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Therapeutic Effects of Green Tea Polyphenol (‒)-Epigallocatechin-3-Gallate (EGCG) in Relation to Molecular Pathways Controlling Inflammation, Oxidative Stress, and Apoptosis. Int J Mol Sci 2022; 24:ijms24010340. [PMID: 36613784 PMCID: PMC9820274 DOI: 10.3390/ijms24010340] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/20/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022] Open
Abstract
(‒)-Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenol in green tea. Thanks to multiple interactions with cell surface receptors, intracellular signaling pathways, and nuclear transcription factors, EGCG possesses a wide variety of anti-inflammatory, antioxidant, antifibrotic, anti-remodelation, and tissue-protective properties which may be useful in the treatment of various diseases, particularly in cancer, and neurological, cardiovascular, respiratory, and metabolic disorders. This article reviews current information on the biological effects of EGCG in the above-mentioned disorders in relation to molecular pathways controlling inflammation, oxidative stress, and cell apoptosis.
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Abdel-Aal ESM, Rabalski I, Mats L, Rai I. Identification and Quantification of Anthocyanin and Catechin Compounds in Purple Tea Leaves and Flakes. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27196676. [PMID: 36235212 PMCID: PMC9570566 DOI: 10.3390/molecules27196676] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/22/2022] [Accepted: 09/30/2022] [Indexed: 11/06/2022]
Abstract
Tea is the first most popular beverage worldwide and is available in several selections such as black (fully oxidized), Oolong (partially oxidized) and green (non-oxidized), in addition to purple tea, an emerging variety derived from the same tea plant (Camellia sinensis). This study investigated purple tea leaves (non-oxidized) and flakes (water extractable) to thoroughly identify their composition of anthocyanins and catechins and to study the effect of a water extraction process on their compositional properties in comparison with green tea. Anthocyanin and catechin compounds were separated and quantified using UPLC, and their identity was confirmed using LC-MS/MS in positive and negative ionization modes. Delphinidin was the principal anthocyaninidin in purple tea, while cyanidin came in second. The major anthocyanin pigments in purple tea were delphinidin-coumaroyl-hexoside followed by delphinidin-3-galactoside and cyanidin-coumaroyl-hexoside. The water extraction process resulted in substantial reductions in anthocyanins in purple tea flakes. There were no anthocyanin compounds detected in green tea samples. Both purple and green tea types were rich in catechins, with green tea containing higher concentrations than purple tea. The main catechin in purple or green tea was epigallocatechin gallate (EGCG) followed by either epicatechin gallate (ECG) or epigallocatechin (EGC), subject to tea type. The extraction process increased the concentration of catechins in both purple and green tea flakes. The results suggest that purple tea holds promise in making healthy brews, natural colorants and antioxidants and/or functional ingredients for beverages, cosmetics and healthcare industries due to its high content of anthocyanins and catechins.
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Affiliation(s)
- El-Sayed M. Abdel-Aal
- Agriculture and Agri-Food Canada, Guelph Research and Development Centre, 93 Stone Road West, Guelph, ON N1G 5C9, Canada
- Correspondence: ; Tel.: +1-(226)-217-8079; Fax: +1-(226)-217-8181
| | - Iwona Rabalski
- Agriculture and Agri-Food Canada, Guelph Research and Development Centre, 93 Stone Road West, Guelph, ON N1G 5C9, Canada
| | - Lili Mats
- Agriculture and Agri-Food Canada, Guelph Research and Development Centre, 93 Stone Road West, Guelph, ON N1G 5C9, Canada
| | - Ishan Rai
- Asilia Inc., Mississauga, ON L5L 5Y7, Canada & Houston, TX 77073, USA
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Green Tea Polyphenol (-)-Epigallocatechin-3-Gallate (EGCG): A Time for a New Player in the Treatment of Respiratory Diseases? Antioxidants (Basel) 2022; 11:antiox11081566. [PMID: 36009285 PMCID: PMC9405266 DOI: 10.3390/antiox11081566] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/03/2022] [Accepted: 08/11/2022] [Indexed: 12/13/2022] Open
Abstract
(-)-Epigallocatechin-3-gallate (EGCG) is a major polyphenol of green tea that possesses a wide variety of actions. EGCG acts as a strong antioxidant which effectively scavenges reactive oxygen species (ROS), inhibits pro-oxidant enzymes including NADPH oxidase, activates antioxidant systems including superoxide dismutase, catalase, or glutathione, and reduces abundant production of nitric oxide metabolites by inducible nitric oxide synthase. ECGC also exerts potent anti-inflammatory, anti-fibrotic, pro-apoptotic, anti-tumorous, and metabolic effects via modulation of a variety of intracellular signaling cascades. Based on this knowledge, the use of EGCG could be of benefit in respiratory diseases with acute or chronic inflammatory, oxidative, and fibrotizing processes in their pathogenesis. This article reviews current information on the biological effects of EGCG in those respiratory diseases or animal models in which EGCG has been administered, i.e., acute respiratory distress syndrome, respiratory infections, COVID-19, bronchial asthma, chronic obstructive pulmonary disease, lung fibrosis, silicosis, lung cancer, pulmonary hypertension, and lung embolism, and critically discusses effectiveness of EGCG administration in these respiratory disorders. For this review, articles in English language from the PubMed database were used.
