Immunosuppressive activity of Pollen Typhae ethanol extract on the immune responses in mice

The immunosuppressive activity of the ethanol extract of Pollen Typhae (EEPT) consisting of a mixture of flavonoids, steroids and volatile oils was studied on the immune responses in mice. EEPT significantly suppressed concanavalin A (Con A)- and lipopolysaccharide (LPS)-stimulated splenocyte proliferation in vitro in a concentration-dependent manner. ICR mice were immunized subcutaneously with OVA on days 0 and 14. Beginning on the day of immunization, the mice were administered intraperitoneally with EEPT at a single dose of 0.25, 0.5, and 1.0 mg at intervals of 7 days for a total of five doses. On day 28, antigen-specific antibodies in serum, and mitogen- and OVA-induced splenocyte proliferation were measured. EEPT significantly suppressed Con A-, LPS- and OVA-induced splenocyte proliferation in the OVA-immunized mice in a dose-dependent manner. Moreover, the OVA-specific total IgG, IgG1 and IgG2b levels in the OVA-immunized mice were significantly reduced by EEPT. The results suggest that EEPT could suppress the cellular and Immoral response in mice, and deserve further researches to be developed as immunosuppressant. (c) 2005 Elsevier Ireland Ltd. All rights reserved.