title: Sorghum phenolics demonstrate estrogenic action and induce apoptosis in nonmalignant colonocytes.
abstract: Evidence indicates sorghum may be protective against colon cancer; however, the mechanisms are unknown. Estrogen is believed to protect against colon cancer development by inducing apoptosis in damaged nonmalignant colonocytes. Three sorghum extracts (white, red, and black) were screened for estrogenic activity using cell models expressing estrogen receptor α (ER-α; MCF-7 breast cancer cells) and β [ER-β; nonmalignant young adult mouse colonocytes (YAMC)]. Black and white sorghum extracts had significant estrogenic activity mediated through both estrogen receptors at 1-5 and 5-10 μg/mL, respectively; but red sorghum did not. Activation of ER-β in YAMC reduced cell growth via induction of apoptosis. Only the black and red sorghums contained 3-deoxyanthocyanins; however, these compounds were non-estrogenic. Flavones with estrogenic properties, luteolin (0.41-2.12 mg/g) and apigenin (1.1-1.4 mg/g), and their O-methyl derivatives (0.70-0.95 mg/g) were detected in white and black sorghums, but not in the red sorghum. On the other hand, naringenin, a flavanone known to interfere with transcriptional activities of estrogen, was only detected in the red sorghum extract (as its 7-O-glycoside) at relatively high concentration (11.8 mg/g). Sorghum flavonoid composition has important implications on possible modes of chemoprotection by sorghum against colon carcinogenesis.
authors.affiliation: Cereal Quality Laboratory, Soil & Crop Science Department, Texas A&M University, College Station, Texas 77843-2474, USA.
authors.forename: Liyi
authors.initials: L
authors.lastname: Yang
authors.forename: Kimberly F
authors.initials: KF
authors.lastname: Allred
authors.forename: Bhimalingeswarappa
authors.initials: B
authors.lastname: Geera
authors.forename: Clinton D
authors.initials: CD
authors.lastname: Allred
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Awika
mesh_terms: D000818:Animals; D047310:Apigenin / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003106:Colon / Q000166:cytology* / Q000473:pathology; D004847:Epithelial Cells / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000378:metabolism; D005260:Female; D044950:Flavanones / Q000494:pharmacology*; D006801:Humans; D047311:Luteolin / Q000494:pharmacology; D051379:Mice; D048789:Phytoestrogens / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D045868:Sorghum / Q000737:chemistry*
chemical_list: D047628:Estrogen Receptor alpha; D044950:Flavanones; D048789:Phytoestrogens; D010936:Plant Extracts; D047310:Apigenin; C005273:naringenin; D047311:Luteolin