ABSTRACT
The infectious salmon anemia virus (ISAV) of Orthomyxoviridae family, is responsible for heavy losses in industry aquaculture around the world, affecting several commercial aquatic organisms, mainly Salmo salar. Therefore, it is important to find effective antiviral therapies. In this work we evaluated in vitro and in vivo the antiviral activity of three natural flavonoids isolated from the resinous exudates of the plant Heliotropium sinuatum (Heliotropiaceae) against ISAV. The results show that 7-O-methyleriodictyol was able to inhibit the infectivity of ISAV in vitro assay with EC 50 of 0.20 ug/mL. Despite having a citotoxicity expressed as CC50 of 12.80 ug/mL, the in vivo study showed that this compound protected 100 percent to the fish infected with ISAV keeping 100 percent fish viability. These results allow the proposal of 7-O-methyleriodictyol as a good candidate to be used as antiviral therapy for ISAV in salmon industry.
El virus de la anemia infecciosa en salmón de la familia Orthomyxoviridae, es el responsable de grandes pérdidas en la industria acuícola alrededor del mundo, afectando diversas especies acuáticas comerciales, principalmente Salmo salar. Por lo tanto, es muy importante encontrar una terapia antiviral efectiva. En el presente trabajo, evaluamos la actividad antiviral in vitro e in vivo de tres flavonoides naturales aislados desde el exudado resinoso de la especie vegetal Heliotropium sinuatum (Heliotropiaceae) contra ISAV. Los resultados mostraron que 7-O-metileriodictiol inhibió la infectividad de ISAV in vitro con un EC50 de 0.20 ug/mL. A pesar de tener una citotoxicidad expresada como un CC50 de 12.80 ug/mL, el estudio in vivo mostró que este compuesto protege en un 100 por ciento a los peces infectados con ISAV manteniendo un 100 por ciento de viabilidad. Estos resultados permiten proponer que 7-O-metileriodictiol es un buen candidato para ser usado como terapia antiviral para ISAV en la industria salmonera.
Subject(s)
Animals , Antiviral Agents/pharmacology , Plant Extracts/chemistry , Flavonoids/isolation & purification , Heliotropium/chemistry , Isavirus , Salmon , Aquaculture , Fish Diseases/drug therapy , Flavonoids/pharmacologyABSTRACT
We have previously described the development of a onetube SYBR Green real-time RT-PCR assay for the detection and quantitation of infectious salmon anemia virus (ISAV) in various biological samples. The twofold aim of the present study was to verify that the optimized SYBR Green real-time RT-PCR conditions could detect ISAV isolates of different geographic origins, and to analyze the growth patterns of the selected ISAV isolates in the Chinook head salmon embryo (CHSE) -214 cells by this assay to better characterize their CHSE-phenotypes. A total of 24 ISAV isolates were used in this study. The results indicated that the SYBR Green real-time RT-PCR could detect ISAV of different geographic origins or laboratory sources. The capacity of ISAV isolates to cause cytopathic effects (CPE) in the CHSE-214 cell line, viral titration of the infected CHSE-cell harvests, and analysis of viral RNA levels in CHSE-214 cells at post-infection day zero, 7 and 14 by SYBR Green real-time RT-PCR confirmed the existence of three CHSE-phenotypes of ISAV: replicating cytopathic, replicating non-cytopathic, and non-replicating non-cytopathic. The identification of these three CHSE- phenotypes of ISAV has important implications from diagnostic and biological points of view.