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Abdulabbas Hasan M, Mohan S, Rahman HS, Othman HH, Hamasalih Omer S, Farasani A. The sub-acute toxicity of kavalactone in rats: a study of the effect of oral doses and the mechanism of toxicity in combination with ethanol. Drug Chem Toxicol 2023; 46:588-596. [PMID: 35506235 DOI: 10.1080/01480545.2022.2069803] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Kava is a herbal supplement and beverage made from the Piper methysticum plant, which is known for its recreational use as a mood enhancer, relaxation, as well as pain relief for centuries. Kava is widely used among alcoholics, but it is dangerous and potentially fatal. The objectives of this study were to examine the sub-acute toxicity effects of different doses of 70% kavalactone (KL) in rats by oral application, as well as to elucidate the mechanisms of toxicity alone and in combination with ethanol (EtOH). The most common side effects observed were abnormal breathing, ataxia, lethargy, loss of appetite, indigestion, and loss of coordination, especially in the 800 mg/kg bw, po bodyweight dosage of kava treatment group alone, and in combination with EtOH. In the sub-acute study, there were dose-related decreases in body weight, feed intake, and water consumption rates. Gross and histopathological findings revealed that the liver was abnormal in color, size, consistency, and the weight significantly increased at a dose of 800 mg/kg bw, po, with KL alone and a greater increase in combination with EtOH. Hepatocellular hypertrophy (HP) and necrosis with Kupffer cells hyperplasia were observed in the periacinar zone of all rats dosed with KL (800 mg/kg bw, po) alone, and extensive changes were observed in combination with EtOH. The periportal (Z1) and mid-zonal (Z2) areas of hepatocytes were less affected as compared to the periacinar zone. These results demonstrate that EtOH exacerbated the sedative and hypnotic activity of KL, and markedly increased toxicity. The histopathological results supported the clinical and biochemical findings and the severity of hepatic damage in a dose-dependent manner.
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Affiliation(s)
- Mohammed Abdulabbas Hasan
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Malaysia.,Department of Biology Science, College of Education for Women, Thi-Qar University, Thi-Qar, Republic of Iraq
| | - Syam Mohan
- Substance Abuse and Toxicology Research Centre, Jazan University, Jazan, Saudi Arabia.,School of Health Sciences, University of Petroleum and Energy Studies, Dehradun, India
| | - Heshu Sulaiman Rahman
- Department of Physiology, College of Medicine, University of Sulaimani, Sulaymaniyah, Republic of Iraq.,Department of Medical Laboratory Sciences, Komar University of Science and Technology, Sulaymaniyah, Republic of Iraq
| | - Hemn Hasan Othman
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Malaysia.,Department of Pharmacology and Toxicology, College of Pharmacy, University of Sulaimani, Sulaymaniyah, Republic of Iraq
| | - Shirwan Hamasalih Omer
- Department of Physiology, College of Medicine, University of Sulaimani, Sulaymaniyah, Republic of Iraq
| | - Abdullah Farasani
- Biomedical Research Unit, Medical Research Center, Jazan University, Jazan, Saudi Arabia.,Department of Medical Laboratory Technology, College of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia
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2
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An Updated Review on the Psychoactive, Toxic and Anticancer Properties of Kava. J Clin Med 2022; 11:jcm11144039. [PMID: 35887801 PMCID: PMC9315573 DOI: 10.3390/jcm11144039] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/07/2022] [Accepted: 07/08/2022] [Indexed: 01/27/2023] Open
Abstract
Kava (Piper methysticum) has been widely consumed for many years in the South Pacific Islands and displays psychoactive properties, especially soothing and calming effects. This plant has been used in Western countries as a natural anxiolytic in recent decades. Kava has also been used to treat symptoms associated with depression, menopause, insomnia, and convulsions, among others. Along with its putative beneficial health effects, kava has been associated with liver injury and other toxic effects, including skin toxicity in heavy consumers, possibly related to its metabolic profile or interference in the metabolism of other xenobiotics. Kava extracts and kavalactones generally displayed negative results in genetic toxicology assays although there is sufficient evidence for carcinogenicity in experimental animals, most likely through a non-genotoxic mode of action. Nevertheless, the chemotherapeutic/chemopreventive potential of kava against cancer has also been suggested. Both in vitro and in vivo studies have evaluated the effects of flavokavains, kavalactones and/or kava extracts in different cancer models, showing the induction of apoptosis, cell cycle arrest and other antiproliferative effects in several types of cancer, including breast, prostate, bladder, and lung. Overall, in this scoping review, several aspects of kava efficacy and safety are discussed and some pertinent issues related to kava consumption are identified.
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3
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Ibrahim R, Nyska A, Dunnick J, Ramot Y. The toxicologic pathology aspects of selected natural herbal products and related compounds. J Toxicol Pathol 2021; 34:181-211. [PMID: 34290474 PMCID: PMC8280299 DOI: 10.1293/tox.2021-0016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 03/17/2021] [Indexed: 12/02/2022] Open
Abstract
Herbal products have been in use for many years, but they are becoming more and more
popular in recent years, and they are currently in widespread use throughout the world. In
this review article we describe the histopathologic findings found after exposure to 12
dietary herbals in studies conducted in rodent model systems. Clear or some evidence for
carcinogenic activity was seen with 6 herbals, with the liver being the most common organ
affected. The intestine was affected by two herbals (aloe vera nondecolorized extract and
senna), three had no clear evidence for carcinogenic activity and one was cardiotoxic
(Ephedrine and Ephedra in combination with caffeine). Information from these studies can
help to better understand potential target organs for further evaluation from exposure to
various herbal products.
