The Experts below are selected from a list of 2625 Experts worldwide ranked by ideXlab platform
Aharon Rabinkov - One of the best experts on this subject based on the ideXlab platform.
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Therapy of Murine Pulmonary Aspergillosis with Antibody-Alliinase Conjugates and Alliin
Antimicrobial Agents and Chemotherapy, 2009Co-Authors: Elena Appel, Alexandra Vallon-eberhard, Aharon Rabinkov, Irina Shin, Keren Sasson, Yona Shadkchan, Nir Osherov, Ori Brenner, Steffen Jung, David MirelmanAbstract:Aspergillus fumigatus is an opportunistic fungal pathogen responsible for invasive aspergillosis in immunocompromised individuals. The high morbidity and mortality rates as well as the poor efficacy of antifungal agents remain major clinical concerns. Allicin (diallyl-dithiosulfinate), which is produced by the garlic enzyme alliinase from the harmless substrate alliin, has been shown to have wide-range antifungal specificity. A monoclonal antibody (MAb) against A. fumigatus was produced and chemically ligated to the enzyme alliinase. The purified antibody-alliinase conjugate bound to conidia and hyphae of A. fumigatus at nanomolar concentrations. In the presence of alliin, the conjugate produced cytotoxic Allicin molecules, which killed the fungus. In vivo testing of the therapeutical potential of the conjugate was carried out in immunosuppressed mice infected intranasally with conidia of A. fumigatus. Intratracheal (i.t.) instillation of the conjugate and alliin (four treatments) resulted in 80 to 85% animal survival (36 days), with almost complete fungal clearance. Repetitive intratracheal administration of the conjugate and alliin was also effective when treatments were initiated at a more advanced stage of infection (50 h). The fungi were killed specifically without causing damage to the lung tissue or overt discomfort to the animals. Intratracheal instillation of the conjugate without alliin or of the unconjugated monoclonal antibody significantly delayed the death of the infected mice, but only 20% of the animals survived. A limitation of this study is that the demonstration was achieved in a constrained setting. Other routes of drug delivery will be investigated for the treatment of pulmonary and extrapulmonary aspergillosis.
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Allicin inhibits cell polarization migration and division via its direct effect on microtubules
Cytoskeleton, 2007Co-Authors: Masha Pragerkhoutorsky, Aharon Rabinkov, David Mirelman, Igor Goncharov, Benjamin Geiger, Alexander D BershadskyAbstract:Allicin (diallyl thiosulfinate) is a major biologically active component of garlic that is known to inhibit cell proliferation and induce apoptosis. The effects of Allicin are attributed to its ability to react with thiol groups. However, the mechanism underlying the cytostatic activity of Allicin, as well as the identity of the relevant subcellular targets, are not known. In the present study, we found that the effects of Allicin on cell polarization, migration, and mitosis are similar to the effects of microtubule-depolymerizing drugs such as nocodazole. Moreover, treatment of cultured fibroblasts with micromolar doses of Allicin results in microtubule depolymerization in cells within minutes of its application, without disrupting the actin cytoskeleton or inducing direct cytotoxic effects. Furthermore, Allicin blocks the polymerization of pure tubulin in vitro in a concentration-dependent manner, suggesting that it acts directly on tubulin dimers. Sulfhydryl (SH)-reducing reagents such as 2-mercaptoethanol and dithiothreitol abolish the effect of Allicin on microtubule polymerization. Thus, Allicin is a potent microtubule-disrupting reagent interfering with tubulin polymerization by reaction with tubulin SH groups.
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apoptotic killing of b chronic lymphocytic leukemia tumor cells by Allicin generated in situ using a rituximab alliinase conjugate
Molecular Cancer Therapeutics, 2005Co-Authors: Fabian D Arditti, Aharon Rabinkov, Talia Miron, Meir Wilchek, Yair Reisner, Alain Berrebi, David MirelmanAbstract:Allicin, a highly active component from freshly crushed garlic, is produced upon the reaction of the small molecular weight molecule alliin, with the enzyme alliinase (EC 4.4.1.4). Because Allicin was shown to be toxic to various mammalian cells in vitro, we devised a novel approach for the therapy of B-cell malignancies based on site-directed generation of Allicin. Alliinase was conjugated to the monoclonal antibody rituximab, which recognizes the CD20 antigen, and the resulting conjugate was targeted to CD20+ B chronic lymphocytic leukemia (B-CLL) and other B-cell lymphomas. Upon addition of alliin, Allicin was formed in situ, killing the CD20+ tumor B cells via apoptosis. Following a 72-hour treatment, an 85% and 96% reduction was observed in the number of viable B-CLL and EBV-transformed B cells, respectively. Using the human/mouse radiation chimera for the evaluation of Allicin targeting in a preclinical animal model, we showed a significant reduction in the number of recovered B-CLL, mantle cell lymphoma, or EBV-transformed B cells. We conclude that our system offers a new powerful and less toxic therapy for B-CLL and other B-cell malignancies. Furthermore, combining alliinase with the appropriate monoclonal antibody may extend the application of this approach to other conditions in which the elimination of a specific cell population is desired.
