Hot water extracts of pressure-roasted dried radish attenuates hepatic oxidative stress via Nrf2 up-regulation in mice fed high-fat diet.

This study investigated the effect of pressure-roasted dried radish (PRDR) against oxidative stress. To prepare PRDR extract, dried radish (DR) was pressure-roasted, boiled, and then freeze-dried. Mice fed a chow diet with oral administration of distilled water (DW) (normal group) or a high-fat diet with DW (control, CON group), DR (DR group, 237 mg/kg bw/day), or PRDR (PRDR group, 237 mg/kg bw/day) (n = 8 each group) for 12 weeks. Hepatic lipid peroxidation level in the DR and PRDR groups was lower than that in the CON group, whereas hepatic glutathione level in these groups was higher (p < 0.05). Hepatic expression of nuclear factor (erythroid-derived 2)-like 2 and its related antioxidant enzymes such as catalase, glutathione S-transferase, and peroxidases was the highest in the PRDR group (p < 0.05). It is apparent that radish attenuate oxidative stress and the process of pressure roasting might contribute positively to this effect.