RESUMEN
For almost two years, the COVID-19 pandemic has constituted a major challenge to human health, particularly due to the lack of efficient antivirals to be used against the virus during routine treatment interventions. Multiple treatment options have been investigated for their potential inhibitory effect on SARS-CoV-2. Natural products, such as plant extracts, may be a promising option, as they have shown an antiviral activity against other viruses in the past. Here, a quantified extract of Hypericum perforatum was tested and found to possess a potent antiviral activity against SARS-CoV-2. The antiviral potency of the extract could be attributed to the naphtodianthrones hypericin and pseudohypericin, in contrast to other tested ingredients of the plant material, which did not show any antiviral activity. Hypericum perforatum and its main active ingredient hypericin were also effective against different SARS-CoV-2 variants (Alpha, Beta, Delta, and Omicron). Concerning its mechanism of action, evidence was obtained that Hypericum perforatum and hypericin may hold a direct virus-blocking effect against SARS-CoV-2 virus particles. Taken together, the presented data clearly emphasize the promising antiviral activity of Hypericum perforatum and its active ingredients against SARS-CoV-2 infections.