This study investigated the potential of Thymus serpyllum L. and Mentha × piperita L. essential oils (EOs), known for their bioactive properties, as adjunctive treatments targeting Basal cell carcinoma cancer stem cells (BCC CSCs). Primary cultures were established from ten BCC tumor samples and their distant resection margins as controls. The chemical composition of the EOs was analyzed by gas chromatography–mass spectroscopy (GC-MS) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The biological effects were evaluated via colony and spheroid formation, scratch assays, MTT and neutral red cytotoxicity assays, and qRT-PCR for Hh (SHH, PTCH1, SMO, and GLI1) and Notch (Notch1 and JAG1) gene expression. GC analysis identified thymol, p-cymene, and linalool as the main components of the EO of T. serpyllum L., and menthone and menthol in the EO of M. × piperita L. IC50 values were 262 µg/mL for T. serpyllum L. and 556 µg/mL for M. × piperita L. and were applied in all experiments. Both EOs significantly reduced CSC clonogenicity and migration (p < 0.05). The EO of T. serpyllum L. downregulated SMO and GLI1, while the EO of M. × piperita L. upregulated PTCH1, Notch1, and JAG1 (p < 0.05). These findings suggest that both EOs exhibit anticancer effects in BCC CSCs by modulating key oncogenic pathways, supporting their potential in BCC therapy.

Pleomorphic adenoma (PA) is the most common neoplasm of salivary glands and consists of epithelial and mesenchymal components. Although a benign lesion, it harbors a potential for recurrence and malignant transformation. Also, due to its histological diversity and unpredictive behavior PA can represent both diagnostic and therapeutic challenge. Matrix metalloproteinases (MMPs) are well known modifiers of extracellular matrix (ECM) PA component and in conjunction with their endogenous tissue inhibitors (TIMPs) may influence PA tumor biology. PLAG1 oncogene also has an important role in PA; however, neither the exact mechanisms of its influence nor its interactions with other genes are completely elucidated. The aims of this study were to assess the expression of PLAG1, MMP-2, MMP-7, MMP-9, TIMP-1 and TIMP-2 genes in PAs, and find a possible association of gene expression levels with clinical/epidemiological parameters of PA patients. Relative mRNA levels were assessed using Quantitative real-time PCR analyses in 15 PAs of the parotid gland and 5 normal salivary glands (NSGs). A statistically significant overexpression of PLAG1 was observed in PA compared to NSG samples (P=0.010); PA had 5.48 times higher mRNA levels than NSG. Out of the three analyzed MMP genes, significantly lower levels of MMP-7 were found in PA patients (P=0.026). TIMP2 was also downregulated in PA samples, compared to NSGs (P=0.040). MMP-7 and TIMP-2 mRNA levels were decreased 2.95 and 2.85 times respectively, in PA samples. No association was found between gene expression and clinical/epidemiological PA parameters. Our results suggest that PLAG1 overexpression with concomitant MMP7 and TIMP2 downregulation may contribute to PA development.