Inhibition of enterovirus 71 infection by polysaccharides extracted from Picochlorum sp. 122 via the AKT and ATM/ATR signaling pathways

Enterovirus 71 (EV71) poses a major threat to public health globally due to severe and even fatal hand, foot, and mouth disease (HFMD). However, no effective antiviral agents are available to treat HFMD caused by this virus. Polysaccharides have been shown to exhibit antiviral activity, and polysaccharides extracted from Picochlorum sp. 122 (PPE) could potentially be used to treat HFMD, but reports on their antiviral activity are limited. In this study, the antiviral activity of PPE against EV71 was verified in Vero cells. PPE was shown to limit EV71 infection, as demonstrated using an MTT assay and by observing the cellular cytopathic effect. In addition, a decrease in VP1 RNA and protein levels indicated that PPE effectively inhibits proliferation of EV71 in Vero cells. An annexin V affinity assay also indicated that PPE protects host cells from apoptosis through the AKT and ATM/ATR signalling pathways. These results demonstrate that PPE has potential as an antiviral drug to treat HFMD caused by EV71.