Discovering the Q-marker of scutellaria baicalensis against viral pneumonia integrated chemical profile identification, pharmacokinetic, metabolomics and network pharmacology.

Ethnopharmacological Relevance: Scutellaria baicalensis (SR), an ancient antiviral herbal medicine, is widely used in treating viral pneumonia and its active constituents, baicalin and baicalein, have been reported to have antiviral activity.

Aim Of The Study: However, reports on Q-markers of SR for antiviral pneumonia are still scarce. This study aims to screen for Q-markers using a comprehensive strategy that integrates identification of chemical profiles, in vivo absorption, metabolic regulation and predicted target.

Materials And Methods: First, the markers were screened by chemical profile identification and pharmacokinetics using HPLC-MS/MS. Then, the therapeutic effects and differential metabolites of SR on viral pneumonia rats were evaluated by HE staining, assessment of inflammation levels and metabolomics analysis. Finally, the mechanisms of action between Q-markers and metabolites were exploited based on network pharmacology.

Conclusion: A total of 139 compounds were identified in SR, of which 35 and 41 were found in rat plasma and urine, respectively. Pharmacokinetic screening identified baicalin, baicalein, wogonin, wogonoside and oroxylin A as potential markers of SR. Furthermore, SR significantly improved interstitial and alveolar oedema, hemorrhage and alveolar collapse after modelling, while reducing the expression of inflammatory factors. Metabolomics revealed that SR significantly regulated the expression of 37 metabolites, mainly involving phenylalanine, tyrosine and tryptophan biosynthesis pathways. Network pharmacology showed that these five biomarkers can regulate the expression of metabolites through the key target SRC, ESR1, HSP90AA1, EGFR, thereby exerting antiviral effects against pneumonia. The study results suggest that baicalin, baicalein, wogonin, wogonoside and oroxylin A serve as primary Q-markers of SR in the treatment of viral pneumonia.