Radioprotective Effect of Curcumin on DNA Double Strand Breaks in Human Blood Lymphocytes after in vitro γ-Irradiation

Curcumin is a component of natural spice Curcuma longa. It is known that this polyphenol has been shown to exhibit anti-inflammatory, anticancer, antiviral, antioxidant and antibacterial activities. The mechanism of curcumin effectiveness on both healthy and cancer tissues is still unclear. Aims: In vitro assessment of curcumin effect on both double-strand breaks and chromosomal translocations frequency, after γ-irradiation. Methods: Human peripheral blood samples were pre-treated with different concentrations of curcumin (0.5 µg/ml; 10 µg/ml; 20 µg/ml and 100 µg/ml). Thereafter they were exposed to 60Co γ-rays using various irradiation doses (0.05 Gy; 0.5 Gy; 1 Gy and 2 Gy). Both γ H2AX/53BP1 foci assay and FISH analysis were used to evaluate DNA double-strand breaks and translocation frequencies. Results: Curcumin pre-treatment exhibited significant lower γ-H2AX/53BP1 foci appearance and reduced translocations frequency in irradiated compared to untreated lymphocytes. At 1 Gy irradiation and 10 µg/ml curcumin, the reduction of total translocations frequency was 42%. We found that at 2 Gy irradiation, the most protective concentration was 0.5 µg/ml curcumin. In this case, translocations declined almost twofold compared to curcumin non-treated cells. Conclusion: The present in vitro study demonstrates that curcumin reduces both γ-H2AX/53BP1 foci and translocations occurrence in peripheral blood lymphocytes, after γ-irradiation.