Inducible nitric oxide synthase inhibitors of Chinese herbs III. Rheum palmatum

Ching Chiung Wang, Yi Ju Huang, Lih Geeng Chen, Lain Tze Lee, Ling-Ling Yang

研究成果: 雜誌貢獻文章同行評審

27 引文 斯高帕斯(Scopus)


In this paper, the effects of bioactive compounds of Rheum palmatum L. on the inhibition of NO production from RAW 264.7 cells were explored. Seven main anthraquinone derivatives were isolated from the root of R. palmatum, and of these, emodin and rhein significantly inhibited nitrite production from lipopolysaccharide (LPS)-activated RAW 264.7 cells. The IC50 values for inhibition of nitrite production by emodin and rhein were 60.7 and 67.3 μM, respectively. After iNOS enzyme activity was stimulated by LPS for 12 h, treatment with emodin or rhein at 20 μg/ml for 18 h did not significantly inhibit NO production. The data show that the inhibitory activity of emodin and rhein is not due to direct inhibition of iNOS enzyme activity. However, expression of iNOS and the COX-2 protein was inhibited by emodin in LPS-activated RAW 264.7 cells, and PGE2 production was reduced. Rhein also inhibited LPS-induced iNOS protein expression, but not COX-2 or PGE2 production. On the other hand, inhibition effects on NO production from RAW 264.7 cells were enhanced and cytotoxic effects decreased by co-treatment with emodin and rhein. In conclusion, emodin and rhein are major iNOS inhibitors of R. palmatum and may possibly serve as bioactive substances for anti-inflammation effects.

頁(從 - 到)869-874
期刊Planta Medica
出版狀態已發佈 - 10月 1 2002

ASJC Scopus subject areas

  • 植物科學
  • 藥物發現
  • 有機化學
  • 藥理


深入研究「Inducible nitric oxide synthase inhibitors of Chinese herbs III. Rheum palmatum」主題。共同形成了獨特的指紋。