The aim of this study was to evaluate the inhibition of the aqueous extract of seeds (AEs) from Guettarda angelica on cell infection by two avian RNA viruses: avian reovirus (ARV) and metapneumovirus (AMPV). The cytotoxic and antiviral activities were evaluated by MTT assay to determine the 50% cytotoxic (CC50) and inhibitory concentrations (IC50). The selectivity index (SI=CC50/IC50) also carried out. AEs exhibited antiviral activity only against ARV presenting IC50 of 23.59g/mL. This inhibition was not due to any cytotoxic effect of AEs since the CC50 on Vero cells was of 400.60g/μL and its SI was of 17.00; this extract also showed a virucidal effect on ARV. Previous studies also demonstrated antiviral activity of AEs extract against three animal herpesviruses. Thus, the seeds from G. angelica showing antiviral activity against DNA and RNA viruses, enveloped and non-enveloped, could be promising source of new antiviral agents encouraging its fractionation to isolate the active compound.373133Agra, M.F., Silva, K.N., Basílio, I.J.L.D., Freitas, P.F.F., Barbosa-Filho, J.M., Survey of medicinal plants used in the region Northeast of Brazil (2008) Revista Brasileira de Farmacognosia., 18 (3), pp. 472-508Barros, A.V., Conceição, A.O., Simoni, I.C., Arns, C.W., Fernandes, M.J.B., Mechanisms of antiviral action of seeds from Guettarda angelica Mart (2010) against bovine and swine herpesviruses in vitro. Virus Reviews & Research., 15 (2), pp. 78-91Barros, A.V., Araújo, L.M., Oliveira, F.F., Conceição, A.O., Simoni, I.C., Fernandes, M.J.B., Arns, C.W., In Vitro evaluation of the antiviral potential of Guettarda angelica against animal herpesviruses (2012) Acta Scientiae Veterinariae., 40 (4), p. 1068Bispo, N.J., Francisco, N.M.C., Schmitt, A.C., Atividade antimicrobiana in vitro do extrato metanólico da planta Guettarda angelica sobre bactérias gram-positivas e gram-negativas (2007) Laes and Haes., 4, pp. 164 - 169Chattopadhyay, D., Naik, T.N., Antivirals of ethonomedicinal origin: structure-activity relationship and scope (2007) Mini-Reviews in Medicinal Chemistry., 7, pp. 275-301Cos, P., Vlietinck, A.J., Vanden Berghe, D., Maesa, L., Antiinfective potential of natural products: How to develop a stronger in vitro 'proof-of-concept' (2006) Journal of Ethnopharmacology., 106, pp. 290-302Dezegrini, R., Silva, S.C., Weiss, M., Kreutz, L.C., Weibin, F., Flores, E.F., Atividade de três drogas antivirais sobre os herpesvírus bovino tipo 1, 2 e 5 em cultivo celular (2010) Pesquisa Veterinária Brasileira., 30 (10), pp. 855-860Gough, R.E., Jones, R.C., Avian metapneumovirus (2008), pp. 100-110. , In Y.M. Saif (12th Ed.) Diseases of Poultry. BlackwellJassim, S.A.A., Naji, M.A., Novel antiviral agents: a medicinal plant perspective (2003) J Applied Microbiology., 95, pp. 412-427Lupini, C., Cecchinato, M., Scagliarini, A., Graziani, R., Catelli, E., In vitro antiviral activity of chestnut and quebracho woods extracts against avian reovirus and metapneumovirus (2009) Research in Veterinary Science., 87, pp. 482-487Newman, D.J., Cragg, G.M., Snader, K.M., Natural products as sources of new drugs over the period 1981-2002 (2003) Journal of Natural Products., 66, pp. 1022-1037Rates, S.M.K., Plants as source of drugs (2001) Toxicon., 39, pp. 603- 613Roner, M.R., Sprayberry, J., Spinks, M., Dhanji, S., Antiviral activity obtained from aqueous extracts of the Chilean soapbark tree (Quillaja saponaria Molina) (2007) Journal of General Virology., 88, pp. 275- 285Rosenberg, J.K., Reovirus Infections (2003), pp. 283-298. , In: H.J. Calnek, C.W. Barnes, W.M. Beard, H.W. Yoder (11th Ed.) Disease of Poultry. Iowa State Univ. Press, AmesSimoni, I.C., Manha, A.P.S., Sciessere, L., Hoe, V.M.H., Takinami, V.H., Fernandes, M.J.B., Evaluation of the antiviral activity of Brazilian cerrado plants against animal viruses (2007) Virus Reviews & Research., 12 (1-2), pp. 25-31Tsuchiya, Y., Shimizu, M., Hiyama, Y., Itoh, K., Hashimoto, Y., Nakayama, M., Horie, T., Morita, N., Antiviral activity of natural occurring flavonoids in vitro (1985) Chemical & Pharmaceutical Bulletin., 33 (9), pp. 3881-388
