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1.
A promising approach for cancer chemoprevention might be a combination therapy utilizing dietary phytochemicals and anticarcinogenic pharmaceuticals at a suboptimal dosage to minimize any potential adverse side effects. To test this hypothesis, various dosages of anthocyanin-rich tart cherry extract were fed in combination with suboptimal levels of the nonsteroidal anti-inflammatory drug sulindac to APCMin mice for 19 weeks. By the end of the feeding period, fewer mice that were fed the anthocyanin-rich extract in combination with sulindac lost more than 10% of body weight than mice fed sulindac alone. Mice that were fed anthocyanin-rich extract (at any dose) in combination with sulindac had fewer tumors and a smaller total tumor burden (total tumor area per mouse) in the small intestine when compared to mice fed sulindac alone. These results suggest that a dietary combination of tart cherry anthocyanins and sulindac is more protective against colon cancer than sulindac alone.  相似文献   

2.
Microbial metabolism is essential in maintaining a healthy mucosa in the large bowel, preferentially through butyrate specific mechanisms. This system depends on starch supply. Two structurally different resistant starches type 3 (RS3) have been investigated with respect to their resistance to digestion, fermentability, and their effects on the composition and turnover of bile acids in rats. RSA (a mixture of retrograded maltodextrins and branched high molecular weight polymers), which is more resistant than RSB (a retrograded potato starch), increased the rate of fermentation accompanied by a decrease of pH in cecum, colon, and feces. Because they were bound to RS3, less bile acids were reabsorbed, resulting in a higher turnover through the large bowel. Because of the rise of volume, the bile acid level was unchanged and the formation of secondary bile acids was partly suppressed. The results proved a strong relation between RS3, short chain fatty acid production, and microflora. However, butyrate specific benefits are only achieved by an intake of RS3 that result in good fermentation properties, which depend on the kind of the resistant starch structures.  相似文献   

3.
Bile acid adsorption by lignified dietary fiber in the human intestine is proposed as a mechanism for lowering blood cholesterol level and reducing colon cancer risk. In this study, we investigated how the concentration and composition of lignin in fiber influences the in vitro adsorption of primary bile acids (glycocholate, taurocholate, and glycochenodeoxycholate) and a secondary bile acid (deoxycholate). Adsorption studies were performed by incubating nonlignified and artificially lignified maize cell walls (dehydrogenation polymer‐cell walls) with bile acids under conditions imitating the small intestine and distal colon. Artificially lignified cell walls had varying but defined lignin concentrations (4.8–19.0%) and compositions (varying from pure guaiacyl to pure syringyl lignins) but a uniform polysaccharide‐protein matrix. Adsorption of bile acids by cell walls was in a range of 6–31% (4–26 nmol of bile acids/mg of cell walls), with glycochenodeoxycholate showing the highest adsorption rates. Neither lignin concentration nor lignin composition influenced bile acid adsorption, thus disproving a major role of lignin in bile acid adsorption.  相似文献   

4.
The aim of this study was to determine effects of konjac glucomannan (KGM) in a high fat corn oil diet on risk factors of colon carcinogenesis, that is, fecal β-glucuronidase, mucinase, and bile acids, and on preventive factors, that is, fecal microflora and cecal short-chain fatty acids (SCFAs). Sprague-Dawley rats (n = 8 animals per group) were fed a normal-fat fiber-free (5% corn oil, w/w) or high-fat (25% corn oil, w/w) diet containing no fiber, KGM (5%, w/w), or inulin (5%, w/w, as a prebiotic control) for 4 weeks. Results indicated that the high-fat fiber-free diet significantly elevated the fecal β-glucuronidase and mucinase activities and total bile acid concentration and decreased cecal SCFA contents, as compared with its normal-fat counterpart. The incorporation of KGM, as well as inulin, into the high-fat fiber-free diet beneficially reduced the fecal β-glucuronidase and mucinase activities and lithocholic acid (secondary bile acid) concentration. Although KGM elevated the daily fecal total bile acid excretion, the change was due to the primary, instead of the secondary, bile acids. In addition, KGM beneficially promoted the daily fecal excretion of bifidobacteria and lactobacilli and cecal SCFA contents, as compared with the high-fat fiber-free diet. Therefore, the present study suggests that KGM potentially attenuated the high fat-induced risk in colon carcinogenesis.  相似文献   

