Immune-enhancement effects of Nakai extracts via MAPK/NF-ƙB signaling pathways in cyclophosphamide-induced immunosuppressed mice.

Unlabelled: This study investigated the immune-enhancement effects of Nakai extract (ANE) and its yeast-fermented extract (FAN) in cyclophosphamide (CPP)-induced immunosuppressed mice. Nakai (AGN) increased the protein level of inducible nitric oxide synthase (iNOS) and the production of nitric oxide (NO) and immune-related cytokines in mouse splenocytes. AGN also restored CPP-induced suppression of NK cell activity and splenocyte proliferation. Furthermore, AGN activated the ERK and p38 MAPK/NF-κB signaling pathways in mouse splenocytes via phosphorylation of signaling molecules. These findings indicate that upregulation of cytokines and enzymes may be closely associated with the MAPK/NF-κB signaling pathways. In conclusion, AGN can restore CPP-induced immunosuppression in mice, although there was no significant difference in the immune-enhancing effect between ANE and FAN. It is suggested that AGN might have the potential to enhance immunity as an immunostimulant under immunosuppressed conditions. Therefore, it could be used as an effective agent or a dietary supplement for improving immunity.

Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01281-6.