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Wei PL, Huang CY, Chang YJ. Propyl gallate inhibits hepatocellular carcinoma cell growth through the induction of ROS and the activation of autophagy. PLoS One 2019; 14:e0210513. [PMID: 30653551 PMCID: PMC6336332 DOI: 10.1371/journal.pone.0210513] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 12/23/2018] [Indexed: 12/19/2022] Open
Abstract
The poor prognosis of hepatocellular carcinoma (HCC) has been attributed to a high frequency of tumor metastasis and recurrence even after successful surgical resection. With less than 30% of patients benefiting from curative treatment, alternative treatment regimens for patients with advanced HCC are needed. Propyl gallate (PG), a synthetic antioxidant used in preserving food and medicinal preparations, has been shown to induce cancer cell death, but the anticancer effects of PG in HCC are unclear. In the present study, we demonstrated that PG inhibited HCC cell proliferation in vitro and in zebrafish models in vivo in a dose- and time-dependent manner. PG also induced cell apoptosis and increased the number of necrotic cells in a time- and dose-dependent manner as determined using a high-content analysis system. We found that PG also increased the intracellular levels of superoxide and reactive oxidative stress as well as the formation of autophagosomes and lysosomes. Regarding the molecular mechanism, PG did not alter the levels of autophagy-related 5 (ATG5), ATG5/12 or Beclin-1 but increased the rate of the LC3-I to LC3-II conversion, suggesting autophagy induction. PG exposure increased the levels of the pro-apoptotic proteins cleaved caspase-3, cleaved PARP, Bax, and Bad and a decreased level of the anti-apoptotic protein Bcl-2. In conclusion, we demonstrate that PG inhibits HCC cell proliferation through enhanced ROS production and autophagy activation. Finally, PG-treated cells induced cell apoptosis and may be a new candidate for HCC therapy.
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Affiliation(s)
- Po-Li Wei
- Department of Surgery, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Division of Colorectal Surgery, Department of Surgery, Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan
- Graduate Institute of Cancer Biology and Drug Discovery, Taipei Medical University, Taipei, Taiwan
- Cancer Research Center and Translational Laboratory, Department of Medical Research, Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan
| | - Chien-Yu Huang
- Department of Surgery, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Division of General Surgery, Department of Surgery, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan
- * E-mail: (YJC); (CYH)
| | - Yu-Jia Chang
- Cancer Research Center and Translational Laboratory, Department of Medical Research, Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
- International PhD Program in Medicine, Taipei Medical University, Taipei, Taiwan
- * E-mail: (YJC); (CYH)
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2
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The critical role of epigallocatechin gallate in regulating mitochondrial metabolism. Future Med Chem 2018. [DOI: 10.4155/fmc-2017-0204
expr 946749968 + 822201775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
Epigallocatechin gallate (EGCG), one of polyphenols isolated from green tea, exhibits biology-benefiting effects with minimum severe adverse. EGCG is known to be a mitochondrion-targeting medicinal agent, regulating mitochondrial metabolism, including mitochondrial biogenesis, mitochondrial bioenergetics, and mitochondria-mediated cell cycle and apoptosis. EGCG might exhibit either antioxidative activity to prevent against oxidative stress or pro-oxidative activity to counteract cancer cells, which depends on the cellular stress situations, cell types and the concentration of EGCG. Recent research has gained positive and promising data. This review will discuss the interaction between EGCG and mitochondrion.
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The critical role of epigallocatechin gallate in regulating mitochondrial metabolism. Future Med Chem 2018; 10:795-809. [DOI: 10.4155/fmc-2017-0204] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Epigallocatechin gallate (EGCG), one of polyphenols isolated from green tea, exhibits biology-benefiting effects with minimum severe adverse. EGCG is known to be a mitochondrion-targeting medicinal agent, regulating mitochondrial metabolism, including mitochondrial biogenesis, mitochondrial bioenergetics, and mitochondria-mediated cell cycle and apoptosis. EGCG might exhibit either antioxidative activity to prevent against oxidative stress or pro-oxidative activity to counteract cancer cells, which depends on the cellular stress situations, cell types and the concentration of EGCG. Recent research has gained positive and promising data. This review will discuss the interaction between EGCG and mitochondrion.
