Splenocyte proliferation, NK cell activation and cytokines production by extract of Scrophularia variegata; an in vitro study on mice spleen cells

Background and objectives: Scrophularia variegata M. Beib. (Scrophulariaceae) is a medicinal plant, used for various inflammatory diseases in Iranian Traditional Medicine. In the present study, we evaluated the immune modulation and antioxidant effects of the hydroalcoholic extract of S. variegata. Methods: The splenocytes were harvested from the spleen of Balb/c mice and were cultured. The splenocyte proliferation, NK cell activity, cytokines production and antioxidant effects were evaluated by MTT assay, enzyme- linked immunosorbent assay (ELISA) and DPPH assay, respectively. Results: The S. variegata extract significantly increased splenocyte proliferation. The results indicated that the extract increased NK cell cytotoxicity of Yac-1 tumor cells and at the concentration of 50-200 µg/mL significantly increased IFN-? and IL-2 cytokines, although the level of IL-4 cytokine was significantly reduced. The antioxidant activity was observed in the extract with IC50 302.34±0.11 ?g/mL.Conclusion: The increasing in the splenocyte proliferation, anti-tumor NK cell cytotoxicity and cytokine secretion were indicated as potent immunomodulatory effects. These results suggest that S. variegata could be considered in the treatment of immunopathological disorders such as allergy and cancer; however, future studies are necessary.