Dietary garcinol inhibits 4-nitroquinoline 1-oxide-induced tongue carcinogenesis in rats.

The effects of dietary feeding with a polyisoprenylated benzophenone, garcinol, isolated from Garcinia indica fruit rind on the development of 4-nitroquinoline 1-oxide (4-NQO)-induced oral carcinogenesis were investigated in male F344 rats. At 7 weeks of age, animals were given 4-NQO at 20 ppm in the drinking water for 8 weeks to induce tongue neoplasms. They also received the diets containing 100 or 500 ppm garcinol either during (for 10 weeks) or after (for 22 weeks) the carcinogen exposure.

Dietary supplementation of the citrus antioxidant auraptene inhibits N,N-diethylnitrosamine-induced rat hepatocarcinogenesis.

Objectives: We have previously reported that an antioxidant, auraptene (AUR), isolated from citrus fruit effectively inhibits chemically induced carcinogenesis in digestive tracts, such as the oral cavity, esophagus and large bowel. In this study, we investigated the modifying effects of dietary supplementation with AUR on N,N-diethylnitrosamine (DEN)-initiated hepatocarcinogenesis in male F344 rats in two different experiments to determine whether the compound exerts a cancer-chemopreventive action in other organs.

Methods: In the first experiment, animals were fed diets containing AUR at dose levels of 100 and 500 ppm for 7 weeks 1 week before, during, and 1 week after the start of liver carcinogenesis induced by DEN (40 ppm in drinking water for 5 weeks) to predict the modulatory effect on hepatocarcinogenesis.

Enhancement of development of azoxymethane-induced colonic premalignant lesions in C57BL/KsJ-db/db mice.

Epidemiological studies have shown that obesity and diabetes mellitus may be risk factors for colon cancer. However, the underlying mechanisms of how these chronic diseases promote colon carcinogenesis remain unknown. C57BL/KsJ-db/db mice have obese and diabetic phenotypes because of disruption of the leptin receptor.

Inhibitory effects of troglitazone, a peroxisome proliferator-activated receptor gamma ligand, in rat tongue carcinogenesis initiated with 4-nitroquinoline 1-oxide.

Ligands for peroxisome proliferator-activated receptor (PPAR) gamma have been implicated in growth inhibition and cell differentiation in certain malignancies. In this study, the effects of troglitazone, a PPAR gamma ligand, given during the postinitiation phase of oral carcinogenesis initiated with 4-nitroquinoline 1-oxide (4-NQO) were investigated in male F344 rats. Rats aged 6 weeks were given 4-NQO at 20 ppm for 8 weeks to induce tongue neoplasms.

Inhibitory Effects of Dietary Monoglucosyl-rutin on Azoxymethane-induced Colon Carcinogenesis in Rats.

The dietary effect of monoglucosyl-rutin (M-R), a flavonoid, on azoxymethane (AOM)-induced colon carcinogenesis was investigated in two experiments with 5 week old, F344 male rats. In the first experiment (5 weeks study), effects of MR on AOM (15 mg/kg body weight 3 times weekly)-induced formation of aberrant crypt foci (ACF) in five groups were assessed. In this experiment, group 3 given 500 ppm M-R with AOM had a significantly smaller number of ACF containing 4 or more aberrant crypts than group 1 with AOM alone, and groups 2 and 3 given 100 ppm or 500 ppm M-R respectively had significantly lower BrdU labeling indices in the epithelial cells of large bowel than group 1.

Inhibitory Effects of Chlorogenic Acid on Azoxymethane-induced Colon Carcinogenesis in Male F344 Rats.

Modifying effects of chlorogenic acid (CA) on carcinogen-induced large bowel carcinogenesis was examined in rats. A total of 150 male F344 rats, 4 weeks old, were divided into 5 groups. At 6 weeks of age, groups 1-3 were given subcutaneous injections of AOM (15 mg/kg body weight) once a week for three weeks.

Azoxymethane-induced beta-catenin-accumulated crypts in colonic mucosa of rodents as an intermediate biomarker for colon carcinogenesis.

It is now well established that bile acids act as colon tumor promoters. However, a previous study provided conflicting data showing that dietary exposure of cholic acid (CHA), a primary bile acid, inhibits the carcinogen-induced formation of aberrant crypt foci (ACF), possible preneoplastic lesions, in colonic mucosa of rodents. Recently we found beta-catenin-accumulated crypts (BCAC) in colonic mucosa of rats initiated with azoxymethane (AOM) and provided evidence that BCAC might be preneoplastic lesions independent from ACF.

beta-Catenin mutation is selected during malignant transformation in colon carcinogenesis.

Activating mutations in the beta-catenin gene is thought to be responsible for the excessive beta-catenin signaling involved in the majority of colon carcinomas in rodent models. Our recent study which indicated that beta-catenin mutations are present frequently in early dysplastic lesions of rat colon induced by a colon-specific carcinogen, azoxymethane led us to perform more specifically a comparative study regarding types of the beta-catenin mutation as well as K-ras mutations between such early appearing lesions and colon tumors. Male F344 rats, 6 weeks old, received s.

Double deletions and missense mutations in the first nucleotide-binding fold of the ATP-binding cassette transporter A1 ( ABCA1) gene in Japanese patients with Tangier disease.

Tangier disease (TD) is a rare autosomal recessive disease characterized by plasma high-density lipoprotein deficiency caused by an ATP-binding cassette transporter A1 ( ABCA1) gene mutation. We describe three different mutations in Japanese patients with TD. The first patient was homozygous for double deletions of 1221 bp between intron 12 and 14 and 19.

Preventive effect of fermented brown rice and rice bran against colon carcinogenesis in male F344 rats.

Epidemiological and preclinical studies demonstrate that nutrition plays an important role in the etiology of cancer. It has been reported that rice components, especially rice germ plays a key role in prevention of cancer. The experiments described here examined the potential anticancer properties of brown rice fermented by Aspergillus Oryzae (FBRA) in male F344 rats using inhibition of the formation of azoxymethene (AOM) induced aberrant crypt foci (ACF) and tumors in the colon as the measure of preventive efficacy.

Dietary silymarin suppresses 4-nitroquinoline 1-oxide-induced tongue carcinogenesis in male F344 rats.

The modifying effect of dietary administration of a polyphenolic antioxidant flavonoid silymarin isolated milk thistle [Silybum marianum (L.) Gaertneri] on 4-nitroquinoline 1-oxide (4-NQO)-induced tongue tumorigenesis was investigated in male F344 rats. Based on the results in pilot studies showing that silymarin treatment together with 4-NQO significantly reduced the occurrence of tongue dysplasia and gavaged with silymarin significantly elevated the phase II detoxifying enzymes' activities in the liver and tongue, the effects of dietary feeding of silymarin on tongue carcinogenesis were investigated in a long-term experiment, where rats were initiated with 4-NQO and fed silymarin containing diets during or after 4-NQO exposure.