Yinsheng Zhao

Inhibition of Azoxymethane-Induced Preneoplastic Lesions in the Rat Colon by a Cooked Stearic Acid Complexed High-Amylose Cornstarch

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.

Analysis of Resistant Starches in Rat Cecal Contents Using Fourier Transform Infrared Photoacoustic Spectroscopy

Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) qualitatively and quantitatively measured resistant starch (RS) in rat cecal contents. Fisher 344 rats were fed diets of 55% (w/w, dry basis) starch for 8 weeks. Cecal contents were collected from sacrificed rats. A corn starch control was compared against three RS diets. The RS diets were high-amylose corn starch (HA7), HA7 chemically modified with octenyl succinic anhydride, and stearic-acid-complexed HA7 starch. To calibrate the FTIR-PAS analysis, samples from each diet were analyzed using an enzymatic assay. A partial least-squares cross-validation plot generated from the enzymatic assay and FTIR-PAS spectral results for starch fit the ideal curve with a R(2) of 0.997. A principal component analysis plot of components 1 and 2 showed that spectra from diets clustered significantly from each other. This study clearly showed that FTIR-PAS can accurately quantify starch content and identify the form of starch in complex matrices.

Characterization and In Vivo Hydrolysis of Amylose–Stearic Acid Complex

ABSTRACT Objectives of this study were to compare thermal properties, swelling power, and enzymatic hydrolysis of a type 5 resistant starch (RS5) with that of normal corn starch (NCS) and high-amylose corn starch (HA7). The RS5 was prepared by complexing debranched HA7 with stearic acid (SA). Because of amylose-helical-complex formation with SA, the RS5 starch granules showed restricted swelling at 95°C. The RS5 displayed a larger RS content (67.8%) than the HA7 (33.5%) and NCS (0.8%), analyzed following AOAC method 991.43 (AACC International Approved Method 32-07.01). When the cooked RS5, HA7, and NCS were used to prepare diets for rats with 55% (w/w) starch content, RS contents of the diets were 33.7, 15.8, and 2.6%, respectively. After the diet was fed to the rats in week 1, ≈16% of the starch in the RS5 diet was found in the feces, substantially greater than that of the HA7 diet (≈6%) and NCS diet (0.1%). The percentage of starch not being utilized in the RS5 diet decreased to ≈5% in week 9, which cou...

Effects of Dietary Resistant Starch on the Wnt Signaling Pathway and Preneoplastic Cells in the Colons of Azoxymethane-Treated Rats

ABSTRACT Dietary resistant starch (RS) has been suggested to reduce colonic neoplasia. To determine the effects of digestion-resistant cornstarch on colonic carcinogenesis and Wnt signaling in azoxymethane (AOM)-treated F344 rats, diets containing naturally occurring RS from corn lines derived partially from Guat209 (GUAT), AR16035 (AR), or a hybrid (ARxGUAT), containing 34.5 ± 2.0, 0.2 ± 0.1, and 1.9 ± 0.1% RS, respectively, were fed at 55% of the diet. GUAT-fed rats had increased cecal content and tissue weight and decreased cecal pH compared with AR- or ARxGUAT-fed rats. Numbers of aberrant crypt foci (ACF) were not different among diet groups. Increased numbers of crypts/focus were observed in AOM-injected rats fed GUAT compared with rats fed other diets. β-catenin mRNA expression of the crypts was significantly increased in GUAT-fed rats injected with AOM relative to those injected with saline. These findings suggest that selected dietary RSs may at some level further enhance colonocyte proliferation and differentiation in an AOM-treated colon.

Abstract A33: Modulation of gene expression by a cooked novel resistant starch in the colon of AOM-treated Fisher 344 rats

We previously reported that a cooked novel steric acid complexed high amylose starch (SAC) diet fed to Azoxymethane (AOM)-treated Fisher 344 rats significantly reduced the preneoplastic lesions, Aberrant Crypt Foci (ACF) and Mucin Depleted Foci (MDF), in comparison with water-boiled normal cornstarch (CS) diet or high amylose cornstarch (HA) diet. To determine the effect of water-boiled SAC diet on the global gene expression patterns we performed Affymetrix Genechip microarray analysis on rat colon mucosa after the rats were treated with AOM and then fed 3 different diets for 8 weeks. Genes that were significantly differentially regulated by AOM or by diet were identified. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis was followed as a subsequent examination confirmed the reliability of this analysis. Microarray and qRT-PCR data showed that AOM affected gene expression for 389 genes when considering q Citation Information: Cancer Prev Res 2011;4(10 Suppl):A33.

