Metabolomics and mass spectrometry imaging reveal the effect of Prunella vulgaris oil on chronic pelvic inflammatory disease: Exploring the mechanism from inhibition of PANX1.

ETHNOPHARMACOLOGICAL RELEVANCE: Prunella vulgaris L. (PV) is a traditional Chinese herbal medicine with the effects of clearing heat and detoxifying toxins, dispersing knots and eliminating swellings, and modern studies have shown it has anti-inflammatory, antibacterial, and immunomodulatory effects. Prunella vulgaris oil (PVO), derived from PV, is a compound with good biological activity in the context of CPID. However, the molecular mechanisms remain unclear.

AIM OF THE STUDY: This study aimed to investigate the therapeutic effects of PVO on CPID and elucidate the potential mechanisms by which PVO regulates PANX1 channels and associated metabolites, thereby exerting anti-inflammatory effects in the treatment of CPID.

METHODS: The CPID rat model of mixed bacterial infection was established, and the expression levels of inflammatory factors, including tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1β), interleukin 6 (IL-6), and interleukin 18 (IL-18), in uterine tissues were quantified using an ELISA kit. Hematoxylin-eosin (HE) staining was employed to evaluate treatment efficacy. A TUNEL assay was conducted to assess apoptosis, and the expression of apoptosis-related proteins, including Caspase-3, Caspase-7, and PANX1, was analyzed via immunofluorescence. Differential metabolites were identified through untargeted metabolomics of uterine tissues, and metabolic pathways were assessed using MetaboAnalyst. Finally, spatial metabolomics was employed to validate the results, and an extensive literature review was integrated to propose potential therapeutic mechanisms.

RESULTS: PVO effectively reduced the inflammatory response and alleviated pelvic pathological symptoms in CPID rats. It regulated the extracellular metabolic balance by inhibiting excessive apoptosis and modulating the caspase-mediated PANX1 channel. Through untargeted metabolomics, 53 differential metabolites were identified. Among these, the key metabolites-UDP-glucuronate, cyclic adenosine diphosphate ribose (cADPR), and NAD+-demonstrated significant alterations both before and after modeling and PVO treatment, with their associated metabolic pathways being significantly enriched in KEGG analysis. Finally, five additional metabolites significantly associated with PANX1 were identified through spatial metabolomics, validating the trends of key metabolites and providing robust evidence for elucidating the underlying mechanisms.

CONCLUSION: In this study, pharmacodynamic results were integrated, and a combined strategy of untargeted and spatial metabolomics was employed to elucidate the potential mechanisms underlying the anti-inflammatory properties of PVO. These findings indicate that PVO inhibits the apoptotic protein Caspase 3/7 and the opening of PANX1, reduces the release of metabolite-specific substances, modulates eight potential biomarkers, and mediates inflammatory and apoptotic homeostasis. These results support the further application of PVO and provide new options for the treatment of chronic inflammatory diseases (CPID).