Introduction: Bronchopulmonary dysplasia (BPD) remains the most significant complication of extreme prematurity, affecting long-term respiratory outcomes. Because current diagnostic criteria identify only established lesions at 36 weeks postmenstrual age, early non-invasive biomarkers are needed. This pilot study aimed to identify a candidate salivary miRNA panel associated with BPD risk and to explore its pathogenetic relevance through in silico analysis. Methods: Saliva was collected from 20 preterm infants (10 with BPD and 10 controls), and miRNA expression was profiled using the GeneChip™ miRNA 4.1 Array Plate. Discriminatory performance was explored by ROC analysis within this discovery cohort, together with power and Spearman correlation analyses. Results: Expression of hsa-let-7b-5p, hsa-let-7c-5p, and hsa-miR-4454 was significantly elevated in the BPD group (p < 0.05, log₂FC ≥ 1.0), with no significant correlation with gestational age or birth weight. Bootstrap-corrected AUC values ranged from 0.905 to 0.937 and were supported by leave-one-out cross-validation. All three miRNAs showed very large effect sizes exceeding the minimum detectable effect at 80% power. Conclusions: In this pilot study, salivary miRNAs represent a hypothesis-generating candidate biomarker signal for BPD that requires external validation in larger, independent cohorts before any diagnostic or prognostic application can be considered.

The recovery of natural antibacterial compounds from medicinal plants is important for pharmaceutical research because extraction efficiency affects both phytochemical yield and their biological activity. This study compared four extraction methods—maceration, ultrasound-assisted extraction, microwave-assisted extraction, and electrically assisted extraction—for recovering antibacterial phytochemicals from Taraxacum officinale F.H.Wigg. Crude extracts were fractionated using solvents of different polarity and their phytochemical compositions were analyzed by high-performance liquid chromatography coupled with mass spectrometry (HPLC–MS). Phloridzin, a phenolic compound with reported antibacterial activity, was selected as a marker of extraction efficiency. Ultrasound-assisted extraction produced an ethyl acetate fraction with the highest phloridzin concentration (3.131 mg/L) and generally achieved higher phytochemical recovery than other methods. Comparative analysis identified ultrasound-assisted extraction as the most promising approach for obtaining antibacterial phytochemicals from T. officinale. These findings support the rational selection of extraction methods for developing plant-derived antibacterial agents and formulations for pharmaceutical, cosmetic, food, and herbal medicine applications.