5.
The effect of a combination of (-)-epigallocatechin-3-gallate (EGCG) with fish oil on intestinal tumorigenesis in Apc (Min/+) mice fed a high-fat diet was investigated in the present study. The combined treatment of EGCG and fish oil for 9 weeks reduced the tumor number by 53% as compared to controls while neither agent alone had a significant effect. Apoptosis was significantly increased in all treatment groups. beta-Catenin nuclear positivity in adenomas from the combination group was lower than control mice, implicating the modulation of Wnt signaling by the combination. Fish oil and the combination significantly reduced prostaglandin E 2 (PGE 2) levels in small intestinal tumors as compared to controls, suggesting modulation of aberrant arachidonic acid metabolism by fish oil. Akt phosphorylation in adenomas was significantly reduced in all treatment groups, which may have contributed to the observed increase in apoptosis. The results indicate that a combination of low doses of EGCG and fish oil can inhibit tumor multiplicity in Apc (Min/+) mice.  相似文献   

6.
7.
RS4‐type resistant wheat starch (RWS) and resistant potato starch (RPS) were subjected successively to in vitro digestion with pepsin and pancreatin‐bile, and the indigestible residues (82.1% db and 74.1% db, respectively) were recovered and subsequently fermented by in vitro techniques using fresh human fecal microbiota as inoculum. Scanning electron microscopy of the indigestible residues showed surface erosion on the residual granules. Total gas production during the in vitro fermentation increased almost linearly over time with the two resistant starches exhibiting similar gas production rates, as well as a similar rate of production of total short‐chain fatty acids (SCFA). The indigestible fractions from both starches produced acetate as the major SCFA and relatively higher levels of butyrate than propionate, but wheat starch tended to produce more butyrate over time than potato starch. Fractional molar ratios of acetate, propionate, and butyrate from the RWS and RPS were 0.586:0.186:0.228 and 0.577:0.200:0.223, respectively. The calculated caloric contributions of the RWS and RPS are ≈33% lower than for unmodified starch and are comparable to those reported in the literature for RS2 and RS3 high‐amylose maize starches.  相似文献   

8.
To investigate the hypocholesterolemic mechanism of barley in vivo, six-week-old C57BL/6J mice were fed a high-fat diet (HFD) or high-fat diet containing barley (HFD-B) for seven weeks. Total and LDL cholesterol concentrations were significantly reduced in the HFD-B group while fecal cholesterol and bile acid was increased. Real-time PCR and immunoblot analysis revealed the induction of FXR expression, which in turn suppressed the expression of ASBT and NPC1L1 in the HFD-B group compared with the controls. In the liver, the expression of HMG-CoA reductase was significantly reduced while LDL receptor expression was unaltered in the HFD-B group compared with the controls. Our data suggest that the hypocholesterolemic effects of barley are primarily the result of reduced dietary cholesterol uptake and bile acid resorption. Reduced expression of intestinal ASBT and NPC1L1 may play a key role in the regulation of dietary cholesterol and bile acid metabolism in mice consuming a diet containing barley.  相似文献   

9.
This study evaluated a novel stearic acid complexed high-amylose cornstarch (SAC) for the prevention of preneoplastic lesions in the colon of azoxymethane (AOM)-treated Fisher 344 rats fed resistant starches at 50-55% of the diet for 8 weeks. Uncooked SAC (r-SAC) diet was compared with raw normal-cornstarch diet (r-CS) or raw high-amylose cornstarch diet (r-HA), and water-boiled CS (w-CS) was compared with w-HA and w-SAC, respectively. w-SAC markedly reduced mucin-depleted foci (MDF) numbers compared with w-HA or w-CS. r-HA significantly decreased aberrant crypt foci (ACF) numbers compared with r-CS or r-SAC. Increased cecum weight and decreased cecum pH were observed in the SAC or HA groups. The highest amounts of total or individual short-chain fatty acids (SCFAs) in cecum and of butyrate or propionate in feces were observed in the AOM-treated w-SAC group. This study revealed the effectiveness of a novel resistant starch in inhibiting colonic preneoplastic lesions and the importance of high-moisture cooking on the suppression of colon carcinogenesis by this resistant starch.  相似文献   

