Immunomodulatory activity of thunberginol A and related compounds isolated from Hydrangeae Dulcis Folium on splenocyte proliferation activated by mitogens.

We investigated the immunomodulatory effects of antiallergic constituents from Hydrangeae Dulcis Folium, the processed leaves of Hydrangea macrophylla SERINGE var. thunbergii MAKINO, on splenocyte proliferation in mice. Thunberginol A and hydrangenol significantly suppressed T lymphocyte proliferation induced by concanavalin A. Thunberginol A also suppressed B lymphocyte proliferation induced by lipopolysaccharide, but other constituents induced significant increases. These inhibitory effects of thunberginol A on splenocyte proliferation seemed to contribute to the suppressive effect on type IV allergy.