Antiviral Activity of Rhein against Enterovirus 71 through Inhibiting Viral Replication and Stability.

Background: Enterovirus 71 (EV71) is one of the most prevalent pathogens responsible for hand, foot, and mouth disease in the Asia-Pacific region. Severe EV71 infections can be fatal in children under the age of 5. As of now, there are no proven anti-EV71 drugs available. Rhein is an anthraquinone derivative, mainly derived from rhubarb plants. Several beneficial pharmacological properties of rhein have been linked to anti-inflammatory, antioxidant, anticancer, and antiviral effects. Aim: This research aims to evaluate rhein's antiviral activity against Enterovirus EV71 in vitro. Methods: The cytotoxicity of rhein was assessed using a Cell Counting Kit-8 kit. The antiviral activities of rhein were characterized by viral RNA level, protein expression level, and infectious ability using quantitative reverse transcription polymerase chain reaction, Western blot assay, and immunofluorescence assay, respectively. The mechanism by which rhein suppresses virus life cycles was examined utilizing a time-of-addition assay. An inactivation assay was performed to evaluate whether rhein directly impaired the virion stability. Results: The findings indicated that rhein exhibited anti-EV71 activity by reducing viral RNA synthesis, protein expression, and infectivity. Rhein demonstrates potent antiviral effects against EV71 at the late-life stage and inhibition of virion stability. Conclusion: Our findings strongly support further research into rhein as a potential treatment for EV71. [ABSTRACT FROM AUTHOR]