In Vitro Assessment of the Cytotoxic Effect of 5-Fluorouracil, Thymoquinone and their Combination on Tongue Squamous Cell Carcinoma Cell Line.

BACKGROUND: Tongue cancer is the most prevalent type of oral cancer. Recently, natural compounds have been considered important resources for several anticancer drugs. Thymoquinone (TQ) exhibits a potent anti-cancer effect. 5-Fluorouracil (5-FU) is a chemotherapeutic drug that has been utilized in the treatment of cancer. Recently, combination therapy has gained popularity as a treatment option for patients with cancer. OBJECTIVES: The present study was carried out to assess the cytotoxic effect of 5-Fluorouracil (5-FU), Thymoquinone (TQ), and their combination on tongue squamous cell carcinoma cell line (HNO-97). METHODS: Tongue carcinoma cell line (HNO-97) was maintained in cultured flasks and the cells were divided into four groups; group Iota: control untreated group, group IotaIota: HNO-97-treated cells with different concentrations of 5-FU from 0.5 microM/ml to 3microM/ml, group IotaIIota: HNO-97-treated cells with different concentrations of TQ from 7.25microM/ml to 23.05microM/ml, and group IotaV: HNO-97-treated cells with both 5-FU and TQ in serial concentrations till (IC50) in a dose of 27.44 microM/ml. Determination of the cytotoxic effect of the tested agents on the HNO-97 cell line was done using methyl thiazole tetrazolium assay, nuclear morphometric analysis, microscopic examination, and annexin-v/ propidium iodide staining assay. RESULT: The findings revealed that the cytotoxic effect of 5-FU, TQ, and their combination on tongue squamous cell carcinoma cell line (HNO-97) was dose-dependent. The microscopic examination revealed that 5-FU, TQ alone, or their combination induced apoptotic cell death. P-value < 0.05 was statistically significant. CONCLUSION: The combination of 5-FU and TQ produced a marked cytotoxic effect on HNO-97 cells.