Showing papers on "Allicin published in 2006"

Clarifying the Real Bioactive Constituents of Garlic

Abstract: Compounds in garlic work synergistically to produce various effects, but, because of garlic's chemical complexity, processing methods yield preparations with differing efficacy and safety. Although thiosulfinates such as allicin have been long misunderstood to be active compounds due to their characteristic odor, it is not necessary for garlic preparations to contain such odorous compounds to be effective, and they decompose and disappear during any processing. Garlic exhibits hypolipidemic, antiplatelet, and procirculatory effects. It prevents cold and flu symptoms through immune enhancement and demonstrates anticancer and chemopreventive activities. In addition, aged garlic extract possesses hepatoprotective, neuroprotective, antioxidative activities, whereas other preparations may stimulate oxidation. Additional effects may be caused by S-allylcysteine, S-allyl mercaptocysteine), saponins, Nalpha-fructosyl arginine, and other substances formed during a long-term extraction process. Although not all of active ingredients of garlic are known, and allicin-like transient components are not directly active, ample research suggests that an allicin-free garlic preparation that is standardized with a bioavailable component such as S-allylcysteine, is active and various effects of garlic may be attributed to it. Furthermore, various chemical constituents in garlic products, including nonsulfur compounds such as saponins, may contribute to the essential biological activities of garlic. Further studies are needed to confirm their bioavailability and associated activities.

The Antioxidant Properties of Garlic Compounds: Allyl Cysteine, Alliin, Allicin, and Allyl Disulfide

Abstract: 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.

Antithrombotic and anticancer effects of garlic-derived sulfur compounds: A review

Abstract: Garlic (Allium sativum L.) has a long history as being a food having a unique taste and odor along with some medicinal qualities. Modern scientific research has revealed that the wide variety of dietary and medicinal functions of garlic can be attributed to the sulfur compounds present in or generated from garlic. Although garlic produces more than 20 kinds of sulfide compounds from a few sulfur-containing amino acids, their functions are different from one another; e.g., allicin, methyl allyl trisulfide, and diallyl trisulfide have antibacterial, antithrombotic, and anticancer activities, respectively. The present paper reviews the physiological functions of garlic in the limited study fields of its antithrombotic and anticancer effects. Before describing these effects, however, we will discuss briefly some characteristics of garlic as a plant and some modes of absorption of orally-administered sulfur compounds from garlic.

Antimalarial Activity of Allicin, a Biologically Active Compound from Garlic Cloves

Abstract: The incidence of malaria is increasing, and there is an urgent need to identify new drug targets for both prophylaxis and chemotherapy. Potential new drug targets include Plasmodium proteases that play critical roles in the parasite life cycle. We have previously shown that the major surface protein of Plasmodium sporozoites, the circumsporozoite protein (CSP), is proteolytically processed by a parasite-derived cysteine protease, and this processing event is temporally associated with sporozoite invasion of host cells. E-64, a cysteine protease inhibitor, inhibits CSP processing and prevents invasion of host cells in vitro and in vivo. Here we tested allicin, a cysteine protease inhibitor found in garlic extracts, for its ability to inhibit malaria infection. At low concentrations, allicin was not toxic to either sporozoites or mammalian cells. At these concentrations, allicin inhibited CSP processing and prevented sporozoite invasion of host cells in vitro. In vivo, mice injected with allicin had decreased Plasmodium infections compared to controls. When sporozoites were treated with allicin before injection into mice, malaria infection was completely prevented. We also tested allicin on erythrocytic stages and found that a 4-day regimen of allicin administered either orally or intravenously significantly decreased parasitemias and increased the survival of infected mice by 10 days. Together, these experiments demonstrate that the same cysteine protease inhibitor can target two different life cycle stages in the vertebrate host.

Influence of garlic (Allium sativum) on the pharmacokinetics of docetaxel.