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efficacy of Allicin the reactive molecule of garlic in inhibiting aspergillus spp in vitro and in a murine model of disseminated aspergillosis
Journal of Antimicrobial Chemotherapy, 2004Co-Authors: Yona Shadkchan, Aharon Rabinkov, David Mirelman, Talia Miron, Meir Wilchek, Einav Shemesh, Nir OsherovAbstract:Objectives: The evaluation of Allicin, the biologically active compound responsible for the antimicrobial activities of freshly crushed garlic cloves, in inhibiting Aspergillus spp. in vitro and in a murine model of disseminated aspergillosis. Methods: Pure Allicin was prepared by reacting synthetic alliin with a stabilized preparation of the garlic enzyme alliinase. We tested the in vitro efficacy of pure Allicin against 31 clinical isolates of Aspergillus spp. using a microdilution broth method and following the NCCLS guidelines (document M-38P). Subse- quently, the in vivo efficacy of Allicin was tested in immunocompetent mice infected intravenously (iv) with Aspergillus fumigatus conidia. Allicin (5 mg/kg body weight) was administered iv once daily for 5 days post-infection or orally (po) (9 mg/kg body weight) for 5 days pre-infection and 10 days post-infection. No ill effects were observed in Allicin-treated uninfected mice. Results: The in vitro MICs and MFCs of Allicin were between 8 and 32 mg/L, indicating that Allicin in its pure form may be an effective fungicide in vitro. Time-kill studies indicate that Allicin exerts its fungicidal activity within 2-12 h of administration in vitro. Allicin treatment significantly prolonged survival of infected mice (P < 0.01) from mean survival time (MST) = 7.7 days in untreated mice to MST = 21.3 and 13.9 days for Allicin iv and po treated mice, respectively. Allicin iv treatment led to a significant (P < 0.001) 10-fold reduction in fungal burden in A. fumigatus infected mice as evaluated by quantitative fungal cultures of kidney tissue samples. Conclusions: These favourable results, despite the short half-life of this compound in vivo, support further studies of controlled sustained release or more prolonged administration of Allicin as a treatment for aspergillosis.
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inhibition of tumor growth by a novel approach in situ Allicin generation using targeted alliinase delivery
Molecular Cancer Therapeutics, 2003Co-Authors: Talia Miron, David Mirelman, Meir Wilchek, Marina Mironchik, Aharon RabinkovAbstract:Allicin (diallyl thiosulfinate), a highly active component in extracts of freshly crushed garlic, is the interaction product of non-protein amino acid alliin ( S -allyl-l-cysteine sulfoxide) with the enzyme alliinase (alliin lyase; EC 4.4.1.4). Allicin was shown to be toxic in various mammalian cells in a dose-dependent manner in vitro . We made use of this cytotoxicity to develop a novel approach to cancer treatment, based on site-directed generation of Allicin. Alliinase from garlic was chemically conjugated to a mAb directed against a specific tumor marker, ErbB2. After the mAb-alliinase conjugate was bound to target tumor cells, the substrate, alliin, was added. In the presence of alliin, tumor-localized alliinase produced Allicin, which effectively killed N87 and CB2, both ErbB2-expressing cells in vitro , whereas 32D cells (a murine hematopoietic progenitor cell line, devoid of the ErbB2 receptors) were not affected. Moreover, using N87, a human tumor cell line xenograft in athymic nude mice, we demonstrated for the first time, a high antitumor activity of Allicin that was produced in situ by the conjugate, on alliin administration in vivo , while at the same time other tissues were unharmed due to the inert nature of alliin and the high clearance rate of Allicin. The effect of the treatment on tumor growth arrest became significant 2 weeks after its onset, and it continued to rise, reaching highly significant inhibition a week later. Ten days after the end of the treatment (day 18), tumor growth inhibition was still the same.
Talia Miron - One of the best experts on this subject based on the ideXlab platform.
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Allicin inhibits cell growth and induces apoptosis through the mitochondrial pathway in hl60 and u937 cells
Journal of Nutritional Biochemistry, 2008Co-Authors: Talia Miron, Meir Wilchek, Ayala Sharp, Yoshihito Nakagawa, Makoto Naoi, Yoshinori Nozawa, Yukihiro AkaoAbstract:Abstract In this article, the effects of Allicin, a biological active compound of garlic, on HL60 and U937 cell lines were examined. Allicin induced growth inhibition and elicited apoptotic events such as blebbing, mitochondrial membrane depolarization, cytochrome c release into the cytosol, activation of caspase 9 and caspase 3 and DNA fragmentation. Pretreatment of HL60 cells with cyclosporine A, an inhibitor of the mitochondrial permeability transition pore (mPTP), inhibited Allicin-treated cell death. HL60 cell survival after 1 h pretreatment with cyclosporine A, followed by 16 h in presence of Allicin (5 μM) was ∼80% compared to Allicin treatment alone (∼50%). Also N -acetyl cysteine, a reduced glutathione (GSH) precursor, prevented cell death. The effects of cyclosporine A and N -acetyl cysteine suggest the involvement of mPTP and intracellular GSH level in the cytotoxicity. Indeed, Allicin depleted GSH in the cytosol and mitochondria, and buthionine sulfoximine, a specific inhibitor of GSH synthesis, significantly augmented Allicin-induced apoptosis. In HL60 cells treated with Allicin (5 μM, 30 min) the redox state for 2GSH/oxidized glutathione shifted from E GSH −240 to −170 mV. The same shift was observed in U937 cells treated with Allicin at a higher concentration for a longer period of incubation (20 μM, 2 h). The apoptotic events induced by various concentrations of Allicin correlate to intracellular GSH levels in the two cell types tested (HL60: 3.7 nmol/10 6 cells; U937: 7.7 nmol/10 6 cells). The emerging mechanistic basis for the antiproliferative function of Allicin, therefore, involves the activation of the mitochondrial apoptotic pathway by GSH depletion and by changes in the intracellular redox status.
