Gene

Biotechnology

Biology

Western blot

Radix (gastropod)

Lipopolysaccharide

Biological activity

Nitric oxide

Anti-inflammatory

Biochemistry

Botany

Immunology

In vivo

Organic chemistry

Pharmacognosy

In vitro

Inflammation

Pharmacology

Nitric oxide synthase

Medicine

Chemistry

Tumor necrosis factor alpha

Traditional medicine

Journal of Ethnopharmacology

Radix Toddaliae Asiaticae has long been used as a traditional ethnic Chinese medicine for the treatment of inflammation and rheumatism. In our earlier communication we have reported the anti-arthritic activity of the ethyl alcohol extract and ethyl acetate fraction from Radix Toddaliae Asiaticae. This study was to examine the anti-inflammatory activity of prenylcoumarin omphalocarpin isolated from the ethyl acetate extract with the bioassay-guided methods. Cultured macrophage RAW 264.7 cells were used for the experiments. The ability of omphalocarpin to modulate the production of nitric oxide (NO), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) was evaluated. Western blot was used to detect the expression of iNOS and COX-2 and the translocation of nuclear factor kappa B (NF-κB) to the nucleus. Meanwhile, the anti-inflammatory activity of omphalocarpin in vivo was also assayed by xylene induced ear edema in mice. It has been shown that omphalocarpin inhibited lipopolysaccharide (LPS)-stimulated NO production and pro-inflammatory mediators secretion, including TNF-α, IL-6 in a dose-dependent manner. Omphalocarpin also strongly suppressed the expression and enzymatic activity of iNOS and COX-2 and the translocation of NF-κB to the nucleus. In vivo assays omphalocarpin exhibited anti-inflammatory activity for alleviation of the ear swelling in xylene induced ear edema test. These results obtained in vitro and in vivo showed that the anti-inflammatory mechanism of omphalocarpin might be attributed to the inhibition of pro-inflammatory mediators including nitric oxide, IL-6 and TNF-α. Omphalocarpin decreased the overproduction of NO through down-regulation of the expression and enzymatic activity of iNOS and COX-2 in LPS-stimulated macrophage, which was due to the suppression of NF-κB activation in the transcriptional level. This is the first report of the anti-inflammatory activity of omphalocarpin.

Anti-inflammatory activity of omphalocarpin isolated from Radix Toddaliae Asiaticae