, its structure was characterized and its anti-inflammatory activity was explored. GTPS3-1, with a molecular weight of 26.05 kDa, was mainly composed of galacturonic acid, galactose, rhamnose and arabinose in a molar ratio of 4.72:2.5:1.68:1 on the basis of monosaccharide composition. Structural analysis results revealed that GTPS3-1 was a highly branched pectin consisting of →3)-Galp-(1→, →2)-Rhap-(1→, →3,5)-Araf-(1→, →3)-Rhap-(1→, GalpA-(1→, →3,4)-Galp-(1→, →4)-GalpA-(1→, →5)-Araf-(1→, →2,4)-Rhap-(1→, Rhap-(1→ and Araf-(1→ according to FT-IR, methylation and NMR analyses. In addition, GTPS3-1 inhibited the production of NO, TNF-α and IL-6 in a dose-dependent manner, which resulted in the amelioration of inflammatory injury in LPS-induced RAW 264.7 cells. These results would provide a theoretical basis for practical application of the novel polysaccharide as an anti-inflammatory adjuvant.

Graphical Abstract

Keywords:

• Laoshan green tea
• pectic polysaccharide
• structural characterization
• anti-inflammatory activity

Declaration of interest statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by the Natural Science Foundation of Shandong Province (ZR2021MH124 and ZR2017LH075), Shandong Science and Technology Research Project of Traditional Chinese Medicine (2020Q057, 2017209 and 2015227), National Nature Science Foundation of China (81274049). We thank LetPub (www.letpub.com) for its linguistic assistance during the preparation of this manuscript.