Stylopine is a major component of the leaf of Chelidonium majus L. (Papaveraceae), which has been used for the removal of warts, papillomas and condylomas, as well as the treatment of liver disease, in oriental countries. Stylopine per se had no cytotoxic effect in unstimulated RAW 264.7 cells, but concentration-dependently reduced nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta), and the IL-6 production and cyclooxygenase-2 (COX-2) activity caused by the LPS stimulation. The levels of inducible nitric oxide synthase (iNOS) and COX-2 protein expressions were markedly suppressed by stylopine in a concentration dependent manner. These results suggest that stylopine suppress the NO and PGE2 production in macrophages by inhibiting the iNOS and COX-2 expressions. These biological activities of stylopine may contribute to the anti-inflammatory activity of Chelidonium majus.

Prunioside A is a unique, highly oxidized monoterpene glycoside isolated from the methanol extract of Spiraea prunifolia var. Simpliciflora's root. The ester derivatives were synthesized from the hydrolyzed compounds of prunioside A by β-glucosidase. The derivatives showed suppressive effects on the generation of nitric oxide in murine machrophage-like RAW 264.7 cells stimulated by lipopolysaccharide and interferon-γ.