942 N. R. BARBOSA ET AL. Copyright © 2004 John Wiley & Sons, Ltd. Phytother. Res. 18, 942–944 (2004) Copyright © 2004 John Wiley & Sons, Ltd. PHYTOTHERAPY RESEARCH Phytother. Res. 18, 942–944 (2004) Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/ptr.1579 SHORT COMMUNICATION Inhibition of Platelet Phospholipase A 2 Activity by Catuaba Extract Suggests Antiinflammatory Properties Nádia R. Barbosa, Lygia Fischmann, Leda L. Talib and Wagner F. Gattaz* Laboratory of Neuroscience, Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, Brazil In the inflammation process, phospholipase A 2 (PLA 2 ) catalyses the cleavage of the sn-2 ester-linked fatty acids from phospholipids, being the enzyme responsible for arachidonic acid (AA) release by cells for the biosynthesis of the prostaglandins and thromboxanes via the cyclooxygenase system, and the leukotrienes and eicosatetraenoids via the lipoxygenase pathway. AA mobilization by PLA 2 and subsequent prostaglandins synthesis is considered to be a pivotal event in inflammation. Therefore, drugs that inhibit PLA 2 , thus blocking the COX and LOX pathways in the AA cascade, may be effective in the treatment of inflammatory processes. New strategies for the treatment of inflammatory processes could be detected by a search for active principles of vegetal origin that control the lipid mediator production by inhibition of PLA 2 . The present data are part of a wide explorative investigation on the effects of Trichilia catigua (catuaba), which found that PLA 2 activity was totally inhibited by catuaba at a concentration of 120 μg/mL, suggesting that this natural substance may have antiinflammatory properties. Copyright © 2004 John Wiley & Sons, Ltd. Keywords: catuaba; phospholipase A2; antiinflammatory effects; inflammation; platelets. * Correspondence to: Professor W. F. Gattaz, Laboratory of Neuroscience, Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, Rua Doutor Ovidio Pires de Campos 785, CEP 05403-010 São Paulo, SP, Brazil. E-mail: gattaz@usp.br Contract/grant sponsor: Laboratorios Catarinense. Contract/grant sponsor: Associação Beneficiente Alzira Denise Hertzog da Silva. Received 8 January 2004 Accepted 12 July 2004 been extensively investigated as potent inhibitors of PLA 2 and have proved to be a potential source of natural antiinflammatory drugs (Garcia-Pastor et al., 1999a; Garcia-Pastor et al., 1999b). Accordingly, new strategies for the treatment of inflammatory processes could be detected by a search for active principles of vegetal origin that control the lipid mediator produc- tion by inhibition of PLA 2 . The present data are part of a wide explorative in- vestigation on the effects of catuaba on different bio- logical processes. A hydroalcoholic extract of Trichilia catigua (catuaba; Meliacea) has been used, for centuries, for a variety of purposes including analgesic, antibacte- rial, physical and mental fatigue, relaxing activity, gen- eral weakness and aphrodisiac (Vaz et al., 1997; Manabe et al., 1992; Antunes et al., 2001; Drewes et al., 2003). In the present study catuaba was found to have potent inhibitory effects on PLA 2 activity in platelets, suggesting thus that this natural substance may have antiinflammatory properties. MATERIALS AND METHODS Platelet isolation. Fresh blood (40 mL) was collected in 10 mL of sodium citrate-coated tubes. Blood sam- ples were homogenized in 1 mL of acid citrate dextrose solution (glucose 123.8 mm, sodium citrate 83.9 mm, citric acid 41.3 mm) and centrifuged for 15 min at 515 × g and room temperature. Supernatants (platelet-rich plasma fractions) were removed and the pH adjusted to 6.5 and centrifuged for 10 min at 1159 × g (room temperature). Pellets were resuspended in 5 mL of wash-solution (trisodium citrate 30 mm pH 6.5, KCl INTRODUCTION Inflammation processes are complex biochemical phe- nomena that are characterized physiologically in tissues by edema, pain and leukocyte infiltration (Vickerstaff and Bielory, 1990). Currently, the most effective anti- inflammatory drugs are glucocorticoids. Glucocorticoids induce many proteins, such as lipocortins. Lipocortins are inhibitors of phospholipase A 2 (PLA 2 ) (Flower and Blackwell, 1979; Di Rosa et al., 1984). In the inflamma- tion process, PLA 2 catalyses the cleavage of the sn-2 ester-linked fatty acids from phospholipids, being the enzyme responsible for arachidonic acid (AA) release by cells for the biosynthesis of the prostaglandins and thromboxanes via the cyclooxygenase (COX) system, and the leukotrienes and eicosatetraenoids via the lipo- xygenase (LOX) pathway (Sohn et al., 2003; Goldstein, 1992; Zheng et al., 1999). Arachidonic acid mobilization by PLA 2 and sub- sequent prostaglandins synthesis is considered to be a pivotal event in inflammation. Therefore, drugs that inhibit PLA 2 , thus blocking the COX and LOX path- ways (Backon, 1998; Dennis, 1997; Bydlowski et al., 1988) in the arachidonic acid cascade, may be effective in the treatment of inflammatory processes. For instance, some terpenoids obtained from a marine source have