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Affiliation(s)
- Ruba Ibrahim
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Dermatology, Hadassah Medical Center, Jerusalem, Israel
| | - Abraham Nyska
- Consultant in Toxicologic Pathology, Yehuda HaMaccabi 31, floor 5, Tel Aviv 6200515, Israel.,Tel Aviv University, Tel Aviv, Israel
| | - June Dunnick
- Toxicology Branch, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Yuval Ramot
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Dermatology, Hadassah Medical Center, Jerusalem, Israel
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4
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Tugcu G, Kırmızıbekmez H, Aydın A. The integrated use of in silico methods for the hepatotoxicity potential of Piper methysticum. Food Chem Toxicol 2020; 145:111663. [PMID: 32827561 DOI: 10.1016/j.fct.2020.111663] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 06/27/2020] [Accepted: 07/30/2020] [Indexed: 02/07/2023]
Abstract
Herbal products as supplements and therapeutic intervention have been used for centuries. However, their toxicities are not completely evaluated and the mechanisms are not clearly understood. Dried rhizome of the plant kava (Piper methysticum) is used for its anxiolytic, and sedative effects. The drug is also known for its hepatotoxicity potential. Major constituents of the plant were identified as kavalactones, alkaloids and chalcones in previous studies. Kava hepatotoxicity mechanism and the constituent that causes the toxicity have been debated for decades. In this paper, we illustrated the use of computational tools for the hepatotoxicity of kava constituents. The proposed mechanisms and major constituents that are most probably responsible for the toxicity have been scrutinized. According to the experimental and prediction results, the kava constituents play a substantial role in hepatotoxicity by some means or other via glutathione depletion, CYP inhibition, reactive metabolite formation, mitochondrial toxicity and cyclooxygenase activity. Some of the constituents, which have not been tested yet, were predicted to involve mitochondrial membrane potential, caspase-3 stimulation, and AhR activity. Since Nrf2 activation could be favorable for prevention of hepatotoxicity, we also suggest that these compounds should undergo testing given that they were predicted not to be activating Nrf2. Among the major constituents, alkaloids appear to be the least studied and the least toxic group in general. The outcomes of the study could help to appreciate the mechanisms and to prioritize the kava constituents for further testing.
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Affiliation(s)
- Gulcin Tugcu
- Yeditepe University, Faculty of Pharmacy, Department of Toxicology, 34755, Atasehir, Istanbul, Turkey
| | - Hasan Kırmızıbekmez
- Yeditepe University, Faculty of Pharmacy, Department of Pharmacognosy, 34755, Atasehir, Istanbul, Turkey
| | - Ahmet Aydın
- Yeditepe University, Faculty of Pharmacy, Department of Toxicology, 34755, Atasehir, Istanbul, Turkey.
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Chalcone flavokawain B induces autophagic-cell death via reactive oxygen species-mediated signaling pathways in human gastric carcinoma and suppresses tumor growth in nude mice. Arch Toxicol 2017; 91:3341-3364. [DOI: 10.1007/s00204-017-1967-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 03/21/2017] [Indexed: 01/04/2023]
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6
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Pantano F, Tittarelli R, Mannocchi G, Zaami S, Ricci S, Giorgetti R, Terranova D, Busardò FP, Marinelli E. Hepatotoxicity Induced by "the 3Ks": Kava, Kratom and Khat. Int J Mol Sci 2016; 17:580. [PMID: 27092496 PMCID: PMC4849036 DOI: 10.3390/ijms17040580] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 02/18/2016] [Accepted: 04/11/2016] [Indexed: 12/23/2022] Open
Abstract
The 3Ks (kava, kratom and khat) are herbals that can potentially induce liver injuries. On the one hand, growing controversial data have been reported about the hepatotoxicity of kratom, while, on the other hand, even though kava and khat hepatotoxicity has been investigated, the hepatotoxic effects are still not clear. Chronic recreational use of kratom has been associated with rare instances of acute liver injury. Several studies and case reports have suggested that khat is hepatotoxic, leading to deranged liver enzymes and also histopathological evidence of acute hepatocellular degeneration. Numerous reports of severe hepatotoxicity potentially induced by kava have also been highlighted, both in the USA and Europe. The aim of this review is to focus on the different patterns and the mechanisms of hepatotoxicity induced by “the 3Ks”, while trying to clarify the numerous aspects that still need to be addressed.
