Constituents of the stem bark of Discopodium penninervium and their LTB4 and COX-1 and -2 inhibitory activities.
The stem bark of Discopodium penninervium afforded a withanolide, 6alpha,7alpha-epoxy-1-oxo-5alpha,12alpha,17alpha-trihydroxywitha-2,24-dienolide (1) and a coloratane sesquiterpene, 7alpha,11alpha-dihydroxy-4(13),8-coloratadien-12,11-olide (4) along with five known compounds, withanone (2), 5alpha,17beta-dihydroxy-6alpha,7alpha-epoxy-1-oxowitha-2,24-dienolide (3), 7alpha,11alpha-dihydroxy-8-drimen-12,11-olide (5), withasomnine (6), and (E,Z)-9-hydroxyoctadeca-10,12-dienoic acid (7). The identity of the compounds was established on the basis of spectroscopic data analysis. All compounds were assessed for inhibition of leukotriene metabolism in an in vitro bioassay using activated human neutrophile granulocytes, and for in vitro cycloxygenase-1 and -2 inhibition from sheep cotyledons and seminal vesicles, respectively. In the leukotriene biosynthesis assay all compounds tested at a concentration of 50 microM exhibited activity with percentage inhibitions ranging from 11.5 to 36.6. The withanolide, 1, displayed a 46.4% inhibition of COX-2 and a 22.9% inhibition of LTB(4) formation at 50 microM concentration. Compounds 4 and 6 inhibited LTB(4) biosynthesis but showed minor inhibition of COX-1 and COX-2. The remaining compounds, on the other hand, were found to be inactive on COX enzymes.
Wube
Abraham Abebe
AA
Institute of Pharmaceutical Sciences, Department of Pharmacognosy, Karl-Franzens University Graz, Universitaetsplatz 4/1, A-8010 Graz, Austria.
Wenzig
Eva-Maria
EM
Gibbons
Simon
S
Asres
Kaleab
K
Bauer
Rudolf
R
Bucar
Franz
F
D000818:Animals; D002478:Cells, Cultured; D051545:Cyclooxygenase 1 / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism; D016861:Cyclooxygenase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D020024:Leukotriene Antagonists / Q000737:chemistry / Q000494:pharmacology*; D007975:Leukotriene B4 / Q000037:antagonists & inhibitors; D015394:Molecular Structure; D024301:Plant Bark / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D012717:Sesquiterpenes / Q000737:chemistry / Q000494:pharmacology; D019657:Solanaceae / Q000737:chemistry*; D054358:Withanolides / Q000737:chemistry / Q000494:pharmacology
D016861:Cyclooxygenase Inhibitors; D020024:Leukotriene Antagonists; D010936:Plant Extracts; D012717:Sesquiterpenes; D054358:Withanolides; D007975:Leukotriene B4; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2