Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/11/2007
Publication Date: 1/15/2008
Citation: Wang, S.Y., Bowman, L., Ding, M. 2008. Methyl Jasmonate Enhances Antioxidant Activity, Flavonoid Content and Antiproliferation of Human Cancer Cells in Blackberries (Rubus spp.). Journal of Agricultural and Food Chemistry. 107:1261-1269. Interpretive Summary: Methyl jasmonate (MJ) is a naturally-occurring chemical produced by plants. It is used by plants to regulate many biochemical and physiological processes, including ripening of fruit. However, little is known about the effect of methyl jasmonate on the quality of blackberries or the levels of antioxidants in the fruit. Antioxidants are important because they are a class of compounds that can prevent damage to cells. We studied the effect of preharvest application of MJ on the content of cancer-fighting antioxidants in blackberry fruit extracts. We found that application of methyl jasmonate increased flavonoids and other antioxidants and secondary metabolites. Methyl jasmonate treated fruit also had higher anti-cancer activities than berries that had not been treated. The antioxidant activities in blackberries vary among different varieties and their activities were higher than those in strawberries and the same or lower than those in blueberries. Furthermore, methyl jasmonate improved fruit quality by increasing sugar content and lowering acid levels. These results indicate that consuming blackberries may be beneficial to human health and methyl jasmonate treatment could enhance their health benefits. Information obtained from this research is useful for other scientists, blackberry growers and consumers interested in antioxidant compounds in fruit.
Technical Abstract: The effects of preharvest methyl jasmonate (MJ) application on fruit quality, antioxidant activity and flavonoid content in blackberries (Rubus spp.) were determined. Anticancer activity against human lung A549 cells and HL-60 leukemia cells was also evaluated. Three blackberry cultivars (Chester Thornless, Hull Thornless and Triple Crown) were used in these experiments. Blackberries treated with MJ (0.01 and 0.1 mM) had higher soluble solids content, and lower titratable acids than untreated fruit as well as enhanced content of flavonoids and increased antioxidant capacity. Extracts of treated fruit showed enhanced inhibition of A549 cell and HL-60 cell proliferation and induced the apoptosis of HL-60 cells. Cultivar Hull Thornless had higher soluble solids and lower titratable acids compared to cv. Chester Thornless and Triple Crown. On the basis of fresh weight of fruit, Hull Thornless also had significantly higher anthocyanin, total phenolic content, antioxidant and antiproliferation activity than other two cultivars.