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Anosike CA, Babandi A, Ezeanyika LUS. Potentiation Effects of Ficus sycomorus Active Fraction Against Permethrin-Resistant Field-Population of Anopheles coluzzii (Diptera: Culicidae). NEOTROPICAL ENTOMOLOGY 2021; 50:484-496. [PMID: 33661503 DOI: 10.1007/s13744-021-00858-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 01/19/2021] [Indexed: 06/12/2023]
Abstract
Insecticide resistance in mosquitoes is increasing amidst growing cases of global malaria, leading to high fatality in mostly Africa. To overcome the resistance as well as environmental effects of the synthetic insecticides, preliminary insecticidal and botanical potentiating effects of sub-lethal concentration (LC25) Ficus sycomorus active fraction (AFFS) and its synergistic potential with standard insecticide permethrin were evaluated against malarial vector Anopheles coluzzii (Coetzee & Wilkerson) populations. The glutathione-S-transferase (GST) inhibitory activity of the AFFS was also investigated compared to standard GST inhibitor, diethyl meleate (DEM). The WHO standard protocol for adult bioassay was used to expose the adult mosquitoes with sub-lethal concentration (LD25=0.49 mg/ml) of the plants' active fraction and permethrin (0.75%). The permethrin susceptibility screening result showed high level of resistance to permethrin in the field populations of A. coluzzii from Kano with 50.29 ± 2.14% average mortality after exposure to WHO diagnostic dose 0.75% permethrin. Post hoc Fisher's exact test showed that combination of sub-lethal concentration of AFFS with permethrin (mortality=73.02±12.10%; p=0.00352; RR=0.6923 and 95% CI = 0.5358-0.8946) was statistically significant, while the combination of sub-lethal concentration of AFFS with DEM showed no statistical difference (mortality=63.22±5.03; p=1; RR=0.6667 and 95% CI=0.4470-0.8438). This potentiation effect was signified to be additive effects with co-toxicity factor (CTF) of - 12.66. There was significant reduction of GST activities in the AFFS- and permethrin -exposed groups compared to unexposed populations of A. coluzzii (p < 0.05). The AFFS additively potentiate the permethrin activities by inhibiting GSTs, bio-transformational enzymes implicated in pyrethroids resistance. This study finding generally signifies the potential for bio-rational insecticide approach for malarial vector control.
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Affiliation(s)
| | - Abba Babandi
- Dept of Biochemistry, Univ of Nigeria, Nsukka, Enugu, Nigeria.
- Dept of Biochemistry, Bayero Univ, Kano, Nigeria.
