There is an urgent need to find therapies to curb the rising threat of infection from Middle East respiratory syndrome coronavirus (MERS-CoV). Researchers in the US and Asia have shown that an existing antiviral drug, resveratrol, may be a potent anti-MERS agent.

“It is crucial that we soon find a vaccine or antiviral drug effective against MERS-CoV infection, especially considering the mortality rate is as high as 35%,” says Tony Wang of the American nonprofit research institute SRI International, who worked on the project with scientists in China and Taiwan.

 MERS-CoV is believed to have originated from camels and was first identified in Saudi Arabia in 2012. As of December 2016, the pathogen had killed 652 people out of 1842 confirmed cases. The infection manifests as an acute respiratory illness, with symptoms including fever, cough and severe breathlessness, and the virus has recently been shown to predominately attack the lungs and lower respiratory tract.

“Resveratrol is a natural derivative found in plants, including grape and cranberry,” says Wang. “It is effective against many conditions, including reducing tumour growth in cancers and limiting inflammation across the body. It has also shown considerable promise in tackling viral infections including respiratory conditions, which is why we selected to trial resveratrol against MERS-CoV.”

The team infected cultured cells with MERS-CoV before treating them with different concentrations of the drug. After 48 hours, they imaged and analyzed each cell culture to determine resveratrol’s ability to reduce cell death from MERS-CoV and limit viral cell expression and proliferation.

The drug proved to be highly effective against MERS in infected cells, and showed limited toxicity to healthy cells even in high concentrations. In any case, notes Wang, the toxicity of resveratrol is negligible in the face of MERS-CoV’s toxicity.

The exact mechanisms inherent in resveratrol’s activity against MERS are not yet clear, but it appears to promote cell survival and limit cellular damage in the face of infection.

 “Our next step is to conduct trials [inside a living organism]…, possibly using humanized mouse models,” says Wang. “We are encouraged by these initial findings and hope they lead to a novel therapy for tackling MERS-CoV.”

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