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apoptotic killing of b chronic lymphocytic leukemia tumor cells by Allicin generated in situ using a rituximab alliinase conjugate
Molecular Cancer Therapeutics, 2005Co-Authors: Fabian D Arditti, Aharon Rabinkov, Talia Miron, Meir Wilchek, Yair Reisner, Alain Berrebi, David MirelmanAbstract:Allicin, a highly active component from freshly crushed garlic, is produced upon the reaction of the small molecular weight molecule alliin, with the enzyme alliinase (EC 4.4.1.4). Because Allicin was shown to be toxic to various mammalian cells in vitro, we devised a novel approach for the therapy of B-cell malignancies based on site-directed generation of Allicin. Alliinase was conjugated to the monoclonal antibody rituximab, which recognizes the CD20 antigen, and the resulting conjugate was targeted to CD20+ B chronic lymphocytic leukemia (B-CLL) and other B-cell lymphomas. Upon addition of alliin, Allicin was formed in situ, killing the CD20+ tumor B cells via apoptosis. Following a 72-hour treatment, an 85% and 96% reduction was observed in the number of viable B-CLL and EBV-transformed B cells, respectively. Using the human/mouse radiation chimera for the evaluation of Allicin targeting in a preclinical animal model, we showed a significant reduction in the number of recovered B-CLL, mantle cell lymphoma, or EBV-transformed B cells. We conclude that our system offers a new powerful and less toxic therapy for B-CLL and other B-cell malignancies. Furthermore, combining alliinase with the appropriate monoclonal antibody may extend the application of this approach to other conditions in which the elimination of a specific cell population is desired.
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efficacy of Allicin the reactive molecule of garlic in inhibiting aspergillus spp in vitro and in a murine model of disseminated aspergillosis
Journal of Antimicrobial Chemotherapy, 2004Co-Authors: Yona Shadkchan, Aharon Rabinkov, David Mirelman, Talia Miron, Meir Wilchek, Einav Shemesh, Nir OsherovAbstract:Objectives: The evaluation of Allicin, the biologically active compound responsible for the antimicrobial activities of freshly crushed garlic cloves, in inhibiting Aspergillus spp. in vitro and in a murine model of disseminated aspergillosis. Methods: Pure Allicin was prepared by reacting synthetic alliin with a stabilized preparation of the garlic enzyme alliinase. We tested the in vitro efficacy of pure Allicin against 31 clinical isolates of Aspergillus spp. using a microdilution broth method and following the NCCLS guidelines (document M-38P). Subse- quently, the in vivo efficacy of Allicin was tested in immunocompetent mice infected intravenously (iv) with Aspergillus fumigatus conidia. Allicin (5 mg/kg body weight) was administered iv once daily for 5 days post-infection or orally (po) (9 mg/kg body weight) for 5 days pre-infection and 10 days post-infection. No ill effects were observed in Allicin-treated uninfected mice. Results: The in vitro MICs and MFCs of Allicin were between 8 and 32 mg/L, indicating that Allicin in its pure form may be an effective fungicide in vitro. Time-kill studies indicate that Allicin exerts its fungicidal activity within 2-12 h of administration in vitro. Allicin treatment significantly prolonged survival of infected mice (P < 0.01) from mean survival time (MST) = 7.7 days in untreated mice to MST = 21.3 and 13.9 days for Allicin iv and po treated mice, respectively. Allicin iv treatment led to a significant (P < 0.001) 10-fold reduction in fungal burden in A. fumigatus infected mice as evaluated by quantitative fungal cultures of kidney tissue samples. Conclusions: These favourable results, despite the short half-life of this compound in vivo, support further studies of controlled sustained release or more prolonged administration of Allicin as a treatment for aspergillosis.
