Mechanistic insights into the dual anti-COVID-19 and anti-inflammatory actions of Zhengqi tablets

Ethnopharmacological relevance: Zhengqi Tablets (ZQP), derived from the "Huoxiang Zhengqi Powder" in the Song dynasty's "Taiping Huimin Ju Fang", have been endorsed by the Expert Consensus on Traditional Chinese Medcine Diagnosis and Treatment of New Coronavirus Infection in Shanghai (Spring Edition, 2022).

Aim of the study: The precise mechanisms underlying the efficacy of ZQP remain incompletely elucidated. To address this gap, we utilized a comprehensive approach integrating computer-aided virtual screening and biological validation to identify the active monomer within ZQP responsible for its anti-coronavirus properties. Furthermore, the key components contributing to ZQP's anti-inflammatory effects were also successfully identified.

Methods: In this study, 690 compounds derived from ZQP were systematically analyzed and selected for computer-aided virtual screening targeting 3CL/M^pro and RdRp. Based on the virtual screening results, we identified the effective components of ZQP and further evaluated their Antiviral properties. Subsequently, LC-MS/MS technology was integrated with virtual screening to pinpoint potential Antiviral monomers within ZQP, and their biological activity was experimentally validated. Furthermore, the effects of ZQP and its active components on cytokine storms and MAPK pathway were assessed using quantitative Real-Time PCR (qRT-PCR), enzyme-linked immunosorbent assay (ELISA) techniques, and Western blot.

Results: Based on the results of virtual screening, the lipid-soluble components from magnolia officinalis and glycyrrhiza uralensis were isolated and subjected to further analysis. Subsequent studies demonstrated that magnolol and honokiol from magnolia officinalis, as well as kaempferol, liquiritin, quercetin, and isoliquiritigenin from glycyrrhiza uralensis, exhibited significant inhibitory activity against 3CL/M^pro. Furthermore, in the LPS-stimulated Raw264.7 macrophage model, the lipid-soluble components of magnolia officinalis and glycyrrhiza uralensis were identified as the principal bioactive constituents responsible for ZQP's anti-inflammatory activity, acting through modulation of the MAPK signaling pathway.

Conclusions: In conclusion, this study underscores the dual therapeutic roles of ZQP in mitigating COVID-19 and attenuating inflammatory responses, thereby providing a foundation for the development of novel Antiviral agents grounded in traditional chinese medicine principles.

COVID-19; Main protease; RNA-Dependent RNA polymerase; Zhengqi Tablets (ZQP); anti-inflammation.