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Affiliation(s)
- Flaminia Pantano
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
| | - Roberta Tittarelli
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
| | - Giulio Mannocchi
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
| | - Simona Zaami
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
| | - Serafino Ricci
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
| | - Raffaele Giorgetti
- Section of Legal Medicine, Università Politecnica delle Marche, 60121 Ancona, Italy.
| | - Daniela Terranova
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
| | - Francesco P Busardò
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
| | - Enrico Marinelli
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
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7
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Iida A, Sasaki E, Yano A, Tsuneyama K, Fukami T, Nakajima M, Yokoi T. Carbamazepine-Induced Liver Injury Requires CYP3A-Mediated Metabolism and Glutathione Depletion in Rats. Drug Metab Dispos 2015; 43:958-968. [DOI: 10.1124/dmd.115.063370] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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8
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Fan XH, Shi WZ, Cheng YX, Yang XF. Effects of Buyang Huanwu Decoction on antioxidant and drug-metabolizing enzymes in rat liver. Chin J Nat Med 2015; 12:449-54. [PMID: 24969526 DOI: 10.1016/s1875-5364(14)60070-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Indexed: 10/25/2022]
Abstract
AIM To study the effect of Buyang Huanwu Decoction (BYHWD) on the antioxidant enzymes and drug-metabolizing enzymes in rat liver. METHOD Following treatment of rats with BYHWD at 6.42, 12.83, or 25.66 g·kg(-1) per day for 15 days, microsomes and cytosols isolated from the liver tissues were prepared by differential centrifugation according to standard procedures. The activities of the antioxidant enzymes and cytochrome b5, NADPH-cytochrome P450 reductase, CYP3A, CYP2E1, UGT, and GST of the rat livers were determined by UV-Vis spectrophotometer. RESULTS The activities of ALT, AST, antioxidant enzymes, and the Hepatosomatic Index in serum were not significantly affected. In cytosols, the activity of CAT was significantly increased at the dosage of 12.83 g·kg(-1), and all the other antioxidant activities and MDA levels were not affected by this treatment. BYHWD had no effect on cytochrome b5, NADPH-cytochrome P450 reductase, CYP3A, and UGT. At the highest dose (25.66 g·kg(-1)), the activity of CYP2E1 was significantly inhibited, and the activities of GST and the level of GSH were increased. CONCLUSION BYHWD is safe for the liver, and has the functions of detoxification and antioxidant. Patients should be cautioned about the herb-drug interaction of BYHWD and CYP2E1 substrates.
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Affiliation(s)
- Xing-Hua Fan
- Department of Pharmacology, College of Pharmacy, Guangxi University of Chinese Medicine, Nanning 530001, China; Department of pharmacy, Liuzhou Worker's Hospital, Liuzhou 545005, China
| | - Wei-Zhou Shi
- Department of Pharmacology, College of Pharmacy, Guangxi University of Chinese Medicine, Nanning 530001, China
| | - Yun-Xiang Cheng
- Department of Pharmacology, College of Pharmacy, Guangxi University of Chinese Medicine, Nanning 530001, China
| | - Xiu-Fen Yang
- Department of Pharmacology, College of Pharmacy, Guangxi University of Chinese Medicine, Nanning 530001, China.
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9
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Hall AP, Elcombe CR, Foster JR, Harada T, Kaufmann W, Knippel A, Küttler K, Malarkey DE, Maronpot RR, Nishikawa A, Nolte T, Schulte A, Strauss V, York MJ. Liver hypertrophy: a review of adaptive (adverse and non-adverse) changes--conclusions from the 3rd International ESTP Expert Workshop. Toxicol Pathol 2012; 40:971-94. [PMID: 22723046 DOI: 10.1177/0192623312448935] [Citation(s) in RCA: 278] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Preclinical toxicity studies have demonstrated that exposure of laboratory animals to liver enzyme inducers during preclinical safety assessment results in a signature of toxicological changes characterized by an increase in liver weight, hepatocellular hypertrophy, cell proliferation, and, frequently in long-term (life-time) studies, hepatocarcinogenesis. Recent advances over the last decade have revealed that for many xenobiotics, these changes may be induced through a common mechanism of action involving activation of the nuclear hormone receptors CAR, PXR, or PPARα. The generation of genetically engineered mice that express altered versions of these nuclear hormone receptors, together with other avenues of investigation, have now demonstrated that sensitivity to many of these effects is rodent-specific. These data are consistent with the available epidemiological and empirical human evidence and lend support to the scientific opinion that these changes have little relevance to man. The ESTP therefore convened an international panel of experts to debate the evidence in order to more clearly define for toxicologic pathologists what is considered adverse in the context of hepatocellular hypertrophy. The results of this workshop concluded that hepatomegaly as a consequence of hepatocellular hypertrophy without histologic or clinical pathology alterations indicative of liver toxicity was considered an adaptive and a non-adverse reaction. This conclusion should normally be reached by an integrative weight of evidence approach.
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Affiliation(s)
- A P Hall
- AstraZeneca Pharmaceuticals, Alderley Park, Macclesfield, Cheshire, UK.
