s-allylcysteine and diallyl-disulfide

Organosulfur compounds (OSCs) are the bioactive components of garlic. Some OSCs have apoptotic or autophagy-inducing effects. Autophagy plays roles in both cytoprotection and apoptosis-related cell death, and the interaction between autophagy and apoptosis is important in the modulation of immune responses. The mechanism of an OSC-mediated effect via the interaction of autophagy and apoptosis is unknown. In this study, the effects of five OSC compounds on autophagy in the macrophage cell line RAW264.7 and primary macrophages were investigated. We found that S-allylcysteine (SAC), diallyl disulde (DADS) and diallyl tetrasulfide (DTS) treatment increased the number of autophagosomes of RAW264.7 cells, inhibited the phosphorylation of ribosomal protein S6 kinase beta-1 (p70S6K/S6K1) which is a substrate of mammalian target of rapamycin (mTOR), and significantly enhanced autophagy flux. The induction of autophagy by SAC, DADS and DTS was inhibited by stably knocking down the expression of autophagy-related gene 5 (ATG5) with short hairpin RNA (shRNA). Further experiments confirmed that SAC, DADS and DTS also induced apoptosis in RAW264.7 cells. The induction of apoptosis and Caspase 3 activity by SAC, DADS and DTS were increased by stably knocking down of ATG5 expression with shRNA in RAW264.7 cells or treating with 5 mM 3-MA in primary macrophages. Our results suggest that SAC, DADS and DTS induce both autophagy and apoptosis. The autophagy induction protects macrophages from apoptosis by inhibiting mTOR phosphorylation activity to maintain the mass of immune cells.

Topics: Allyl Compounds; Animals; Apoptosis; Autophagosomes; Autophagy; Cells, Cultured; Cysteine; Disulfides; Garlic; Macrophages; Mice; Organic Chemicals; Phosphorylation; Protective Agents; RAW 264.7 Cells; Sulfides; Sulfur Compounds; TOR Serine-Threonine Kinases

Garlic and its processed preparations contain numerous sulfur compounds that are difficult to analyze in a single run using HPLC.. The aim of this study was to develop a rapid and convenient sulfur-specific HPLC method to analyze sulfur compounds in aged garlic extract (AGE).. We modified a conventional postcolumn HPLC method by employing a hexaiodoplatinate reagent. Identification and structural analysis of sulfur compounds were conducted by LC-mass spectrometry (LC-MS) and nuclear magnetic resonance. The production mechanisms of cis-S-1-propenylcysteine (cis-S1PC) and S-allylmercaptocysteine (SAMC) were examined by model reactions.. Our method has the following advantages: less interference from nonsulfur compounds, high sensitivity, good correlation coefficients (r > 0.98), and high resolution that can separate >20 sulfur compounds, including several isomers, in garlic preparations in a single run. This method was adapted for LC-MS analysis. We identified cis-S1PC and γ-glutamyl-S-allyl-mercaptocysteine in AGE. The results of model reactions suggest that cis-S1PC is produced from trans-S1PC through an isomerization reaction and that SAMC is produced by a reaction involving S-allylcysteine/S1PC and diallyldisulfide during the aging period.. We developed a rapid postcolumn HPLC method for both qualitative and quantitative analyses of sulfur compounds, and this method helped elucidate a potential mechanism of cis-S1PC and SAMC action in AGE.

Topics: Allyl Compounds; Chromatography, High Pressure Liquid; Cysteine; Disulfides; Garlic; Humans; Isomerism; Mass Spectrometry; Plant Extracts; Sulfur; Sulfur Compounds

The anti-neuroinflammatory capacities of raw and steamed garlic extracts as well as five organosulfur compounds (OSCs) were examined in lipopolysaccharide (LPS)-stimulated BV2 microglia. According to those results, steaming pretreatment blocked the formation of alliinase-catalyzed OSCs such as allicin and diallyl trisulfide (DATS) in crushed garlic. Raw garlic, but not steamed garlic, dose-dependently attenuated the production of LPS-induced nitric oxide (NO), interleukin-1β (IL-1β), tumor necrosis factor (TNF)-α, and monocyte chemoattractant protein-1 (MCP-1). DATS and diallyl disulfide at 200 and 400 μM, respectively, displayed significant anti-neuroinflammatory activity. Meanwhile, even at 1 mM, diallyl sulfide, S-allyl cysteine and alliin did not display such activity. Inhibition of nuclear factor-κB activation was the mechanism underlying this protective effect of raw garlic and DATS. Analysis results indicated that the anti-neuroinflammatory capacity of raw garlic is due to the alliin-derived OSCs. Importantly, DATS is a highly promising therapeutic candidate for treating inflammation-related neurodegenerative diseases.