10.
The aim of this study was to investigate the effects of konjac glucomannan (KGM) and inulin on the balance between pro-oxidative status and antioxidative defense systems in the colon, liver, and plasma of rats fed a high-fat fiber-free diet. Male Sprague-Dawley rats (n = 8 animals per group) were fed a high-fat (25% corn oil, w/w) fiber-free diet or that supplemented with KGM or inulin fiber (5%, w/w) for 4 weeks. The index of pro-oxidative status, malondialdehyde (MDA), and blood lymphocyte DNA damage; the antioxidative defense, that is, antioxidant enzymes (glutathione peroxidase, superoxide dismutase, catalase) in the colonic mucosa and liver; and the plasma antioxidant levels were determined. The fermentation of fiber was shown in fecal short-chain fatty acids. Incorporation of KGM and inulin into the high-fat fiber-free diet beneficially reduced the MDA levels of the colon and liver and DNA damage in blood lymphocytes. On the other hand, both fibers enhanced the antioxidative defense systems by up-regulating the gene expressions of glutathione peroxidase and catalase in the colonic mucosa and of superoxide dismutase and catalase in the liver. Furthermore, KGM and inulin promoted antioxidative status in the blood by elevating the α-tocopherol level. KGM and inulin were well-fermented in rats and increased the concentration and daily excretion of fecal short-chain fatty acids, especially acetate and butyrate. These results suggest that in vivo utilization of KGM and inulin stimulated both local and systemic antioxidative defense systems in rats.  相似文献   

11.
Rye bran and aleurone, wheat bran and aleurone, and oat bran and cell wall concentrate were compared in their in vitro gut fermentation patterns of individual phenolic acids and short-chain fatty acids, preceded by enzymatic in vitro digestion mimicking small intestinal events. The formation of phenolic metabolites was the most pronounced from the wheat aleurone fraction. Phenylpropionic acids, presumably derived from ferulic acid (FA), were the major phenyl metabolites formed from all bran preparations. The processed rye, wheat, and oat bran fractions contained more water-extractable dietary fiber (DF) and had smaller particle sizes and were thus more easily fermentable than the corresponding brans. Rye aleurone and bran had the highest fermentation rate and extent probably due to high fructan and water-extractable arabinoxylan content. Oat samples also had a high content of water-extractable DF, β-glucan, but their fermentation rate was lower. Enzymatic digestion prior to in vitro colon fermentation changed the structure of oat cell walls as visualized by microscopy and increased the particle size, which is suggested to have retarded the fermentability of oat samples. Wheat bran was the most slowly fermentable among the studied samples, presumably due to the high proportion of water-unextractable DF. The in vitro digestion reduced the fructan content of wheat samples, thus also decreasing their fermentability. Among the studied short-chain fatty acids, acetate dominated the profiles. The highest and lowest production of propionate was from the oat and wheat samples, respectively. Interestingly, wheat aleurone generated similar amounts of butyrate as the rye fractions even without rapid gas production.  相似文献   

12.
In comparison to classical fruit juice processing, polyphenols and dietary fiber can be extracted from pomace by means of pectinases and cellulases. In the present study, rats were fed with such produced extraction juices from apples, grapes, and red beets as drinking fluids instead of water for 4 weeks to evaluate their physiological effects. In all test groups, the intake of extraction juices was greater as compared to control (water intake), resulting in a higher urine excretion. In the apple and grape group, pH values in feces was lower than control. Administration of extraction juices from apples increased fecal counts of Lactobacillus and Bifidobacterium. More acetate and total short-chain fatty acids appeared in intestinal contents of the apple and red beet group. Furthermore, the intestinal contents of test groups contained higher concentrations of primary bile acids, cholesterol, and cholesterol metabolites but lower concentrations of secondary bile acids. The total amount of steroids excreted by these groups was also greater than control. Quercetin and isorhamnetin appeared in urine of rats fed extraction juices from apples and grapes; in urine of the former group, phloretin was found also. Administration of the extraction juices, enriched in secondary plant metabolites and dietary fiber, resulted in beneficial nutritional effects in rats.  相似文献   

