Abstract: To explore an ideal alternative approach for radiation protection, this study quantified vitamin C (≥ 2.5%) and total flavonoids (≥ 2%) in Rosa roxbunghii Tratt. juice concentrate. Its antioxidant capacity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation, and hydroxyl radical scavenging assays, and its efficacy in radiation protection was assessed by cell and animal experiments. Results showed that R. roxbunghii Tratt. juice concentrate scavenged all three free radicals and significantly suppressed the reduction in HL-7702 cell viability caused by ionizing radiation. Compared with the radiation model group, the spleen index and superoxide dismutase (SOD) activity in the serum and spleen, the malondialdehyde (MDA) content in the serum and liver, and the glutathione content in the serum, liver and spleen of mice treated with 1.0 g/kg of R. roxbunghii Tratt. juice concentrate for 30 days were significantly alleviated, and it also had a protective effect against liver function damage caused by radiation. This study lay the basis for establishing quality grading standards for R. roxbunghii Tratt. juice concentrate and for its application to functional foods.

Key words: Rosa roxbunghii Tratt. juice concentrate, vitamin C, flavonoids, antioxidant, ionizing radiation