Green tea extracts and tea catechins have been shown to prevent or alleviate diabetes. The present study tests the hypothesis that green tea leaves in powder form (GTP), which also contain fiber and other water non-extractable materials, are more effective than the corresponding green tea extracts (GTE) in impeding the development of diabetes in / mice. Female / mice were treated with a diet containing 1% of GTE, 2% of GTE, 2% of GTP (with the same catechin content as 1% GTE) or 1% GTP.
View Article and Find Full Text PDFIn this study, we investigated the effects of a newly synthesized α-galacto-oligosaccharide mixture (α-GOSg), 0.5% in drinking water, on high-fat/western-style diet (HFWD)-induced metabolic abnormality in mice in a study of 13 weeks. Raffinose family oligosaccharides (RFOs) were included as a comparison.
View Article and Find Full Text PDFTocopherols (T) and tocotrienols (T3), all existing in α, β, γ, and δ-forms, are the eight forms of vitamin E (VE). In this study, we investigated the effects of gut microbiota on the degradation and tissue levels of different VE forms by treating mice with antibiotics in drinking water for 12 days. The mice also received an intragastric (i.
View Article and Find Full Text PDFScope: The effects of green tea polyphenols, Polyphenon E (PPE), and black tea polyphenols, theaflavins (TFs), on gut microbiota and development of diabetes in db/db mice are investigated and compared.
Methods And Results: Supplementation of PPE (0.1%) in the diet of female db/db mice for 7 weeks decreases fasting blood glucose levels and mesenteric fat while increasing the serum level of insulin, possibly through protection against β-cell damage.
Biochim Biophys Acta Mol Cell Biol Lipids
October 2018
Objective: To investigate and compare the effects of two common dietary phytosterols, stigmasterol and β-sitosterol, in altering lipid metabolism and attenuating nonalcoholic fatty liver disease (NAFLD).
Methods: Stigmasterol and β-sitosterol were administered to mice at 0.4% in a high-fat western-style diet (HFWD) for 17 weeks.
The previous studies have shown that tea polyphenols are metabolized by gut microbiota. This study investigated the effect of gut microbiota on the bioavailability, tissue levels, and degradation of tea polyphenols. Mice were treated with antibiotics (ampicillin/sulfamethoxazole/trimethoprim) in drinking water and the control mice received water for 11 days, and they were given an AIN93M diet enriched with 0.
View Article and Find Full Text PDFTo study the effects of stigmasterol and β-sitosterol on high-fat Western diet (HFWD)-induced nonalcoholic fatty liver disease (NAFLD), lipidomic analyses were conducted in liver samples collected after 33 weeks of the treatment. Principal component analysis showed these phytosterols were effective in protecting against HFWD-induced NAFLD. Orthogonal projections to latent structures-discriminate analysis (OPLS-DA) and S-plots showed that triacylglycerols (TGs), phosphatidylcholines, cholesteryl esters, diacylglycerols, and free fatty acids (FFAs) were the major lipid species contributing to these discriminations.
View Article and Find Full Text PDFBone marrow-derived cells have important roles in cancer development and progression. Our previous studies demonstrated that murine bone marrow-derived myofibroblasts (BMFs) enhanced tumor growth. In this study, we investigated the mechanisms of BMF actions.
View Article and Find Full Text PDFEpigallocatechin-3-gallate (EGCG), atorvastatin (ATST), and their combination have been previously shown to inhibit colon carcinogenesis in animal models. We further investigated their inhibitory activities in azoxymethane (AOM) and dextran sulfate sodium (DSS)-treated Balb/cJ mice and CD-1 mice in 2 slightly different models. The mice were maintained on the AIN93M diet, or a similar diet containing 0.
View Article and Find Full Text PDFTo develop a relevant mouse model for prostate cancer prevention research, we administered a dietary carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), to CYP1A-humanized mice. In comparison with mouse Cyp1a2, human CYP1A2 preferentially activates PhIP to a proximate carcinogen. Following a single oral dose of PhIP (200 mg/kg body weight), we observed inflammation, atrophy of acini, low-grade prostatic intraepithelial neoplasia (PIN; after 20 weeks), and high-grade PIN (HgPIN; after 30 to 50 weeks) in dorsolateral, ventral, and coagulating anterior prostate glands of these mice.
View Article and Find Full Text PDFThe cancer preventive activity of vitamin E has been extensively discussed, but the activities of specific forms of tocopherols have not received sufficient attention. Herein, we compared the activities of δ-tocopherol (δ-T), γ-T, and α-T in a colon carcinogenesis model. Male F344 rats, seven weeks old, were given two weekly subcutaneous injections of azoxymethane (AOM) each at a dose of 15 mg/kg body weight.
View Article and Find Full Text PDFThe present study investigated the antioxidant and anti-inflammatory actions of tocopherols in mice and determined whether the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is involved in these activities. A mixture of tocopherols (γ-TmT) that is rich in γ-tocopherol was used. Nrf2 knockout (Nrf2 -/-) and wild-type mice were maintained on 0.
View Article and Find Full Text PDFThe aim of this study was to investigate the effects of (-)-epigallocatechin-3-gallate (EGCG) on newly developed high-fat/Western-style diet-induced obesity and symptoms of metabolic syndrome. Male C57BL/6J mice were fed a high fat/Western-style (HFW; 60% energy as fat and lower levels of calcium, vitamin D(3), folic acid, choline bitartrate, and fiber) or HFW with EGCG (HFWE; HFW with 0.32% EGCG) diet for 17 wks.
View Article and Find Full Text PDFCancer Prev Res (Phila)
March 2011
In contrast to strong epidemiologic, preclinical, and secondary clinical evidence for vitamin E (tocopherols) in reducing cancer risk, large-scale clinical cancer-prevention trials of α-tocopherol have been negative. This vexing contrast helped spur substantial preclinical efforts to better understand and improve the antineoplastic activity of tocopherol through, for example, the study of different tocopherol forms. We previously showed that the γ-tocopherol-rich mixture (γ-TmT) effectively inhibited colon and lung carcinogenesis and the growth of transplanted lung-cancer cells in mice.
View Article and Find Full Text PDF2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), the most abundant heterocyclic amine produced during the cooking of meats and fish, is suspected to be a human carcinogen. Metabolic activation of PhIP is primarily mediated by the enzyme cytochrome P450 (CYP) 1A2. Metabolism of PhIP by CYP1A2 differs considerably between humans and rodents, with more N(2)-hydroxylation (activation) and less 4'-hydroxylation (detoxication) in humans.
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