Carvacrol-Based Formulations Modulate Sirtuins and Exert Cytotoxic and Antimicrobial Effects in Lung Cancer Models

Lung cancer remains a leading cause of cancer-related mortality and is frequently complicated by respiratory infections, supporting interest in agents with both antitumoral and antimicrobial potential. This study evaluated two standardized thyme-derived, carvacrol-based formulations, Vacrol and S-Mix, in lung cancer-associated experimental models. A549 lung adenocarcinoma and BEAS-2B bronchial epithelial cells were treated with the formulations, and cell viability, clonogenic capacity, SIRT1-SIRT7 protein expression, in ovo tumor growth, histopathological changes, and antimicrobial activity against pneumonia-associated reference strains were assessed. S-Mix showed stronger short-term cytotoxicity in A549 cells, reaching an IC₅₀ of 1 mM after 72 h, whereas Vacrol produced more pronounced modulation of selected sirtuin proteins, particularly SIRT1, SIRT4, and SIRT5. Both formulations suppressed colony formation under prolonged exposure. In the CAM model, Vacrol was associated with greater macroscopic suppression of tumor growth and vascularization, while S-Mix produced more prominent histopathological cellular injury. Vacrol also showed antimicrobial activity against tested respiratory pathogens, with MIC values ranging from 0.5 to 4 mg/mL, MBC values ranging from 1 to 4 mg/mL and volatile-phase activity against Streptococcus pneumoniae as well as Klebsiella pneumoniae. These findings suggest that carvacrol-based formulations exert distinct cytotoxic, sirtuin-modulatory, antitumoral, and antimicrobial effects, warranting further mechanistic and translational validation.