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Xie Y, Sen B, Wang G. Mining terpenoids production and biosynthetic pathway in thraustochytrids. BIORESOURCE TECHNOLOGY 2017; 244:1269-1280. [PMID: 28549813 DOI: 10.1016/j.biortech.2017.05.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 04/28/2017] [Accepted: 05/01/2017] [Indexed: 05/26/2023]
Abstract
Terpenoids are major bioactive compounds produced by microalgae and other eukaryotic microorganisms. Mining metabolic potential of marine microalgae for commercial production of terpenoids suggest thraustochytrids as one of the promising cell factories. The identification of potential thraustochytrid strains and relevant laboratory scale bioprocesses has been pursued largely. Further investigations in the improvement of terpenoids biosynthesis expect relevant molecular mechanisms to be understood directing metabolic engineering of the pathways. In this review, fermentative and mechanistic studies to identify key enzymes and pathways that are associated to terpenoids biosynthesis in thraustochytrids are discussed. Exploration of biosynthesis mechanisms in other model organisms facilitated identification of potential molecular targets for engineering terpenoids biosynthetic pathway in thraustochytrids. In addition, the preliminary genetic manipulation and in silico analysis in this review provides a platform for system-level metabolic engineering towards thraustochytrid strains improvement. Overall, the review contributes comprehensive information to allow better terpenoids productivity in thraustochytrids.
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Affiliation(s)
- Yunxuan Xie
- Center for Marine Environmental Ecology, School of Environmental Science & Engineering, Tianjin University, Tianjin 300072, China
| | - Biswarup Sen
- Center for Marine Environmental Ecology, School of Environmental Science & Engineering, Tianjin University, Tianjin 300072, China
| | - Guangyi Wang
- Center for Marine Environmental Ecology, School of Environmental Science & Engineering, Tianjin University, Tianjin 300072, China.
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Topal A, Çomakli S, Özkaraca M, Baran A, Köktürk M, Parlak V, Sağlam YS, Atamanalp M, Ceyhun SB. Immunofluorescence evaluation of 4-hydroxynonenal and 8-hydroxy-2-deoxyguanosine activation in zebrafish (Daino rerio) larvae brain exposed (microinjected) to propyl gallate. CHEMOSPHERE 2017; 183:252-256. [PMID: 28550782 DOI: 10.1016/j.chemosphere.2017.05.110] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 05/15/2017] [Accepted: 05/18/2017] [Indexed: 06/07/2023]
Abstract
Propyl gallate (PG) is a chemical compound obtained by esterification of propanol with gallic acid. Due to its antioxidative properties, it is widely used in cosmetics and pharmaceutical industries as well as to protect the oils in foods such as butter, milk-based desserts, chewing gum, mayonnaise, meat, soups, cereals, spices and seasonings from rancidity. This study has been designed to assessment 8-OHdG and 4-HNE activity, and histopathological changes in the brain tissues of zebrafish larvae, which is a lecithotrophic organism, after 96 h of PG exposure via microinjecting to yolk sac of embryo. To this end, approximately 5 nL of various concentrations of PG (1, 10, and 50 ppm) has been injected into yolk sac of fertilized embryo (final exposure concentrations are 5, 50, 250 pg/egg) with micro manipulator system. After 96 h exposure time, propyl gallate caused immunofluorescence positivity of 8-OHdG and 4-HNE in the brain tissues of zebrafish larvae. PG was not effect brain tissue histopathological in low concentrations (1 and 10 ppm) but highest concentration (50 ppm) caused degenerative changes in brain. These results suggests that PG treatment could lead oxidative DNA damage by causing an increase 8-OHdG and 4-HNE activities. This strategy will enable us to better understand the mechanisms of propyl gallate in brain tissues of zebrafish larvae.