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Feng X, Wu X, Wu Y, Zhao Z, Xiang C, Bai X, Liu X, Zhao J, Takeda S, Qing Y. Critical roles of tyrosyl-DNA phosphodiesterases in cell tolerance to carnosol-induced DNA damage. Cell Biol Int 2020; 44:1640-1650. [PMID: 32301547 DOI: 10.1002/cbin.11357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 04/02/2020] [Accepted: 04/11/2020] [Indexed: 02/05/2023]
Abstract
Carnosol is a natural compound with pharmacological action due to its anti-cancer properties. However, the precise mechanism for its anti-carcinogenic effect remains elusive. In this study, we used lymphoblastoid TK6 cell lines to identify the DNA damage and repair mechanisms of carnosol. Our results showed that carnosol induced DNA double-strand breaks (DSBs). We also found that cells lacking tyrosyl-DNA phosphodiesterase 1 (TDP1), an enzyme related to topoisomerase 1 (TOP1), and tyrosyl-DNA phosphodiesterase 2 (TDP2), an enzyme related to topoisomerase 2 (TOP2), were supersensitive to carnosol. Carnosol was found to induce the formation of the TOP1-DNA cleavage complex (TOP1cc) and TOP2-DNA cleavage complex (TOP2cc). When comparing the accumulation of γ-H2AX foci and the number of chromosomal aberrations (CAs) with wild-type (WT) cells, the susceptivity of the TDP1-/- and TDP2-/- cells were associated with an increased DNA damage. Our results provided evidence of carnosol inducing DNA lesions in TK6 cells and demonstrated that the damage induced by carnosol was associated with abnormal topoisomerase activity. We conclude that TDP1 and TDP2 play important roles in the anti-cancer effect of carnosol.
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Affiliation(s)
- Xiaoyu Feng
- Department of Pharmacology, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, China
| | - Xiaohua Wu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yang Wu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Zilu Zhao
- Department of Pharmacology, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, China
| | - Cuifang Xiang
- Department of Pharmacology, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, China
| | - Xin Bai
- Department of Pharmacology, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, China
| | - Xin Liu
- Department of Pharmacology, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, China
| | - Jingxia Zhao
- Department of Pharmacology, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, China
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Yong Qing
- Department of Pharmacology, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, China
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Kirsanov KI, Vlasova OA, Fetisov TI, Zenkov RG, Lesovaya EA, Belitsky GA, Gurova K, Yakubovskaya MG. Influence of DNA-binding compounds with cancer preventive activity on the mechanisms of gene expression regulation. ADVANCES IN MOLECULAR ONCOLOGY 2019. [DOI: 10.17650/2313-805x-2018-5-4-41-63] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- K. I. Kirsanov
- N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health of Russia; Peoples’ Friendship University of Russia
| | - O. A. Vlasova
- N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health of Russia
| | - T. I. Fetisov
- N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health of Russia
| | - R. G. Zenkov
- N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health of Russia
| | - E. A. Lesovaya
- N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health of Russia; I.P. Pavlov Ryazan State Medical University
| | - G. A. Belitsky
- N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health of Russia
| | | | - M. G. Yakubovskaya
- N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health of Russia
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Kim YA, Tarahovsky YS, Gaidin SG, Yagolnik EA, Muzafarov EN. Flavonoids determine the rate of fibrillogenesis and structure of collagen type I fibrils in vitro. Int J Biol Macromol 2017. [DOI: 10.1016/j.ijbiomac.2017.06.070] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Krupkova O, Ferguson SJ, Wuertz-Kozak K. Stability of (−)-epigallocatechin gallate and its activity in liquid formulations and delivery systems. J Nutr Biochem 2016; 37:1-12. [DOI: 10.1016/j.jnutbio.2016.01.002] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 01/20/2016] [Accepted: 01/28/2016] [Indexed: 12/24/2022]
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Muema JM, Bargul JL, Nyanjom SG, Mutunga JM, Njeru SN. Potential of Camellia sinensis proanthocyanidins-rich fraction for controlling malaria mosquito populations through disruption of larval development. Parasit Vectors 2016; 9:512. [PMID: 27660043 PMCID: PMC5034625 DOI: 10.1186/s13071-016-1789-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 09/02/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Anopheles arabiensis and A. gambiae (sensu stricto) are the most prolific Afrotropical malaria vectors. Population control efforts of these two vectors have been hampered by extremely diverse larval breeding sites and widespread resistance to currently available insecticides. Control of mosquito larval stages using bioactive compounds of plant origin has the potential to suppress vector populations leading to concomitant