Background and methodology:
Strawberries have been shown to have high total antioxidant capacity compared to many other fruits, and this antioxidant activity varies among different cultivars. Strawberries also contain antioxidants such as ellagic acid, vitamin C, hydroxycinnamic acids, anthocyanins, and other flavonoids. Studies have found that the phytochemicals in extracts of strawberries inhibit the proliferation of cancer cells in humans. This study investigated the effect of extracts from strawberry cultivars grown in organic and conventional cultivation systems on the proliferation of human colon cancer cells HT29 and breast cancer cells MCF-7.
The strawberry extracts decreased the proliferation of both colon cancer cells and breast cancer cells. The inhibition of cell proliferation varied according to the concentration of the extracts. The extracts from organically grown strawberries inhibited cancer cell proliferation of both HT29 and MCF-7 to a significantly higher extent at the two highest concentrations, 0.5 percent and 0.25 percent, than the conventionally grown strawberries. The growth inhibitory effect was significant at these concentrations when the inhibition effect of all organically-grown cultivars was compared with that of all conventionally-grown cultivars. On average, with the highest concentration of extracts, the HT29 cells were inhibited to a higher degree (53 percent) than the MCF-7 cells (43 percent).
Olsson, M.E., Andersson, C.S., Oredsson, S., Berglund, R.H. and Gustavsson, K.E. (2006). Antioxidant levels and inhibition of cancer cell proliferation in vitro by extracts from organically and conventionally cultivated strawberries. Journal ofAgricultural and Food Chemistry 54(4):1248-1255. Available on-line at: http://dx.doi.org/10.1021/jf0524776