title: Immunosuppressive activity of the ethanol extract of Siegesbeckia orientalis on the immune responses to ovalbumin in mice.
abstract: The in vitro and in vivo immunosuppressive activity of the ethanol extract of Siegesbeckia orientalis (EESO) was studied on the immune responses in mice. EESO 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 ovalbumin (OVA) on days 0 and 14. Beginning on the day of immunization, the mice were administered intraperitoneally with EESO at a single dose of 0.25, 0.5, and 1.0 mg at intervals of 7 days. On day 28, OVA-specific antibodies in serum, and mitogen- and OVA-induced splenocyte proliferation were measured. EESO significantly suppressed Con A-, LPS- and OVA-induced splenocyte proliferation in the OVA-immunized mice in a dose-dependent manner. The OVA-specific serum IgG, IgG1, and IgG2b levels in the OVA-immunized mice were also significantly reduced by EESO. Moreover, reducing effect on the IgG1 antibody of EESO at the dose of 1.0 mg was more significant than that of cyclosporin A (CsA; positive drug). The results suggest that EESO could suppress the cellular and humoral response to ovalbumin in mice, and deserve further investigations to be developed as immunosuppressant.
authors.affiliation: College of Animal Science, Zhejiang University, Hangzhou 310029, PR China. sunhx@zju.edu.cn
authors.forename: Hong-Xiang
authors.initials: HX
authors.lastname: Sun
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
mesh_terms: D000818:Animals; D000906:Antibodies / Q000097:blood / Q000276:immunology; D019659:Asteraceae / Q000737:chemistry*; D002478:Cells, Cultured; D000431:Ethanol; D005260:Female; D007166:Immunosuppressive Agents / Q000737:chemistry* / Q000276:immunology* / Q000494:pharmacology; D051379:Mice; D008813:Mice, Inbred ICR; D008938:Mitosis / Q000187:drug effects; D008969:Molecular Sequence Data; D010047:Ovalbumin / Q000276:immunology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D013154:Spleen / Q000187:drug effects / Q000276:immunology
chemical_list: D000906:Antibodies; D007166:Immunosuppressive Agents; D010936:Plant Extracts; D000431:Ethanol; D010047:Ovalbumin