Inhibition of N-acetyltransferase activity and gene expression in human colon cancer cell lines by diallyl sulfide.
ABSTRACT Diallyl sulfide (DAS) is one of the major components of garlic (Allium sativum) and is widely used in the world for food. In this study, DAS was selected for testing the inhibition of arylamine N-acetyltransferase (NAT) activity (N-acetylation of 2-aminofluorene) and gene expression (mRNA NAT) in human colon cancer cell lines (colo 205, colo 320 DM and colo 320 HSR). The NAT activity was examined by high performance liquid chromatography and indicated that a 24 h DAS treatment decreases N-acetylation of 2-aminofluorene in three colon (colo 205, 320 DM and colo 320 HSR) cancer cell lines. The NAT enzymes (protein) were analyzed by western blotting and flow cytometry and it indicated that DAS decreased the levels of NAT in three colon (colo 205, 320 DM and colo 320 HSR) cancer cell lines. The gene expression of NAT (mRNAT NAT) was determined by polymerase chain reaction (PCR), it was shown that DAS affect mRNA NAT expression in examined human colon cancer cell lines. This report is the first to demonstrate that DAS does inhibit human colon cancer cell NAT activity and gene expression.
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ABSTRACT: Currently reliance on natural products is gaining popularity to combat various physiological threats including oxidative stress, cardiovascular complexities, cancer insurgence, and immune dysfunction. The use of traditional remedies may encounter more frequently due to an array of scientific evidence in their favor. Garlic (Allium sativum) holds a unique position in history and was recognized for its therapeutic potential. Recent advancements in the field of immunonutrition, physiology, and pharmacology further explored its importance as a functional food against various pathologies. Extensive research work has been carried out on the health promoting properties of garlic, often referred to its sulfur containing metabolites i.e. allicin and its derivatives. Garlic in its preparations are effective against health risks and even used as dietary supplements such as age garlic extract (AGE) and garlic oil etc. Its components/formulations can scavenge free radicals and protect membranes from damage and maintains cell integrity. It also provides cardiovascular protection mediated by lowering of cholesterol, blood pressure, anti-platelet activities, and thromboxane formation thus providing protection against atherosclerosis and associated disorders. Besides this, it possesses antimutagenic and antiproliferative properties that are interesting in chemopreventive interventions. Several mechanisms have been reviewed in this context like activation of detoxification phase-I and II enzymes, reactive oxygen species (ROS) generation, and reducing DNA damage etc. Garlic could be useful in preventing the suppression of immune response associated with increased risk of malignancy as it stimulates the proliferation of lymphocytes, macrophage phagocytosis, stimulates the release of interleukin-2, tumor necrosis factor-alpha and interferon-gamma, and enhances natural killer cells. In this paper much emphasis has been placed on garlic's ability to ameliorate oxidative stress, core role in cardiovascular cure, chemopreventive strategies, and indeed its prospective as immune booster.Critical reviews in food science and nutrition 07/2009; 49(6):538-51. · 3.73 Impact Factor
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ABSTRACT: The gene dehalA encoding a novel dichloromethane dehalogenases (DehalA), has been cloned from Bacillus circulans WZ-12 CCTCC M 207006. The open reading frame of dehalA, spanning 864 bp, encoded a 288-amino acid protein that showed 85.76% identity to the dichloromethane dehalogenases of Hyphomicrobium sp. GJ21 with several commonly conserved sequences. These sequences could not be found in putative dichloromethane (DCM) dehalogenases reported from other bacteria and fungi. DehalA was expressed in Escherichia coli BL21 (DE3) from a pET28b(+) expression system and purified. The subunit molecular mass of the recombinant DehalA as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was approximately 33 kDa. Subsequent enzymatic characterization revealed that DehalA was most active in a acidic pH range at 30 degrees , which was quite different from that observed from a facultative bacterium dichloromethane dehalogenases of Methylophilus sp. strain DM11. The Michaelis-Menten constant of DCM dehalogenase was markedly lower than that of standard DCM dehalogenases.Bioprocess and Biosystems Engineering 04/2009; 32(6):845-52. · 1.87 Impact Factor
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ABSTRACT: The inhibitory effects of diallyl sulfide (DAS) derived from allicin on in vitro and in vivo proliferation of human osteosarcoma MG-63 cells and the action mechanism, and the influence of DAS on invasive capability of MG-63 cells were investigated in order to search for the novel medicines for osteosarcoma. In the in vitro experiment, MG-63 cells were treated with different concentrations of DSA, and the morphological changes of MG-63 cells were observed under an inverted phase microscope. MTT method was used to assay the proliferation of MG-63 cells. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) was used to detect the VEGF mRNA expression level in MG-63 cells. By using Transwell invasion assay, the influence of DAS on invasive ability of MG-63 cells was tested. In the in vivo experiment, the nude mice MG-63 cells tumor-bearing model was established, and different concentrations of DAS were injected beside the tumor. Twenty-one days after treatment, the mice were killed, the tumor size and tumor inhibition rate were calculated. The microvessel density (MVD) was determined by using immunohistochemistry. In the in vitro experiment, different concentrations of DAS could obviously inhibit proliferation of MG-63 cells in a time- and concentration-dependent manner. RT-PCR revealed that the expression levels of VEGF mRNA in DSA groups (different concentrations) were significant reduced as compared with those in control group (all P<0.05). Transwell invasion assay indicated that in 20 and 40 μg/mL DAS groups, the number of migratory cells was 91.4±8.3 and 81.8±7.4 respectively, which was significantly declined as compared with that in control group (150.4±14.7, both P<0.05). In the in vivo experiment, DAS could significantly suppress the growth of MG-63 tumor-bearing tissue. Immunohistochemistry demonstrated that different concentrations (20 and 40 μg/mL) of DAS could significantly decrease MVD of MG-63 tumor-bearing tissue (all P<0.05). It was suggested that DAS could inhibit the growth of MG-63 cells probably by suppressing the expression of VEGF mRNA.Journal of Huazhong University of Science and Technology 08/2012; 32(4):581-5. · 0.58 Impact Factor