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10
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Johnson TE, Hermanson D, Wang L, Kassie F, Upadhyaya P, O'Sullivan MG, Hecht SS, Lu J, Xing C. Lung Tumorigenesis Suppressing Effects of a Commercial Kava Extract and Its Selected Compounds in A/J Mice. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2012; 39:727-42. [DOI: 10.1142/s0192415x11009202] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Lung cancer is the most deadly malignancy in the US. Chemoprevention is potentially a complementary approach to smoking cessation for lung cancer control. Recently, we reported that a commercially available form of kava extract significantly inhibits 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and benzo(a)pyrene (BaP)-induced lung tumorigenesis in A/J mice at a dose of 10 mg per gram diet. In the present study, we examined the dose-dependent lung tumor inhibitory activities of kava and investigated potential active constituent(s). Mice treated with carcinogen alone contained 12.1±5.8 lung adenomas per mouse 22 weeks after final carcinogen administration. Mice that were fed diets containing kava at dosages of 1.25, 2.5, 5, and 10 mg/g of diet had 8.4±3.5, 6.6±3.5, 4.3±2.4, and 3.8±2.3 lung adenomas per mouse, respectively. This corresponds to a reduction of 31%, 46%, 65% and 69% in tumor multiplicity, which were all statistically significant (p < 0.05). Analyses of lung adenoma tissues derived from kava-treated animals revealed that kava significantly inhibited adenoma cell proliferation while it had no detectable effect on cell death, indicating that kava primarily suppressed lung tumorigenesis in A/J mice via inhibition of cell proliferation. Flavokawains A, B, and C, three chalcone-based components from kava, demonstrated greatly reduced chemopreventive efficacies even at concentrations much higher than their natural abundance, suggesting that they alone were unlikely to be responsible for kava's chemopreventive activity. Kava at all dosages and treatment regimens did not induce detectable adverse effects, particularly with respect to liver. Specifically, kava treatment showed no effect on liver integrity indicator enzymes or liver weight, indicating that kava may be potentially safe for long-term chemopreventive application.
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Affiliation(s)
- Thomas E. Johnson
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - David Hermanson
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Lei Wang
- The Hormel Institute, University of Minnesota, Austin, MN 55912, USA
| | - Fekadu Kassie
- University of Minnesota Cancer Center, Minneapolis, MN 55455, USA
- Oncology and Comparative Medicine, University of Minnesota, St. Paul, MN 55108, USA
| | - Pramod Upadhyaya
- University of Minnesota Cancer Center, Minneapolis, MN 55455, USA
| | - Michael G. O'Sullivan
- University of Minnesota Cancer Center, Minneapolis, MN 55455, USA
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN 55108, USA
| | - Stephen S. Hecht
- University of Minnesota Cancer Center, Minneapolis, MN 55455, USA
| | - Junxuan Lu
- The Hormel Institute, University of Minnesota, Austin, MN 55912, USA
- University of Minnesota Cancer Center, Minneapolis, MN 55455, USA
| | - Chengguo Xing
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
- University of Minnesota Cancer Center, Minneapolis, MN 55455, USA
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Murray M. Toxicological actions of plant-derived and anthropogenic methylenedioxyphenyl-substituted chemicals in mammals and insects. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2012; 15:365-395. [PMID: 22934566 DOI: 10.1080/10937404.2012.705105] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The methylenedioxyphenyl (MDP) substituent is a structural feature present in many plant chemicals that deter foraging by predatory insects and herbivores. With increasing use of herbal extracts in alternative medicine, human exposure to MDP-derived plant chemicals may also be significant. Early studies found that most MDP agents themselves possess relatively low intrinsic toxicity, but strongly influence the actions of other xenobiotics in mammals and insects by modulating cytochrome P-450 (CYP)-dependent biotransformation. Thus, after exposure to MDP chemicals an initial phase of CYP inhibition is followed by a sustained phase of CYP induction. In insects CYP inhibition by MDP agents underlies their use as pesticide synergists, but analogous inhibition of mammalian CYP impairs the clearance of drugs and foreign compounds. Conversely, induction of mammalian CYP by MDP agents increases xenobiotic oxidation capacity. Exposure of insects to MDP-containing synergists in the environment, in the absence of coadministered pesticides, may also enhance xenobiotic detoxication. Finally, although most MDP agents are well tolerated, several, typified by safrole, aristolochic acid, and MDP-kavalactones, are associated with significant toxicities, including the risk of hepatotoxicity or tumorigenesis. Thus, the presence of MDP-substituted chemicals in the environment may produce a range of direct and indirect toxicities in target and nontarget species.
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Affiliation(s)
- Michael Murray
- Pharmacogenomics and Drug Development Group, Faculty of Pharmacy, University of Sydney, New South Wales, 2006, Australia.
