Triterpenoids and Polysaccharide Fractions of Ganoderma tsugae Exert Different Effects on Antiallergic Activities

Abstract EN

This study was to investigate antiallergic effects of triterpenoids (Gt-TRE) and polysaccharide (Gt-PS) extracts from Ganoderma tsugae, using mast cell line RBL-2H3, T cell line EL4, primary T cells, and transfected RAW264.7 macrophage cells.

The results showed that histamine secreted from activated RBL-2H3 mast cells was significantly suppressed by Gt-TRE but not Gt-PS.

Interleukin- (IL-) 4 secreted from activated EL4 cells was significantly suppressed by Gt-TRE but not Gt-PS.

Further primary CD4+ T cells cultures also confirmed that Gt-TRE ( 5 ~ 50 µg/mL) significantly suppressed Th2 cytokines IL-4 and IL-5 secretions but had no effect on Th1 cytokines IL-2 and interferon (IFN)-γ.

Gt-PS did not affect IL-4 and IL-5 secretions until higher doses (400, 500 µg/mL) and significantly suppressed IFNγ secretions but enhanced IL-2 at these high doses.

The reporter gene assay indicated that Gt-TRE inhibited but Gt-PS enhanced the transcriptional activity of NF-κB in activated transfected RAW264.7 cells and transfected EL4 cells.

IL-4 secreted by this transfected EL-4 cells was also significantly decreased by Gt-TRE but not by Gt-PS, suggesting that these two fractions may exert different effects on NF-κB related cytokines expression.

These data suggested that triterpenoids fraction of Ganoderma tsugae might be the main constituents to alleviate allergic asthma.