Three anti-inflammatory stigmastane steroids from Alchornea floribunda leaves

The anti-inflammatory activity of Alchornea cordifolia has been reported in previous studies [1,2,3]. In the present study, bioactivity – guided fractionation led to the isolation of three stigmastane steroids from 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 5mg/ear inhibited xylene – induced ear edema in mice, with edema inhibitions of 59.9, 51.5 and 51.54% respectively. At 20mg/kg (ip), all the compounds significantly (p<0.05) inhibited acute inflammation induced by subplanta injection of undiluted egg albumen in rats' paw. Compound 1 exhibited a higher anti-inflammatory effect (% edema inhibition=50. 0) than prednisolone (% edema inhibition=48.0) at 3h. 1 and 3 at concentrations of 50 and 100µg/ml significantly (p<0.05) stabilized heat-induced haemolysis of human erythrocytes in vitro, but have no effect on hypotonicity-induced haemolysis. Spectral analysis elucidated the compounds as stigmastane –3, 6– dione (1), stigmastane –22– ene –3, 6– dione (2) and 3– hydroxystigmastane –22– ene (3). 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 anti-inflammatory steroids from Alchornea floribunda leaves.

Acknowledgements: Institute of Anorganic Chemistry and Structure Chemistry, Heinrich-Heine-Universität, Germany. DrRuAngelie Edrada-Ebel Strathclyde Institute of Pharmacy and Biomedical Sciences University of Strathclyde Glasgow, Scotland.

References: 1. Osadebe, PO., Okoye, FBC. (2003)J Ethnopharmacol 89:19–24. 2. Manga et al. (2004). J Ethnopharmacol 92:209–214. 3. Osadebe et al. (2008). RPMP 22:589–595.