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12
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Fu S, Rowe A, Ramzan I. Kavalactone Metabolism in Rat Liver Microsomes. Phytother Res 2011; 26:1057-61. [DOI: 10.1002/ptr.3695] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 09/01/2011] [Accepted: 09/29/2011] [Indexed: 01/04/2023]
Affiliation(s)
- Shuang Fu
- Faculty of Pharmacy; University of Sydney; NSW; 2006; Australia
| | - Anthony Rowe
- Faculty of Pharmacy; University of Sydney; NSW; 2006; Australia
| | - Iqbal Ramzan
- Faculty of Pharmacy; University of Sydney; NSW; 2006; Australia
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13
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Herb-drug interactions: Focus on metabolic enzymes and transporters. Arch Pharm Res 2011; 34:1843-63. [DOI: 10.1007/s12272-011-1106-z] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 09/06/2011] [Accepted: 09/08/2011] [Indexed: 11/26/2022]
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14
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Li Y, Mei H, Wu Q, Zhang S, Fang JL, Shi L, Guo L. Methysticin and 7,8-dihydromethysticin are two major kavalactones in kava extract to induce CYP1A1. Toxicol Sci 2011; 124:388-99. [PMID: 21908763 PMCID: PMC5736320 DOI: 10.1093/toxsci/kfr235] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Kava is a plant traditionally used for making beverages in Pacific Basin countries and has been used for the treatment of nervous disorders in the United States. The pharmacological activity of kava is achieved through kavalactones in kava extract, which include kawain, 7,8-dihydrokawain, yangonin, 5,6-dehydrokawain, methysticin, and 7,8-dihydromethysticin. Recent studies have shown that kava extract induces hepatic CYP1A1 enzyme; however, the mechanisms of CYP1A1 induction have not been elucidated, and the kavalactones responsible for CYP1A1 induction have not yet been identified. Using a combination of biochemical assays and molecular docking tools, we determined the functions of kava extract and kavalactones and delineated the underlying mechanisms involved in CYP1A1 induction. The results showed that kava extract displayed a concentration-dependent effect on CYP1A1 induction. Among the six major kavalactones, methysticin triggered the most profound inducing effect on CYP1A1 followed by 7,8-dihydromethysticin. The other four kavalactones (yangonin, 5,6-dehydrokawain, kawain, and 7,8-dihydrokawain) did not show significant effects on CYP1A1. Consistent with the experimental results, in silico molecular docking studies based on the aryl hydrocarbon receptor (AhR)-ligand binding domain homology model also revealed favorable binding to AhR for methysticin and 7,8-dihydromethysticin compared with the remaining kavalactones. Additionally, results from a luciferase gene reporter assay suggested that kava extract, methysticin, and 7,8-dihydromethysticin were able to activate the AhR signaling pathway. Moreover, kava extract-, methysticin-, and 7,8-dihydromethysticin-mediated CYP1A1 induction was blocked by an AhR antagonist and abolished in AhR-deficient cells. These findings suggest that kava extract induces the expression of CYP1A1 via an AhR-dependent mechanism and that methysticin and 7,8-dihydromethysticin contribute to CYP1A1 induction. The induction of CYP1A1 indicates a potential interaction between kava or kavalactones and CYP1A1-mediated chemical carcinogenesis.
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Affiliation(s)
- Yan Li
- Division of Systems Biology, National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration, Jefferson, Arkansas 72079
| | - Hu Mei
- Division of Systems Biology, National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration, Jefferson, Arkansas 72079
| | - Qiangen Wu
- Division of Biochemical Toxicology, National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration, Jefferson, Arkansas 72079
| | - Suhui Zhang
- Division of Systems Biology, National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration, Jefferson, Arkansas 72079
| | - Jia-Long Fang
- Division of Biochemical Toxicology, National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration, Jefferson, Arkansas 72079
| | - Leming Shi
- Division of Systems Biology, National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration, Jefferson, Arkansas 72079
| | - Lei Guo
- Division of Biochemical Toxicology, National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration, Jefferson, Arkansas 72079
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16
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Behl M, Nyska A, Chhabra RS, Travlos GS, Fomby LM, Sparrow BR, Hejtmancik MR, Chan PC. Liver toxicity and carcinogenicity in F344/N rats and B6C3F1 mice exposed to Kava Kava. Food Chem Toxicol 2011; 49:2820-9. [PMID: 21871523 PMCID: PMC3190036 DOI: 10.1016/j.fct.2011.07.067] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 07/25/2011] [Accepted: 07/27/2011] [Indexed: 02/06/2023]
Abstract
Kava Kava is an herbal supplement used as an alternative to antianxiety drugs. Although some reports suggest an association of Kava Kava with hepatotoxicity , it continues to be used in the United States due to lack of toxicity characterization. In these studies F344/N rats and B6C3F1 mice were administered Kava Kava extract orally by gavage in corn oil for two weeks, thirteen weeks or two years. Results from prechronic studies administered Kava Kava at 0.125 to 2g/kg body weight revealed dose-related increases in liver weights and incidences of hepatocellular hypertrophy. In the chronic studies, there were dose-related increases in the incidences of hepatocellular hypertrophy in rats and mice administered Kava Kava for up to 1g/kg body weight. This was accompanied by significant increases in incidences of centrilobular fatty change. There was no treatment- related increase in carcinogenic activity in the livers of male or female rats in the chronic studies. Male mice showed a significant dose-related increase in the incidence of hepatoblastomas. In female mice, there was a significant increase in the combined incidence of hepatocellular adenoma and carcinoma in the low and mid dose groups but not in the high dose group. These findings were accompanied by several nonneoplastic hepatic lesions.
