Antioxidant Capacity and Protective Effects on Neuronal PC-12 Cells of Domestic Bred Kiwifruit

This study was conducted to comparatively evaluate antioxidant capacity (AC) of seven cultivars of kiwifruit (Actinidia spp.) and their protective effects on neuronal PC-12 cells. The contents of total phenolics (TP) and total flavonoids (TF) of kiwifruits were also examined. Five cultivars of kiwifruit, Actinidia chinensis (cv. Haehyang and cv. Haegeum), A. eriantha (cv. Bidan), A. arguta A. deliciosa (cv. Mansoo), and A. arguta (cv. Chiak), were bred in Korea, while two cultivars, A. deliciosa (cv. Hayward) and A. linguiensis (accession number 041AE), originated from New Zealand and China, respectively. Skin extracts of kiwifruit showed higher TP, TF, and AC than flesh extracts. The highest levels of TP and AC were found in cv. Bidan flesh extract among cultivars studied, but the TF content of cv. Bidan flesh extract was the lowest. The kiwifruit bred in Korea had higher AC than their counterparts. AC of kiwifruit had a highly positive linear correlation with TP and TF. The flesh extracts from cv. Hayward, cv. Haehyang, and cv. Haegeum significantly (p < 0.05) prevented PC-12 cells from oxidative stress induced using H2O2 compared to a control with H2O2 only. Overall, our results suggest that kiwifruit bred in Korea may offer a good source of antioxidants and serve as functional materials.