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Affiliation(s)
- Ahmet Topal
- Department of Basic Sciences, Faculty of Fisheries, Atatürk University, TR-25240 Erzurum, Turkey
| | - Selim Çomakli
- Department of Pathology, Faculty of Veterinary, Atatürk University, TR-25240 Erzurum, Turkey
| | - Mustafa Özkaraca
- Department of Pathology, Faculty of Veterinary, Atatürk University, TR-25240 Erzurum, Turkey
| | - Alper Baran
- Erzurum Vocational School, Department of Food Quality Control and Analysis, Atatürk University, TR-25240 Erzurum, Turkey
| | - Mine Köktürk
- Department of Aquaculture, Faculty of Fisheries, Atatürk University, TR-25240 Erzurum, Turkey; Fisheries Faculty, Aquatic Biotechnology Laboratory, Atatürk University Erzurum, TR-25240, Turkey
| | - Veysel Parlak
- Department of Aquaculture, Faculty of Fisheries, Atatürk University, TR-25240 Erzurum, Turkey
| | - Yavuz Selim Sağlam
- Department of Pathology, Faculty of Veterinary, Atatürk University, TR-25240 Erzurum, Turkey
| | - Muhammed Atamanalp
- Department of Aquaculture, Faculty of Fisheries, Atatürk University, TR-25240 Erzurum, Turkey
| | - Saltuk Buğrahan Ceyhun
- Department of Aquaculture, Faculty of Fisheries, Atatürk University, TR-25240 Erzurum, Turkey; Fisheries Faculty, Aquatic Biotechnology Laboratory, Atatürk University Erzurum, TR-25240, Turkey.
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Silva I, Polaquini C, Regasini L, Ferreira H, Pavan F. Evaluation of cytotoxic, apoptotic, mutagenic, and chemopreventive activities of semi-synthetic esters of gallic acid. Food Chem Toxicol 2017; 105:300-307. [DOI: 10.1016/j.fct.2017.04.033] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 04/03/2017] [Accepted: 04/24/2017] [Indexed: 12/30/2022]
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Singh D, Mathur AS, Tuli DK, Puri M, Barrow CJ. Propyl gallate and butylated hydroxytoluene influence the accumulation of saturated fatty acids, omega-3 fatty acid and carotenoids in thraustochytrids. J Funct Foods 2015. [DOI: 10.1016/j.jff.2015.03.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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8
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Eler GJ, Santos IS, de Moraes AG, Comar JF, Peralta RM, Bracht A. n-Octyl Gallate as Inhibitor of Pyruvate Carboxylation and Lactate Gluconeogenesis. J Biochem Mol Toxicol 2014; 29:157-64. [DOI: 10.1002/jbt.21680] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 10/10/2014] [Accepted: 10/23/2014] [Indexed: 11/06/2022]
Affiliation(s)
- Gabrielle Jacklin Eler
- Department of Biochemistry; University of Maringá; Avenida Colombo Maringá 87020900 Brazil
| | - Israel Souza Santos
- Department of Biochemistry; University of Maringá; Avenida Colombo Maringá 87020900 Brazil
| | | | | | - Rosane Marina Peralta
- Department of Biochemistry; University of Maringá; Avenida Colombo Maringá 87020900 Brazil
| | - Adelar Bracht
- Department of Biochemistry; University of Maringá; Avenida Colombo Maringá 87020900 Brazil
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Eler GJ, Santos IS, de Moraes AG, Mito MS, Comar JF, Peralta RM, Bracht A. Kinetics of the transformation of n-propyl gallate and structural analogs in the perfused rat liver. Toxicol Appl Pharmacol 2013; 273:35-46. [DOI: 10.1016/j.taap.2013.08.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 08/08/2013] [Accepted: 08/26/2013] [Indexed: 10/26/2022]
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Georgieva R, Momchilova A, Petkova D, Koumanov K, Staneva G. Effect of N-Propyl Gallate on Lipid Peroxidation in Heterogenous Model Membranes. BIOTECHNOL BIOTEC EQ 2013. [DOI: 10.5504/bbeq.2013.0061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Maioli MA, Alves LC, Perandin D, Garcia AF, Pereira FTV, Mingatto FE. Cytotoxicity of monocrotaline in isolated rat hepatocytes: effects of dithiothreitol and fructose. Toxicon 2011; 57:1057-64. [PMID: 21530570 DOI: 10.1016/j.toxicon.2011.04.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 04/07/2011] [Accepted: 04/12/2011] [Indexed: 12/18/2022]
