J

The inhibitory effects of the oral administration of Hana-yuzu (Citrus hanaju) and New Summer Orange (Citrus tamurana) on mouse gastritis induced by cold-restraint stress and the relationship with their antioxidative activities were investigated. Whole pastes of Hana-yuzu and New Summer Orange significantly suppressed mouse gastritis at doses of 100 and 200 mg/kg body weight. The suppressive effect of Hana-yuzu tended to be higher than that of New Summer Orange. Among the parts of Hana-yuzu, the paste of the albedo at a dose of 200 mg/kg body weight and the aqueous extract of the flavedo at a dose of 200 ?L/kg body weight significantly suppressed mouse gastritis. These samples also significantly suppressed the increases in lipid peroxide levels in the stomachs of mice with gastritis. In the in vitro experiments, the aqueous extracts of the flavedo and albedo showed strong activities as substrates for peroxidase and radical scavengers. Considerable amounts of some antioxidative components, ?-cryptoxanthin, ?-carotene, and auraptene, were determined in the pastes of Hana-yuzu flavedo and albedo. The sum of the flavedo and albedo weight accounted for ca. 82% of the whole Hana-yuzu. These results suggest that Hana-yuzu is an available food material for the prevention of gastritis and the antioxidative activities of its flavedo and albedo appear to contribute to the antiinflammatory effects.