Abstract: Purpose: The herbal supplement garlic ( Allium sativum ) is commonly used by cancer patients. Preclinical studies have shown that allicin, a major component of garlic, may affect cytochrome P 450 3A4 (CYP3A4) activity. This study examines the influence of garlic supplementation on the pharmacokinetics of docetaxel, a CYP3A4 substrate. Experimental Design: Women with metastatic breast cancer were treated with docetaxel (30 mg/m 2 ) given weekly for 3 of 4 weeks. Three days after the initial dose of docetaxel, patients received 600 mg of garlic twice daily for 12 consecutive days. Docetaxel pharmacokinetics were assessed during the first three administrations. Results: In 10 evaluable patients, the mean baseline clearance of docetaxel was 30.8 L/h/m 2 [95% confidence intervals (95% CI), 16.7-44.9]. Coadministration of garlic reduced mean clearance of docetaxel to 23.7 L/h/m 2 (95% CI, 15.5-31.8) and 20.0 L/h/m 2 (95% CI, 13.3-26.7) on days 8 and 15, respectively ( P = 0.17). Additional pharmacokinetic variables of docetaxel, including peak concentration ( P = 0.79), area under the curve ( P = 0.36), volume of distribution ( P = 0.84), and half-life ( P = 0.36), were also not statistically significantly different. The mean area under the curve ratio between day 15 and day 1 was 3.74 in three individuals with the CYP3A5 * 1A /* 1A genotype (all African American) compared with 1.02 in six individuals with the CYP3A5 * 3C /* 3C genotype (all Caucasian). Conclusions: This study indicates that garlic does not significantly affect the disposition of docetaxel. However, it cannot be excluded that garlic decreases the clearance of docetaxel in patients carrying a CYP3A5 * 1A allele.

Garlic-derived organosulfides induce cytotoxicity, apoptosis, cell cycle arrest and oxidative stress in human colon carcinoma cell lines.

Abstract: Organosulfur compounds (OSC) from garlic, especially allicin (ALI), diallyl sulfide (DAS), diallyl disulfide (DADS), and diallyl trisulfide (DATS) are recognized as a group of potential chemopreventive agents. In this study, we examined the effects of OSC on human Caco-2 and HT-29 colon carcinoma cell lines. Apoptosis induction (Annexin-V-FITC/PI, fluorescein diacetate/PI, sub-G1 fraction), modulation of DNA cell cycle (G2/M arrest, phospho-H3 mitotic marker), transmembrane mitochondrial potential (JC-1) and intracellular GSH amount (monochlorobimane assay) were measured by flow cytometry and fluorimetry. Our results showed that order of OSC-induced cell death in Caco-2 and HT-29 cells increased in the range as follows: ALI < DAS = DADS < DATS and ALI = DAS < DADS < DATS, respectively. Both cell lines used are relatively resistant to OSC induced cytotoxicity, because compound concentrations required to obtain significant effect are in high micromolar range. ALI was less toxic than equimolar doses of other OSC tested with the exception of GSH modulation and G2/M arrest in Caco-2 cells. DADS-treated HT-29 cells and both DATS-treated cell lines exhibit inverse correlation between p-H3 positivity and compound concentration due to higher apoptotic rate. These results show the correlation of sulfur atoms number in OSC with their capacity in apoptosis induction and support the role of redox-sensitive "sulfhydryl switches" in maintaining intracellular redox milieu.

Identification of Two Novel Pigment Precursors and a Reddish-Purple Pigment Involved in the Blue-Green Discoloration of Onion and Garlic

Abstract: By using a model reaction system representing blue-green discoloration that occurs when purees of onion (Allium cepa L.) and garlic (Allium sativum L.) are mixed, we isolated two pigment precursors (PPs) and a reddish-purple pigment (PUR-1) and determined their chemical structures. PPs were isolated from a heat-treated solution containing color developer (CD) and either l-valine or l-alanine, and their structures were determined as 2-(3,4-dimethylpyrrolyl)-3-methylbutanoic acid (PP-Val), and 2-(3,4-dimethyl-1H-pyrrolyl) propanoic acid (PP-Ala), respectively. Next, PUR-1 was isolated from a heat-treated solution containing PP-Val and allicin, and its structure was determined as (1E)-1-(1-((1S)-1-carboxy-2-methylpropyl)-3,4-dimethyl-1H-pyrrol-2-yl)-prop-1-enylene-3-(1-((1S)-1-carboxy-2-methylpropyl)-3,4-dimethyl-1H-pyrrol-2-ylidenium). The structure of PUR-1 suggested that PP molecules containing a 3,4-dimethyl pyrrole ring had been cross-linked by an allyl group of allicin to form conjugated pigments. While PUR-1 is a dipyrrole compound exhibiting a reddish-purple color, a color shift toward blue to green can be expected as the cross-linking reaction continues to form, for example, tri- or tetrapyrrole compounds.

