New constituents from Mikania laevigata Shultz Bip. ex Baker

A new phenylpropanoid and two new diterpenes were isolated from the leaves of the plant Mikania laevigata Shultz Bip. ex Baker. The structures of these compounds were established by 1D- and 2D-nuclear magnetic resonance spectroscopic techniques and mass spectrometry data. Taraxerol, lupeol, coumarin, syringaldehyde, trans-melilotoside, cis-melilotoside, adenosine, patuletin 3-O-beta-D-glucopyranoside, kaempferol 3-O-beta-D-glucopyranoside, quercetin 3-O-beta-D-glucopyranoside, methyl 3,5-di-O-caffeoyl quinate, and 3,3`,5-trihydroxy-4`,6,7-trimethoxyflavone were isolated too. In addition, the compounds dihydrocoumarin, spathulenol, caryophyllene oxide, kaurenoic acid, beyerenoic acid, and lupeol acetate were identified by GC-MS. (C) 2010 Elsevier Ltd. All rights reserved.

Anti-inflammatory activity and possible mechanism of extract from Mikania laevigata in carrageenan-induced peritonitis

Objectives The aim was to test the potential use of an extract of Mikania laevigata (popularly known in Brazil as guaco), made from leaves harvested in different months of the year, oil neutrophil migration after all inflammatory Stimulus and investigate the underlying molecular mechanisms. Methods We examined the effect of guaco on vascular permeability and leucocyte function in carrageenan-induced peritonitis in mice. Key findings Our results demonstrated that guaco extract administered subcutaneously (3 mg/kg) decreased the vascular permeability and also leucocyte rolling and adhesion to the inflamed tissues by a mechanism dependent on nitric oxide. Specifically, inhibitors of nitric oxide synthase remarkably abrogated the guaco extract-mediated suppression of neutrophil migration to the inflammatory site. In addition, guaco extract-mediated suppression of neutrophil migration appeared to be dependent on the production of the cytokines interleukin-1 beta and tumour necrosis factor-alpha. One of the major constituents of the guaco extract, coumarin, was able to inhibit the neutrophil migration towards the inflammatory focus. Conclusions In conclusion the anti-inflammatory effect induced by guaco extract may be by inhibition of pro-inflammatory cytokine production at the inflammatory site.