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inhibition of tumor growth by a novel approach in situ Allicin generation using targeted alliinase delivery
Molecular Cancer Therapeutics, 2003Co-Authors: Talia Miron, David Mirelman, Meir Wilchek, Marina Mironchik, Aharon RabinkovAbstract:Allicin (diallyl thiosulfinate), a highly active component in extracts of freshly crushed garlic, is the interaction product of non-protein amino acid alliin ( S -allyl-l-cysteine sulfoxide) with the enzyme alliinase (alliin lyase; EC 4.4.1.4). Allicin was shown to be toxic in various mammalian cells in a dose-dependent manner in vitro . We made use of this cytotoxicity to develop a novel approach to cancer treatment, based on site-directed generation of Allicin. Alliinase from garlic was chemically conjugated to a mAb directed against a specific tumor marker, ErbB2. After the mAb-alliinase conjugate was bound to target tumor cells, the substrate, alliin, was added. In the presence of alliin, tumor-localized alliinase produced Allicin, which effectively killed N87 and CB2, both ErbB2-expressing cells in vitro , whereas 32D cells (a murine hematopoietic progenitor cell line, devoid of the ErbB2 receptors) were not affected. Moreover, using N87, a human tumor cell line xenograft in athymic nude mice, we demonstrated for the first time, a high antitumor activity of Allicin that was produced in situ by the conjugate, on alliin administration in vivo , while at the same time other tissues were unharmed due to the inert nature of alliin and the high clearance rate of Allicin. The effect of the treatment on tumor growth arrest became significant 2 weeks after its onset, and it continued to rise, reaching highly significant inhibition a week later. Ten days after the end of the treatment (day 18), tumor growth inhibition was still the same.
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A spectrophotometric assay for Allicin, alliin, and alliinase (alliin lyase) with a chromogenic thiol: reaction of 4-mercaptopyridine with thiosulfinates.
Analytical biochemistry, 2002Co-Authors: Talia Miron, Irina Shin, David Mirelman, Guy Feigenblat, Lev Weiner, Meir Wilchek, Aharon RabinkovAbstract:Allicin (diallylthiosulfinate) is the best known active compound of garlic. It is generated upon the interaction of the nonprotein amino acid alliin with the enzyme alliinase (alliin lyase, EC 4.4.1.4). Previously, we described a simple spectrophotometric assay for the determination of Allicin and alliinase activity, based on the reaction between 2-nitro-5-thiobenzoate (NTB) and Allicin. This reagent is not commercially available and must be synthesized. In this paper we describe the quantitative analysis of alliin and Allicin, as well as of alliinase activity with 4-mercaptopyridine (4-MP), a commercially available chromogenic thiol. The assay is based on the reaction of 4-MP (lambda(max)=324nm) with the activated disulfide bond of thiosulfinates -S(O)-S-, forming the mixed disulfide, 4-allylmercaptothiopyridine, which has no absorbance at this region. The structure of 4-allylmercaptothiopyridine was confirmed by mass spectrometry. The method was used for the determination of alliin and Allicin concentrations in their pure form as well as of alliin and total thiosulfinates concentrations in crude garlic preparations and garlic-derived products, at micromolar concentrations. The 4-MP assay is an easy, sensitive, fast, noncostly, and highly efficient throughput assay of Allicin, alliin, and alliinase in garlic preparations.
David Mirelman - One of the best experts on this subject based on the ideXlab platform.
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Therapy of Murine Pulmonary Aspergillosis with Antibody-Alliinase Conjugates and Alliin
Antimicrobial Agents and Chemotherapy, 2009Co-Authors: Elena Appel, Alexandra Vallon-eberhard, Aharon Rabinkov, Irina Shin, Keren Sasson, Yona Shadkchan, Nir Osherov, Ori Brenner, Steffen Jung, David MirelmanAbstract:Aspergillus fumigatus is an opportunistic fungal pathogen responsible for invasive aspergillosis in immunocompromised individuals. The high morbidity and mortality rates as well as the poor efficacy of antifungal agents remain major clinical concerns. Allicin (diallyl-dithiosulfinate), which is produced by the garlic enzyme alliinase from the harmless substrate alliin, has been shown to have wide-range antifungal specificity. A monoclonal antibody (MAb) against A. fumigatus was produced and chemically ligated to the enzyme alliinase. The purified antibody-alliinase conjugate bound to conidia and hyphae of A. fumigatus at nanomolar concentrations. In the presence of alliin, the conjugate produced cytotoxic Allicin molecules, which killed the fungus. In vivo testing of the therapeutical potential of the conjugate was carried out in immunosuppressed mice infected intranasally with conidia of A. fumigatus. Intratracheal (i.t.) instillation of the conjugate and alliin (four treatments) resulted in 80 to 85% animal survival (36 days), with almost complete fungal clearance. Repetitive intratracheal administration of the conjugate and alliin was also effective when treatments were initiated at a more advanced stage of infection (50 h). The fungi were killed specifically without causing damage to the lung tissue or overt discomfort to the animals. Intratracheal instillation of the conjugate without alliin or of the unconjugated monoclonal antibody significantly delayed the death of the infected mice, but only 20% of the animals survived. A limitation of this study is that the demonstration was achieved in a constrained setting. Other routes of drug delivery will be investigated for the treatment of pulmonary and extrapulmonary aspergillosis.
