Role of genistein on the yield, structure and immunomodulatory activity of exopolysaccharides

• Published in: Food & function 2022-02, Vol.13 (3), p.1393-147
• Main Authors: Xie, Liuming, Huang, Zhibing, Meng, Hui, Fan, Zhibing, Shi, Xiaoyi, Xie, Jianhua
• Format: Article
• ISSN: 2042-6496; 2042-650X
• DOI: 10.1039/d1fo03621a

Manipulating the structures, physicochemical properties, and monosaccharide compositions of exopolysaccharides (EPS) isolated from microorganisms has been reported to enhance their biological activities. Hence, the aim of this work was to examine the effects of genistein addition during fermentation on the amount, physicochemical properties, and immunomodulatory activity of EPS secreted by M. purpureus . Results showed that genistein addition significantly increased M. purpureus biomass and EPS yield to 2.42 g L −1 and 6.08 g L −1 , respectively, and affected the physicochemical properties and structures of EPS. Furthermore, EPS produced by genistein-treated M. purpureus (G-EMP) improved the immunomodulatory activity of RAW264.7 macrophages by increasing the secretion of nitric oxide and cytokines. Moreover, phospho-Jun N-terminal kinase (p-JNK), phospho-extracellular regulated protein kinase (p-ERK), phospho-p38 (p-p38) mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) phospho-p65 (p65) proteins were remarkably upregulated by G-EMP stimulation, blocking Toll-like receptor 4 (TLR4) that dramatically reduced the pinocytic and phagocytic capacities. Overall, these findings provide potential rationales for the application of genistein in improving the EPS yield of M. purpureus . Monascus purpureus polysaccharides based on biomodification of genistein (G-EMP) exhibited stronger immunomodulatory activity in macrophages.