Effects of constituents from the bark of Magnolia obovata on nitric oxide production in lipopolysaccharide-activated macrophages

Chem Pharm Bull (Tokyo). 2001 Jun;49(6):716-20. doi: 10.1248/cpb.49.716.


The methanolic extract from a Japanese herbal medicine, the bark of Magnolia obovata, was found to inhibit nitric oxide (NO) production in lipopolysaccharide (LPS)-activated macrophages. By bioassay-guided separation, three neolignans (magnolol, honokiol, obovatol) and three sesquiterpenes (alpha-eudesmol, beta-eudesmol, gamma-eudesmol) were obtained as active constituents. A trineolignan (magnolianin), a phenylpropanoid glycoside (syringin), lignan glycosides (liriodendrin, (+)-syringaresinol 4'-O-beta-D-glucopyranoside) and a sesquiterpene (caryophyllene oxide) did not show any activity. On the other hand, sesquiterpene-neolignans (eudesmagnolol, clovanemagnolol, caryolanemagnolol, eudeshonokiol A, eudesobovatol A) showed the strong cytotoxic effects. Active constituents (magnolol, honokiol, obovatol) showed weak inhibition for inducible NO synthase (iNOS) enzyme activity, but potent inhibition of iNOS induction and activation of nuclear factor-kappaB.

MeSH terms

  • Animals
  • Cell Line
  • Lipopolysaccharides / pharmacology*
  • Macrophage Activation / drug effects*
  • Macrophages / drug effects*
  • Macrophages / metabolism
  • Magnoliopsida / chemistry*
  • Mice
  • Nitric Oxide / biosynthesis*
  • Plant Extracts / pharmacology*


  • Lipopolysaccharides
  • Plant Extracts
  • Nitric Oxide