Radioprotective Effect of Sinapic Acid Against Genotoxicity and Apoptosis Induced by Ionizing Radiation on Human Lymphocytes

Background: Sinapic Acid (SA), as a natural phenolic compound, is widely spread in plants. Objectives: In this study, the radioprotective effect of SA was investigated against genotoxicity and apoptosis induced by ionizing radiation in human lymphocytes. Methods: In this experimental study, peripheral blood samples were collected from human volunteers and incubated with SA at different concentrations (50-1000 μM) for three hours. The whole blood samples were exposed to X-ray at the dose of 1.5 Gy. Lymphocytes were cultured with mitogenic stimulation to determine the micronuclei in cytokinesis-blocked binucleated lymphocyte. The apoptotic lymphocytes were evaluated by flow cytometry in SA treated and/or irradiated samples. The antioxidant activities of SA were assayed by two different methods. Results: SA significantly decreased the frequency of micronuclei and apoptosis in human lymphocytes exposed to ionizing radiation. The maximum protection and higher decrease in the frequency of micronuclei in lymphocytes were observed at 1000 μM of SA with 73% of efficacy. SA exhibited strong free radical scavenging and antioxidant activity at a concentration-dependent antioxidant activity. Conclusion: This data provides that SA is a powerful radioprotective agent that can protect human normal cells against the genetic damage and apoptosis induced by ionizing irradiation.