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Allicin inhibits cell polarization migration and division via its direct effect on microtubules
Cytoskeleton, 2007Co-Authors: Masha Pragerkhoutorsky, Aharon Rabinkov, David Mirelman, Igor Goncharov, Benjamin Geiger, Alexander D BershadskyAbstract:Allicin (diallyl thiosulfinate) is a major biologically active component of garlic that is known to inhibit cell proliferation and induce apoptosis. The effects of Allicin are attributed to its ability to react with thiol groups. However, the mechanism underlying the cytostatic activity of Allicin, as well as the identity of the relevant subcellular targets, are not known. In the present study, we found that the effects of Allicin on cell polarization, migration, and mitosis are similar to the effects of microtubule-depolymerizing drugs such as nocodazole. Moreover, treatment of cultured fibroblasts with micromolar doses of Allicin results in microtubule depolymerization in cells within minutes of its application, without disrupting the actin cytoskeleton or inducing direct cytotoxic effects. Furthermore, Allicin blocks the polymerization of pure tubulin in vitro in a concentration-dependent manner, suggesting that it acts directly on tubulin dimers. Sulfhydryl (SH)-reducing reagents such as 2-mercaptoethanol and dithiothreitol abolish the effect of Allicin on microtubule polymerization. Thus, Allicin is a potent microtubule-disrupting reagent interfering with tubulin polymerization by reaction with tubulin SH groups.
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apoptotic killing of b chronic lymphocytic leukemia tumor cells by Allicin generated in situ using a rituximab alliinase conjugate
Molecular Cancer Therapeutics, 2005Co-Authors: Fabian D Arditti, Aharon Rabinkov, Talia Miron, Meir Wilchek, Yair Reisner, Alain Berrebi, David MirelmanAbstract:Allicin, a highly active component from freshly crushed garlic, is produced upon the reaction of the small molecular weight molecule alliin, with the enzyme alliinase (EC 4.4.1.4). Because Allicin was shown to be toxic to various mammalian cells in vitro, we devised a novel approach for the therapy of B-cell malignancies based on site-directed generation of Allicin. Alliinase was conjugated to the monoclonal antibody rituximab, which recognizes the CD20 antigen, and the resulting conjugate was targeted to CD20+ B chronic lymphocytic leukemia (B-CLL) and other B-cell lymphomas. Upon addition of alliin, Allicin was formed in situ, killing the CD20+ tumor B cells via apoptosis. Following a 72-hour treatment, an 85% and 96% reduction was observed in the number of viable B-CLL and EBV-transformed B cells, respectively. Using the human/mouse radiation chimera for the evaluation of Allicin targeting in a preclinical animal model, we showed a significant reduction in the number of recovered B-CLL, mantle cell lymphoma, or EBV-transformed B cells. We conclude that our system offers a new powerful and less toxic therapy for B-CLL and other B-cell malignancies. Furthermore, combining alliinase with the appropriate monoclonal antibody may extend the application of this approach to other conditions in which the elimination of a specific cell population is desired.
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efficacy of Allicin the reactive molecule of garlic in inhibiting aspergillus spp in vitro and in a murine model of disseminated aspergillosis
Journal of Antimicrobial Chemotherapy, 2004Co-Authors: Yona Shadkchan, Aharon Rabinkov, David Mirelman, Talia Miron, Meir Wilchek, Einav Shemesh, Nir OsherovAbstract:Objectives: The evaluation of Allicin, the biologically active compound responsible for the antimicrobial activities of freshly crushed garlic cloves, in inhibiting Aspergillus spp. in vitro and in a murine model of disseminated aspergillosis. Methods: Pure Allicin was prepared by reacting synthetic alliin with a stabilized preparation of the garlic enzyme alliinase. We tested the in vitro efficacy of pure Allicin against 31 clinical isolates of Aspergillus spp. using a microdilution broth method and following the NCCLS guidelines (document M-38P). Subse- quently, the in vivo efficacy of Allicin was tested in immunocompetent mice infected intravenously (iv) with Aspergillus fumigatus conidia. Allicin (5 mg/kg body weight) was administered iv once daily for 5 days post-infection or orally (po) (9 mg/kg body weight) for 5 days pre-infection and 10 days post-infection. No ill effects were observed in Allicin-treated uninfected mice. Results: The in vitro MICs and MFCs of Allicin were between 8 and 32 mg/L, indicating that Allicin in its pure form may be an effective fungicide in vitro. Time-kill studies indicate that Allicin exerts its fungicidal activity within 2-12 h of administration in vitro. Allicin treatment significantly prolonged survival of infected mice (P < 0.01) from mean survival time (MST) = 7.7 days in untreated mice to MST = 21.3 and 13.9 days for Allicin iv and po treated mice, respectively. Allicin iv treatment led to a significant (P < 0.001) 10-fold reduction in fungal burden in A. fumigatus infected mice as evaluated by quantitative fungal cultures of kidney tissue samples. Conclusions: These favourable results, despite the short half-life of this compound in vivo, support further studies of controlled sustained release or more prolonged administration of Allicin as a treatment for aspergillosis.