13.
This study was designed to investigate the cancer preventive activities of wheat bran (WB) oil. We studied the colon cancer preventive effects of WB oil and its subfractions in the Apc(min/+) mouse model, a recognized mouse model for human colorectal cancer, and used human colon cancer cell lines (HCT-116 and HT-29) to identify possible active fractions in WB oil. Our results showed that the oil fraction of WB was more active than the water fraction against the growth of human colon cancer cell lines and that 2% WB oil significantly inhibited the overall tumorigenesis by 35.7% (p < 0.0001) in the Apc(min/+) mouse model. The WB oil was further fractioned into nonpolar lipids and phytochemicals and the phytochemical fraction was fractionated into phytosterols and phytosterol ferulates, 5-alk(en)ylresorcinols, and unidentified constituents by normal phase silica gel column chromatography. Results on cell culture showed that the phytochemical fraction had a higher inhibitory effect on HCT-116 human colon cancer cells than that of WB oil, whereas the nonpolar lipid fraction had less growth inhibitory effectiveness. However, neither fractions showed a stronger inhibition than WB oil in the Apc(min/+) mouse model. The current results demonstrate, for the first time, the intestinal cancer preventive activity of WB oil. The active ingredients, however, remain to be identified.  相似文献   

14.
This study examined the effects of different extracts of adlay seed on the growth of human lung cancer cells in vitro and in vivo. The data showed that a methanolic extract, but not a water extract, of adlay seed exerted an antiproliferative effect on A549 lung cancer cells by inducing cell cycle arrest and apoptosis. It was also found that tumor growth in vivo was inhibited by the methanolic extract in a dose-dependent manner. The chemopreventive effect of adlay seed on the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis in A/J mice was also investigated. Groups of mice were pre-fed with different diets, followed by feeding with NNK-containing drinking water for 8 months. The results indicated that feeding with diet containing 30% of powdered adlay seed reduced the number of surface lung tumors by approximately 50%. Taken together, these results indicate that the components of adlay seed exert an anticancer effect in vitro and in vivo and may be useful for the prevention of lung tumorigenesis.  相似文献   

15.
Dietary antioxidants may provide a cost-effective strategy to promote health in obesity by targeting oxidative stress and inflammation. We recently found that the antioxidant-rich grape skin extract (GSE) also exerts a novel anti-hyperglycemic activity. This study investigated whether 3-month GSE supplementation can improve oxidative stress, inflammation, and hyperglycemia associated with a Western diet-induced obesity. Young diet-induced obese (DIO) mice were randomly divided to three treatment groups (n = 12): a standard diet (S group), a Western high fat diet (W group), and the Western diet plus GSE (2.4 g GSE/kg diet, WGSE group). By week 12, DIO mice in the WGSE group gained significantly more weight (24.6 g) than the W (20.2 g) and S groups (11.2 g); the high fat diet groups gained 80% more weight than the standard diet group. Eight of 12 mice in the W group, compared to only 1 of 12 mice in the WGSE group, had fasting blood glucose levels above 140 mg/dL. Mice in the WGSE group also had 21% lower fasting blood glucose and 17.1% lower C-reactive protein levels than mice in the W group (P < 0.05). However, the GSE supplementation did not affect oxidative stress in diet-induced obesity as determined by plasma oxygen radical absorbance capacity, glutathione peroxidase, and liver lipid peroxidation. Collectively, the results indicated a beneficial role of GSE supplementation for improving glycemic control and inflammation in diet-induced obesity.  相似文献   

