Evaluation of the virucidal effects of rosmarinic acid against enterovirus 71 infection via in vitro and in vivo study

Wen-Yu Lin,Tzyy-Rong Jinn,Yu-Jen Yu

doi:10.1186/s12985-019-1203-z

Wen-Yu Lin, Tzyy-Rong Jinn + Show 1 more

Open Access

https://doi.org/10.1186/s12985-019-1203-z

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Journal: Virology journal	Publication Date: Jul 31, 2019
Citations: 31	License type: open-access

Affiliation: China Medical University

Abstract

BackgroundAlthough enterovirus 71 (EV71) is an important public health threat, especially in the Asia-Pacific region, there are still no effective drugs or vaccines to treat and prevent EV71 infection. Therefore, it is critical to develop prophylactic and therapeutic agents against EV71. Rosmarinic acid (RA), a phytochemical, has been discovered to possess a broad spectrum of biological activities.MethodsThe virucidal effects of RA on EV71 were determined by MTT, western blot, median cell culture infectious dose, apoptosis detection, plaque reduction, semi-quantitative real-time polymerase chain reaction, immunofluorescence detection, molecular docking analysis, and mouse protection assay.ResultsRA showed a strong protective effect against EV71 infection in human rhabdomyosarcoma cells when the multiplicity of infection was 1, with a low IC50 value (4.33 ± 0.18 μM) and high therapeutic index (340). RA not only protected cells from EV71-induced cytopathic effects, but also from EV71-induced apoptosis. The results of time-of-addition analysis demonstrated that the inhibitory activity of RA was highest at the early stage of viral infection. Consistent with this, the infectivity of EV71 in the early stage of viral infection also was observed to be limited in neonatal mice treated with RA. Further, molecular docking predicts that RA could replace the natural pocket factor within the VP1 capsid-binding hydrophobic pocket.ConclusionsThis study suggests that RA has the potential to be developed as an antiviral agent against initial EV71 infection to prevent or reduce EV71-induced pathogenesis and complications, since RA can effectively reduce EV71 infection in the early stages of viral infection.

Highlights

Enterovirus 71 (EV71) is an important public health threat, especially in the Asia-Pacific region, there are still no effective drugs or vaccines to treat and prevent enterovirus 71 (EV71) infection
Analysis of the virucidal efficacy of Rosmarinic acid (RA) against EV71 To assess the virucidal efficacy of RA, RD cells were infected with EV71 at different multiplicity of infection (MOI) (0.1, 0.5, 1, and 3) while being treated simultaneously with 1, 3, 5, or 10 μM RA for 24 h at 37 °C (Fig. 1a)
The viability of cells simultaneously infected with EV71 at a MOI of 1 and treated with RA at concentrations of 1, 3, 5, and 10 μM was 14.5% ± 4.01, 43.6% ± 7.43, 60.6% ± 2.32, and 88.0% ± 6.05%, respectively (Fig. 1a)

Summary

Introduction

Enterovirus 71 (EV71) is an important public health threat, especially in the Asia-Pacific region, there are still no effective drugs or vaccines to treat and prevent EV71 infection. Foot, and mouth disease (HFMD) induced by enterovirus 71 (EV71) is a critical public health threat, especially in the Asia-Pacific region [1]. Some phytochemicals extracted from different medicinal herbs have been shown to inhibit EV71 infection in cultured cells, such as oblongifolins J and M, gallic acid, polydatin, resveratrol, aurintricarboxylic acid, kaempferol, baicalin, and apigenin [3,4,5]. Punicalagin [6] and chebulagic acid [7] have been found to inhibit EV7 infection both in cultured cells and in mouse models.

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