A glucogalactomanan polysaccharide isolated from Agaricus bisporus causes an inflammatory response via the ERK/MAPK and IκB/NFκB pathways in macrophages

Abstract In the present study, a glucogalactomanan polysaccharide isolated from Agaricus bisporus named as TJ3 was investigated its immunomodulatory effects and molecular mechanisms in RAW 264.7 cells. Functional analysis showed TJ3 could inhibit the proliferation of RAW 264.7 cells in a certain concentration range. Moreover, TJ3 treatment increased the expression of inducible nitric oxide synthase (iNOS), which was responsible for increasing nitric oxide (NO) production. TJ3 also increased the expression of cyclooxygenase-2 (COX-2) and the mRNA levels of interleukin 1β (IL-1β), interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α) and COX-2 in RAW 264.7 cells. In addition, further elucidation of molecular mechanisms showed that ERK/MAPK and IκB/NFκB pathways were activated by TJ3 treatment via increased phosphorylation levels of ERK1/2 and IκB-α, respectively. These findings indicated that TJ3 had a huge promising immunostimulatory activity and its induced immune responses probably through stimulating the ERK/MAPK and IκB/NFκB pathways. Our results demonstrate that TJ3 may be used as a potent immune modulator.