The 2011 ASHS Annual Conference

Broccoli (Brassica oleracea L. ssp. Italica) is a good source of several health promoting phytochemical compounds including glucosinolates (GSs) and flavonoids.  Dietary supplementation of selenium (Se) in human diets has also been shown to reduce the risk of cancer. This research reports on enhancement of health promoting bioactivity in broccoli floret tissue through the combined treatment of selenium and methyl jasmonic acid (MeJA).  Two broccoli genotypes were subjected to root fertilization with solutions of Na₂SeO₄ and MeJA sprays to aerial portions of the plants. A low level of Se fertilization (0.17 mM of Na₂SeO₄) in conjunction with MeJA treatment displayed no significant changes in total aliphatic GS concentrations with 1.9 and 1.5 fold increases in indolyl and total GSs concentrations, respectively across the two genotypes. To analyze health promoting bioactivity of broccoli tissues subjected to different treatments, activity of the antioxidant enzyme, GPx1 (glutathione peroxidase 1), and the phase I and II detoxification enzymes, CYP1A (cytochrome P450 1A) and NQO1 (NADPH-dependent quinone oxidoreductase 1), whose activities are associated with reduced cancer risk, were measured in vitro in a mouse hepatoma cell line. Se or Se combined with MeJA treatment significantly increased activity of hepatic GPx1. MeJA and the combined treatment of MeJA with Se also significantly increased activities of hepatic CYP1A and NQO1. These results suggest that Se- and indolyl GS-enriched broccoli with improved health-promoting properties can be generated by the combined treatment of Se with MeJA.