RT Journal Article SR Electronic T1 Rosmarinic Acid/ Blue Light Combination Treatment Inhibits Head and Neck Squamous Cell Carcinoma In Vitro JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 751 OP 758 DO 10.21873/anticanres.14006 VO 40 IS 2 A1 CHRISTI N. WAER A1 PREET KAUR A1 ZOHRA TUMUR A1 DEE DEE HUI A1 BONNIE LE A1 CARLOS GUERRA A1 BRADLEY HENSON A1 DALIA SELEEM A1 JILL LEWIS YR 2020 UL http://ar.iiarjournals.org/content/40/2/751.abstract 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.