Abstract
The leaves, fruits and dry pericarps of Japanese pepper (Zanthoxylum pipertum (L.) DC.) have been utilized as foods and Chinese medicines for a long time. We report here that polyphenol components, proanthocyanidins (PANs), from pericarps of Japanese pepper inhibit the growth of subacute respiratory syndrome-coronaviruses (SARS-CoV) in cultured Vero cells. “Cytostatic states” were induced in Vero cells, i.e. following cell growth was inhibited 5% without any sign of cell death by 5.5 μg·mL−1 PANs treatment. Simultaneously, the virus growth was inhibited 50% [50% inhibitory concentration (IC50 = 5.5 μg·mL−1)] in those cells. The anti-viral activity of PANs might be due to strong inhibition of protein synthesis (macromolecular synthesis) and more than 3-fold induction of intracellular anti-oxidants, manganese superoxide dismutase (Mn-SOD) in the cells. As the anti-viral effects were dependent on cellular conditions induced by PANs treatments, the inhibition of viral growth does not seem to be virus-specific. These findings suggest that PANs from Japanese pepper have a potential to be developed into a chemotherapeutic material to treat viral diseases.
