Isolation, characterization, immunoregulatory, and antioxidant activities of polysaccharides from Morinda officinalis fermented by Bacillus sp. DU-106

Abstract Morinda officinalis ( M. officinalis ) polysaccharides are valuable ingredients with various bioactive functions. This work aimed to investigate whether fermentation could enhance the bioactivities of M. officinalis polysaccharides. A strain of Bacillus sp. DU-106 was introduced to ferment M. officinalis . Two polysaccharides (namely NMP-1 and FMP-1) were isolated from raw M. officinalis and fermented M. officinalis , respectively. The structure, immunoregulatory, and antioxidant activities of NMP-1 and FMP-1 were investigated. Bacillus sp. DU-106 fermentation changed the monosaccharide composition and conformation of M. officinalis polysaccharides. After fermentation, FMP-1 dramatically stimulated IL-1β secretion in RAW 264.7 macrophages. In vitro , Bacillus sp. DU-106 fermentation of M. officinalis enhanced the DPPH radical, hydroxyl radical, and superoxide anion scavenging activities. In vivo , FMP-1 extended the lifespan and ameliorated oxidative injury of Caenorhabditis elegans . Collectively, Bacillus sp. DU-106 fermentation significantly enhanced the immunoregulatory and antioxidant activities of M. officinalis polysaccharides.