Abstract: The protective effect of flavonoids from seed shells of Juglans mandshurica (FSSJM) against oxidative damage in mice was explored. A mouse model of oxidative damage was built by X-ray radiation. Before radiation, using berbamine hydrochloride gavaged at 56 mg/(kg·d) as the positive control, FSSJM were consecutively given to mice by gavage at three different doses of 100, 200 and 400 mg/(kg·d) for 14 days. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), and the contents of malondialdehyde (MDA) and glutathione (GSH) in serum and liver tissues of 24 h radiated mice were determined by spectrophotometry. Liver tissues of 14 day radiated mice were observed morphologically, and the expression of Bax and Bcl-2 protein in liver and spleen were analyzed by immunohistochemisty. The results showed that FSSJM could increase the activities of SOD, GSH-Px and CAT in serum and liver of mice, decrease MDA content, and increase GSH content. Furthermore, FSSJM could repair damaged liver tissues, along with increasing Bcl-2 protein expression and decreasing Bax protein expression. Therefore, FSSJM can protect against radiation-induced oxidative damage.

Key words: Juglans mandshurica seed shells grown in Northeast China, flavonoids, radiation, oxidative damage, protection