Abstract
Monocrotaline (MCT) is a pyrrolizidine alkaloid present in plants of the Crotalaria species that causes cytotoxicity and genotoxicity, including hepatotoxicity in animals and humans. It is metabolized by cytochrome P-450 in the liver to the alkylating agent dehydromonocrotaline (DHM). In previous studies using isolated rat liver mitochondria, we observed that DHM, but not MCT, inhibited the activity of respiratory chain complex I and stimulated the mitochondrial permeability transition with the consequent release of cytochrome c. In this study, we evaluated the effects of MCT and DHM on isolated rat hepatocytes. DHM, but not MCT, caused inhibition of the NADH-linked mitochondrial respiration. When hepatocytes of rats pre-treated with dexamethasone were incubated with MCT (5 mM), they showed ALT leakage, impaired ATP production and decreased levels of intracellular reduced glutathione and protein thiols. In addition, MCT caused cellular death by apoptosis. The addition of fructose or dithiotreitol to the isolated rat hepatocyte suspension containing MCT prevented the ATP depletion and/or glutathione or thiol oxidation and decreased the ALT leakage and apoptosis. These results suggest that the toxic effect of MCT on hepatocytes may be caused by metabolite-induced mitochondrial energetic impairment, together with a decrease of cellular glutathione and protein thiols.
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Affiliation(s)
- Marcos A Maioli
- Laboratório de Bioquímica Metabólica e Toxicológica, UNESP-Univ Estadual Paulista, Campus de Dracena, 17900-000 Dracena, SP, Brazil
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13
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The action of n-propyl gallate on gluconeogenesis and oxygen uptake in the rat liver. Chem Biol Interact 2009; 181:390-9. [DOI: 10.1016/j.cbi.2009.07.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Revised: 05/29/2009] [Accepted: 07/09/2009] [Indexed: 11/18/2022]
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Frey C, Pavani M, Cordano G, Muñoz S, Rivera E, Medina J, Morello A, Diego Maya J, Ferreira J. Comparative cytotoxicity of alkyl gallates on mouse tumor cell lines and isolated rat hepatocytes. Comp Biochem Physiol A Mol Integr Physiol 2006; 146:520-7. [PMID: 16707268 DOI: 10.1016/j.cbpa.2006.03.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2005] [Revised: 03/22/2006] [Accepted: 03/23/2006] [Indexed: 11/24/2022]
Abstract
Alkyl esters of gallic acid inhibited the respiration rate of mouse sarcoma 786A and mouse mammary adenocarcinoma TA3 cell lines and its multiresistant variant TA3-MTX-R more effectively than gallic acid, both in the absence and in the presence of the uncoupler CCCP. The order of inhibition of the respiration rate by gallates in intact cells was n-octyl- approximately iso-amyl- approximately n-amyl- approximately iso-butyl->n-butyl->iso-propyl->n-propyl-gallate>>gallic acid. Sarcoma 786A was significantly more susceptible to all seven esters than the TA3 cell line. Respiration rates of the TA3-MTX-R cell line showed almost the same sensitivity to these esters as the TA3 cell line. However, hepatocytes were significantly less sensitive than all tumor cells tested. These alkyl gallates blocked mitochondrial electron flow, mainly at the NADH-CoQ segment, preventing ATP synthesis, which would lead to cellular death. These esters also inhibited, in the same order of potencies as respiration, the growth of 786A, TA3 and TA3-MTX-R cells in culture. In mice carrying TA3 or TA3-MTX-R tumor cells, an important decrease of the tumor growth rate and an increase of survival were observed when mice were treated with iso-butyl gallate alone or in combination with doxorubicin. These results indicate that alkyl gallates are selectively cytotoxic to tumor cells, which may be due to the mitochondrial dysfunctions of these cells.
