title: Okanin, a chalcone found in the genus Bidens, and 3-penten-2-one inhibit inducible nitric oxide synthase expression via heme oxygenase-1 induction in RAW264.7 macrophages activated with lipopolysaccharide.
abstract: Excess production of nitric oxide by activated macrophages via inducible nitric oxide synthase leads to the development of various inflammatory diseases. Heme oxygenase-1 expression via activation of nuclear factor-erythroid 2-related factor 2 inhibits nitric oxide production and inducible nitric oxide synthase expression in activated macrophages. Okanin is one of the most abundant chalcones found in the genus Bidens (Asteraceae) that is used as various folk medications in Korea and China for treating inflammation. Here, we found that okanin (possessing the α-β unsaturated carbonyl group) induced heme oxygenase-1 expression via nuclear factor-erythroid 2-related factor 2 activation in RAW264.7 macrophages. 3-Penten-2-one, of which structure, as in okanin, possesses the α-β unsaturated carbonyl group, also induced nuclear factor-erythroid 2-related factor 2-dependent heme oxygenase-1 expression, while both 2-pentanone (lacking a double bond) and 2-pentene (lacking a carbonyl group) were virtually inactive. In lipopolysaccharide-activated RAW264.7 macrophages, both okanin and 3-penten-2-one inhibited nitric oxide production and inducible nitric oxide synthase expression via heme oxygenase-1 expression. Collectively, our findings suggest that by virtue of its α-β unsaturated carbonyl functional group, okanin can inhibit nitric oxide production and inducible nitric oxide synthase expression via nuclear factor-erythroid 2-related factor 2-dependent heme oxygenase-1 expression in lipopolysaccharide-activated macrophages.
authors.affiliation: Department of Neurosurgery, Wonkwang University School of Medicine, 344-2 Shinyong-dong, Iksan 570-749, Republic of Korea.
authors.forename: Jin-Sang
authors.initials: JS
authors.lastname: Kil
authors.forename: Young
authors.initials: Y
authors.lastname: Son
authors.forename: Yong-Kwan
authors.initials: YK
authors.lastname: Cheong
authors.forename: Nam-Ho
authors.initials: NH
authors.lastname: Kim
authors.forename: Hee Jong
authors.initials: HJ
authors.lastname: Jeong
authors.forename: Ji-Wung
authors.initials: JW
authors.lastname: Kwon
authors.forename: Eoh-Jin
authors.initials: EJ
authors.lastname: Lee
authors.forename: Tae-Oh
authors.initials: TO
authors.lastname: Kwon
authors.forename: Hun-Taeg
authors.initials: HT
authors.lastname: Chung
authors.forename: Hyun-Ock
authors.initials: HO
authors.lastname: Pae