Inhibitory effect of Scrophulariae Radix extract on $TNF-{\alpha},\;IL-1{\beta}$, IL-6 and Nitric Oxide production in lipopolysaccharide - activated Raw 264.7 cells

Objectives : Scrophulariae Radix (SRE) is commonly used in combination with other herbs as a nutrient and health strengthening agent, and to remove 'heat' and replenish vital essence. The water-based extract of this herb can lower blood pressure in both anesthetized and concious animals, and exhibits an anti-inflammatory activity. But, there is lack of studies regarding the effects of SRE on the immunological activities in molecular levels. The present study was conducted to evaluate the effect of SRE on the regulatory mechanism of cytokines and nitric oxide (NO) in Raw 264.7 cells. Method : After the treatment of Scrophulariae Radix methanol extract, cell viability was measured by MTT assay, NO production was monitored by measuring the nitrite content in culture medium. COX-2 and iNOS were determined by Immunoblot analysis, and levels of cytokine were analyzed by sandwich immunoassays. Results : Results provided evidence that SRE inhibited the production of nitrite and nitrate (NO), inducible nitric oxide synthase (iNOS), and interleukin-6 (IL-6), and the activation of phospholylation of inhibitor in Raw 264.7 cells activated with lipopolysaccharide (LPS). Conclusion : These findings suggest that Scrophulariae Radix can produce anti-inflammatory effect, which may playa role in adjunctive therapy in Gram-negative bacterial infections.