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Affiliation(s)
- Christian Frey
- Department of Organic and Physical Chemistry, Faculty of Chemical and Pharmaceutical Sciences, Olivos 1007, Santiago-7, Chile
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Galati G, Lin A, Sultan AM, O'Brien PJ. Cellular and in vivo hepatotoxicity caused by green tea phenolic acids and catechins. Free Radic Biol Med 2006; 40:570-80. [PMID: 16458187 DOI: 10.1016/j.freeradbiomed.2005.09.014] [Citation(s) in RCA: 252] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2005] [Revised: 08/23/2005] [Accepted: 09/08/2005] [Indexed: 02/07/2023]
Abstract
Tea phenolic acids and catechins containing gallic acid moieties are most abundant in green tea, and various medical benefits have been proposed from their consumption. In the following, the cytotoxicities of these major tea phenolics toward isolated rat hepatocytes have been ranked and the mechanisms of cytotoxicity evaluated. The order of cytotoxic effectiveness found was epigallocatechin-3-gallate>propyl gallate>epicatechin-3-gallate>gallic acid, epigallocatechin>epicatechin. Using gallic acid as a model tea phenolic and comparing it with the tea catechins and gallic acid-derivative food supplements, the major cytotoxic mechanism found with hepatocytes was mitochondrial membrane potential collapse and ROS formation. Epigallocatechin-3-gallate was also the most effective at collapsing the mitochondrial membrane potential and inducing ROS formation. Liver injury was also observed in vivo when these tea phenolics were administered ip to mice, as plasma alanine aminotransferase levels were significantly increased. In contrast, GSH conjugation, methylation, metabolism by NAD(P)H:quinone oxidoreductase 1, and formation of an iron complex were important in detoxifying the gallic acid. In addition, for the first time, the GSH conjugates of gallic acid and epigallocatechin-3-gallate have been identified using mass spectrometry. These results add insight into the cytotoxic and cytoprotective mechanisms of the simple tea phenolic acids and the more complex tea catechins.
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Affiliation(s)
- Giuseppe Galati
- Department of Pharmacology, University of Toronto, Toronto, ON, Canada
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Szkudelski T, Okulicz M, Bialik I, Szkudelska K. The influence of fasting on liver sulfhydryl groups, glutathione peroxidase and glutathione-S-transferase activities in the rat. J Physiol Biochem 2005; 60:1-6. [PMID: 15352379 DOI: 10.1007/bf03168215] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Sulfhydryl groups, glutathione peroxidase (GPx) and glutathione-S-transferase (GST) are important elements of the antioxidant defence in the organism. The efficacy of their antioxidant action is influenced by many factors. In this work, the effect of fasting on total, protein-bound and nonprotein sulfhydryl groups and on the activity of liver and serum GPx and GST in rats were determined. Male Wistar rats were divided into two groups: non-fasted and 18-hour fasted. In fasted animals liver content of nonprotein sulfhydryl groups (represented predominantly by reduced glutathione; GSH) was diminished by 22% in comparison to non-fasted group, whereas total and protein-bound -SH groups were unaffected. The activity of liver and serum GPx was unchanged in food deprived rats. In these animals the activity of GST in serum was reduced by 26%. Fasting had no significant effect on the activity of GST in the liver. Our results demonstrate that in rats deprived of food for 18 hours liver and serum GPx and GST are not involved in protection against action of reactive oxygen species formed during fasting. The observed drop in the content of liver nonprotein sulfhydryl groups without concomitant rise in the activity of GPx and GST indicates that this effect may be due to augmented degradation of GSH, its potentiated efflux from hepatocytes and formation of conjugates with intermediates arising as a result of reactive oxygen species action.
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Affiliation(s)
- T Szkudelski
- Department of Animal Physiology and Biochemistry, University of Agriculture, 60-637 Wolynska 35, Poznan, Poland.
