Effects of Curcumin on Vesicular Stomatitis Virus (VSV) Infection and Dicer‐1 Expression

Abstract

Vesicular stomatitis virus (VSV), part of Rhabdoviridae, can cause severe illness in many important livestock, such as horses, cattle, and sheep. Curcumin (CUR) is a polyphenolic extract from the spice turmeric, and has a variety of pharmacological benefits including anti‐inflammatory, antioxidant and anti‐viral activities. However, there is limited work on its effects on VSV infection, or a mechanistic description of its anti‐viral properties. The initial goal of this study was to determine if CUR could restrict VSV infection in Vero cells, and if so, to determine the minimal concentration required for restriction. We observed that 10μM of CUR provided robust inhibition of recombinant VSV‐EGFP infection of Vero cells, as measured via plaque assay and fluorescence, with approximately 33% reduced infection at MOI 0.0002 and nearly 90% reduction at MOI 0.00002 after 24 hours. We hypothesized RNAi mechanisms may be effective at restricting VSV infection, and measured Dicer‐1 mRNA via qPCR. We found cells infected with VSV‐EGFP and treated with CUR had higher levels of Dicer‐1 expression than VSV‐EGFP infected cells treated with vehicle (DMSO); Actin was used as reference gene. Preliminary results indicate CUR alone has limited effect on Dicer‐1 expression in the absence of VSV infection. This may indicate that VSV infection itself alters Dicer‐1 expression; CUR restriction of VSV infection may rescue the effect on Dicer‐1 expression by inhibiting VSV replication through an as yet unidentified mechanism. It is know that VSV infection induces oxidative stress to promote apoptosis, and thus the antioxidant properties of curcumin may be the primary effect on VSV restriction, which future studies will investigate.Support or Funding InformationDept. of Botany & Microbiology, Neuroscience Program, and Summer Science Research Program at Ohio Wesleyan Univ.; Ohio Wesleyan Univ. Theory‐to‐Practice Grant.