Kinetic and mechanistic studies of allicin as an antioxidant

Abstract: We have undertaken a detailed study of the antioxidant activity of allicin, one of the main thiosulfinates in garlic, in order to obtain quantitative information on it as a chain-breaking antioxidant. The antioxidant actions of allicin against the oxidation of cumene and methyl linoleate (ML) in chlorobenzene were studied in detail using HPLC. The hydroperoxides formed during the course of the inhibited oxidation of ML were analyzed as their corresponding alcohols by HPLC, and it is apparent that an allylic hydrogen atom of the allicin is responsible for the antioxidant activity. Furthermore, it is clear that the radical-scavenging reactions of allicin proceed via a one-step hydrogen atom transfer based on the results of the reaction with 2,2-diphenyl-1-picrylhydrazyl (DPPH) in the presence of Mg2+ and calculation of the ionization potential value. In addition, we determined the stoichiometric factor (n), the number of peroxyl radicals trapped by one antioxidant molecule, of allicin by measuring the reactivity toward DPPH in chlorobenzene, and the value of n for allicin was about 1.0. Therefore, we measured the rate constants, kinh, for the reaction of allicin with peroxyl radicals during the induction period of the cumene and the ML oxidation. As a result, we found that allicin reacts with peroxyl radicals derived from cumene and ML with the rate constants kinh = 2.6 × 103 M−1s−1 and 1.6 × 105 M−1s−1 in chlorobenzene, respectively. Our results demonstrate for the first time reliable quantitative kinetic data and the antioxidative mechanism of allicin as an antioxidant.

Enhancement of the fungicidal activity of amphotericin B by allicin, an allyl-sulfur compound from garlic, against the yeast Saccharomyces cerevisiae as a model system.

Abstract: Amphotericin B (AmB) is a representative antibiotic for the control of serious fungal infections, and its fungicidal activity was greatly enhanced by allicin, an allyl-sulfur compound from garlic. In addition to the plasma membrane permeability change, AmB induced vacuole membrane damage so that the organelles were visible as small discrete particles. Although allicin was ineffective in promoting AmB-induced plasma membrane disability, this compound enhanced AmB-induced structural damage to the vacuolar membrane even at a non-lethal dose of the antibiotic. Allicin could also enhance the antifungal activity of AmB against the pathogenic fungus Candida albicans and against Aspergillus fumigatus. In contrast, allicin did not enhance the cytotoxic activity of AmB against cells of human promyelocytic leukemia (HL-60), a vacuole-less organism.

Chemical constituents and antimicrobial activity of a traditional herbal medicine containing garlic and black cumin

Abstract: A combination of crushed garlic (Allium sativum) and black cumin seeds (Nigelia sativum) has been used as a traditional remedy for urinary tract infections. In-vitro antimicrobial testing suggested that the mixture of two spices in the ratio of 1:1 has antimicrobial effects on both Staphylococcus aureus and Escherichia coli species. Analyses of the extract of garlic and black cumin by GC-MS as well as LC–MS & MSP2P confirmed that the main components of garlic were allicin, γ-glutamyl-S-allylcysteine and allicin transformed products such as diallyldisulfide and vinyldithiins. Components of black cumin were thymoquinone, p-cymene, p-tert-butylcatechol, and pinene. Isolated samples of allicin by preparative HPLC from garlic extract and reference samples of diallyldisulfide and thymoquinone were tested individually and in combination for their antimicrobial activities against S. aureus and E. coli. All of these compounds showed modest antimicrobial effects individually (except diallyldisulfide against E. coli) and in combination.

