Dietary conjugated linolenic acid inhibits azoxymethane-induced colonic aberrant crypt foci in rats.
The modifying effects of dietary feeding of conjugated linolenic acid (CLN) isolated from the seeds of bitter gourd (Momordica charantia) on the development of azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) were investigated in male F344 rats to predict its possible cancer chemopreventive efficacy. The effect of CLN on the proliferating cell nuclear antigen (PCNA) index in colonic ACF was also examined. Rats were given subcutaneous injections of AOM (20 mg/kg body weight) once a week for 2 weeks to induce ACF. They also received the experimental diet containing 0.01%, 0.1% or 1% CLN for 5 weeks, starting one week before the first dosing of AOM. AOM exposure produced a substantial number of ACF (108 +/- 21/rat) at the end of the study (week 4). Dietary administration of CLN caused a significant reduction in the frequency of ACF: 87 +/- 14 (19.4% reduction, P < 0.05) at a dose of 0.01%, 69 +/- 28 (36.1% reduction, P < 0.01) at a dose of 0.1% and 40 +/- 6 (63.0% reduction, P < 0.001) at a dose of 1%. Also, CLN administration lowered the PCNA index and induced apoptosis in ACF. These findings might suggest possible chemopreventive activity of CLN in the early phase of colon tumorigenesis through modulation of cryptal cell proliferation activity and/or apoptosis.
Kohno
Hiroyuki
H
Department of Pathology, Kanazawa Medical University, Uchinada, Ishikawa 920-0293, Japan. h-kohno@kanazawa-med.ac.jp
Suzuki
Rikako
R
Noguchi
Ryoko
R
Hosokawa
Masashi
M
Miyashita
Kazuo
K
Tanaka
Takuji
T
D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D017209:Apoptosis; D001397:Azoxymethane; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000517:prevention & control*; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D005227:Fatty Acids / Q000032:analysis; D019787:Linoleic Acid / Q000008:administration & dosage*; D008297:Male; D011230:Precancerous Conditions / Q000139:chemically induced / Q000517:prevention & control*; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344; D018160:Receptors, Cytoplasmic and Nuclear / Q000502:physiology; D014157:Transcription Factors / Q000502:physiology
D000975:Antioxidants; D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D018809:Proliferating Cell Nuclear Antigen; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors; D019787:Linoleic Acid; D001397:Azoxymethane