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Affiliation(s)
- Mamta Behl
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Abraham Nyska
- Integrated Laboratory Systems Inc., Research Triangle Park, NC 27709
| | - Rajendra S. Chhabra
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Gregory S. Travlos
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | | | | | | | - Po C. Chan
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
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17
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Yang X, Salminen WF. Kava extract, an herbal alternative for anxiety relief, potentiates acetaminophen-induced cytotoxicity in rat hepatic cells. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2011; 18:592-600. [PMID: 21397479 DOI: 10.1016/j.phymed.2011.02.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 02/06/2011] [Indexed: 05/30/2023]
Abstract
The widely used over-the-counter analgesic acetaminophen (APAP) is the leading cause of acute liver failure in the United States and due to this high incidence, a recent FDA Advisory Board recommended lowering the maximum dose of APAP. Kava herbal dietary supplements have been implicated in several human liver failure cases leading to the ban of kava-containing products in several Western countries. In the US, the FDA has issued warnings about the potential adverse effects of kava, but kava dietary supplements are still available to consumers. In this study, we tested the potential of kava extract to potentiate APAP-induced hepatocyte cytotoxicity. In rat primary hepatocytes, co-treatment with kava and APAP caused 100% loss of cell viability, while the treatment of kava or APAP alone caused ∼50% and ∼30% loss of cell viability, respectively. APAP-induced glutathione (GSH) depletion was also potentiated by kava. Co-exposure to kava decreased cellular ATP concentrations, increased the formation of reactive oxygen species, and caused mitochondrial damage as indicated by a decrease in mitochondrial membrane potential. In addition, similar findings were obtained from a cultured rat liver cell line, clone-9. These observations indicate that kava potentiates APAP-induced cytotoxicity by increasing the magnitude of GSH depletion, resulting in oxidative stress and mitochondrial dysfunction, ultimately leading to cell death. These results highlight the potential for drug-dietary supplement interactions even with widely used over-the-counter drugs.
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Affiliation(s)
- Xi Yang
- Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079, USA
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18
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Olsen LR, Grillo MP, Skonberg C. Constituents in kava extracts potentially involved in hepatotoxicity: a review. Chem Res Toxicol 2011; 24:992-1002. [PMID: 21506562 DOI: 10.1021/tx100412m] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Aqueous kava root preparations have been consumed in the South Pacific as an apparently safe ceremonial and cultural drink for centuries. However, several reports of hepatotoxicity have been linked to the consumption of kava extracts in Western countries, where mainly ethanolic or acetonic extracts are used. The mechanism of toxicity has not been established, although several theories have been put forward. The composition of the major constituents, the kava lactones, varies according to preparation method and species of kava plant, and thus, the toxicity of the individual lactones has been tested in order to establish whether a single lactone or a certain composition of lactones may be responsible for the increased prevalence of kava-induced hepatotoxicity in Western countries. However, no such conclusion has been made on the basis of current data. Inhibition or induction of the major metabolizing enzymes, which might result in drug interactions, has also gained attention, but ambiguous results have been reported. On the basis of the chemical structures of kava constituents, the formation of reactive metabolites has also been suggested as an explanation of toxicity. Furthermore, skin rash is a side effect in kava consumers, which may be indicative of the formation of reactive metabolites and covalent binding to skin proteins leading to immune-mediated responses. Reactive metabolites of kava lactones have been identified in vitro as glutathione (GSH) conjugates and in vivo as mercapturates excreted in urine. Addition of GSH to kava extracts has been shown to reduce cytotoxicity in vitro, which suggests the presence of inherently reactive constituents. Only a few studies have investigated the toxicity of the minor constituents present in kava extract, such as pipermethystine and the flavokavains, where some have been shown to display higher in vitro cytotoxicity than the lactones. To date, there remains no indisputable reason for the increased prevalence of kava-induced hepatotoxicity in Western countries.
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Affiliation(s)
- Line R Olsen
- Department of Pharmaceutics and Analytical Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Denmark.
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19
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Abstract
Kava is traditionally consumed by South Pacific islanders as a drink and became popular in Western society as a supplement for anxiety and insomnia. Kava extracts are generally well tolerated, but reports of hepatotoxicity necessitated an international reappraisal of its safety. Hepatotoxicity can occur as an acute, severe form or a chronic, mild form. Inflammation appears to be involved in both forms and may result from activation of liver macrophages (Kupffer cells), either directly or via kava metabolites. Pharmacogenomics may influence the severity of this inflammatory response.
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20
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Zhang LY, Rowe A, Ramzan I. Does inflammation play a role in kava hepatotoxicity? Phytother Res 2010; 25:629-30. [PMID: 20842679 DOI: 10.1002/ptr.3301] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Accepted: 08/06/2010] [Indexed: 12/13/2022]
Abstract
The pathophysiology of kava hepatotoxicity remains inconclusive. There is circumstantial evidence for the roles of toxic metabolites, inhibition of cyclooxygenase (COX) enzymes and depletion of liver glutathione. Pharmacogenomic effects are likely, particularly for Cytochrome P450 genes. Experimental and clinical cases of hepatotoxicity show evidence of hepatitis. The question remains whether this inflammation is caused by components of kava directly, or indirectly due to the downstream effects.
