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/cm2) 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 (H2O2) and nitric oxide levels were quantified using CM-H2DCFH-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 H2O2 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 H2O2 production, and not via induction of apoptosis.
Keywords: EGF receptor; Head and neck cancer; light; oxidative stress; phytochemicals.
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