Effect of curcumin on γ-ray-induced cell response

Abstract

The purpose of the present study is to evaluate the effect of curcumin as a natural compound against radiation induced γ-foci and stable chromosome aberrations. Whole blood samples form three human volunteers were pretreated with curcumin at different concentrations (0.5, 10, 20 and 100 μg/ml). After 1-hour incubation, the lymphocytes were exposed to γ-rays (0.05, 0.5, 1 and 2 Gy). Radiation induced changes in cells were quantified using γ-H2AX/53BP1 assay and FISH analysis. Our results have shown that curcumin significantly reduced the frequency of both γ-foci and translocations. We found concentration-dependent increase of curcumin protective effect on γ-H2AX/53BP1 foci formation at all radiation doses. Concerning the translocations, after 0.05 and 0.5 Gy γ-rays the values of genomic frequencies are comparable within each dose and we did not observe any impact of curcumin. The most protective effect after 1 Gy exposure was found at 100 μg/ml curcumin. At 2 Gy irradiation, the maximum protection was achieved at 0.5 and 10 μg/ml of curcumin. Concentrations of 20 and 100 μg/ml also prevent lymphocytes but to less extent. Our in vitro study indicates radioprotective efficacy of curcumin against γ-ray induced damages in human lymphocytes. This observation suggests that curcumin may play a role to protect patients undergoing radiological procedures.

Keywords: FISH analysis of translocations; curcumin; radioprotective effect; γ-H2AX/53BP1 foci; γ-rays.

Fig. 1

Immunolocalization of γ-H2AX/53BP1 foci in lymphocytes, irradiated with 0.5 Gy γ-rays (×100 objective). A, B and C – curcumin non-treated cells; D, E and F – cells treated with 100 μg/ml curcumin; Visualization of γ-H2AX protein (A) and (D); Visualization of 53BP1 protein (B) and (E); Nuclear DAPI staining (C) and (F).

Fig. 2

Three-colored FISH of chromosome pairs #1 (green), #4 (red) #11 (yellow) (×100 objective). The arrows show reciprocal translocation between chromosome #1 and unstained chromosome (A); The same metaphase counterstained with DAPI (B).

Fig. 3

Effect of curcumin (concentrations: 0; 0.5; 10; 20 and 100 μg/ml) on the frequency of γ-foci, induced after in vitro irradiation with γ-rays (0; 0.05; 0.5; 1 and 2 Gy); (P < 0.05). Values are given as mean frequency; Error bars indicate standard error.

Fig. 4

Curcumin effect on AST genomic frequency in peripheral blood lymphocytes, after γ-irradiation (ranged from 0 Gy to 2 Gy) (P < 0.05); Error bars indicate standard error.