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21
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Tang J, Dunlop RA, Rowe A, Rodgers KJ, Ramzan I. Kavalactones Yangonin and Methysticin induce apoptosis in human hepatocytes (HepG2) in vitro. Phytother Res 2010; 25:417-23. [PMID: 20734326 DOI: 10.1002/ptr.3283] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 06/30/2010] [Indexed: 12/20/2022]
Abstract
While cases of severe kava hepatotoxicity have been reported, studies examining the toxicity of individual kavalactones are limited. The present study examined the in vitro hepatotoxicity of kavain, methysticin and yangonin on human hepatocytes (HepG2) and the possible mechanism(s) involved. Cytotoxicity was assessed using lactate dehydrogenase (LDH) and ethidium bromide (EB) assays. The mode of cell death was analysed with acridine orange/ethidium bromide dual staining with fluorescence microscopy. Glutathione oxidation was measured using the ortho-phthalaldehyde (OPT) fluorescence assay. Kavain had minimal cytotoxicity, methysticin showed moderate concentration-dependent toxicity and yangonin displayed marked toxicity with ~ 40% reduction in viability in the EB assay. Acridine orange/ethidium bromide staining showed the predominant mode of cell death was apoptosis rather than necrosis. No significant changes were observed in glutathione levels, excluding this as the primary mechanism of cell death in this model. Further studies may elucidate the precise apoptotic pathways responsible and whether toxic kavalactone metabolites are involved.
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Affiliation(s)
- J Tang
- Faculty of Pharmacy, University of Sydney, NSW, Australia
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22
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Abstract
Kava is known for its recreational, ceremonial and medicinal use in the Pacific. The aqueous non-alcoholic drink of kava rhizome produces intoxicating, relaxing and soothing effects. While kava's medicinal effects receive worldwide recognition, kava-containing products came under scrutiny after over 100 reports of spontaneous adverse hepatic effects. Many mechanisms have been postulated to explain the unexpected toxicity, one being pharmacokinetic interactions between kavalactones and co-administered drugs involving cytochrome P450 enzyme system. Alcohol is often co-injested in kava hepatotoxicity cases. This review evaluates the possible hepatotoxicity mechanisms involving alcohol and kava.
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Affiliation(s)
- X Z Li
- Faculty of Pharmacy, University of Sydney, NSW, Australia.
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23
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Guo L, Mei N, Liao W, Chan PC, Fu PP. Ginkgo biloba extract induces gene expression changes in xenobiotics metabolism and the Myc-centered network. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2010; 14:75-90. [PMID: 20141330 DOI: 10.1089/omi.2009.0115] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The use of herbal dietary supplements in the United States is rapidly growing, and it is crucial that the quality and safety of these preparations be ensured. To date, it is still a challenge to determine the mechanisms of toxicity induced by mixtures containing many chemical components, such as herbal dietary supplements. We previously proposed that analyses of the gene expression profiles using microarrays in the livers of rodents treated with herbal dietary supplements is a potentially practical approach for understanding the mechanism of toxicity. In this study, we utilized microarrays to analyze gene expression changes in the livers of male B6C3F1 mice administered Ginkgo biloba leaf extract (GBE) by gavage for 2 years, and to determine pathways and mechanisms associated with GBE treatments. Analysis of 31,802 genes revealed that there were 129, 289, and 2,011 genes significantly changed in the 200, 600, and 2,000 mg/kg treatment groups, respectively, when compared with control animals. Drug metabolizing genes were significantly altered in response to GBE treatments. Pathway and network analyses were applied to investigate the gene relationships, functional clustering, and mechanisms involved in GBE exposure. These analyses indicate alteration in the expression of genes coding for drug metabolizing enzymes, the NRF2-mediated oxidative stress response pathway, and the Myc gene-centered network named "cell cycle, cellular movement, and cancer" were found. These results indicate that Ginkgo biloba-related drug metabolizing enzymes may cause herb-drug interactions and contribute to hepatotoxicity. In addition, the outcomes of pathway and network analysis may be used to elucidate the toxic mechanisms of Ginkgo biloba.
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Affiliation(s)
- Lei Guo
- Division of Systems Toxicology, National Center for Toxicological Research, FDA, Jefferson, Arkansas 72079, USA
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24
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Guo L, Mei N, Xia Q, Chen T, Chan PC, Fu PP. Gene expression profiling as an initial approach for mechanistic studies of toxicity and tumorigenicity of herbal plants and herbal dietary supplements. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2010; 28:60-87. [PMID: 20390968 PMCID: PMC5736312 DOI: 10.1080/10590500903585416] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Dietary supplements are consumed by more than 300 million people worldwide, and herbal dietary supplements represent the most rapidly growing portion of this industry. Even though adverse health effects of many herbal dietary supplements have been reported, safety assurances are not being addressed adequately. Toxicological data on the identification of genotoxic and tumorigenic ingredients in many raw herbs are also lacking. Currently, more than 30 herbal dietary supplements and active ingredients have been selected by the National Toxicology Program (NTP) for toxicity and tumorigenicity studies. Due to the complexity of the chemical components present in plant extracts, there are no established methodologies for determining the mechanisms of toxicity (particularly tumorigenicity) induced by herbs, such as Gingko biloba leaf extract (GBE) and other herbal plant extracts. Consequently, the understanding of toxicity of herbal dietary supplements remains limited. We have proposed that application of DNA microarrays could be a highly practical initial approach for revealing biological pathways and networks associated with toxicity induced by herbal dietary supplements and the generation of hypotheses to address likely mechanisms. The changes in expression of subsets of genes of interest, such as the modulation of drug metabolizing genes, can be analyzed after treatment with an herbal dietary supplement. Although levels of gene expression do not represent fully the levels of protein activities, we propose that subsequent biochemical and genomic experiments based on these initial observations will enable elucidation of the mechanisms leading to toxicity, including tumorigenicity. This review summarizes the current practices of microarray analysis of gene expressions in animals treated with herbal dietary supplements and discusses perspectives for the proposed strategy.
