IDEHU   05542
INSTITUTO DE ESTUDIOS DE LA INMUNIDAD HUMORAL PROF. RICARDO A. MARGNI
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
In vitro antiprotozoal activity of the organic extract and isolated compounds from Ambrosia tenuifolia Sprengel (Asteraceae)
Autor/es:
SÜLSEN, VALERIA; CAZORLA, SILVIA; FRANK, FERNANDA; MALCHIODI, EMILIO; ANESINI, CLAUDIA; COUSSIO, JORGE; MARTINO, VIRGINIA; MUSCHIETTI, LILIANA
Lugar:
Perugia, Italia
Reunión:
Congreso; XV Congresso Italo-Latinoamericano di Etnomedicina Ivano Morelli; 2006
Institución organizadora:
Societa Italo-Latinoamericana di Etnomedicina (SILAE)
Resumen:
American trypanosomiasis and leishmaniasis are a major worldwide health problem with high endemicity in Latin America. The side effects and the emerging resistance to available drugs has led to the urgent need for new therapeutic agents against these diseases. We have already reported the trypanocidal activity of the organic extract (CH2Cl2-MeOH [1:1]) of Ambrosia tenuifolia as a result of our ongoing search on antiparasitic compounds from natural sources (1). Based on this result a bioassay- guided fractionation was carried out for the isolation of its active compounds. Column chromatography (CC) of this extract on Si gel, afforded 5 fractions (F1-F5). The most active fraction, F4 (88.50 % of growth inhibition at 10 mg/ml) was further fractionated by CC on Sephadex LH-20 giving rise to compounds 1 and 2 from fractions F4(85-92) and F4(105-107) respectively. These compounds were identified as peruvin (1) (3aR,4aS,7aR,8S,9aR)-decahydro-7a-hydroxy-4a,8-dimethyl-3-methyleneazuleno[6,5-b]furan-2,5-dione) and hispidulin (2) (5,7,4´-trihydroxy, 6-methoxy flavone) by means of spectroscopic analysis (IR, UV, MS 1HRMN). IC50 (50% inhibitory concentration) values of compounds 1 and 2 against epimastigote forms of Trypanosoma cruzi were 2.07 mg/ml and 14.00 mg/ml respectively. Besides, hispidulin was active against promastigote forms of Leishmania mexicana showing an IC50 value of 2.09 mg/ml. Both compounds were tested for in vitro cytotoxic activity on lymphoid cell suspensions. The CC50 (concentration required for 50 % cytotoxicity) values were 35 µg/ml for peruvin and >50 µg/ml for hispidulin. This is the first time that the trypanocidal activity of 1 and 2 and the leishmanicidal activity of 2 are reported. Further in vivo studies and evaluation of underlying mechanisms are required. Leishmanicidal activity of peruvin and identification of other active compounds in the extract is now in progress.  (1) Sülsen V., C. Güida, J. Coussio, C. Paveto, L. Muschietti, V. Martino (2006) In vitro evaluation of trypanocidal activity in plants used in Argentine traditional medicine. Parasitology Research 98 (4):370-374.