Inhibition of inducible nitric oxide synthase and cyclooxygenase-2 expression by flavonoids isolated from Tanacetum microphyllum.
Plant flavonoids show anti-inflammatory activity both in vitro and in vivo. Some flavonoids have been reported previously to inhibit nitric oxide (NO) and prostaglandin E2 (PGE2) production by suppressing inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression. The present study focuses on the effect of various naturally occurring flavonoids (santin, ermanin, centaureidin and 5,3'-dihydroxy-4'-methoxy-7-methoxycarbonylflavonol) on modulation of lipopolysaccharide (LPS)-induced iNOS and COX-2 expression in RAW 264.7 cells. Western blotting showed that all flavonoids suppressed the induction of both iNOS and COX-2. Ermanin and 5,3'-dihydroxy-4'-methoxy-7-methoxycarbonylflavonol were the most potent inhibitors. This study suggests that inhibition of iNOS and COX-2 expression by flavonoids may be one of the mechanisms responsible for their anti-inflammatory effects, and that they may be potential agents for use in the treatment of inflammatory diseases.
Guerra
José Antonio
JA
Department of Pharmacology, Faculty of Pharmacy, University Complutense, Ciudad Universitaria s/n, 28040, Madrid, Spain.
Molina
María  Francisca
M
Abad
María José
MJ
Villar
Angel María
AM
Paulina
Bermejo
B
D000818:Animals; D002460:Cell Line; D051546:Cyclooxygenase 2 / Q000378:metabolism; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology*; D051379:Mice; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors* / Q000378:metabolism; D031203:Tanacetum / Q000737:chemistry*
D052246:Cyclooxygenase 2 Inhibitors; D004791:Enzyme Inhibitors; D005419:Flavonoids; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2