Phytomedicine 10: 176–184, 2003 © Urban & Fischer Verlag http://www.urbanfischer.de/journals/phytomed Phytomedicine 0944-7113/03/10/02-03-176 $ 15.00/0  Introduction Medicinal plants have long been used for the treatment of many diseases. Recently, several experimental studies have contributed scientific evidence for the pharmaco- logical effects of these medicinal plants observed in folk medicine. Croton celtidifolius Baill, commonly known as “sangue-de-adave”, is a tree found in the Atlantic For- est, mainly in the south of Brazil, including the state of Santa Catarina. The bark and leaf infusions of this plant have been popularly used for the treatment of leukemia, ulcer, rheumatism and other inflammatory diseases. Inflammatory diseases are accompanied by the chronic release of cytokines and reactive oxygen and Anti-inflammatory and antioxidant effects of Croton celtidifolius bark G. M. Nardi 1 ,R. Felippi 1 , S. DalBó 1 , J. M. Siqueira-Junior 1 , D. C. Arruda 1 , F. Delle Monache 2 , A. K. Timbola 3 , M. G. Pizzolatti 3 , K. Ckless 4 , R. M. Ribeiro-do-Valle 1 1 Departamento de Farmacologia, CCB, UFCS, Florianópolis, Brazil 2 Instituto di Biochimica e Biochimica Clinica, CNR, Universitá Cattolica Del Sacro Cuore, Rome, Italy 3 Departamento de Química, CFM, UFSC, Florianópolis, SC, Brazil 4 Departamento de Bioquímica, CCB, UFCS, Florianópolis, Brazil. [Present address: Department of Pathology, University of Vermont, HRSF Building, Burlington, USA] Summary Croton celtidifolius Baill commonly known as “sangue-de-adave” is a tree found in the Atlantic For- est of south of Brazil, mainly in Santa Catarina. The bark and leaf infusions of this medicinal plant have been popularly used for the treatment of inflammatory diseases. In this study we evaluated the anti-inflammatory and antioxidant properties of crude extract (CE), aqueous fraction (AqF), ethyl acetate fraction (EAF), butanolic fraction (BuF) and catechin, gallocatechin and sub-fractions, 19SF, 35SF and 63SF that contained a mixture of proanthocyanidins and were derived from the EAF fraction. The CE, AqF, EAF, BuF, catechin and sub-fractions 35SF and 63SF reduced paw edema induced by carrageenan. The CE, fractions, sub-fractions and isolated compounds showed antioxidant properties in vitro, all were able to scavenge superoxide anions at a concentration of 100 μg·ml –1 . The EAF, catechin and gallocatechin were most effective in the deoxyribose assay, IC50 0.69 (0.44–1.06), 0.20 (0.11–0.39), 0.55 (0.28–1.08) μg·ml –1 respectively. The CE and other frac- tions and sub-fractions inhibited deoxyribose degradation up to 1 μg·ml –1 . In the hydrophobic sys- tem only AqF did not show lipid peroxidation inhibition. The CE, other fractions, sub-fractions and isolated compounds inhibited lipidid peroxidation only at a concentration of 100 μg·ml –1 . In sum- mary, this study demonstrates that Croton celtidifolius bark has significant anti-inflammatory and antioxidant activity. Key words: Croton celtidifolius, paw edema, antioxidants, reactive oxygen species, proanthocyanidins, anti-inflammatory