reduction in disease transmission rates. In this study, we evaluated the efficacy of Camellia sinensis crude leaf extract and its fraction against the larvae of A. arabiensis and A. gambiae (s.s.). METHODS Late third/early fourth instar larvae (L3/L4) of A. arabiensis and A. gambiae (s.s.) were exposed to increasing doses of C. sinensis leaf extract and its active fraction for 72 h, with mortality rates recorded every 24 h in both control and test groups. Ultra performance liquid chromatography electron spray ionization quadruple time of flight coupled with mass spectrometry (UPLC/ESI-Qtof/MS) was used to determine the main active constituents in the fraction. RESULTS The major bioactive chemical constituents in the C. sinensis leaf extract were identified to be proanthocyanidins. The extract significantly interfered with larval survival and adult emergence in both species (ANOVA, F (5,24) = 1435.92, P < 0.001). Additionally, larval exposure to crude extract at 250 ppm and 500 ppm for 24 h resulted in larval mortality rates of over 90 % in A. gambiae (s.s.) and 75 % in A. arabiensis. A relatively lower concentration of 100 ppm resulted in moderate mortality rates of < 50 % in both species, but induced growth disruption effects evident as abnormal larval-pupal intermediates and disrupted adult emergence. The estimated LC50 concentrations of the crude leaf extract against A. arabiensis and A. gambiae (s.s.) larvae at 24 h were 154.58 ppm (95 % CI: 152.37-158.22) and 117.15 ppm (95 % CI: 112.86-127.04), respectively. The bioactive polar fraction caused 100 % larval mortality in both vector species at 25 ppm. CONCLUSIONS Our findings demonstrate the potential of green tea extract and its active constituents in disrupting mosquito larval development. This could contribute to the control of mosquito populations and improved management of malaria.
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Affiliation(s)
- Jackson M Muema
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya.
| | - Joel L Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya.,Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya
| | - Steven G Nyanjom
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya
| | - James M Mutunga
- Malaria Research Programme, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya
| | - Sospeter N Njeru
- Present Address: Fritz Lipmann Institute (FLI) - Leibniz Institute for Age Research, D-07745, Jena, Germany
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Kawarai T, Narisawa N, Yoneda S, Tsutsumi Y, Ishikawa J, Hoshino Y, Senpuku H. Inhibition of Streptococcus mutans biofilm formation using extracts from Assam tea compared to green tea. Arch Oral Biol 2016; 68:73-82. [PMID: 27107380 DOI: 10.1016/j.archoralbio.2016.04.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 03/22/2016] [Accepted: 04/10/2016] [Indexed: 01/14/2023]
Abstract
OBJECTIVE Streptococcus mutans, a gram-positive oral bacterium, has been identified as one of the principal etiological agents of human dental caries. To clarify the nature of the difference anti-biofilm effect against S. mutans between Assam tea from Camellia sinensis var. assamica, partially fermented, and green tea from Camellia sinensis, non-fermented, active agents from the teas were purified. METHODS Effects of Assam tea and green tea samples on biofilm were assessed by using the conventional titer plate method and the human saliva-coated hydroxyapatite discs. The purification and identification of inhibitors were performed by using ultrafiltration with centrifugal filter devices and high performance liquid chromatography. RESULTS Assam tea has stronger biofilm inhibition activity against S. mutans than green tea. A substance of <10kDa in mass in Assam tea had a high concentration of galloylated catechins and a stronger biofilm inhibiting activity than green tea. In contrast, substances >10kDa in mass from green tea included higher concentrations of polysaccharides composed of galacturonic acid, such as pectin, that enhance biofilm formation. CONCLUSIONS The higher concentrations of galloylated catechins in Assam tea may assist in prevention of dental caries, whereas in green tea, this mode of inhibition was likely offset by the presence of pectin. Purification of catechins in partially fermented Assam tea with lower-molecular-weight polysaccharide than pectin may be useful for developing oral care products such as toothpaste and oral care gel pastes.
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Affiliation(s)
- Taketo Kawarai
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan; Department of Microbiology, School of Life Dentistry at Tokyo, The Nippon Dental University, Tokyo, Japan
| | - Naoki Narisawa
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan; Department of Food Science and Technology, College of Bioresource Sciences, Nihon University, Kanagawa, Japan
| | - Saori Yoneda
- Department of Bacteriology, Ohu University, Fukushima, Japan
| | | | - Jun Ishikawa
- Department of Bioactive Molecules, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yasutaka Hoshino
- Department of Bioactive Molecules, National Institute of Infectious Diseases, Tokyo, Japan
| | - Hidenobu Senpuku
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.
