Journal of Ethnopharmacology 99 (2005) 211–214 Ethnoveterinary medicine in the search for antimicrobial agents: Antifungal activity of some species of Pterocaulon (Asteraceae) Ana Cristina Stein a , Maximiliano Sortino b , C´ esar Avancini c,1 , Susana Zacchino b , Gilsane von Poser a,∗ a Programa de P´ os Gradua¸ c˜ ao em Ciˆ encias Farmacˆ euticas, Universidade Federal do Rio Grande do Sul-Av. Ipiranga 2752, 90610-000 Porto Alegre, RS, Brazil b Facultad de Ciencias Bioqu´ ımicas y Farmac´ euticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina c Faculdade de Veterin´ aria, Depto. de Medicina Veterin´ aria Preventiva, Universidade Federal do Rio Grande do Sul-Av. Bento Gon¸ calves 9090, 90540-000 Porto Alegre, RS, Brazil Received 28 May 2004; received in revised form 5 January 2005; accepted 7 February 2005 Available online 18 April 2005 Abstract Based on informal interview, ethnoveterinary information about plants used in the treatment of skin diseases were obtained. Plants from the genus Pterocaulon (Asteraceae) known as “quitoco” are used to treat problems popularly diagnosed as “mycoses”, which can have both fungic and bacterial etiology. In order to validate this traditional practice, the crude methanolic extracts and fractions from the aerial parts of three species of Pterocaulon (Pterocaulon alopecuroides (Lam.) D.C., Pterocaulon balansae Chodat. and Pterocaulon polystachyum D.C.) grown in southern Brazil were analyzed for the in vitro antifungal activity against a panel of standardized and clinical opportunistic pathogenic yeasts and filamentous fungi including dermatophytes by the agar dilution method. The crude methanolic extract of Pterocaulon alopecuroides was the most active followed by the extract of Pterocaulon polystachyum. Pterocaulon balansae crude methanolic extract was the less active but its lipophilic fractions showed remarkable activity mainly against the dermatophytes. © 2005 Published by Elsevier Ireland Ltd. Keywords: Pterocaulon species; Asteraceae; Ethnoveterinary; Antifungal activity; Broth dilution assay 1. Introduction Dermal and mucosal human fungal infections have in- creased at an alarming rate in the last 30 years, mainly due to the growing population of immunocompromised individuals such as cancer patients receiving chemotherapy and patients submitted to organ transplantation, being treated with im- munosuppressive drugs. HIV-positive patients strongly con- tribute to this problem since they have developed resistence to treatment with fluconazole, the most currently used anti- fungal (Groll et al., 1996; Denning et al., 1997; Portillo et al., 2001; Schmourlo et al., 2005). ∗ Corresponding author. Tel.: +55 51 3165258; fax: +55 51 3305610. E-mail address: gilsane@farmacia.ufrgs.br (G. von Poser). 1 Tel.: 55 51 33166123. With few exceptions, veterinary and human mycology deals with the same fungal pathogens (Acha and Szyfres, 2003) and, therefore, the traditional or popular experience regarding the treatment of animal mycoses (ethnoveterinary treatments) is considered nowadays a valuable knowledge for the discovery of new antifungal drugs for human beings (McCorkle, 1986; Mathias-Mundy and McCorkle, 1995). Both human and animal mycoses are not always success- fully treated, since the available antifungal drugs are ineffec- tive, produce many adverse effects, show recurrence, or lead to the development of resistance. There is a general consen- sus that new antifungal agents which overpass these disad- vantages are strongly needed (Selitrennikoff, 2001). Although most antibiotics in clinical use have been ob- tained from microorganisms, a renewed interest in plant an- timicrobials in the last 20 years has been emerged. Only a very 0378-8741/$ – see front matter © 2005 Published by Elsevier Ireland Ltd. doi:10.1016/j.jep.2005.02.011