Rosmarinic Acid/ Blue Light Combination Treatment Inhibits Head and Neck Squamous Cell Carcinoma .

Background/aim: This study investigated a novel combined therapy of rosmarinic acid (RA)/blue light on head and neck squamous cell carcinoma (HNSCC) cell proliferation in vitro.

Materials And Methods: HNSCC cells were exposed to BL (500 mW/cm) for 90 s, and incubated with 80 μg/ml RA for 1 hour. Cell viability was determined after 24 h using WST-1 assay. Western blot was used to detect treatment-induced changes in epidermal growth factor receptor (EGFR) activation. Hydrogen peroxide (HO) and nitric oxide levels were quantified using CM-HDCFH-DA assays. Apoptosis was assessed using Annexin V/PI staining and flow cytometry.

Results: RA/blue light treatment resulted in a significant reduction in cell viability, EGFR activation and HO levels in all HNSCC cell lines. However, no significant changes in NO production or apoptosis induction were found.

Conclusion: RA/blue light effectively decreased HNSCC cell proliferation through reduction in EGFR activation and HO production, and not via induction of apoptosis.