16.
Male adult Wistar rats were randomly divided into six groups in a 2 x 3 factorial design and fed diets containing different levels of Tremella fuciformis Berk (TFB) dietary fiber (0, 5, or 10%) and 1 g of cholesterol/100 g of diet with or without 0.7% Nebacitin for 4 weeks. TFB contained 6.2% soluble dietary fiber and 57.3% insoluble dietary fiber. The results showed that the serum LDL-cholesterol, hepatic total cholesterol, and triglyceride levels were significantly decreased (P < 0.05) in the rats fed diets with TFB content with or without Nebacitin. However, the serum total cholesterol, VLDL-cholesterol, and triglyceride levels were significantly decreased (P < 0.05) by Nebacitin. In feces, the presence of TFB (T5, T10, AT5, and AT10) in the diet significantly increased the total neutral steroids and bile acid excretions and undigested fiber concentrations as compared to T0 or AT0. In the small intestine, the Nebacitin diets increased the weights of both cecum and colon-rectum contents and lowered short-chain fatty acid (SCFA) concentrations of serum and cecal contents more than no Nebacitin diets did. It was suggested that the hypocholesterolemic effect of TFB dietary fiber may be mediated by the increase in fecal neutral steroids and total bile acids excretion and the increase in SCFA productions. The TFB edible mushroom dietary supplement altered the intestinal physiology of the rats.  相似文献   

17.
Previous studies reported that peracetylated (-)-epigallocatechin-3-gallate (AcEGCG) has antiproliferative and anti-inflammatory activities. Here, we evaluated the chemopreventive effects and underlying molecular mechanisms of dietary administration of AcEGCG and EGCG in dextran sulfate sodium (DSS)-induced colitis in mice. The mice were fed a diet supplemented with either AcEGCG or EGCG prior to DSS induction. Our results indicated that AcEGCG administration was more effective than EGCG in preventing the shortening of colon length and the formation of aberrant crypt foci (ACF) and lymphoid nodules (LN) in mouse colon stimulated by DSS. Our study observes that AcEGCG treatment inhibited histone 3 lysine 9 (H3K9) acetylation but did not affect histone acetyltransferase (HAT) activity and acetyl- CREB-binding protein (CBP)/p300 levels. In addition, pretreatment with AcEGCG decreased the proinflammatory mediator levels by down-regulating of PI3K/Akt/NFκB phosphorylation and p65 acetylation. We also found that treatment with AcEGCG increased heme oxygenase-1(HO-1) expression via activation of extracellular signal-regulated protein kinase (ERK)1/2 signaling and acetylation of NF-E2-related factor 2 (Nrf2), thereby abating DSS-induced colitis. Moreover, dietary feeding with AcEGCG markedly reduced colitis-driven colon cancer in mice. Taken together, these results demonstrated for the first time the in vivo chemopreventive efficacy and molecular mechanisms of dietary AcEGCG against inflammatory bowel disease (IBD) and potentially colon cancer associated with colitis. These findings provide insight into the biological actions of AcEGCG and might establish a molecular basis for the development of new cancer chemopreventive agents.  相似文献   