Dependence of synergistic fungicidal activity of Cu2+ and allicin, an allyl sulfur compound from garlic, on selective accumulation of the ion in the plasma membrane fraction via allicin-mediated phospholipid peroxidation.

Abstract: Allicin was effective in decreasing the lethal concentration of Cu (2+) against various fungal strains including a plant pathogen, Fusarium oxysporum, so that the minimum fungicidal concentration (MFC) of the ion for the fungus could be reduced to 2 % of that detected without allicin. In Saccharomyces cerevisiae, Cu (2+) was not apparently taken up by cells when added alone at a non-lethal concentration, whereas the ion was efficiently incorporated into cells in the presence of allicin, as in the case of cells treated with the ion at a lethal concentration. Although allicin likely increased cellular permeability to Cu (2+) due to its promotive effect on plasma membrane phospholipid peroxidation, these cell-surface events did not result in endogenous reactive oxygen species (ROS) production, a typical toxic effect of the ion. Cu (2+) was detected in the cytoplasmic fraction of cells that had been treated with the ion at a lethal concentration, whereas the ion was entrapped in the plasma membrane fraction upon their treatment with the ion at a low concentration in combination with allicin. Cu (2+) could be solubilized from the plasma membrane fraction by a procedure for the extraction of hydrophobic proteins rather than the extraction of phospholipids, suggesting its complexation with a plasma membrane protein as a result of allicin treatment. Such a subcellular localization of Cu (2+) resulted in the selective leakage of intracellular K (+), but not in the disruptive damage on the plasma membrane, and was considered to underlie the synergistic fungicidal activity of Cu (2+) and allicin.

Inducing apoptosis and upregulation of Bax and Fas ligand expression by allicin in hepatocellular carcinoma in Balb/c nude mice.

Abstract: 许多健康好处被归功于到蒜素，包括 vasorelaxantactivities。然而，位于这些效果下面的分子的机制仍然保持未知。在临床的 anti-HCC 处理使用蒜素，蒜素和 Adriamycin (ADM ) 的不同剂量被带进把 HCC BEL7402 房间注入裸体老鼠的下的织物建立的移植肿瘤模型。有蒜素和 ADM 的处理与 Bax 和 Fasligand (FasL ) 导致 mRNA 导致了肿瘤回归。

Effects of garlic (Allium sativum) and its chief compound, allicin, on acute lethality of cyanide in rats

Abstract: Cyanide, known as a potent suicidal, homicidal and chemical warfare agent, is widely found in plants and used in industry. Cytochrome oxidase, the main enzyme in cell respiration, is inhibited by cyanide resulting to acute or chronic toxicity. The effects of garlic (Allium sativum) and its chief compound, allicin, on the acute lethality of cyanide were studied in rats. Three groups of rats were fed a diet containing 10%, 20% and 30% garlic powder for 48 h and then were challenged with 10 mg/kg cyanide. The lethality of cyanide intoxication was markedly reduced in rats which received garlic by diet and the rate of protection was dose-dependent. The effect of 1,000 ppm of allicin on cyanide lethality was equal to 20% of garlic in diet. These results suggest that sulfur compounds of garlic may have a protective effect against cyanide intoxication.

Growth Inhibitory Activity of Sulfur Compounds of Garlic against Pathogenic Microorganisms

Abstract: Efforts have been made to explore the possibility of using garlic as an antimicrobial therapeutic agent since garlic extract and its individual sulfur compounds show antimicrobial activities against all kinds of microorganisms including bacteria, molds, yeasts and protozoa. Staphylococcus aureus has been the most studied bacteria along with many other Gram positive and negative pathogenic bacteria, including species of the genera Clostridium, Mycobacterium, Escherichia, Klebsiella, Bacillus, Salmonella and Shigella. Candida albicans has been the most studied among the eukaryotic microorganisms. A pathogenic protozoa, Giardia intestinalis, was also tested. All the microorganisms tested was inhibited by garlic extract or its sulfur components. Garlic has been known to be growth inhibitory only when fresh garlic is crushed, since allicin-generating reaction is enzyme-catalyzed. Allicin is known to be growth inhibitory through a non-specific reaction with sulfhydryl groups of enzyme proteins that are crucial to the metabolism of microorganisms. Another plausible hypothesis is that allicin inhibits specific enzymes in certain biological processes, e.g. acetyl CoA synthetase in fatty acid synthesis in microorganisms. Allicin transforms into other compounds like ajoene and various sulfides which are also inhibitory to microorganisms, but not as potent as their mother compound. It is reported recently that garlic heated at cooking temperatures is growth inhibitory especially against yeasts, and that the growth inhibitory compound is allyl alcohol thermally generated from alliin in garlic.

