Journal of Ethnopharmacology 122 (2009) 430–433 Contents lists available at ScienceDirect Journal of Ethnopharmacology journal homepage: www.elsevier.com/locate/jethpharm Screening of the topical anti-inflammatory activity of the bark of Acacia cornigera Willdenow, Byrsonima crassifolia Kunth, Sweetia panamensis Yakovlev and the leaves of Sphagneticola trilobata Hitchcock M. Maldini a , S. Sosa b , P. Montoro a , A. Giangaspero b , M.J. Balick c , C. Pizza a,∗ , R. Della Loggia b a Department of Pharmaceutical Science, University of Salerno, via Ponte don Melillo, 84084, Fisciano (Sa), Italy b Department of Materials and Natural Resources, University of Trieste, Via A. Valerio 6, 34127 Trieste, Italy c Institute of Economic Botany, The New York Botanical Garden, Bronx, NY 10458-5126, USA article info Article history: Received 28 November 2008 Received in revised form 27 January 2009 Accepted 2 February 2009 Available online 11 February 2009 Keywords: Sweetia panamensis Byrsonima crassifolia Acacia cornigera Sphagneticola trilobata Anti-inflammatory activity abstract Ethnopharmacological relevance: An investigation of topical anti-inflammatory activity was undertaken on plants used in Central America traditional medicine. Aim of study: Four herbal drugs used in the folk medicine of Central America to treat inflammatory skin affections (Acacia cornigera bark, Byrsonima crassifolia bark, Sphagneticola trilobata leaves and Sweetia panamensis bark) were evaluated for their topical anti-inflammatory activity. Materials and methods: Petroleum ether, chloroform and methanol extracts were obtained for herbal medicines and then extracts were tested on Croton oil-induced ear dermatitis model in mice. Results: Almost all the extracts reduced the Croton oil-induced ear dermatitis in mice and the chloroform ones showed the highest activity, with ID 50 (dose giving 50% oedema inhibition) values ranging from 112 g/cm 2 (Byrsonima crassifolia) to 183 g/cm 2 (Sphagneticola trilobata). As reference, ID 50 of the non- steroidal anti-inflammatory drug indomethacin was 93 g/cm 2 . Conclusions: Lipophilic extracts from these species can be regarded as potential sources of anti- inflammatory principles. © 2009 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Inflammation is a complex biological response of vascular tis- sues to harmful stimuli, such as pathogens, damaged cells, or irritants. It is a defence mechanism aimed to remove the injurious stimuli and initiate the tissue healing process. Anyway, inflamed tis- sues can respond to noxious stimuli producing different bioactive mediators which interact with many cell types and molecules to amplify the phlogistic reaction. This event can lead to uncontrolled inflammatory response that may cause or sustain a pathologic pro- cess involved in different pathologies. Inflammation is treated with steroidal and non-steroidal anti-inflammatory drugs, known for their efficacy but also for a number of undesirable side effects (Saklatvala, 2002; O’connor et al., 2003; Davies et al., 2006; Schoepe et al., 2006). Thus, new effective and safe anti-inflammatory agents are needed. It has been widely shown that herbal drugs are used, in tradi- tional medicine of many countries, to cure various inflammatory ∗ Corresponding author. Tel.: +39 089 969765; fax: +39 089 969602. E-mail address: pizza@unisa.it (C. Pizza). conditions, representing potential source of anti-inflammatory agents. Nevertheless, though their use is supported by an old tra- dition among native peoples, scientific studies demonstrating the real pharmacological properties of these plants are often lacking. Therefore, scientific studies are required to judge the real efficacy of the medicinal properties popularly claimed for some plants. This study is aimed to evaluate the topical anti-inflammatory properties of four medicinal plants, used in the traditional medicine of Central America to prepare decoctions, infusions or baths as remedies against inflammatory-based disorders: Sweetia pana- mensis (Bentham) Yakovlev (Fabaceae) bark, Byrsonima crassifolia (L.) Kunth (Malpighiaceae) bark, Acacia cornigera (L.) Willdenow (Mimosaceae) bark and Sphagneticola trilobata (L.) Pruski [=Wedelia trilobata (L.) Hitchcock; Asteraceae] leaves. Sphagneticola trilobata is a weed employed to treat back- ache, muscle cramps, rheumatism, stubborn wounds, sores and swellings, and arthritic painful joints (Arvigo and Balik, 1993). A study on the biological properties of Sphagneticola trilobata demon- strated its antimicrobial properties for the n-hexane and ethyl acetate extracts of the aerial parts without flowers against Gram- positive and/or Gram-negative bacteria, but not against yeasts and fungi (Taddei and Rosas-Romero, 1999). The bark and thorns of Aca- cia cornigera are used as snakebite remedy and to treat onset of 0378-8741/$ – see front matter © 2009 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.jep.2009.02.002