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inhibition of tumor growth by a novel approach in situ Allicin generation using targeted alliinase delivery
Molecular Cancer Therapeutics, 2003Co-Authors: Talia Miron, David Mirelman, Meir Wilchek, Marina Mironchik, Aharon RabinkovAbstract:Allicin (diallyl thiosulfinate), a highly active component in extracts of freshly crushed garlic, is the interaction product of non-protein amino acid alliin ( S -allyl-l-cysteine sulfoxide) with the enzyme alliinase (alliin lyase; EC 4.4.1.4). Allicin was shown to be toxic in various mammalian cells in a dose-dependent manner in vitro . We made use of this cytotoxicity to develop a novel approach to cancer treatment, based on site-directed generation of Allicin. Alliinase from garlic was chemically conjugated to a mAb directed against a specific tumor marker, ErbB2. After the mAb-alliinase conjugate was bound to target tumor cells, the substrate, alliin, was added. In the presence of alliin, tumor-localized alliinase produced Allicin, which effectively killed N87 and CB2, both ErbB2-expressing cells in vitro , whereas 32D cells (a murine hematopoietic progenitor cell line, devoid of the ErbB2 receptors) were not affected. Moreover, using N87, a human tumor cell line xenograft in athymic nude mice, we demonstrated for the first time, a high antitumor activity of Allicin that was produced in situ by the conjugate, on alliin administration in vivo , while at the same time other tissues were unharmed due to the inert nature of alliin and the high clearance rate of Allicin. The effect of the treatment on tumor growth arrest became significant 2 weeks after its onset, and it continued to rise, reaching highly significant inhibition a week later. Ten days after the end of the treatment (day 18), tumor growth inhibition was still the same.
Meir Wilchek - One of the best experts on this subject based on the ideXlab platform.
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Allicin inhibits cell growth and induces apoptosis through the mitochondrial pathway in hl60 and u937 cells
Journal of Nutritional Biochemistry, 2008Co-Authors: Talia Miron, Meir Wilchek, Ayala Sharp, Yoshihito Nakagawa, Makoto Naoi, Yoshinori Nozawa, Yukihiro AkaoAbstract:Abstract In this article, the effects of Allicin, a biological active compound of garlic, on HL60 and U937 cell lines were examined. Allicin induced growth inhibition and elicited apoptotic events such as blebbing, mitochondrial membrane depolarization, cytochrome c release into the cytosol, activation of caspase 9 and caspase 3 and DNA fragmentation. Pretreatment of HL60 cells with cyclosporine A, an inhibitor of the mitochondrial permeability transition pore (mPTP), inhibited Allicin-treated cell death. HL60 cell survival after 1 h pretreatment with cyclosporine A, followed by 16 h in presence of Allicin (5 μM) was ∼80% compared to Allicin treatment alone (∼50%). Also N -acetyl cysteine, a reduced glutathione (GSH) precursor, prevented cell death. The effects of cyclosporine A and N -acetyl cysteine suggest the involvement of mPTP and intracellular GSH level in the cytotoxicity. Indeed, Allicin depleted GSH in the cytosol and mitochondria, and buthionine sulfoximine, a specific inhibitor of GSH synthesis, significantly augmented Allicin-induced apoptosis. In HL60 cells treated with Allicin (5 μM, 30 min) the redox state for 2GSH/oxidized glutathione shifted from E GSH −240 to −170 mV. The same shift was observed in U937 cells treated with Allicin at a higher concentration for a longer period of incubation (20 μM, 2 h). The apoptotic events induced by various concentrations of Allicin correlate to intracellular GSH levels in the two cell types tested (HL60: 3.7 nmol/10 6 cells; U937: 7.7 nmol/10 6 cells). The emerging mechanistic basis for the antiproliferative function of Allicin, therefore, involves the activation of the mitochondrial apoptotic pathway by GSH depletion and by changes in the intracellular redox status.
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apoptotic killing of b chronic lymphocytic leukemia tumor cells by Allicin generated in situ using a rituximab alliinase conjugate
Molecular Cancer Therapeutics, 2005Co-Authors: Fabian D Arditti, Aharon Rabinkov, Talia Miron, Meir Wilchek, Yair Reisner, Alain Berrebi, David MirelmanAbstract:Allicin, a highly active component from freshly crushed garlic, is produced upon the reaction of the small molecular weight molecule alliin, with the enzyme alliinase (EC 4.4.1.4). Because Allicin was shown to be toxic to various mammalian cells in vitro, we devised a novel approach for the therapy of B-cell malignancies based on site-directed generation of Allicin. Alliinase was conjugated to the monoclonal antibody rituximab, which recognizes the CD20 antigen, and the resulting conjugate was targeted to CD20+ B chronic lymphocytic leukemia (B-CLL) and other B-cell lymphomas. Upon addition of alliin, Allicin was formed in situ, killing the CD20+ tumor B cells via apoptosis. Following a 72-hour treatment, an 85% and 96% reduction was observed in the number of viable B-CLL and EBV-transformed B cells, respectively. Using the human/mouse radiation chimera for the evaluation of Allicin targeting in a preclinical animal model, we showed a significant reduction in the number of recovered B-CLL, mantle cell lymphoma, or EBV-transformed B cells. We conclude that our system offers a new powerful and less toxic therapy for B-CLL and other B-cell malignancies. Furthermore, combining alliinase with the appropriate monoclonal antibody may extend the application of this approach to other conditions in which the elimination of a specific cell population is desired.
