Abstract
BACKGROUND: To overcome disadvantages of germinated brown rice, we germinated rough rice and tested effects of its useful ingredients on prevention of diabetes. OBJECTIVE: This study investigated the in vitro antioxidant and in vivo antidiabetic effects of rough rice (Oryza sativa L.) with hulls, before and after germination. Rough rice was germinated for 4 days and extracted with water at 120°C. DESIGN: This study measured antioxidants and antioxidative effects and inhibitory activities against α-amylase and α-glucosidase of rough rice before and after germination and investigated antidiabetic effects of rough rice through animal experiments. RESULTS: All these factors increased after germination. Also, α-amylase and α-glucosidase inhibition and glucose uptake by 3T3-L1 adipocytes were significantly increased after germination. Oral administration of the germinated rough rice extract for 8 weeks significantly increased insulin levels and decreased blood glucose levels in a C57BLKS/J-db/db mice model. Immunohistochemical analysis showed that germinated rough rice effectively protected against liver, kidney, and pancreatic tissue damage. DISCUSSION: Useful ingredients in germinated rough rice could be used to prevent diabetes. CONCLUSIONS: These results suggest that germinated rough rice extract had a beneficial effect on diabetes by increasing the antioxidant activity and further purification studies are necessary to elucidate the mechanism of the extract's antidiabetic activity.