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Galati G, O'Brien PJ. Potential toxicity of flavonoids and other dietary phenolics: significance for their chemopreventive and anticancer properties. Free Radic Biol Med 2004; 37:287-303. [PMID: 15223063 DOI: 10.1016/j.freeradbiomed.2004.04.034] [Citation(s) in RCA: 683] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2003] [Revised: 04/20/2004] [Accepted: 04/28/2004] [Indexed: 10/26/2022]
Abstract
Flavonoids, including isoflavones, are natural components in our diet and, with the burgeoning interest in alternative medicine, are increasingly being ingested by the general population. Plant phenolics, which form moieties on flavonoid rings, such as gallic acid, are also widely consumed. Several beneficial properties have been attributed to these dietary compounds, including antioxidant, anti-inflammatory, and anticarcinogenic effects. Flavonoid preparations are marketed as herbal medicines or dietary supplements for a variety of alleged nontoxic therapeutic effects. However, they have yet to pass controlled clinical trials for efficacy, and their potential for toxicity is an understudied field of research. This review summarizes the current knowledge regarding potential dietary flavonoid/phenolic-induced toxicity concerns, including their pro-oxidant activity, mitochondrial toxicity (potential apoptosis-inducing properties), and interactions with drug-metabolizing enzymes. Their chemopreventive activity in animal in vivo experiments may result from their ability to inhibit phase I and induce phase II carcinogen metabolizing enzymes that initiate carcinogenesis. They also inhibit the promotion stage of carcinogenesis by inhibiting oxygen radical-forming enzymes or enzymes that contribute to DNA synthesis or act as ATP mimics and inhibit protein kinases that contribute to proliferative signal transduction. Finally, they may prevent tumor development by inducing tumor cell apoptosis by inhibiting DNA topoisomerase II and p53 downregulation or by causing mitochondrial toxicity, which initiates mitochondrial apoptosis. While most flavonoids/phenolics are considered safe, flavonoid/phenolic therapy or chemopreventive use needs to be assessed as there have been reports of toxic flavonoid-drug interactions, liver failure, contact dermatitis, hemolytic anemia, and estrogenic-related concerns such as male reproductive health and breast cancer associated with dietary flavonoid/phenolic consumption or exposures.
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Affiliation(s)
- Giuseppe Galati
- Department of Pharmacology and Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada M5S 2S2
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18
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Khare S, Banai Y, Gokulan K, Smith R, Linthicum DS, Modiano JF. Early changes in metabolism of leukemic cell lines upon induction of apoptosis by cytotoxic drugs. Eur J Pharmacol 2003; 465:23-30. [PMID: 12650829 DOI: 10.1016/s0014-2999(03)01425-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We evaluated real-time changes in extracellular acidification rates of human U937 and K562 leukemic cells treated with camptothecin or taxol. U937 cells treated with camptothecin or taxol for 30-60 min showed a continuous, irreversible decrease in extracellular acidification rate that was sensitive to amiloride. In contrast, U937 cells exposed to sodium azide showed an immediate, steep decrease in extracellular acidification rate that was reversible upon azide withdrawal. K562 cells required a >20-fold higher dose of camptothecin to promote similar changes in the extracellular acidification rate, with a corresponding resistance in their susceptibility to camptothecin- or taxol-induced apoptosis. The data show that irreversible commitment to apoptosis is associated with rapid metabolic changes that are reflected by decreased extracellular acidification rate and regulated by the Na(+)/H(+) antiporter. Moreover, detection of extracellular acidification rate changes was not restricted to a particular cell type or apoptosis pathway, making this a potentially useful tool to screen compounds for pro-apoptotic activity.
