Rhodiolae Kirliowii Radix et Rhizoma and Crataegus pinnatifida Fructus Extracts Effectively Inhibit BK Virus and JC Virus Infection of Host Cells

The human polyomaviruses BK (BKPyV) and JC (JCPyV) are ubiquitous pathogens long associated with severe disease in immunocompromised individuals. BKPyV causes polyomavirus-associated nephropathy and hemorrhagic cystitis, whereas JCPyV is the causative agent of the fatal demyelinating disease progressive multifocal leukoencephalopathy. No effective therapies targeting these viruses are currently available. The goal of this study was to identify Chinese medicinal herbs with antiviral activity against BKPyV and JCPyV. We screened extracts of Chinese medicinal herbs for the ability to inhibit hemagglutination by BKPyV and JCPyV virus-like particles (VLPs) and the ability to inhibit BKPyV and JCPyV binding and infection of host cells. Two of the 40 herbal extracts screened, Rhodiolae Kirliowii Radix et Rhizoma and Crataegus pinnatifida Fructus, had hemagglutination inhibition activity on BKPyV and JCPyV VLPs and further inhibited infection of the cells by BKPyV and JCPyV, as evidenced by reduced expression of viral proteins in BKPyV-infected and JCPyV-infected cells after treatment with Rhodiolae Kirliowii Radix et Rhizoma or Crataegus pinnatifida Fructus extract. The results in this work show that both Rhodiolae Kirliowii Radix et Rhizoma and Crataegus pinnatifida Fructus may be sources of potential antiviral compounds for treating BKPyV and JCPyV infections.