LC-MS Characterization and Antiviral Proficiency of Fish Mint (Houttuynia cordata) Aqueous Extract Against EV-A71

Background and Objectives: Enterovirus A71 (EV-A71), is a hand, foot and mouth disease that has become one of the major health concerns in the Asia-Pacific region. Prior studies have reported that Houttuynia cordata (H. cordata) extract may possess antiviral activity against EV-A71. In this study, the chemical composition of H. cordata aqueous extract and its anti- EV-A71 properties were studied. Materials and Methods: Anti-EV-A71 properties were studied according to different viral infection stages using cell survivability and viral titration assay repeatability against different EV-A71 sub-genotypes and stability in human saliva and hydrochloric acid was also tested. The total carbohydrate and protein content of the extract were estimated and active compounds were screened using LC-MS analysis. Results: The H. cordata extract exhibits significant inhibition against EV-A71 at a concentration of 1 mg/ml with minimal cytotoxicity. This antiviral effect is robust and resilient even in the presence of human salivary enzymes and an acidic environment. Intriguingly, our study indicates that the SCARB2 receptor does not seem to play a role in mediating the anti-EV-A71 activity. These promising results extend to various sub-genotypes of EV-A71. The total carbohydrate and protein content in the extract was 521.13 µg/ml and 21 µg/ml, respectively. LC-MS analysis unveiled the presence of 4 known and 16 unknown compounds, expanding our understanding of its composition. Conclusion: These results underscore the potential of H. cordata aqueous extract and its constituents as promising candidates for the development of novel antiviral agents. Furthermore, our findings contribute to the broader field of antiviral research and highlight the potential of traditional Chinese medicine in combating viral infections.