Topics: Allium; Allyl Compounds; Animals; Cell Line; Chemokine CCL2; Cysteine; Disulfides; Garlic; Inflammation; Interleukin-1beta; Lipopolysaccharides; Mice; Microglia; Neurodegenerative Diseases; NF-kappa B; Nitric Oxide; Plant Extracts; Sulfides; Sulfur Compounds; Tumor Necrosis Factor-alpha

The aim of this study was to assess the antigenotoxic activity of several garlic organosulfur compounds (OSC) in the human hepatoma cell line HepG2, using comet assay. The OSC selected were allicin (DADSO), diallyl sulfide (DAS), diallyl disulfide (DADS), S-allyl cysteine (SAC) and allyl mercaptan (AM). To explore their potential mechanisms of action, two approaches were performed: (i) a pre-treatment protocol which allowed study of the possible modulation of drug metabolism enzymes by OSC before treatment of the cells with the genotoxic agent; (ii) a co-treatment protocol by which the ability of OSC to scavenge direct-acting compounds was assessed. Preliminary studies showed that, over the concentration range tested (5-100 microM), the studied OSC neither affected cell viability nor induced DNA damage by themselves. In the pre-treatment protocol, aflatoxin B1 genotoxicity was significantly reduced by all the OSC tested except AM. DADS was the most efficient OSC in reducing benzo(a)pyrene genotoxicity. SAC and AM significantly decreased DNA breaks in HepG2 cells treated with dimethylnitrosamine. Additionally, all the OSC studied were shown to decrease the genotoxicity of the direct-acting compounds, hydrogen peroxide and methyl methanesulfonate. This study demonstrated that garlic OSC displayed antigenotoxic activity in human metabolically competent cells.

Topics: Aflatoxin B1; Allyl Compounds; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Survival; Cysteine; Disulfides; DNA Damage; Garlic; Humans; Liver Neoplasms; Mutagens; Sulfhydryl Compounds; Sulfides; Sulfinic Acids; Sulfur Compounds

Garlic and garlic extracts, through their antioxidant activities, have been reported to provide protection against free radical damage in the body. This study investigated antioxidant properties of garlic compounds representing the four main chemical classes, alliin, allyl cysteine, allyl disulfide, and allicin, prepared by chemical synthesis or purification. Alliin scavenged superoxide, while allyl cysteine and allyl disulfide did not react with superoxide. Allicin suppressed the formation of superoxide by the xanthine/xanthine oxidase system, probably via a thiol exchange mechanism. Alliin, allyl cysteine, and allyl disulfide all scavenged hydroxyl radicals; the rate constants calculated based on deoxyribose competitive assay were 1.4-1.7 x 10(10), 2.1-2.2 x 10(9), and 0.7-1.5 x 10(10) M (1) second(1), respectively. Contrary to previous reports, allicin did not exhibit hydroxyl radical scavenging activity in this study. Alliin, allicin, and allyl cysteine did not prevent induced microsomal lipid peroxidation, but both alliin and allyl cysteine were hydroxyl scavengers, and allyl disulfide was a lipid peroxidation terminator. In summary, our findings indicated that allyl disulfide, alliin, allicin, and allyl cysteine exhibit different patterns of antioxidant activities as protective compounds against free radical damage.

Topics: Allyl Compounds; Antioxidants; Cysteine; Disulfides; Free Radical Scavengers; Garlic; Hydrogen Peroxide; Hydroxyl Radical; Lipid Peroxidation; Sulfinic Acids; Superoxides

Multiple components present in garlic and various garlic preparations are known to exert pleiotropic protective effects as demonstrated in various in vitro and in vivo model systems. However, garlic pleiotropy in relation to Alzheimer's pathophysiology has not been explored extensively. Current study investigated anti-amyloidogenic, anti-inflammatory and anti-tangle effects of dietary aged garlic extract (AGE) (2%) and compared with its prominent constituents, i.e. S-allyl-cysteine (SAC) (20 mg/kg) and di-allyl-disulfide (DADS) (20 mg/kg) in Alzheimer's Swedish double mutant mouse model (Tg2576). Possible cholesterol-dependent and cholesterol-independent mechanisms of actions of AGE, SAC and DADS in exerting anti-amyloidogenic, anti-inflammatory and anti-tangle effects are discussed. Finally, ameliorative effects of dietary interventions were found to be in the order of AGE>SAC>DADS. If validated pre-clinically, dietary intervention with herbal alternative such as AGE having pleiotropic useful properties and least adverse effects may provide greater therapeutic benefit over a single-ingredient synthetic pharmaceutical drug having serious side effects in treating Alzheimer's disease.

