title: Anti-inflammatory and membrane-stabilizing stigmastane steroids from Alchornea floribunda leaves.
abstract: Alchornea floribunda (Euphorbiaceae) leaves are widely used in African ethnomedicine for the management of acute and chronic inflammatory disorders. In the present study, bioactivity-guided fractionation led to the isolation of two known (1 and 3) and one new (2) stigmastane steroids from the hexane extract of Alchornea floribunda leaves. The anti-inflammatory activities of these compounds were evaluated using IN VITRO and IN VIVO animal models. The compounds 1, 2, and 3 at 50 and 100 microg/ear significantly (p < 0.05) inhibited xylene-induced ear edema in mice in a dose-dependent manner. The topical anti-inflammatory effect of 1 and 2 are significantly (p < 0.05) higher than that of indomethacin and prednisolone. At 20 mg/kg (i. p.), all the compounds significantly (p < 0.05) inhibited acute inflammation induced by subplantar injection of egg albumen in rats. Compound 1 exhibited an anti-inflammatory effect (50.9 % edema inhibition) comparable (p < 0.05) to that of prednisolone (48.0 % edema inhibition) at 3 h. Compounds 1, 2, and 3 (50 microg/mL) significantly (p < 0.05) inhibited heat-induced haemolysis of human erythrocytes in vitro, but had no effect on hypotonicity-induced hemolysis. The compounds were elucidated as (24R)-5alpha-stigmast-3,6-dione ( 1), 5alpha-stigmast - 23-ene-3,6-dione ( 2), and 3beta-hydroxy-5alpha-stigmast-24-ene ( 3) by spectral analysis. The results of this study show that these compounds may, in part, account for the anti-inflammatory effect of Alchornea floribunda leaves. This is the first report on the isolation and structure elucidation of these anti-inflammatory steroids from Alchornea floribunda leaves.
authors.affiliation: Department of Pharmaceutical Chemistry, University of Nigeria, Nsukka, Enugu State, Nigeria. basdenc@yahoo.com
authors.forename: Festus B C
authors.initials: FB
authors.lastname: Okoye
authors.forename: Patience O
authors.initials: PO
authors.lastname: Osadebe
authors.forename: Peter
authors.initials: P
authors.lastname: Proksch
authors.forename: Ru Angelie
authors.initials: RA
authors.lastname: Edrada-Ebel
authors.forename: Chukwuemeka S
authors.initials: CS
authors.lastname: Nworu
authors.forename: Charles O
authors.initials: CO
authors.lastname: Esimone
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D002462:Cell Membrane / Q000187:drug effects*; D002783:Cholestenones / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004487:Edema / Q000139:chemically induced / Q000188:drug therapy*; D004912:Erythrocytes / Q000187:drug effects; D019665:Euphorbiaceae / Q000737:chemistry*; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D051379:Mice; D015394:Molecular Structure; D010840:Phytosterols / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D018515:Plant Leaves; D051381:Rats; D017208:Rats, Wistar; D014992:Xylenes
chemical_list: C549090:5alpha-stigmastane-23-ene-3,6-dione; D000893:Anti-Inflammatory Agents; D002783:Cholestenones; D010840:Phytosterols; D010936:Plant Extracts; D014992:Xylenes