Sanhan Huashi Formula and Its Bioactive Compounds Exert Antiviral and Anti-Inflammatory Effects on COVID-19

Sanhan Huashi formula (SHHS), a traditional Chinese medicine (TCM), has shown significant therapeutic effects on coronavirus disease 2019 (COVID-19) in clinical settings. However, its specific mechanism and components still require further clarification. In vitro experiments with Vero-E6 cells infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) demonstrated that SHHS effectively inhibited viral invasion and proliferation. Complementary in vivo experiments using K18-human angiotensin converting enzyme 2 (hACE2) mice exposed to virus-like particles (VLPs) further confirmed that SHHS impeded SARS-CoV-2 entry. Although SHHS did not demonstrate direct antiviral effects in K18-hACE2 mice challenged with SARS-CoV-2, it significantly alleviated pathological damage and decreased the expression of chemokines such as C–C motif ligand (CCL)-2, CCL-3, C–X–C motif ligand (CXCL)-1, CXCL-6, CXCL-9, CXCL-10, and CXCL-11 in the lungs, suggesting that SHHS exerts immunomodulatory and anti-inflammatory effects via the CCL-2–CXCL axis. Additional research using a lipopolysaccharide (LPS)-induced acute lung injury (ALI) and RAW264.7 cell model validated the ability of SHHS to reduce the levels of inflammatory biomarkers, including interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α). Using advanced analytical techniques such as ultrahigh-performance liquid chromatography coupled with linear trap quadrupole Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap-MS) and surface plasmon resonance (SPR), nodakenin was identified as a potent antiviral component of SHHS that targets the 3C-like protease (3CLpro), a finding supported by the hydrogen–deuterium exchange mass spectrometry (HDX-MS) and molecular docking analyses. Furthermore, nodakenin demonstrated a significant antiviral effect, reducing the viral load by more than 66%. This investigation reveals that SHHS can combat COVID-19 by inhibiting viral invasion and promoting anti-inflammatory effects.