Lavandula stoechas Ethanol Extracts Induce Apoptosis in Breast, Bladder, and Glioblastoma Cancer Cells.

Background

Lavandula stoechas has attracted increasing attention for its potential anticancer properties; however, evidence regarding its effects on apoptotic signaling across different tumor types remains limited.

Methods

In this study, the effects of dry and fresh ethanol extracts of Lavandula stoechas L. subsp. stoechas (LsDE and LsFE) were investigated in MDA-MB-231 triple-negative breast cancer, RT4 bladder carcinoma, and T98G glioblastoma cell lines, providing a comparative evaluation of their apoptotic effects. Long-term proliferative capacity was assessed using clonogenic survival assays, while apoptosis-related responses were evaluated by Annexin V-FITC/propidium iodide staining, quantitative RT-PCR of BAX and BCL2 and Western blot analysis of Bax, Bcl-2, and cleaved PARP1.

Results

Both extracts significantly reduced clonogenic survival in all tested cancer cell lines, with LsDE showing stronger inhibitory effects in RT4 and T98G cells. Annexin V/PI analysis revealed cell type-dependent response patterns. In MDA-MB-231 cells, both extracts increased the proportion of PI-positive cells, suggesting a loss of membrane integrity, whereas RT4 cells exhibited increased early apoptotic and membrane-compromised populations. In contrast, T98G cells showed comparatively limited changes associated with apoptosis. Transcriptional analysis demonstrated extract- and cell line-specific modulation of the BAX/BCL2 ratio. Western blot analysis further demonstrated activation of mitochondrial apoptotic signaling through coordinated regulation of Bax and Bcl-2 and increased PARP1 cleavage. LsFE showed the strongest apoptosis-associated changes in MDA-MB-231 cells, whereas LsDE showed stronger effects in T98G cells, while both extracts were effective in modulating these proteins in RT4 cells.

Conclusions

These findings indicate that ethanol extracts of L. stoechas impair long-term proliferative capacity and induce tumor type-dependent modulation of apoptosis-related markers. This study provides an integrated experimental framework that combines clonogenic survival assays, apoptosis analyses, gene expression, and protein-level measurements, supporting further investigation of L. stoechas extracts in cancer research.