Saxifraga stolonifera curtis for ear inflammation: antibacterial efficacy and key bioactive constituents

Saxifraga stolonifera Curtis (SSC), a highly esteemed Traditional Chinese Medicine with profound ethnomedicinal value, has been historically employed to treat inflammatory ear disorders. Contemporary preclinical studies have verified its effectiveness in combating otitis media (OM). However, the underlying pharmacological mechanisms, particularly its anti-inflammatory and antibacterial properties remain unclear. This study aimed to systematically elucidate the chemical basis, antibacterial activity and molecular mechanisms underlying SSC’s anti-OM activity. UHPLC-Q-TOF-MS was employed for comprehensive phytochemical profiling of SSC total extracts. Antibacterial assays were conducted against three OM-associated bacterial strains: Staphylococcus aureus (SA), Pseudomonas aeruginosa (PA), and Klebsiella pneumoniae (KP), using SSC total extracts and its total flavonoid (TF). Network pharmacology analysis identified OM-related targets and pathways, followed by molecular docking validation. qPCR was used to assess mRNA expression of inflammatory cytokines (IL-6, TNF-α, IL-1β) in LPS-induced J774A.1 macrophages. Twenty-five bioactive compounds were characterized, including 11 newly reported constituents. Antibacterial results showed SSC exhibited the strongest inhibitory effect against KP, while TF showed relatively strong activity against PA; overall, SSC outperformed TF, suggesting contributions from non-flavonoid components. Network pharmacology revealed 11 core targets interconnected with inflammatory pathways. Molecular docking confirmed strong binding affinities between key components (bergenin, 11-O-galloylbergenin) and targets (HSP90AA1, EGFR). SSC total extracts significantly downregulated pro-inflammatory cytokine mRNA levels in vitro. SSC exerts anti-OM effects through a “dual mechanism”: antibacterial activity (with SSC total extract showing stronger efficacy than TF) and anti-inflammatory regulation via TNF/MAPK/NF-κB pathways. This integrative study validates SSC’s traditional use and provides a basis for developing SSC-based therapeutics for OM.