Abstract Rationale Urolithin A (UA) is a gut microbiota derived metabolite formed from dietary ellagitannins. UA has been shown to enhance muscle function by improving mitochondrial health, but its potential anti-inflammatory and cytoprotective roles in the lung remain poorly understood. This study investigated whether UA modulates oxidative stress, mitophagy, and inflammatory responses in lung epithelial and endothelial cells. Methods Molecular properties of UA were predicted using ChemDraw, and pharmacokinetic/pharmacodynamic (PK/PD) profiles were estimated with SwissADME. Human A549 lung epithelial cells were treated with UA (0.1–10 µM) to assess its effects on mitochondrial reactive oxygen species (ROS) and mitophagy. For mitochondrial ROS kinetics, cells were exposed to UA for 15–360 minutes with or without rotenone (2 µM), and fluorescence intensity was normalized to nuclear staining. Mitophagy was evaluated after 24-hour UA exposure using MitoSOX Red staining and live-cell imaging.Primary human lung endothelial cells were pretreated with UA (10 µM) for 30 minutes prior to Pseudomonas aeruginosa (1 × 108 CFU/mL) challenge. Western blotting was used to assess NFκB phosphorylation. Endothelial barrier integrity was continuously monitored using Electric Cell-Substrate Impedance Sensing (ECIS) on 8W10E+ PET slides (Applied Biophysics). Statistical analysis was performed using two-way ANOVA with Tukey’s post hoc test. Results Computational modeling revealed that UA exhibits favorable physicochemical properties (LogP = 2.06, LogS = –3.33) and high predicted gastrointestinal absorption, supporting its potential for drug delivery. UA significantly reduced rotenone-induced mitochondrial ROS at all concentrations tested without pro-oxidant activity, confirming potent antioxidant effects. Prolonged UA exposure induced concentration-dependent mitophagy, evidenced by increased MitoSOX fluorescence and perinuclear puncta formation.In endothelial cells, UA pretreatment attenuated P. aeruginosa–induced NFκB phosphorylation and partially preserved endothelial barrier function, indicating suppression of inflammatory activation and vascular leakage. UA also mitigated P. aeruginosa–induced mitochondrial dysfunction, including excessive ROS production, loss of membrane potential, impaired respiration, and ATP depletion. Conclusions Urolithin A displays favorable molecular and pharmacological characteristics that support its potential as a therapeutic agent. It reduces mitochondrial dysfunction and cellular inflammation via mitophagy activation. UA is a promising new therapy for P. aeruginosa–induced cellular injury and inflammation. This abstract is funded by: NIH
Wang et al. (Fri,) studied this question.