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Sinha S, Shukla S, Khan S, Tollefsbol TO, Meeran SM. Epigenetic reactivation of p21CIP1/WAF1 and KLOTHO by a combination of bioactive dietary supplements is partially ERα-dependent in ERα-negative human breast cancer cells. Mol Cell Endocrinol 2015; 406:102-14. [PMID: 25725373 PMCID: PMC5132185 DOI: 10.1016/j.mce.2015.02.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 02/16/2015] [Accepted: 02/18/2015] [Indexed: 12/21/2022]
Abstract
Available treatment strategies against estrogen receptor (ER)-negative breast cancer patients are limited due to their poor response to hormonal therapy. We have shown previously that the combinations of green tea polyphenols (GTPs), a dietary DNA methyltransferase inhibitor, and sulforaphane (SFN), a dietary histone deacetylase inhibitor, reactivate ERα expression in ERα-negative MDA-MB-231 cells. Here, we investigated the functional significance of ERα reactivation in the reactivation of silenced tumor suppressor genes (TSGs) in ERα-negative human breast cancer cells. We found that the treatment of MDA-MB-231 cells with the combinations of GTPs and SFN leads to the reactivation of silenced TSGs such as p21(CIP1/WAF1) and KLOTHO through active chromatin modifications. Further, GTPs- and SFN-mediated reactivation of TSGs was, at least in part, dependent on ERα reactivation in ERα-negative MDA-MB-231 cells. Collectively, our findings suggest that a novel combination of bioactive dietary supplements could further be explored as an effective therapeutic option against hormonal refractory breast cancer.
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Affiliation(s)
- Sonam Sinha
- Laboratory of Cancer Epigenetics, Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226 031, India
| | - Samriddhi Shukla
- Laboratory of Cancer Epigenetics, Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226 031, India
| | - Sajid Khan
- Laboratory of Cancer Epigenetics, Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226 031, India
| | | | - Syed M Meeran
- Laboratory of Cancer Epigenetics, Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow 226 031, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi, India.
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Lindsey RH, Pendleton M, Ashley RE, Mercer SL, Deweese JE, Osheroff N. Catalytic core of human topoisomerase IIα: insights into enzyme-DNA interactions and drug mechanism. Biochemistry 2014; 53:6595-602. [PMID: 25280269 PMCID: PMC4204876 DOI: 10.1021/bi5010816] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Coordination between the N-terminal gate and the catalytic core of topoisomerase II allows the proper capture, cleavage, and transport of DNA during the catalytic cycle. Because the activities of these domains are tightly linked, it has been difficult to discern their individual contributions to enzyme-DNA interactions and drug mechanism. To further address the roles of these domains, we analyzed the activity of the catalytic core of human topoisomerase IIα. The catalytic core and the wild-type enzyme both maintained higher levels of cleavage with negatively (as compared to positively) supercoiled plasmid, indicating that the ability to distinguish supercoil handedness is embedded within the catalytic core. However, the catalytic core alone displayed little ability to cleave DNA substrates that did not intrinsically provide the enzyme with a transport segment (i.e., substrates that did not contain crossovers). Finally, in contrast to interfacial topoisomerase II poisons, covalent poisons did not enhance DNA cleavage mediated by the catalytic core. This distinction allowed us to further characterize the mechanism of etoposide quinone, a drug metabolite that functions primarily as a covalent poison. Etoposide quinone retained some ability to enhance DNA cleavage mediated by the catalytic core, indicating that it still can function as an interfacial poison. These results further define the distinct contributions of the N-terminal gate and the catalytic core to topoisomerase II function. The catalytic core senses the handedness of DNA supercoils during cleavage, while the N-terminal gate is critical for capturing the transport segment and for the activity of covalent poisons.
