Objective: An in vitro study was made to evaluate the effect of curcumin and irradiation upon oral squamous cell carcinoma.
Materials and method: Curcumin was administered at doses of 3, 3.75, 4.50 and 5.25 μM in PE/CA-PJ15 oral squamous cell carcinoma cultures irradiated with different doses (1, 2.5 and 5 Gy), followed by evaluation of the effects upon cell viability after 24, 48 and 72 h, based on the MTT colorimetric test.
Results: The application of curcumin to the PECA/PJ15 tumor cells during 24, 48 and 72 h of incubation without irradiation exerted an inhibitor effect upon cell viability. The curcumin concentration at which the inhibition of cell viability proved maximum was 5.25 μM, with statistically significant differences for 24 h (p = 0.002), 48 h (p < 0.001) and 72 h of incubation (p < 0.001). In contrast, the combination of curcumin and irradiation exerted a synergic effect-the greatest effects in relation to cell viability being recorded with a curcumin concentration of 3.75 μM and 5 Gy of irradiation, in the studied cell line.
Conclusions: Curcumin increases cytotoxic activity in the PE/CA PJ15 cell line, while the combination of curcumin and irradiation exerts a synergic effect.