Submitted to: Journal American Society Hortscience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/8/2007
Publication Date: 9/1/2007
Citation: Wang, S.Y., Lewers, K.S., Bowman, L., Ding, M. 2007. Antioxidant Activities and Inhibition of Cancer Cell Proliferation in Wild Strawberries. Journal American Society Hortscience. 132(5):647-658. Interpretive Summary: Antioxidants are natural plant chemicals that play an important role as a health promoting factor for people that consume them in food. Wild strawberries are good source for obtaining desirable traits to be used in breeding programs. However, little information is available on antioxidant activities and their inhibitory effects on the growth of cancer cells in any species of wild strawberries. We set out to investigate antioxidant capacity of some wild strawberries and found that antioxidant capacity and anti-cancer activity vary among different wild strawberry types. Several wild strawberries have high antioxidant activities and have the potential to reduce cancer risk. Our results indicate that they may be used in breeding programs to increase antioxidants. Information obtained from this research is valuable for other scientists, strawberry growers and consumers interested in antioxidant compounds and in improving human health.
Technical Abstract: Fruit extracts from seventeen representatives of three species of strawberries (Fragaria virginiana Mill., F. chiloensis (L.) Mill., and F. x ananassa Duchesne ex Rozier) were tested for activities against free radicals, the activities of antioxidant enzymes and the ability to inhibit proliferation of A549 human lung epithelial cancer cells. The free radicals tested in this study included peroxyl radicals, hydroxyl radicals, singlet oxygen and superoxide radicals. The activities of antioxidant enzymes included glutathione peroxidase, superoxide dismutase, guaiacol peroxidase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, glutathione reductase and the activities of non-enzyme antioxidant components included ascorbic acid and glutathione. Correlations between the antiproliferation of cancer cells and these antioxidant activities were calculated. At the species level, extracts from F. virginiana fruit inhibited the proliferation of A549 human lung epithelial cancer cells to a significantly higher extent than the extracts from fruit of either F. chiloensis or F. x ananassa. Extracts from fruit of F. virginiana also had significantly greater antioxidant activities and higher activities of antioxidant enzymes and nonenzyme components than extracts from the other two species. Among both species and individual genotypes, there was a high positive correlation between antiproliferation of A549 cancer cell and antioxidant activities against free radicals, activities of antioxidant enzymes, and activities of non-enzyme components. Although fruit extracts from all the strawberry genotypes inhibited proliferation of A594 cancer cells, fruit extracts from seven F. virginiana genotypes showed significantly greater antiproliferative effects than those from any of the F. x ananassa or F. chiloensis genotypes. Genotypes CFRA 0982, JP 95-1-1, NC 95-19-1, RH 30, NC 96-48-1, JP 95-9-6, and LH 50-4, may be especially useful in developing cultivars with high antioxidant capacities and anticancer potential.