Changes in blood leucocyte pattern in piglets from sows treated with garlic preparations

Abstract: Changes in white blood cell pattern in piglets, as a consequence of administration of aged garlic extract (AGE) or allicin to sows during pregnancy and lactation, were presented. The experiment was performed on piglets born by sows of Large Polish White breed. Animals were kept under standard rearing conditions with free access to fresh water and well balanced diet. The piglets obtained from 18 sows were divided into three groups: one control and two experimental ones. Within those groups there were formed 7 age-differentiated subgroups (each subgroup n = 6): non-suckling newborn piglets (0 d) and at the age of 1, 3, 7, 14, 28 and 35 d. Starting from the 91 st d of pregnancy up to the piglets’ weaning on 28 th d of their life, the sows were daily administered per os AGE at the dosage of 10 ml/100 kg b.w. or allicin at the dosage of 1.6 mg/ 100 kg b.w., whereas the controls received 10 ml/100 kg b.w. of vehiculum. The blood samples were collected from the piglets on days 0, 1, 3, 7, 14, 28 and 35 of their life and analysed immediately. The results showed in most cases a significant increase in the white blood cell counts in different periods of piglets’ life. This indicates an improvement in animal performance following treatment with the investigated garlic preparations.

Effects of topical allicin on second-intention wound healing in dogs (histological aspects)

Abstract: Alllicin is one of the pharmacologically active garlic sulfur compounds that have antimicrobial (antibacterial, antiviral, antifungal and antiparasitic) and vasodilating effects. Five normal, male, mixed-breed dogs were selected to investigate the effects of allicin (5 mg/ml in methyl cellulose gel) as a topical treatment for full-thickness, excisional wounds. The dogs were approximately 3 years old. The histological aspects of second-intention wound healing were studied. Eight full-thickness skin wounds (20×20 mm) were created on the back of each dog. On days 0, 7, 14 and 21, each dog received two wounds, symmetrically, and were assigned to one of two groups: control (methyl cellulose gel) or test (allicin 5 mg/ml methyl cellulose gel). Wounds were treated once daily for a week. Left-side wounds were treated with allicfin (test group) and right-side wounds were treated with methylcellulose gel (control group). At day 28 (4 weeks) after initial wounding, biopsies were taken from wounds for histological examination. The density of inflammatory cells in the center of the day 7 wounds was significantly lower in test group (P=0.041), but the density of fibrocytes and fibroblasts in the center of day 7 wounds was significantly higher in the test group (P=0.042). No significant differences were observed in the amount of collagen and fibrin between the test and control wounds (P>0.05).

Inducing apoptosis and upregulation of Bax and Fas ligand expression by allicin in hepatocellular carcinoma in Balb/c nude mice

Abstract: 许多健康好处被归功于到蒜素，包括 vasorelaxantactivities。然而，位于这些效果下面的分子的机制仍然保持未知。在临床的 anti-HCC 处理使用蒜素，蒜素和 Adriamycin (ADM ) 的不同剂量被带进把 HCC BEL7402 房间注入裸体老鼠的下的织物建立的移植肿瘤模型。有蒜素和 ADM 的处理与 Bax 和 Fasligand (FasL ) 导致 mRNA 导致了肿瘤回归。

Complementary, holistic, and integrative medicine: garlic.

