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 R2 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.Reprinted with permission from Journal of Agricultural and Food Chemistry 61 (2013): 1818–1822, doi:10.1021/jf3042616. Copyright 2013 American Chemical Society.</p

Genomic investigations of unexplained acute hepatitis in children

Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children

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 (

Technologies and experimental approaches at the National Institutes of Health Botanical Research Centers

Many similarities exist between research on combinatorial chemistry and natural products and research on dietary supplements and botanicals at the National Institutes of Health (NIH) Botanical Research Centers. The technologies used at the centers are similar to those used by other NIH-sponsored investigators. All centers rigorously examine the authenticity of botanical dietary supplements and determine the composition and concentrations of the phytochemicals therein, most often by liquid chromatography–mass spectrometry. Several of the centers specialize in fractionation and highthroughput evaluation to identify the individual bioactive agent or a combination of agents. Some centers are using DNA microarray analyses to determine the effects of botanicals on gene transcription with the goal of uncovering the important biochemical pathways they regulate. Other centers focus on bioavailability and uptake, distribution, metabolism, and excretion of the phytochemicals as for all xenobiotics. Because phytochemicals are often complex molecules, synthesis of isotopically labeled forms is carried out by plant cells in culture, followed by careful fractionation. These labeled phytochemicals allow the use of accelerator mass spectrometry to trace the tissue distribution of 14C-labeled proanthocyanidins in animal models of disease. State-of-the-art proteomics and mass spectrometry are also used to identify proteins in selected tissues whose expression and posttranslational modification are influenced by botanicals and dietary supplements. In summary, the skills needed to carry out botanical centers’ research are extensive andmay exceed those practiced by most NIH investigators