Dietary Fish Oil Reduces DNA Adduct Formation While Estradiol Upregulates Apoptosis in Response to DNA Damage in the Rat Colon
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : Cameron M. Armstrong Kimberly F. Allred Clinton D. Allred
- چاپ و سال / کشور: 2011
Description
Background Dietary fish oil is associated with a decrease in colon cancer incidence: in part through a reduction in DNA adduct formation and an induction of colonocyte apoptosis. Estradiol (E2) has also been demonstrated to be protective against colon cancer incidence. Studies evaluating fish oil diets and DNA adduct formation in the colon have been conducted in male models without regard to possible interactions with E2. Aims The aim of this study was to evaluate the effects of E2 and fish oil both together and separately in female rats at the point of DNA damage. Methods Ovariectomized female Sprague–Dawley rats were fed either a corn oil or fish oil diet in the presence or absence of E2 for two weeks prior to being sacrificed at four time points following injection with azoxymethane. O6-methyldeoxyguanosine (O6-MedG) DNA adducts and apoptosis were examined using immunohistochemistry. Results Dietary fish oil reduced DNA adduct formation independent of the presence of E2 at both 9 and 12 h post carcinogen. E2 itself did not suppress adduct formation. E2 significantly induced apoptosis 12 h after carcinogen independent of diet, primarily in the luminal third of the crypts. Fish oil was not associated with increased colonocyte apoptosis. Conclusions These data demonstrate that fish oil is protective against DNA damage in the colon regardless of gender through reduction of O6-MedG adduct formation. Additionally, E2 is capable of inducing apoptosis directly at the point of DNA damage
Dig Dis Sci DOI 10.1007/s10620-011-1667-1 Received: 29 October 2010 / Accepted: 1 March 2011
