Structure-dependent immune modulating activity of okra polysaccharide on THP-1 macrophages. (January 2019)

• Record Type: Journal Article
• Authors: Trakoolpolpruek, Thanathon; Moonmangmee, Somporn; Chanput, Wasaporn
• Is Part Of: Bioactive carbohydrates and dietary fibre. Volume 17(2019)
• Publication Date: 2019-01
• Subjects: Immune modulating activity -- Macrophage -- Okra -- Polysaccharide -- THP-1; Functional foods -- Periodicals; Fiber in human nutrition -- Periodicals; Carbohydrates -- Periodicals; Glycoproteins -- Periodicals; Functional Food -- Periodicals; Dietary Fiber -- Periodicals; Carbohydrates -- Periodicals; Carbohydrates; Fiber in human nutrition; Functional foods; Glycoproteins; Periodicals; 613.28
• DOI: 10.1016/j.bcdf.2018.10.002
• Languages: English
• ISSNs: 2212-6198

Abstract

Abstract: Polysaccharides from various plants exhibit immune modulating activity directly through immune cell activity. Polysaccharide structural features are vital in such activity. Okra ( Abelmoschus esculentus L. Moench) polysaccharides have proven their potency as immune modulators. This study aimed to investigate the structure-dependent immune modulating activity of water-extracted okra ( Abelmoschus esculentus L. Moench) polysaccharide on THP-1 macrophages. Native water-extracted okra polysaccharides (OP) with high molecular weights (>640 kDa) were digested with a polygalacturonase enzyme. Digestion promoted the removal of pectin linear regions (Homogalacturonan; HG), consequently reduced their molecular weight. Digested okra polysaccharides (OPD) were fractionated through size exclusion chromatography to obtain OPDF1 (>640 kDa) and OPDF2 (≤18 kDa). Results revealed all polysaccharide derivatives as nontoxic to THP-1 macrophages. OP-treated THP-1 macrophages increased IL-8, IL-1β, and TNF-α gene expression ( p < 0.05) compared to unstimulated cells. Immune stimulating activity could not be observed in OPD, OPDF1, or OPDF2. These results indicated that the high molecular weight (MW) and HG associated with Rhamnogalacturonan I (RG-I) are important okra pectic polysaccharide structural features for macrophages stimulation. Highlights: Polygalacturonase enzyme could digest okra polysaccharide into different structures and molecular weights. Both intact and enzymatic digested okra polysaccharide were non-cytotoxic towards THP-1 macrophages. Intact okra polysaccharide displayed immune stimulating activity, but not the enzymatic digested ones.