Journal of Ethnopharmacology 112 (2007) 585–589 Ethnopharmacological communication Anti-inflammatory activity of flavonoids from Eupatorium arnottianum M. Clavin a, , S. Gorzalczany b , A. Macho c , E. Mu ˜ noz c , G. Ferraro a , C. Acevedo b , V. Martino a a Department of Pharmacognosy, Faculty of Pharmacy and Biochemistry, University of Buenos Aires, Jun´ ın 956, 1113 Buenos Aires, Argentina b Department of Pharmacology, Faculty of Pharmacy and Biochemistry, University of Buenos Aires, Jun´ ın 956, 1113 Buenos Aires, Argentina c Cellular Biology, Physiology and Immunology. University of C´ ordoba, Av. Men´ endez Pidal S/n, E-14004 C ´ ordoba, Spain Received 10 October 2006; received in revised form 4 April 2007; accepted 11 April 2007 Available online 24 April 2007 Abstract Three anti-inflammatory compounds: nepetin, jaceosidin and hispidulin have been isolated and identified from Eupatorium arnottianum Griseb. dichloromethane extract. Nepetin reduced the TPA mouse ear edema by 46.9% and jaceosidin by 23.2% (1 mg/ear). Both compounds inhibited the NF B induction by 91 and 77%, respectively. Furthermore phytochemical analysis of the ethanol extract has led to the identification of eriodictyol, hyperoside, rutin, caffeic and chlorogenic acids. All these compounds are reported for the first time in this species. The finding of topical antiinflammatory activity exerted by Eupatorium arnottianum extract and the identification of active principles could support the use of this plant for the treatment of inflammatory affections. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Eupatorium arnottianum; Chromolaena arnottiana; Asteraceae; Anti-inflammatory activity; Flavonoids; NF B 1. Introduction The genus Eupatorium belongs to the Eupatoriae tribe and its taxonomy has been reviewed some years ago. It comprises 44 species, distributed in Eastern and Western Asia, Europe, and in America from the North-East of the United States up to the North and Centre of Argentina (King and Robinson, 1970). Eupatorium cannabinum and Eupatorium perfoliatum are the more representative species of the genus and are widely used in phytotherapy as choleretic, hepatoprotective, and against fever, colds and rheumatism. They are chemically characterized by the presence of sesquiterpene lactones, flavonoids, alkaloids and polysaccha- rides (Woerdenbag, 1993). Though these species have been extensively studied, there are few reports about the bioactivities and the chemical composition of the argentine medicinal representatives of the genus. Corresponding author. Tel.: +54 11 4964 8247/8; fax: +54 11 4508 3642. E-mail address: mclavin@ffyb.uba.ar (M. Clavin). Fifteen medicinal Eupatorium species are described as native to Argentina. They have been used by indian and rural popula- tions as febrifugue, antiseptic, for the treatment of different kind of pains and inflammation, headaches and to cure sores and pim- ples (Toursarkissian, 1980; Mart´ ınez Crovetto, 1981; Zardini, 1984). As a part of our investigation project in the evaluation of biological activities related to ethnopharmacological uses of argentine medicinal Eupatorium species, we have demonstrated antinociceptive, antimicrobial, immunostimulant and antiplas- modial effects for Eupatorium arnottianum (Clavin et al., 2000; Penna et al., 1997; Fern´ andez et al., 2002; Debenedetti et al., 2002). Eupatorium arnottianum Griseb. (“clavel”, “tuji”) is an herb that grows in the North-East and Centre of Argentina and South of Bolivia. It is used by rural populations of Santa Victoria e Iruy´ a (Salta, Argentina) for gastric pains (Iharlegui and Hurrell, 1992) and by “kallawaya” healers from the bolivian altiplano against asthma, bronchitis, colds and topically in plasters for bone fractures and dislocations (Giraoult, 1987). Previous phy- tochemical studies report the presence of cadinene derivatives, 0378-8741/$ – see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.jep.2007.04.007