Abstract
the 5-FU Cytotoxic Efficacy against the Tongue Squamous Cell Carcinoma BACKGROUND: 5-fluorouracil (5-FU) is an anti-cancer drug used to inhibit the proliferation of many different tumor cells. However, some side effects have been noted while using this drug. Oleuropein (OLEU), a natural compound, has been mentioned to have inhibitory effects on various cancers. Hence, its combination with 5-FU would allow its use in significantly lower doses. AIM: The main objective of this study was to assess the cytotoxic effect of OLEU and the chemotherapeutic drug 5-FU on Tongue Squamous Cell Carcinoma Cell Line (HNO-97) and Human Normal Oral Epithelial Cell Line (OEC) by either using each drug separately or in combination. MATERIALS AND METHODS: Cell viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the half-maximal inhibitory concentration (IC50) was calculated. In addition, flowcytometry and an in vitro scratch assay were performed to analyze the cell cycle and assess the inhibitory effects of OLEU on the migration of cells, respectively. RESULTS: The MTT assay demonstrated that using OLEU and/or has shown significant inhibitory effects on normal and cancer cell lines, with a favorable impact for OLEU on cancer cell lines rather than normal ones. Furthermore, a substantial increase in the cell inhibitory percentage was reported between the single and the combination treated groups as compared to the non-treated control group. Moreover, cell cycle analysis through flowcytometry showed that OLEU had induced cell cycle arrest at the G0/1 phase, decreased S phase, and G2/M phase either independently or in combination after 24 h and 48 h, when compared with a non-treated control group. Finally, a scratch assay test showed that OLEU could inhibit migration via delayed wound healing. CONCLUSIONS: The present study findings suggest that OLEU can exert an anti-cancer effect on HNO-97 and has the potential to boost 5-FU cytotoxic effects and reduce its adverse effects. Ultimately, OLEU can inhibit cancer migration and metastasis from the initial tumor