Antiviral potential of ivermectin against foot-and-mouth disease virus, serotype O, A and Asia-1.

ABSTRACT

Each year, foot-and-mouth disease leads to enormous economic losses to the livestock industry. Currently, the killed whole virus is widely using to control FMD. However, vaccination is constrained by lack of or incomplete protection. Therefore, along with vaccination, we need to find the antivirals against FMD. This study was conducted to investigate the antiviral potential of ivermectin against multiple serotypes of FMDV. Initially, an MTT assay was performed on the BHK-21 cell line to determine assay ivermectin cytotoxicity. Viral inhibition assays using the non-cytotoxic concentration of ivermectin were performed to check the antiviral potential of ivermectin on different stages of virus replication. At 2.5 µM and 5 µM concentrations of ivermectin, the virus titer was reduced significantly (p < 0.001) by two to three log in all three strains of viruses at both non-toxic concentrations (2.5 and 5 µM). The virus titer in strain O control was 106.0 TCID50/0.1 mL and was reduced to 104.1 TCID50/0.1 mL at a concentration of 2.5 µM and 103.10 TCID50/0.1 mL at 5 µM concentration. In the case of strain Asia-1, the virus titer was reduced to 103.8 TCID50/0.1 mL at 2.5 µM and 103.01TCID50/0.1 mL at 5 µM concentration. The titer of strain A was reduced from 105.8 TCID50/0.1 mL to 103.9 TCID50/0.1 mL at 2.5 µM concentration and 103.1 TCID50/0.1 mL at 5 µM concentration. Moreover, the virus titer was reduced more at the replication stage as compared to attachment and entry stages. This study showed the in vitro anti-FMDV potential of ivermectin for the first time and predicted its potential use against FMDV infections.