1 1Miyazaki Prefectural Industrial Support Foundation, Research Promotion Bureau for Collaboration of Regional Entities, 16500-2, Higashi-kaminaka. Sadowara-cho, Miyazaki City, Miyazaki, 880-0303, Japan
| 2 2Unkai Shuzo Co., Ltd., Research & Development, 1800-5, Aza mameshinkai, Oaza Minamimata. Aya-cho, Higashimorokata-gun, Miyazaki, 880-1303, Japan
| 3 3Miyazaki Prefectural Food Research & Development Center, Food Development Department, 16500-2, Higashi-kaminaka. Sadowara-cho, Miyazaki City, Miyazaki, 880-0303, Japan
| 4 4Miyazaki Prefectural Food Research & Development Center, Food Development Dept.
| 5 5Faculty of Medicine, University of Miyazaki, Dept. of Internal Medicine 2, 5200 Oaza Kihara, Kiyotake-cho, Miyazaki-gun, Miyazaki, 889-1692, Japan
| 6 6Kagoshima University Grasuate School of Medical & Dental Sciences, Dept. of Digestive and Life-style Related Disease, 8-35-1, Sakragaoka, Kagoshima City, Kagoshima, 890-8520, Japan
| 7 7Faculty of Agriculture, University of Miyazaki, Dept. of Biochemistry & Applied Biosciences, 1-1, Nishi, Gakuenkibanadai, Miyazaki City, Miyazaki, 889-2192, Japan
Blueberry (Vaccinium sp.) fruits contain high concentrations of polyphenols such as anthocyanin. It is well known that polyphenols have antioxidant activity, so it is likely that the fruit has a possible preventative effect against several diseases like cancer. However, only a few reports so far have studied the human health benefits of the leaves. In this study, the antioxidant activity and antiviral effects of blueberry leaves were investigated. The leaves of three groups of blueberry, northern highbush blueberry (NHB), southern highbush blueberry (SHB), and rabbiteye blueberry (REB), were examined. These leaves were harvested in July and extracted with 80% ethanol. Samples were analyzed for antioxidant activity (DPPH radical scavenging activity) and antiviral activity against hepatitis C virus using the replicon cell assay (Lomann et al., 1999). The antioxidant activity showed significant variability between cultivars and species, with REB having about two times the activity of NHB and SHB. Antiviral activity was observed in the extracts of the leaves and the fruit, and the activity of the leaves was higher than that of the fruit. Among the cultivars and species evaluated, the antiviral activity of REB was higher than that of NHB and SHB. In addition, we discovered a positive correlation (r=0.68) between the antioxidant activity and the antiviral activity, using the leaves of hybrid seedlings of REB. Therefore, it is possible to speculate that the antiviral activity bears some relation to the antioxidant activity.