PT - JOURNAL ARTICLE AU - CHRISTI N. WAER AU - PREET KAUR AU - ZOHRA TUMUR AU - DEE DEE HUI AU - BONNIE LE AU - CARLOS GUERRA AU - BRADLEY HENSON AU - DALIA SELEEM AU - JILL LEWIS TI - Rosmarinic Acid/ Blue Light Combination Treatment Inhibits Head and Neck Squamous Cell Carcinoma <em>In Vitro</em> AID - 10.21873/anticanres.14006 DP - 2020 Feb 01 TA - Anticancer Research PG - 751--758 VI - 40 IP - 2 4099 - http://ar.iiarjournals.org/content/40/2/751.short 4100 - http://ar.iiarjournals.org/content/40/2/751.full SO - Anticancer Res2020 Feb 01; 40 AB - 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.