18.
Ellagitannin-containing foods (strawberries, walnuts, pomegranate, raspberries, oak-aged wine, etc.) have attracted attention due to their cancer chemopreventive, cardioprotective, and antioxidant effects. Ellagitannins (ETs) are not absorbed as such but are metabolized by the intestinal flora to yield urolithins (hydroxydibenzopyran-6-one derivatives). In this study, Iberian pig is used as a model to clarify human ET metabolism. Pigs were fed either cereal fodder or acorns, a rich source of ETs. Plasma, urine, bile, lumen and intestinal tissues (jejunum and colon), feces, liver, kidney, heart, brain, lung, muscle, and subcutaneous fat tissue were analyzed. The results demonstrate that acorn ETs release ellagic acid (EA) in the jejunum, then the intestinal flora metabolizes EA sequentially to yield tetrahydroxy- (urolithin D), trihydroxy- (urolithin C), dihydroxy- (urolithin A), and monohydroxy- (urolithin B) dibenzopyran-6-one metabolites, which were absorbed preferentially when their lipophilicity increased. Thirty-one ET-derived metabolites were detected, including 25 urolithin and 6 EA derivatives. Twenty-six extensively conjugated metabolites were detected in bile, glucuronides and methyl glucuronides of EA and particularly urolithin A, C, and D derivatives, confirming a very active enterohepatic circulation. Urolithins A and B as well as dimethyl-EA-glucuronide were detected in peripheral plasma. The presence of EA metabolites in bile and in urine and its absence in intestinal tissues suggested its absorption in the stomach. Urolithin A was the only metabolite detected in feces and together with its glucuronide was the most abundant metabolite in urine. No metabolites accumulated in any organ analyzed. The whole metabolism of ETs is shown for the first time, confirming previous studies in humans and explaining the long persistency of urolithin metabolites in the body mediated by an active enterohepatic circulation.  相似文献   

19.
The mechanism of the hypocholesterolemic effect of olive oils was investigated in 60 Wistar rats adapted to cholesterol-containing and cholesterol-free diets. The rats were divided in six diet groups of 10. The control group was fed only basal diet (BD), which contained wheat starch, casein, cellulose, and mineral and vitamin mixtures. For the five other groups, 10 g/100 g virgin (virgin group) or lampante (lampante group) olive oils, 1 g/100 g cholesterol (chol group), or both cholesterol and oil (chol/virgin and chol/lampante groups) were added to the BD. The experiment lasted 4 weeks. Before and after the experiment the bile was collected, and its flow and biliary bile acids and cholesterol concentrations were registered. Plasma lipids, liver cholesterol, plasma antioxidative potential (TRAP), fecal output, fecal bile acids, and fecal cholesterol excretion were measured. Groups did not differ before the experiment. After the experiment significant hypocholesterolemic and antioxidant effects were registered mainly in groups of rats fed cholesterol-containing diets supplemented with both olive oils (chol/virgin and chol/lampante). Significant increases in the bile flow and in the bile cholesterol and bile acids concentrations were observed (19.2% and 16.9%, 30.5% and 18.2%, and 79.6% and 45.6% for the chol/virgin and chol/lampante groups, respectively). Also, significant increases of the fecal output and fecal excretion of bile acids and cholesterol in rats of these groups were found. In conclusion, olive oils positively affect plasma lipid metabolism. The hypocholesterolemic effect of olive oils is genuine and is most likely mediated through increases in bile flow and biliary cholesterol and bile acids concentrations and subsequent increases in their fecal excretion.  相似文献   

20.
Conjugated linoleic acids (CLA) were enzymatically acidolyzed with olive oil to produce structured lipids (SL), and their antiatherosclerotic properties were investigated in C57BL/6J mice. Twenty-eight mice were divided into four groups and fed control diet or atherogenic diets supplemented with high cholesterol and high fat (HCHF) containing 5% of lard, olive oil, or SL based on control diet for 4 weeks. The supplementation of SL diet (0.6% CLA) significantly reduced the levels of serum total cholesterol and total triglyceride and increased high-density lipoprotein cholesterol level as compared to lard and olive oil diet groups (p < 0.05). The activity of liver acyl CoA:cholesterol acyltransferase (ACAT) of mice fed the SL diet was significantly lower than that of mice fed the lard or olive oil diet. A reduced formation of aortic fatty streak was observed in SL group. The extent of CLA incorporation depended on tissues or types of phospholipids. More CLA was incorporated in adipose tissue (1.85 mol %) than in the liver (0.33 mol %). Besides, more CLA was found in phosphatidylethanolamine (PE) (0.47 mol %) than in phosphatidylcholine (PC) (0.05 mol %) of hepatic phospholipids. Hepatic phospholipids (PC and PE) of mice fed the SL diet contained reduced contents of arachidonic and linoleic acid compared with mice fed the olive oil or lard diet. The present study suggests that SL could be considered as a functional oil for preventing risks of atheroscelerosis.  相似文献   

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