Deoxypodophyllotoxin, naturally occurring flavolignan, inhibits lipopolysaccharide-induced iNOS expression require inhibition of NF-B activation in RAW264.7 macrophage cells
Deoxypodophyllotoxin (DPT), a naturally occurring flavolignan with anti-inflammatory activity, was isolated from Anthriscus sylvestris Hoffm., and we examined its effects on the expression of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-stimulated, murine macrophage-like RAW264.7 cells. Western blot analysis performed with specific anti-iNOS antibodies showed that a decrease in nitric oxide (NO) was accompanied by a decrease in the iNOS protein level. To clarify the mechanistic basis for DPT's ability to inhibit iNOS induction, we examined the effect of DPT on NF-κB transcriptional activity and DNA binding activity. DPT potently suppressed both reporter gene activity and DNA binding activity. These findings suggest that DPT in RAW264.7 cells abolished LPS-induced iNOS expression by inhibiting the transcription factor, NF-B.
Acknowledgements: This work was supported by Korea Research Foundation Grant (KRF-2006–005-J01102).
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