Abstract A74: Inhibition of azoxymethane‐induced preneoplastic lesions in the rat colon by a novel resistant starch cooked by different methods

The purpose of this study was to test the inhibitory effects of a novel resistant starch cooked by two different methods on azoxymethane (AOM)-induced colon carcinogenesis in rats. The novel resistant starch (RS)(patent pending) was processed from commercial high amylose cornstarch. A normal cornstarch (CS) and the high amylose cornstarch (HA) were used as negative and positive control starch groups, respectively. Two cooking methods were applied to all the three starches: (1) making each starch into bread using a standard bakery procedure (cB). (2) using boiling water, high moisture cooking method (cW). Then the starches were mixed with other ingredients based on AIN-93 formulations into 6 rat diets: bread normal-cornstarch diet (cB-CS), bread high-amylose-cornstarch diet (cB-HA), bread novel-resistant-starch diet (cB-RS), boiling-water-high-moisture normal-cornstarch diet (cW-CS), boiling-water-high-moisture high-amylose-cornstarch diet (cW-HA), and boiling-water-high-moisture novel-resistant-starch diet (cW-RS). Six groups of 5-week-old male Fischer 344 rats including 15 animals each were injected with two doses of 20 mg/kg bw AOM one week apart and fed the above diets respectively. Another six groups of male Fischer 344 rats with 5 animals in each group were injected with saline and fed the same six kinds of diets as the AOM treated groups. The rats were fed for 8 weeks after the second injection and then killed. Caecum weight and pH, Aberrant Crypt Foci (ACF) and Mucin Depleted Foci (MDF) were investigated. ACF and MDF were only seen with AOM treatment. The ACF numbers for cB-CS, cB-HA, cB-RS, cW-CS, cW-HA, and cW-RS groups were 29, 29, 17, 225, 256, and 121, respectively. The MDF numbers for the above diet groups were 6.1, 4.9, 1.9, 10.7, 8.7 and 2.1, respectively. ACF and MDF numbers were significantly reduced in rats fed novel resistant starch diet in comparison with rats fed the other two diets (P<0.0001). When comparing the two cooking methods, the cB diet groups also showed a significantly decrease in preneoplastic lesion numbers compared with the cW diet groups (P<0.0003). Increased caecum weight and decreased caecum pH were also observed in the novel resistant starch diet group in comparison with the other two diet groups (P<0.05). These results suggested that the novel resistant starch, which is less digestible than regular cornstarch or commercial high amylose cornstarch, may inhibit colonic carcinogenesis. The cooking method could also be important since the bread baking procedure showed significantly more effectiveness in the inhibition than the boiling water high moisture method. The inhibition might be related to increased caecal fermentation.

Abstract B136: Inhibition of azoxymethane-induced mucin depleted foci in the rat colon by a novel resistant starch

The purpose of this study was to test the inhibitory effects of a novel resistant starch on azoxymethane (AOM)-induced colon carcinogenesis in rats. The novel resistant starch was processed from a commercial high amylose cornstarch(patent pending). Three groups of 5-week-old male Fischer 344 rats including 15 animals each were injected with AOM and fed normal cornstarch diet, high amylose cornstarch diet, and novel resistant starch diet respectively. Another three groups of male Fischer 344 rats with 5 animals in each group were injected with saline and fed the same three kinds of diets as control groups. Two injections were performed one week apart. Each of the 3 diets contained 55% water boiled high moisture starch, together with 45% of other ingredients necessary for rats’ nutritive requirements. The rats were fed with the above diets for 9 weeks after the second injection and then killed. Liver weight, caecal fermentation (caecum weight and pH), and a predictor of carcinogenicity - Mucin Depleted Foci (MDF) - were investigated. MDF were only seen with AOM treatment and were significantly reduced in rats fed novel resistant starch diet in comparison with rats fed the other two diets. Increased caecum weight and decreased caecum pH were also observed in the novel resistant starch diet group in comparison with the other two diet groups. No significant difference was found comparing liver weights. These results suggested that the novel resistant starch, which is less digestible than regular cornstarch or commercial high amylose cornstarch, may inhibit colonic carcinogenesis, and the inhibition might be related to increased caecal fermentation.