Curcumin's Radioprotective Effects on Zebrafish Embryos

Radiation modifiers are largely studied for their contribution to enlarging the treatment window. Curcumin is already known for its antioxidant properties; however, its role as a radioprotector in preclinical studies is affected by the well-known low absorption and bioavailability of curcumin. In this study, curcumin's radioprotection ability has been evaluated in zebrafish larvae, by taking advantage of quantifying curcumin absorption and evaluating its fluorescence in transparent embryos. A curcumin range of 1-10 μM was tested to select the non-toxic concentrations to be used for a pre-treatment of photon beam irradiation using a 2-15 Gy range of doses. The post-treatment analysis within 120 h post-fertilization (hpf) included an assessment of mortality and malformation rates and behavioral and gene expression analysis. A total of 2.5 and 5 μM of curcumin pre-treatment showed a radioprotective role, significantly reducing the frequency of embryo malformations and damaged entities. This sparing effect disappeared using 15 Gy, showing the radiation effect's prevalence. Gene expression analysis reconducted this radioprotective ability for antioxidant gene network activation. The curcumin-induced activation of the antioxidant gene network promoted radioprotection in zebrafish.