Polyamine metabolism and transforming growth factor-beta signaling are affected in Caco-2 cells by differentially cooked broccoli extracts.
The health benefits of consuming cruciferous vegetables are widely considered to be due to the biological activity of glucosinolate degradation products. However, it is conceivable that other phytochemicals within crucifers may also have biological activity that may contribute to health benefits. In this study, we analyzed global gene expression in Caco-2 cells exposed to extracts derived from broccoli that had been heat treated to different extents to result in contrasting profiles of glucosinolates and their degradation products. Extracts microwaved for 0, 1, and 4 min contained 9.5, 25.5, and 0 micromol/L sulforaphane and induced changes in expression of 381, 1017, and 101 genes, respectively (>2 fold; P < 0.01). Seventy-two genes showed similar changes in expression after treatment with all 3 extracts. These included genes involved in polyamine catabolism and transforming growth factor (TGF)-beta signaling. Consistent with these changes in gene expression, subsequent studies demonstrated that exposing cells to these extracts, including the 4-min extract that contained no glucosinolate degradation products, increased putrescine and N-acetyl-spermine concentration, and suppressed the TGFbeta1-mediated induction of phosphorylated Smad 2. This is the first report, to our knowledge, of phytochemicals from a cruciferous vegetable affecting both a signaling pathway and a catabolic process.
Furniss
Caroline S M
CS
Institute of Food Research, Norwich Research Park, Colney Lane, Norwich NR4 7UA, UK. caroline.furniss@bbsrc.ac.uk
Bennett
Richard N
RN
Bacon
James R
JR
LeGall
Gwen
G
Mithen
Richard F
RF
D001937:Brassica; D018938:Caco-2 Cells; D018929:Cell Culture Techniques; D003296:Cooking; D006801:Humans; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D010936:Plant Extracts / Q000494:pharmacology*; D011073:Polyamines / Q000378:metabolism*; D012334:RNA, Neoplasm / Q000235:genetics / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D016212:Transforming Growth Factor beta / Q000187:drug effects / Q000502:physiology*
D010936:Plant Extracts; D011073:Polyamines; D012334:RNA, Neoplasm; D016212:Transforming Growth Factor beta