methyl-jasmonate and indole

Broccoli is rich in bioactive components, such as sulforaphane and indole-3-carbinol, which may impact cancer risk. The glucosinolate profile of broccoli can be manipulated through treatment with the plant stress hormone methyl jasmonate (MeJA). Our objective was to produce broccoli with enhanced levels of indole glucosinolates and determine its impact on prostate carcinogenesis. Brassica oleracea var. Green Magic was treated with a 250 μM MeJA solution 4 days prior to harvest. MeJA-treated broccoli had significantly increased levels of glucobrassicin, neoglucobrassicin, and gluconasturtiin (P < .05). Male transgenic adenocarcinoma of mouse prostate (TRAMP) mice (n = 99) were randomized into three diet groups at 5-7 weeks of age: AIN-93G control, 10% standard broccoli powder, or 10% MeJA broccoli powder. Diets were fed throughout the study until termination at 20 weeks of age. Hepatic CYP1A was induced with MeJA broccoli powder feeding, indicating biological activity of the indole glucosinolates. Following ∼ 15 weeks on diets, neither of the broccoli treatments significantly altered genitourinary tract weight, pathologic score, or metastasis incidence, indicating that broccoli powder at 10% of the diet was ineffective at reducing prostate carcinogenesis in the TRAMP model. Whereas broccoli powder feeding had no effect in this model of prostate cancer, our work demonstrates the feasibility of employing plant stress hormones exogenously to stimulate changes in phytochemical profiles, an approach that may be useful for optimizing bioactive component patterns in foods for chronic-disease-prevention studies.

Topics: Acetates; Animals; Brassica; Carcinogenesis; Cyclopentanes; Glucosinolates; Indoles; Male; Mice, Inbred C57BL; Oxylipins; Plant Extracts; Plant Growth Regulators; Prostatic Neoplasms

The indole-3-glycerol phosphate lyase Igl is the structural gene of volatile indole biosynthesis in the tritrophic interaction in maize. The gene is activated on transcriptional level with the same kinetics and to the same level by the fatty acid-amino acid conjugates (FAC's) volicitin (17S)-(N-(17-hydroxylinolenoyl)-L-glutamine) and N-linolenoyl-L-glutamine. Both conjugates are present in the regurgitates of herbivorous caterpillars. Modifications of the fatty acid moiety of the FACs greatly reduces the elicitation of Igl and only the L-stereo-isomer of the FACs shows biological activity in the system. Volicitin treatment leads to a fast increase of AOS and AOC transcription levels and methyl jasmonate application induces Igl transcription. Hence, the induction of jasmonate biosynthesis appears to be an integral part of the elicitor mediated increase of Igl gene transcription.

Topics: Acetates; alpha-Linolenic Acid; Amino Acids, Cyclic; Animals; Aristolochic Acids; Aspirin; Cyclooxygenase Inhibitors; Cyclopentanes; Genes, Plant; Glutamine; Indole-3-Glycerol-Phosphate Synthase; Indoles; Intramolecular Oxidoreductases; Lepidoptera; Linolenic Acids; Oxylipins; Pyrazoles; Stereoisomerism; Structure-Activity Relationship; Transcriptional Activation; Zea mays