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efficacy of Allicin the reactive molecule of garlic in inhibiting aspergillus spp in vitro and in a murine model of disseminated aspergillosis
Journal of Antimicrobial Chemotherapy, 2004Co-Authors: Yona Shadkchan, Aharon Rabinkov, David Mirelman, Talia Miron, Meir Wilchek, Einav Shemesh, Nir OsherovAbstract:Objectives: The evaluation of Allicin, the biologically active compound responsible for the antimicrobial activities of freshly crushed garlic cloves, in inhibiting Aspergillus spp. in vitro and in a murine model of disseminated aspergillosis. Methods: Pure Allicin was prepared by reacting synthetic alliin with a stabilized preparation of the garlic enzyme alliinase. We tested the in vitro efficacy of pure Allicin against 31 clinical isolates of Aspergillus spp. using a microdilution broth method and following the NCCLS guidelines (document M-38P). Subse- quently, the in vivo efficacy of Allicin was tested in immunocompetent mice infected intravenously (iv) with Aspergillus fumigatus conidia. Allicin (5 mg/kg body weight) was administered iv once daily for 5 days post-infection or orally (po) (9 mg/kg body weight) for 5 days pre-infection and 10 days post-infection. No ill effects were observed in Allicin-treated uninfected mice. Results: The in vitro MICs and MFCs of Allicin were between 8 and 32 mg/L, indicating that Allicin in its pure form may be an effective fungicide in vitro. Time-kill studies indicate that Allicin exerts its fungicidal activity within 2-12 h of administration in vitro. Allicin treatment significantly prolonged survival of infected mice (P < 0.01) from mean survival time (MST) = 7.7 days in untreated mice to MST = 21.3 and 13.9 days for Allicin iv and po treated mice, respectively. Allicin iv treatment led to a significant (P < 0.001) 10-fold reduction in fungal burden in A. fumigatus infected mice as evaluated by quantitative fungal cultures of kidney tissue samples. Conclusions: These favourable results, despite the short half-life of this compound in vivo, support further studies of controlled sustained release or more prolonged administration of Allicin as a treatment for aspergillosis.
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inhibition of tumor growth by a novel approach in situ Allicin generation using targeted alliinase delivery
Molecular Cancer Therapeutics, 2003Co-Authors: Talia Miron, David Mirelman, Meir Wilchek, Marina Mironchik, Aharon RabinkovAbstract:Allicin (diallyl thiosulfinate), a highly active component in extracts of freshly crushed garlic, is the interaction product of non-protein amino acid alliin ( S -allyl-l-cysteine sulfoxide) with the enzyme alliinase (alliin lyase; EC 4.4.1.4). Allicin was shown to be toxic in various mammalian cells in a dose-dependent manner in vitro . We made use of this cytotoxicity to develop a novel approach to cancer treatment, based on site-directed generation of Allicin. Alliinase from garlic was chemically conjugated to a mAb directed against a specific tumor marker, ErbB2. After the mAb-alliinase conjugate was bound to target tumor cells, the substrate, alliin, was added. In the presence of alliin, tumor-localized alliinase produced Allicin, which effectively killed N87 and CB2, both ErbB2-expressing cells in vitro , whereas 32D cells (a murine hematopoietic progenitor cell line, devoid of the ErbB2 receptors) were not affected. Moreover, using N87, a human tumor cell line xenograft in athymic nude mice, we demonstrated for the first time, a high antitumor activity of Allicin that was produced in situ by the conjugate, on alliin administration in vivo , while at the same time other tissues were unharmed due to the inert nature of alliin and the high clearance rate of Allicin. The effect of the treatment on tumor growth arrest became significant 2 weeks after its onset, and it continued to rise, reaching highly significant inhibition a week later. Ten days after the end of the treatment (day 18), tumor growth inhibition was still the same.
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A spectrophotometric assay for Allicin, alliin, and alliinase (alliin lyase) with a chromogenic thiol: reaction of 4-mercaptopyridine with thiosulfinates.
Analytical biochemistry, 2002Co-Authors: Talia Miron, Irina Shin, David Mirelman, Guy Feigenblat, Lev Weiner, Meir Wilchek, Aharon RabinkovAbstract:Allicin (diallylthiosulfinate) is the best known active compound of garlic. It is generated upon the interaction of the nonprotein amino acid alliin with the enzyme alliinase (alliin lyase, EC 4.4.1.4). Previously, we described a simple spectrophotometric assay for the determination of Allicin and alliinase activity, based on the reaction between 2-nitro-5-thiobenzoate (NTB) and Allicin. This reagent is not commercially available and must be synthesized. In this paper we describe the quantitative analysis of alliin and Allicin, as well as of alliinase activity with 4-mercaptopyridine (4-MP), a commercially available chromogenic thiol. The assay is based on the reaction of 4-MP (lambda(max)=324nm) with the activated disulfide bond of thiosulfinates -S(O)-S-, forming the mixed disulfide, 4-allylmercaptothiopyridine, which has no absorbance at this region. The structure of 4-allylmercaptothiopyridine was confirmed by mass spectrometry. The method was used for the determination of alliin and Allicin concentrations in their pure form as well as of alliin and total thiosulfinates concentrations in crude garlic preparations and garlic-derived products, at micromolar concentrations. The 4-MP assay is an easy, sensitive, fast, noncostly, and highly efficient throughput assay of Allicin, alliin, and alliinase in garlic preparations.