Topics: Allyl Compounds; Alzheimer Disease; Amyloid beta-Protein Precursor; Animals; Blotting, Western; Brain; Cysteine; Disease Models, Animal; Disulfides; Enzyme-Linked Immunosorbent Assay; Female; Garlic; Humans; Immunohistochemistry; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Neuroprotective Agents; Phosphorylation; Plant Extracts; Protein Processing, Post-Translational; tau Proteins

It was shown that aged garlic extract (AGE), garlic powder and the following garlic-derived compounds: S-allylcysteine (SAC), diallyl sulfide (DAS) and diallyl disulfide (DADS), ameliorate gentamicin (GM)-induced nephrotoxicity in rats. However, it was not established if the above mentioned extracts and compounds of garlic could interfere with the antibiotic action of GM. To address this point, AGE, garlic powder extract (GPE), SAC, DAS and DADS were assessed for their ability to interfere with the in vitro antibiotic activity of GM in Escherichia coli cultures. It was found that the above mentioned extracts and compounds of garlic were unable to decrease the antibiotic capacity of GM and even SAC, DAS and DADS alone inhibited the growth of Escherichia coli and enhanced the antibiotic effect of GM. Our data show that SAC, DAS and DADS are antibacterial compounds against E. coli and suggest that AGE, GPE, SAC, DAS and[sol ]or DADS may be administered along with GM-treatment to ameliorate GM-induced nephrotoxicity without interfering with its antibiotic activity.

Topics: Allyl Compounds; Anti-Bacterial Agents; Cysteine; Disulfides; Drug Interactions; Escherichia coli; Garlic; Gentamicins; Humans; Microbial Sensitivity Tests; Phytotherapy; Plant Extracts; Protective Agents; Sulfides

The organosulfur compounds (OSCs), present in garlic, are studied for their protective effect against human cancers. P-glycoprotein (P-gp) and multidrug resistance protein 2 (Mrp2) are two transporters involved in the defense of cells and in the development of multidrug resistance. Whereas OSCs increase glutathione S-transferase activity (GST), Mrp2 plays a role in the transport of glutathione (GSH)-conjugates. In this study, we have investigated the effect of two OSCs, diallyl disulfide (DADS) and S-allyl cysteine (SAC), on P-gp and Mrp2 expression in renal brush-border membranes. By Western blot analysis, our results show that DADS induces Mrp2 expression (by 7-fold), which correlates with the rise of GST activity and GSH levels. Surprisingly, a co-administration of OSC with cisplatin, an anticancer drug, significantly increased Mrp2 gene and protein expression (by 30-fold), suggesting that DADS could potentiate the effects of cisplatin. Interestingly, SAC and cisplatin in co-treatment decreased P-gp protein expression and mdr1b isoform mRNA levels. In addition, modulation of the mdr1b isoform and Mrp2 by cisplatin was completely abolished by a glutathione precursor, N-acetyl cysteine. These results indicate that OSCs present in a garlic-rich diet might alter chemotherapeutic treatments using P-gp or Mrp2 substrates.

Topics: Acetylcysteine; Allyl Compounds; Animals; Anticarcinogenic Agents; ATP Binding Cassette Transporter, Subfamily B, Member 1; Blotting, Western; Cell Membrane; Cisplatin; Cysteine; Disulfides; Garlic; Glutathione; Glutathione Transferase; Kidney; Kidney Cortex; Liver; Male; Microvilli; Mitochondrial Proteins; Plant Extracts; Protein Isoforms; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; Ribosomal Proteins; RNA, Messenger; Saccharomyces cerevisiae Proteins

Organosulphur compounds from garlic, especially diallyl disulphide (DADS) at non-toxic concentrations, affected production and secretion of some matrix metalloproteinases (MMPs) and of tissue inhibitor of metalloproteinase-1 (TIMP-1), one of their inhibitors, by human umbilical vein endothelial cells. Addition of DADS to the culture medium resulted in a concentration-dependent reduction of secreted MMP-2 protein and activity as well as TIMP-1 protein. In the presence of inducers (phorbol 12-myristate 13-acetate, forskolin and tumor necrosis factor alpha) addition of DADS caused a distinct concentration-dependent decrease of MMP-9 and TIMP-1 secretion, while not affecting MMP-9 mRNA levels. Intracellular protein levels remained low and were not affected. Other organosulphur compounds like allyl mercaptan and S-allylcysteine showed no or less clear effects on MMP-secretion or TIMP-1-secretion. These results suggest that DADS may mediate some of the biological effects ascribed to garlic preparations through affecting MMP-TIMP balance.

