Antiviral Potential of Lauric Acid against Dengue Virus 2: Evidence from a Luciferase-Based Replicon Assay

Dengue virus (DENV) infection generates a significant health burden throughout the world, and there are no clinically approved antiviral drugs, as of now. The virus also depends on lipid metabolism in the host to conduct effective replication and this makes lipid-directed compounds promising as therapeutic options. We assessed the antiviral effect of lauric acid, a 12-carbon medium-chain fatty acid, against DENV serotype 2 (DV2) in the presence of a stable cell line, DV2-replicon, expressing all the non-structural proteins (NS1-NS5) and a luciferase reporter. Active viral replication in replicon cells was established by morphological examination and immunofluorescence of cells. The MTT assay was used to determine the cytotoxicity of lauric acid revealing the LD50 of 2.52 uM, so higher concentrations were toxic as the effect of the drug is dose-related. The antiviral effect was tested through replicon inhibition (luciferase) assay which showed an incredible inhibition of viral RNA replication with a IC50 of 1.70 uM and this is equivalent to antiviral mycophenolphycic acid. The cytopathic effects, as well as a decrease in the activity of luciferase, proved the presence of viral translation and replication inhibition within the process of the treatment of the lauric acid. These results propose that lauric acid has cytotoxic and antiviral dual effect and can be a possible inhibitor of DENV replication. The toxicity needs to be reduced and future research is necessary to explain its molecular pathway and also to come up with the best delivery methods.