Silymarin exerts antioxidant and antiviral effects on Zika virus infection.

The Zika virus (ZIKV) - Orthoflavivirus zikaense - epidemic and its association with severe neurological disorders have created an urgent need to understand the disease pathogenesis and identify potential therapeutic targets. In previous investigations, we have shown that oxidative stress is associated with the pathogenesis of ZIKV infection in vitro and in vivo, and that silymarin has anti-ZIKV action in vitro. Here, we characterised the antioxidant and antiviral effects of silymarin against ZIKV infection in an animal model. We observed an increase in the levels of biomarkers of oxidative damage and in antioxidant enzyme activities in the livers of ZIKV-infected C57BL/6 mice. However, these effects were reversed in ZIKV-infected animals that were treated with silymarin. Furthermore, silymarin reduced the viral load in the livers of animals. Next, by in vitro studies, we confirmed that the anti-ZIKV action of silymarin is independent of its antioxidant activity. This work reinforces the potential use of silymarin against Zika fever.