Prostaglandins and nitric oxide produced by inducible cyclooygenase (COX-2) and nitric oxide synthase (iNOS), respectively, have been implicated as important mediators in the processes of inflammation and carcinogenesis. These potential COX-2 and iNOS inhibitors have been considered as antiinflammatory and cancer chemopreventive agents. In this study, we investigated the effect of natural sesquiterpenoids isolated from plants of the Zingiberaceae family on the activities of COX-2 and iNOS in cultured lipopolysaccharide (LPS)-activated mouse macrophage cell RAW 264.7 to discover new lead compounds as COX-2 or iNOS inhibitors. Xanthorrhizol, a sesquiterpenoid, isolated from the rhizome of Curcuma xanthorrhiza Roxb. (Zingiberaceae), exhibited a potent inhibition of COX-2 (IC50 = 0.2 μg/mL) and iNOS activity (IC50 = 1.0 μg/mL) in the assay system of prostaglandin E2 (PGE2) accumulation and nitric oxide production, respectively. Western blot analyses revealed that the inhibitory potential of xanthorrhizol on the COX-2 activity coincided well with the suppression of COX-2 protein expression in LPS-induced macrophages. In addition, sesquiterpenoids β-turmerone and ar-turmerone isolated from the rhizome of Curcuma zedoaria Roscoe (Zingiberaceae) also showed a potent inhibitory activity of COX-2 (β -turmerone, IC50 = 1.6 μg/mL; ar-turmerone, IC50 = 5.2 μg/mL) and iNOS (β-turmerone, IC50 = 4.6 μg/mL; ar-turmerone, IC50 = 3.2 μg/mL). These results suggest that natural sesquiterpenoids from C. xanthorrhiza and C. zedoaria might be lead candidates for further developing COX-2 or iNOS inhibitors possessing cancer chemopreventive or anti-inflammatory properties.
|Number of pages||8|
|Journal||Journal of Environmental Pathology, Toxicology and Oncology|
|Publication status||Published - 2002 Jun 29|
All Science Journal Classification (ASJC) codes
- Pathology and Forensic Medicine
- Health, Toxicology and Mutagenesis