Topics: Allyl Compounds; Cell Survival; Cells, Cultured; Cysteine; Disulfides; Endothelium, Vascular; Garlic; Humans; Matrix Metalloproteinases; Sulfhydryl Compounds; Tissue Inhibitor of Metalloproteinase-1; Umbilical Veins

These studies examined the ability of garlic powder or allyl sulfur compounds to modify selenite protection against 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary epithelial cell DNA adducts. In Study 1, female rats (n = 5) were fed diets containing sodium selenite at 0.1, 0.5, or 1.0 mg Se/kg and garlic powder at 0, 20, or 40 g/kg diet. Total DNA adducts correlated inversely with selenite or garlic powder intake. Garlic powder enhanced the selenite inhibition of mammary DNA adducts. In Study 2, selenite (2.0 mg Se/kg diet), garlic powder (20 g/kg diet), water-soluble S-allyl cysteine (SAC; 5.2 mumol/kg diet), and oil-soluble diallyl disulfide (DADS; 5.2 mumol/kg diet) inhibited (p < 0.05) total DNA adducts by 45%, 40%, 80%, and 75%, respectively. Combining selenite with garlic powder, SAC, or DADS further inhibited DNA adducts. Selenite, but not garlic powder, SAC, or DADS, enhanced liver glutathione S-transferase and uridine diphosphate-glucuronosyltransferase activities. Selenite, garlic powder, SAC, or DADS did not affect liver cytochrome P-450 1A1 activities. The present studies provide evidence that synergistic protection against the initiation of DMBA carcinogenesis occurs when selenite is supplemented in conjunction with garlic or its allyl sulfur components.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Allyl Compounds; Animals; Antineoplastic Agents; Carcinogens; Cysteine; Disulfides; DNA Adducts; Drug Interactions; Epithelium; Female; Garlic; Glucuronosyltransferase; Glutathione Transferase; Mammary Glands, Animal; Plants, Medicinal; Rats; Rats, Sprague-Dawley; Sodium Selenite

A water extract of raw garlic (RGE) and two organosulfur compounds, diallyl sulfide and S-allylcysteine (SAC), were evaluated for their relative effectiveness in reducing benzo[a]pyrene (BaP)-DNA adduct formation in stimulated human peripheral blood lymphocytes in vitro. In replicate experiments, RGE significantly inhibited BaP-DNA adduct formation at concentrations of 0.001, 0.01, and 0.1 mg/ml. SAC also significantly decreased BaP-DNA adduct formation at concentrations of 0.01 and 0.1 mg/ml. For diallyl sulfide, no significant reduction in BaP-DNA adduct formation was found. BaP-DNA adduct formation was not associated with cell viability or proliferation of peripheral blood lymphocytes after the various treatments. No clear scavenging activity was detected for the garlic constituents. Aryl hydrocarbon hydroxylase activity was not decreased, nor was formation of sulfate and glucuronide conjugates of 3-hydroxy-BaP increased in the presence of RGE and SAC, indicating that increased glutathione S-transferase activity or a more efficient repair of BaP-DNA adducts may explain the observed effects. In addition, reactive oxygen species-induced 8-oxodeoxyguanosine in DNA was reduced in the presence of SAC. It is concluded that raw garlic and SAC may be useful in the prevention of BaP-associated tumorigenesis and that further evaluation of their preventive potential in humans at risk appears feasible.