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Affiliation(s)
- R Hunter Lindsey
- Department of Biochemistry, ‡Department of Pharmacology, and §Department of Medicine (Hematology/Oncology), Vanderbilt University School of Medicine , Nashville, Tennessee 37232-0146, United States
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Ashley RE, Osheroff N. Natural products as topoisomerase II poisons: effects of thymoquinone on DNA cleavage mediated by human topoisomerase IIα. Chem Res Toxicol 2014; 27:787-93. [PMID: 24650156 PMCID: PMC4033629 DOI: 10.1021/tx400453v] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
![]()
The
seeds of Nigella sativa (often
referred to as black seed) have long been utilized as a medicinal
herb in Middle Eastern, Northern African, and Indian cultures. Historically,
black seed has been used to treat a variety of illnesses associated
with inflammation. More recent studies have found that it induces
apoptosis and displays anticancer activity in animal and cellular
models. The major bioactive compound of black seed is thymoquinone,
which shares structural features with 1,4-benzoquinone and other covalent
topoisomerase II poisons. Because a number of anticancer drugs target
type II topoisomerases, we determined the effects of thymoquinone
and a series of related quinones on human topoisomerase IIα.
Thymoquinone enhanced enzyme-mediated DNA cleavage ∼5-fold,
which is similar to the increase seen with the anticancer drug etoposide.
In order to enhance cleavage, compounds had to have at least two positions
available for acylation. Furthermore, activity was decreased by the
inclusion of electron-donating groups or bulky substituents. As predicted
for a covalent topoisomerase II poison, the activity of thymoquinone
(and related compounds) was abrogated by the addition of a reducing
agent. Also, thymoquinone inhibited topoisomerase IIα activity
when incubated with the enzyme prior to the addition of DNA. Cleavage
complexes formed in the presence of the compound were stable for at
least 8 h. Lastly, black seed extract and black seed oil both increased
levels of enzyme-mediated DNA cleavage, suggesting that thymoquinone
is active even in more complex herbal formulations. These findings
indicate that thymoquinone can be added to the growing list of dietary
and medicinal natural products with activity against human type II
topoisomerases.
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Affiliation(s)
- Rachel E Ashley
- Departments of †Biochemistry and ‡Medicine (Hematology/Oncology), Vanderbilt University School of Medicine , Nashville, Tennessee 37232-0146, United States
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Ketron AC, Osheroff N. Phytochemicals as Anticancer and Chemopreventive Topoisomerase II Poisons. PHYTOCHEMISTRY REVIEWS : PROCEEDINGS OF THE PHYTOCHEMICAL SOCIETY OF EUROPE 2014; 13:19-35. [PMID: 24678287 PMCID: PMC3963363 DOI: 10.1007/s11101-013-9291-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Phytochemicals are a rich source of anticancer drugs and chemopreventive agents. Several of these chemicals appear to exert at least some of their effects through interactions with topoisomerase II, an essential enzyme that regulates DNA supercoiling and removes knots and tangles from the genome. Topoisomerase II-active phytochemicals function by stabilizing covalent protein-cleaved DNA complexes that are intermediates in the catalytic cycle of the enzyme. As a result, these compounds convert topoisomerase II to a cellular toxin that fragments the genome. Because of their mode of action, they are referred to as topoisomerase II poisons as opposed to catalytic inhibitors. The first sections of this article discuss DNA topology, the catalytic cycle of topoisomerase II, and the two mechanisms (interfacial vs. covalent) by which different classes of topoisomerase II poisons alter enzyme activity. Subsequent sections discuss the effects of several phytochemicals on the type II enzyme, including demethyl-epipodophyllotoxins (semisynthetic anticancer drugs) as well as flavones, flavonols, isoflavones, catechins, isothiocyanates, and curcumin (dietary chemopreventive agents). Finally, the leukemogenic potential of topoisomerase II-targeted phytochemicals is described.
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Affiliation(s)
- Adam C. Ketron
- Department of Biochemistry and the Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232 USA
| | - Neil Osheroff
- Departments of Biochemistry and Medicine (Hematology/Oncology) and the Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232 USA
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Lin X, Chen Z, Zhang Y, Gao X, Luo W, Li B. Interactions among chemical components of Cocoa tea (Camellia ptilophylla Chang), a naturally low caffeine-containing tea species. Food Funct 2014; 5:1175-85. [DOI: 10.1039/c3fo60720h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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