Structure-dependent Immune Modulating Activity of Okra Polysaccharide on THP-1 Macrophages

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.
Source: Bioactive Carbohydrates and Dietary Fibre - Category: Food Science Source Type: research