Topics: Allyl Compounds; Anticarcinogenic Agents; Benzo(a)pyrene; Cell Division; Cell Survival; Cells, Cultured; Cysteine; Disulfides; DNA Adducts; Free Radical Scavengers; Garlic; Humans; Lymphocytes; Plant Extracts; Plants, Medicinal; Reactive Oxygen Species

Our previous studies demonstrated that dietary garlic powder supplementation inhibits N-nitrosamine induced DNA alkylation in liver and mammary tissue. The present studies compared the impact of dietary supplementation with garlic powder or two garlic constituents, water-soluble S-allyl cysteine (SAC) and oil-soluble diallyl disulfide (DADS), on the incidence of mammary tumorigenesis induced by N-methyl-N-nitrosourea (MNU). Female Sprague-Dawley rats were fed semi-purified casein based diets with or without supplements of garlic powder(20g/kg), SAC (57 micromol/kg) or DADS (57 micromol/kg) for 2 weeks prior to treatment with MNU (15 mg/kg body wt). Garlic powder, SAC and DADS supplementation significantly delayed the onset of mammary tumors compared to rats receiving the unsupplemented diet. Tumor incidence 23 weeks after MNU treatment was reduced by 76, 41 and 53% in rats fed garlic, SAC and DADS, respectively, compared to controls (P<0.05). Total tumor number was reduced 81, 35 and 65% by these supplements, respectively (P<0.05). In a separate study the quantity of mammary DNA alkylation occurring 3 h after MNU treatment was reduced in rats fed garlic, SAC or DADS (P<0.05). Specifically, O(6)-methylguanine adducts were reduced by 27, 18 and 23% in rats fed supplemental garlic, SAC and DADS, respectively, compared to controls. N(7)-Methylguanine adducts decreased by 48, 22 and 21% respectively, compared to rats fed the control diet. These studies demonstrate that garlic and associated allyl sulfur components, SAC and DADS, are effective inhibitors of MNU-induced mammary carcinogenesis.

Topics: Allyl Compounds; Animals; Anticarcinogenic Agents; Carcinogens; Cysteine; Disulfides; Eating; Female; Garlic; Mammary Neoplasms, Experimental; Methylnitrosourea; Plant Oils; Plants, Medicinal; Rats; Rats, Sprague-Dawley; Weight Gain

Diallyl disulfide (DADS), an oil-soluble organosulfur compound in processed garlic, was more effective in inhibiting the in vitro growth of human tumor cell lines: HCT-15 (colon), A549 (lung), and SK MEL-2 (skin) than isomolar quantities of the water-soluble compound S-allyl cysteine (SAC). Addition of DADS (100 microM) was cytostatic to all three cell lines. The importance of the allyl and the disulfide groups were revealed by the lack of a comparable depression in the growth of HCT-15 cells exposed to its saturated analogue, dipropyl disulfide (DPDS). Treatment with DADS also resulted in a dose-dependent increase in intracellular free calcium in cells. A dose-dependent decrease in the activity of calcium-dependent ATPase enzyme occurred in HCT-15 cells exposed to increasing quantities of DADS. A correlation (r = -0.975) was found between the intracellular free calcium levels and the Ca-ATPase activity in DADS-treated cells. These studies document that DADS, a constituent of garlic oil, is an effective inhibitor of the growth of human neoplastic cells. Alterations in calcium hemostasis are likely involved in the growth inhibition/cytotoxicity caused by DADS.

Topics: Allyl Compounds; Antineoplastic Agents; Calcium; Calcium-Transporting ATPases; Cell Division; Cysteine; Disulfides; Egtazic Acid; Ethylmaleimide; Garlic; Humans; Kinetics; Molecular Structure; Neoplasms; Plants, Medicinal; Tumor Cells, Cultured

Six organosulfur compounds found in garlic were examined for their ability to alter the growth of canine mammary tumor cells (CMT-13) in culture. Water-soluble organosulfur compounds (S-allyl-cysteine, S-ethyl-cysteine and S-propyl-cysteine) did not significantly alter the growth of CMT-13 cells when added to cultures at 1.0 mM or less. However, oil-soluble organosulfur compounds (diallyl sulfide, diallyl disulfide and diallyl trisulfide) markedly inhibited growth. Increasing addition of diallyl disulfide (DADS) resulted in a progressive decrease in CMT-13 cell growth. Addition of glutathione before DADS markedly decreased the severity of the growth inhibition. Treatment with DL-buthionine-SR-sulfoxamine, a specific inhibitor of glutathione synthesis, accentuated the growth inhibition caused by DADS. These studies show that some organosulfur compounds found in garlic are effective inhibitors of the growth of the neoplastic CMT-13 cell. The inhibitory effects of these compounds are modified by intracellular glutathione.

Topics: Allyl Compounds; Analysis of Variance; Animals; Anticarcinogenic Agents; Cell Division; Cysteine; Disulfides; Dogs; Female; Garlic; Glutathione; Growth Inhibitors; Mammary Neoplasms, Experimental; Plant Oils; Plants, Medicinal; Sulfides; Sulfur; Tumor Cells, Cultured