Protecting HaCaT cells from ionizing radiation using persimmon tannin- gel composite.

Persimmon tannin (extract of L.f [Ebenaceae]) and gel extract of (L.) Burm.f. [Asphodelaceae]) are known as anti-radiation agents. However, radiation resistance of the persimmon tannin- gel composite remains inconclusive. To investigate the capacity of the persimmon tannin- gel composite to protect against ionising radiation at the cellular level. HaCaT (human epidermal keratinocytes) cells were pre-treated with PT-A-1 (the mass ratio of persimmon tannin and gel was 2:1) or the single component (persimmon tannin or gel) at various concentrations (0, 50, 100, 200, 400, 800 μg/mL. Control group: medium with no HaCaT cells), and then radiated with X-rays (radiation dose: 4, 8, 12, 16, and 20 Gy). Cell viability, cell apoptosis, and radiation-induced intracellular reactive oxygen species (ROS) generation were analysed by CCK-8, Hoechst 33258 staining/flow cytometry, and 2',7'-dichlorfluorescein diacetate (DCFH-DA) assay, respectively, for 12 or 24 h incubation after radiation. The optimal radiation dose and post-radiation incubation period were determined to be 8 Gy and 12 h. CCK-8 activity detection showed that the cell activity was 77.85% ( < 0.05, IC = 55.67 μg/mL). The apoptotic rate was the lowest (4.32%) at 200 μg/mL of PT-A-1 towards HaCaT cells. ROS production was the most effectively suppressed by 200 μg/mL PT-A-1 towards HaCaT cells. The persimmon tannin- gel composite has good radioprotective effect, and which will facilitate its clinic application as a potential natural anti-radiation agent in future.