Activity of the antimicrobial peptide P34 against bovine alphaherpesvirus type 1/Atividade do peptideo antimicrobiano P34 contra o alfaherpesvirus bovino tipo 1

Previous studies have demonstrated the antimicrobial activity of the peptide P34. In this study, the antiviral potential of P34 and the in vitro mechanism of action were investigated against bovine alphaherpesvirus type 1 (BoHV1). P34 exhibited low toxicity, a high selectivity index (22.9) and a percentage of inhibition of up to 100% in MDBK cells. Results from antiviral assays indicated that P34 did not interact with cell receptors, but it was able to inhibit the viral penetration immediately after pre-adsorption. In addition, BoHV1 growth curve in MDBK cells in the presence of P34 revealed a significant reduction in virus titer only 8h post-infection, also suggesting an important role at late stages of the replicative cycle. Virucidal effect was observed only in cytotoxic concentrations of the peptide. These findings showed that the antimicrobial peptide P34 may be considered as a potential novel inhibitor of in vitro herpesviruses and must encourage further investigation of its antiherpetic activity in animal models as well as against a wide spectrum of viruses. Key words: antiviral, herpesvirus, peptide. A atividade antimicrobiana do peptideo P34 ja foi previamente demonstrada. Neste estudo, o potencial antiviral do P34 e o mecanismo de agao in vitro contra o alfaherpesvirus bovino tipo 1 (BoHVl) foram investigados. O P34 exibiu baixa toxicidade, alto indice de seletividade (22.9) e percentagem de inibigao viral de ate 100% em celulas MDBK. Os resultados dos ensaios antivirais indicaram que nao interage com receptores celulares, mas e capaz de inibir a penetragao viral, imediatamente apos a pre -adsorgao. Alem disso, a curva de crescimento do BoHVl em celulas MDBK na presenga do P34 revelou uma significativa redugao no titulo somente apos 8h de infecgao, sugerindo tambem uma importante atividade do peptideo nas fases finais do ciclo replicativo. Efeito virucida frente / BoHVl foi observado apenas em concentragoes citotoxicas do peptideo. Os dados obtidos indicam que o peptideo antimicrobiano P34 pode ser considerado um potencial composto inibidor de herpesvirus, in vitro, e estimulam posteriores investigagoes sobre sua atividade anti-herpetica em modelos animais, bem como contra outros virus. Palavras-chave: antiviral, herpesvirus, peptideo.