In Vitro Validation of Camphene as a Potential Antiviral Agent Against Betanodavirus Causing Viral Nervous Necrosis in Barramundi

Abstract

Viral infections are a major threat to the aquaculture industry throughout the world. Betanodavirus is one of the most infectious viruses that cause the highest mortality in larval and juvenile stages of Latescalcarifer commonly known as Barramundi. It is a single-stranded positive- sense RNA virus and causes viral nervous necrosis(VNN).VNN is caused by a RNA virus that gets transmitted both horizontally and vertically so the most effective method against this virus is to vaccinate the fish, however, vaccination becomes difficult since the disease is associated with outbreaks in larval and juvenile stages which are not that much immunocompetent. In our previous in silico studies, we proved the stability of camphene as a better phytochemical agent. In continuation to prove the authenticity of camphene as a potential antiviral agent against betanodavirus, its in vitro validation was performed. Sea bass kidney cell line (SISK) was selected for carrying out the in vitro studies and cytotoxicity studies of camphene in the SISK were done by MTT assay. Based on the analysis of the MTT assay, different dosages of camphene were selected viz.,0.2, 0.5, 1, 1.5, 2, 2.5, 5, 10, 20, 30 μg/ml. The SISK cells were infected with a virus inoculum(200μl). Further, the antiviral activity of camphene on infected SISK cells by Betanodaviruswas elucidated with the help of quantitative Real-time PCR(qPCR) on the 3rd and 5th day of infection. Analysis of results depicted that the dose of camphene 2 to 10 μg/ml is the safest dose against Betanodavirus. Hence this is aptly revealed that camphene can be used as a potential antiviral agent against Betanodavirus.