Abstract: 1. Larissa Shamseer, BSc* 2. Theresa L. Charrois, BScPharm, MSc* 3. Sunita Vohra, MD, MSc* 1. *Complementary and Alternative Research and Education (CARE) Program, Department of Pediatrics, University of Alberta, Canada, on behalf of the American Academy of Pediatrics Provisional Section on Complementary, Holistic, and Integrative Medicine Allium sativum , commonly known as garlic, is a perennial plant native to central Asia that now is farmed worldwide. It is a member of the Liliaceae family and also is called Russian penicillin and allium . Intact, the plant is odorless; its pungency arises when garlic is crushed, yielding the sulfur-containing, pharmacologically active component allicin. Garlic was one of the earliest cultivated plants and has been used in many cultures for its culinary and medicinal purposes. It has been used widely as a folk remedy to ward off the common cold and flu. In the first century, Ayurvedic medicine claimed a role for garlic in the prevention and treatment of heart disease (1) that has been studied by medical research since the 1920s with intriguing and often mixed results. (2)(3) In traditional Chinese medicine, garlic has been used as an antimicrobial and for fever prevention. Despite use in many cultures for its purported pharmacologic effects, there is a gap in the literature surrounding the pediatric use of garlic. The cardiovascular effects of garlic are purported to include the lowering of lipids and blood pressure and the reduction of platelet aggregation in adults. (4)(5)(6) McCrindle and associates (7) examined the effects of a commercial garlic extract on lipids in children (8 to 18 y of age) who had first-degree relatives afflicted with familial hypercholesterolemia or premature atherosclerotic cardiovascular disease and a minimum fasting total cholesterol concentration higher than 185 mg/dL (4.8 mmol/L) in a double-blind, randomized, controlled trial (RCT). The extract was administered in 300-mg doses (containing 0.6 …

Method for producing high quality garlic powder

Abstract: The invention discloses a method for preparing high quality garlic powder. Firstly, fresh garlic is used as raw material to obtain garlic powder of generating high allicin through slicing, microwave vacuum drying or freeze drying, disintegrating and sieving, secondly, fresh garlic is used as raw material to obtain garlic powder only with alliin which is precursor substance of the allicin through killing enzyme, disintegrating, heated-air drying or fluidized-bed drying or vacuum drying, disintegrating, and disintegrating and sieving, and then the garlic powder which is obtained in the first step and the second step is remixed according to the weight ratio of 1:0.1-1:10. The garlic powder which is prepared by the process has the advantages that the reservation rate of allicin can reach over 92%, and the energy-consumption and production cost are low in the process of preparation.

Preparation method of high allicin garlic powder capsule

Abstract: A process for preparing high-garlicin garlic clove powder capsule for preventing and treating tumor, hyperlipemia and arteriosclerosis, and relieving fatigue features that the microwave vacuum drying method is combined with vacuum drying method for preparing high-garlicin garlic clove powder, and the air suspension filming method is used for preparing garlic powder microcapsules

Effect of 2-hydroxypropyl-β-cyclodextrin on solubility and stability of garlic oil

Abstract: Objective To investigate the effects of 2-hydroxypropyl-β-cyclodextrin(HP-β-CD) on the solubility and stability of garlic oil.Methods The solubility of allicin of garlic oil in various concentration of HP-β-CD water solution was determined by GC.The content of allicin was used as an index to compare the stability of garlic oil HP-β-CD water solution with garlic oil Tween-80 water solution under the conditions of 40 ℃,60 ℃,and light(4 500 lx).The effects of pH value,antioxidants,nitrogen gas,and sterilizing on the stability of allicin of garlic oil in 5% HP-β-CD water solution were investigated.Results The solubility of allicin of garlic oil in water could be improved remarkably by HP-β-CD and increased linearly along with the increasing of HP-β-CD concentration.The allicin of garlic oil was more stable in HP-β-CD water solution than in Tween-80 water solution while in pH value 5.0 and with nitrogen gas.The stablity of allicin of garlic oil was decreased under the conditions of heating,lighting,or adding antioxidants.Conclusion HP-β-CD could evidently increase the solubility of allicin of garlic oil in water and improve its stability.