Gómez-García Manuel, Puente Héctor, Argüello Héctor, Mencía-Ares Óscar, Rubio Pedro, Carvajal Ana
Department of Animal Health, Faculty of Veterinary Medicine, Universidad de León, León, Spain.
Front Vet Sci. 2021 Mar 29;8:652000. doi: 10.3389/fvets.2021.652000. eCollection 2021.
Organic acid and essential oils (EOs), well-known antimicrobials, could also possess antiviral activity, a characteristic which has not been completely addressed up to now. In this study, the effect of two organic acids (formic acid and sodium salt of coconut fatty acid distillates) and two single EO compounds (thymol and cinnamaldehye) was evaluated against porcine epidemic diarrhea virus (PEDV). The concentration used for each compound was established by cytotoxicity assays in Vero cells. The antiviral activity was then evaluated at three multiplicities of infection (MOIs) through visual cytopathic effect (CPE) evaluation and an alamarBlue assay as well as real-time reverse-transcription PCR (RT-qPCR) and viral titration of cell supernatants. Formic acid at at a dose of 1,200 ppm was the only compound which showed antiviral activity, with a weak reduction of CPE caused by PEDV. Through the alamarBlue fluorescence assay, we showed a significant anti-CPE effect of formic acid which could not be observed by using an inverted optical microscope. RT-qPCR and infectivity analysis also showed that formic acid significantly reduced viral RNA and viral titers in a PEDV MOI-dependent manner. Our results suggest that the antiviral activity of formic acid could be associated to its inhibitory effect on viral replication. Further studies are required to explore the anti-PEDV activity of formic acid under field conditions alone or together with other antiviral agents.
有机酸和精油（EOs）作为著名的抗菌剂，也可能具有抗病毒活性，然而这一特性至今尚未得到充分研究。在本研究中，评估了两种有机酸（甲酸和椰子脂肪酸馏出物钠盐）以及两种单一的EO化合物（百里香酚和肉桂醛）对猪流行性腹泻病毒（PEDV）的作用。每种化合物的使用浓度通过对Vero细胞进行细胞毒性试验来确定。然后通过观察细胞病变效应（CPE）、alamarBlue检测、实时逆转录聚合酶链反应（RT-qPCR）以及对细胞上清液进行病毒滴定，在三种感染复数（MOIs）下评估抗病毒活性。剂量为1200 ppm的甲酸是唯一显示出抗病毒活性的化合物，它能轻微减轻PEDV引起的CPE。通过alamarBlue荧光检测，我们发现甲酸具有显著的抗CPE效应，而使用倒置光学显微镜则无法观察到这一效应。RT-qPCR和感染性分析还表明，甲酸能以依赖PEDV MOI的方式显著降低病毒RNA和病毒滴度。我们的结果表明，甲酸的抗病毒活性可能与其对病毒复制的抑制作用有关。需要进一步研究以探索甲酸在田间条件下单独或与其他抗病毒剂联合使用时的抗PEDV活性。