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Pengaruh Pengolahan Terhadap Nilai Fungsional Bawang Putih (Allium sativum)
'University of Surabaya', 2020Co-Authors: Thalia, Chessa Uly, Chrisnasari Ruth, Rosita Dewi, Ardhia DheasyAbstract:Abstract-Organosulphur compounds in garlic has bactericidal effect and antioxidant potentials. However, toxic effects and strong odor produced by the compound Allicin contribute to the reduction of garlic consumption. The production of Allicin compound can be inhibited by skipping grinding and substituting it with other methods such as heating with oven and soaking in salt water, so the production pathway of organosulphur compounds will produce S-allyl cysteine which have lower toxic effect and antioxidant activity up to six fold compared to Allicin. This research is done as a preliminary test to know the effect of process towards functional value of garlic. The results showed that the best treatment for black garlic (80℃ for 40 days) and pickled garlic (salt concentration of 3% for 40 days) has antioxidant activity (37,03%, 72,30%, and 32,17%), phenolic content (0,50mg GAE/g sample, 1,09mg GAE/g sample, and 0,146mg GAE/g sample), vitamin C content (0,068% b/b, 0,348% b/b, and 0,054% b/b), and protein content (3,1% N, 7,61% N, and 1,45% N) respectively that was significantly different (pvalue < 0,05), antimicrobial activity and total plate count test was not significantly different (pvalue > 0,05). Therefore, the process that gives the highest functional value was the black garlic. Keywords: garlic, black garlic, pickled garlic, functional food, antioxidant activity, phenols, alliin, S-allyl cysteine Abstrak-Senyawa organosulfur dalam bawang putih memiliki efek bakteriosidal dan potensi sebagai antioksidan. Namun, adanya efek toksik dan bau menyengat yang dihasilkan oleh senyawa allisin mengurangi daya konsumsi masyarakat. Produksi senyawa allisin dapat dihambat dengan menghilangkan penggerusan dan melakukan pengolahan yang lain, yaitu pengovenan dan perendaman pada air garam, sehingga jalur produksi senyawa organosulfur akan menghasilkan S-allyl cysteine dengan efek toksik jauh lebih kecil namun aktivitas antioksidan enam kali lebih tinggi dibandingkan allisin. Penelitian ini sebagai uji pendahuluan untuk mengetahui pengaruh pengolahan terhadap nilai fungsional bawang putih. Dari hasil uji, bawang putih, perlakuan terbaik bawang hitam (suhu 80℃ selama 40 hari), dan pickled garlic (kadar garam 3% selama 40 hari) secara berturut-turut memiliki aktivitas antioksidan (37,03%, 72,30%, dan 32,17%), senyawa fenolik total (0,50mg GAE/g sampel, 1,09mg GAE/g sampel, dan 0,146mg GAE/g sampel), kadar vitamin C (0,068% b/b, 0,348% b/b, dan 0,054% b/b), dan kadar protein (3,1% N, 7,61% N, dan 1,45% N) yang berbeda signifikan (pvalue < 0,05), aktivitas antimikroba dan uji total plate count tidak berbeda signifikan (pvalue > 0,05), sehingga pengolahan yang memberikan nilai fungsional tertinggi yaitu bawang hitam. Kata kunci: bawang putih, bawang hitam, pickled garlic, pangan fungsional, aktivitas antioksidan, fenolik, alliin, S-allyl cysteine
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Pengaruh Pengolahan terhadap Nilai Fungsional Bawang Putih (Allium Sativum)
'University of Surabaya', 2020Co-Authors: Thalia C. U., Chrisnasari R., Rosita Dewi, Ardhia DheasyAbstract:-Senyawa organosulfur dalam bawang putih memiliki efek bakteriosidal dan potensi sebagai antioksidan. Namun, adanya efek toksik dan bau menyengat yang dihasilkan oleh senyawa allisin mengurangi daya konsumsi masyarakat. Produksi senyawa allisin dapat dihambat dengan menghilangkan penggerusan dan melakukan pengolahan yang lain, yaitu pengovenan dan perendaman pada air garam, sehingga jalur produksi senyawa organosulfur akan menghasilkan S-allyl cysteine dengan efek toksik jauh lebih kecil namun aktivitas antioksidan enam kali lebih tinggi dibandingkan allisin. Penelitian ini sebagai uji pendahuluan untuk mengetahui pengaruh pengolahan terhadap nilai fungsional bawang putih. Dari hasil uji, bawang putih, perlakuan terbaik bawang hitam (suhu 80℃ selama 40 hari), dan pickled garlic (kadar garam 3% selama 40 hari) secara berturut-turut memiliki aktivitas antioksidan (37,03%, 72,30%, dan 32,17%), senyawa fenolik total (0,50mg GAE/g sampel, 1,09mg GAE/g sampel, dan 0,146mg GAE/g sampel), kadar vitamin C (0,068% b/b, 0,348% b/b, dan 0,054% b/b), dan kadar protein (3,1% N, 7,61% N, dan 1,45% N) yang berbeda signifikan (pvalue < 0,05), aktivitas antimikroba dan uji total plate count tidak berbeda signifikan (pvalue > 0,05), sehingga pengolahan yang memberikan nilai fungsional tertinggi yaitu bawang hitam. Kata kunci: bawang putih, bawang hitam, pickled garlic, pangan fungsional, aktivitas antioksidan, fenolik, alliin, S-allyl cysteine