Europe PMC · 2026-03-19
Researchers found that an extract from white mulberry leaves can suppress a key SARS-CoV-2 enzyme by up to 99% in lab cells, and computational screening identified the compound naringin as the most promising natural inhibitor — outperforming the pharmaceutical drug nirmatrelvir in predicted binding strength.
White mulberry leaf extract inhibited SARS-CoV-2 main protease expression by up to 99% at the mRNA level (IC₅₀ = 105 μg/mL) and up to 80% at the protein level in CHO cells.
Three compounds — naringin, nicotiflorin, and cyclomorusin — showed stronger predicted binding to the viral enzyme (-9.6 to -9.8 kcal/mol) than the reference drug nirmatrelvir (-9.0 kcal/mol).
Molecular dynamics simulation identified naringin as the most stable inhibitor candidate, with the lowest binding free energy of -63.03 kcal/mol among the top hits.