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Affiliation(s)
- Sangeeta Khare
- Department of Pathobiology, Texas A&M University, College Station, TX, USA
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Epstein CB, Hale W, Butow RA. Numerical methods for handling uncertainty in microarray data: an example analyzing perturbed mitochondrial function in yeast. Methods Cell Biol 2002; 65:439-52. [PMID: 11381609 DOI: 10.1016/s0091-679x(01)65026-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- C B Epstein
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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20
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D'Auria FD, Tecca M, Strippoli R, Simonetti N. In vitro activity of propyl gallate-azole drug combination against fluconazole- and itraconazole-resistant Candida albicans strains. Lett Appl Microbiol 2001; 32:220-3. [PMID: 11298929 DOI: 10.1046/j.1472-765x.2001.00893.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS The influence of an antioxidant, propyl gallate (PG), on the in vitro antifungal activity of itraconazole and fluconazole, was investigated to determine whether PG could increase the antifungal activity and reduce strain resistance. METHODS AND RESULTS Susceptibility tests were performed against azole-resistant isolates of Candida albicans by the microbroth dilution method in the presence of PG at 400 microg ml-1. PG-triazole combination brought about a marked reduction of inhibitory azole concentration. In particular, the MIC90 for itraconazole and fluconazole dropped from 1 microg ml-1 to 0.125 microg ml-1 and from > 64 microg ml-1-8 microg ml-1, respectively. CONCLUSION It is likely that more than one mechanism is involved in the above synergistic interaction, including effects of PG on ATP synthesis, thus reducing the ABC transporters activity, or an effect on the target of azole, i.e. the P-450 cytochrome. SIGNIFICANCE AND IMPACT OF THE STUDY The PG-triazole combination may have a role in future topical antifungal strategies but other studies are warranted.
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Affiliation(s)
- F D D'Auria
- Institute of Microbiology, Faculty of Pharmacy, University of Rome 'La Sapienza', Rome, Italy.
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Sciuto AM, Moran TS. Effect of dietary treatment with n-propyl gallate or vitamin E on the survival of mice exposed to phosgene. J Appl Toxicol 2001; 21:33-9. [PMID: 11180278 DOI: 10.1002/jat.729] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Phosgene, widely used in industrial processes, can cause life-threatening pulmonary edema and acute lung injury. One mechanism of protection against phosgene-induced lung injury may involve the use of antioxidants. The present study focused on dietary supplementation in mice using n-propyl gallate (nPG)--a gallate acid ester compound used in food preservation--and vitamin E. Five groups of male mice were studied: group 1, control-fed with Purina rodent chow 5002; group 2, fed 0.75% nPG (w/w) in 5002; group 3, fed 1.5% nPG (w/w) in 5002; group 4 fed 1% (w/w) vitamin E in 5002; and group 5, fed 2% (w/w) vitamin E also in 5002. Mice were fed for 23 days. On day 23 mice were exposed to 32 mg m-3 (8 ppm) phosgene for 20 min (640 mg. min m-3) in a whole-body exposure chamber. Survival rates were determined at 12 and 24 h. In mice that died within 12 h, the lungs were removed and lung wet weights, dry weights, wet/dry weight ratios, lipid peroxidation (thiobarbituric acid reactive substances, TBARS) and glutathione (GSH) were assessed. Vitamin E had no positive effect on any outcome measured. There was no significant difference between 1.5% nPG and any parameter measured or survival rate compared with 5002 + phosgene. However, dietary treatment with 0.75% nPG significantly increased survival rate (P </= 0.002) and lowered TBARS (P </= 0.05) compared with 5002 + phosgene at 12 h after exposure. Mice fed 0.75% nPG had a lower wet/dry wt ratio compared with those fed 1.5% nPG and a significantly increased lung tissue GSH 36%, compared with the 5002 + phosgene group. In conclusion, dietary treatment with a low level of the antioxidant nPG protected mice by decreasing lipid peroxidation and increasing lung tissue GSH. The higher level of nPG and both levels of vitamin E diets were ineffective, suggesting that a ceiling threshold level of antioxidants in lung tissue is required for survival against phosgene-induced lung injury. Published in 2001 by John Wiley & Sons, Ltd.
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Affiliation(s)
- A M Sciuto
- US Army Medical Research Institute of Chemical Defense, Pharmacology Division, Neurotoxicology Branch, Aberdeen Proving Ground, MD 21010-5400, USA
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