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Affiliation(s)
- Lei Guo
- Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, FDA, AR 72079, USA.
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25
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Guo L, Shi Q, Dial S, Xia Q, Mei N, Li QZ, Chan PC, Fu P. Gene expression profiling in male B6C3F1 mouse livers exposed to kava identifies--changes in drug metabolizing genes and potential mechanisms linked to kava toxicity. Food Chem Toxicol 2009; 48:686-96. [PMID: 19948201 DOI: 10.1016/j.fct.2009.11.050] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Revised: 11/16/2009] [Accepted: 11/25/2009] [Indexed: 10/20/2022]
Abstract
The association of kava products with liver-related health risks has prompted regulatory action in many countries. We used a genome-wide gene expression approach to generate global gene expression profiles from the livers of male B6C3F1 mice administered kava extract by gavage for 14 weeks, and identified the differentially expressed drug metabolizing genes in response to kava treatments. Analyses of gene functions and pathways reveal that the levels of significant numbers of genes involving drug metabolism were changed and that the pathways involving xenobiotics metabolism, Nrf2-mediated oxidative stress response, mitochondrial functions and others, were altered. Our results indicate that kava extract can significantly modulate drug metabolizing enzymes, potentially leading to herb-drug interactions and hepatotoxicity.
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Affiliation(s)
- Lei Guo
- Division of Systems Toxicology, National Center for Toxicological Research, FDA, Jefferson, AR 72079, USA.
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26
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Shaik AA, Hermanson DL, Xing C. Identification of methysticin as a potent and non-toxic NF-kappaB inhibitor from kava, potentially responsible for kava's chemopreventive activity. Bioorg Med Chem Lett 2009; 19:5732-6. [PMID: 19716299 DOI: 10.1016/j.bmcl.2009.08.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 07/31/2009] [Accepted: 08/03/2009] [Indexed: 12/13/2022]
Abstract
Nuclear factor-kappaB (NF-kappaB) is a transcription factor that plays an essential role in cancer development. The results of our recent chemopreventive study demonstrate that kava, a beverage in the South Pacific Islands, suppresses NF-kappaB activation in lung adenoma tissues, potentially a mechanism responsible for kava's chemopreventive activity. Methysticin is identified as a potent NF-kappaB inhibitor in kava with minimum toxicity. Other kava constituents, including four kavalactones of similar structures to methysticin, demonstrate minimum activities in inhibiting NF-kappaB.
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Affiliation(s)
- Ahmad Ali Shaik
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 308 Harvard St SE, Minneapolis, MN 55455, United States
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27
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Fu PP, Chiang HM, Xia Q, Chen T, Chen BH, Yin JJ, Wen KC, Lin G, Yu H. Quality assurance and safety of herbal dietary supplements. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2009; 27:91-119. [PMID: 19412857 DOI: 10.1080/10590500902885676] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Since the U.S. Congress passed the Dietary Supplement Health and Education Act (DSHEA) in 1994, use of herbal products has been growing rapidly worldwide. To ensure consumer health protection, the quality and safety of herbal plants, particularly those used for dietary supplement preparations, must be determined. To date, toxicological data on the identification of genotoxic and tumorigenic ingredients in many raw herbs and their mechanisms of action are lacking. Thus, identification of carcinogenic components in herbal plants is timely and important. In this review, the issues of quality control and safety evaluation of raw herbs and herbal dietary supplements are discussed. Two examples of tumorigenicity and mechanism of tumor induction are discussed: aristolochic acid and riddelliine, both of which have been detected in Chinese herbal plants. It is proposed that an organized effort with international participation on cancer risk assessment should be actively pursued so that the safety of commercial herbal plants and herbal dietary supplements can be ensured.
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Affiliation(s)
- Peter P Fu
- National Center for Toxicological Research, Jefferson, Arkansas, USA.
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28
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Analysis of gene expression changes of drug metabolizing enzymes in the livers of F344 rats following oral treatment with kava extract. Food Chem Toxicol 2008; 47:433-42. [PMID: 19100306 DOI: 10.1016/j.fct.2008.11.037] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Revised: 10/31/2008] [Accepted: 11/26/2008] [Indexed: 11/24/2022]
Abstract
The association of kava product use with liver-related risks has prompted regulatory action in many countries. We studied the changes in gene expression of drug metabolizing enzymes in the livers of Fischer 344 male rats administered kava extract by gavage for 14 weeks. Analysis of 22,226 genes revealed that there were 14, 41, 110, 386, and 916 genes significantly changed in the 0.125, 0.25, 0.5, 1.0, and 2.0 g/kg treatment groups, respectively. There were 16 drug metabolizing genes altered in all three high-dose treatment groups, among which seven genes belong to cytochrome P450 isozymes. While gene expression of Cyp1a1, 1a2, 2c6, 3a1, and 3a3 increased; Cyp 2c23 and 2c40 decreased, all in a dose-dependent manner. Real-time PCR analyses of several genes verified these results. Our results indicate that kava extract can significantly modulate drug metabolizing enzymes, particularly the CYP isozymes, which could cause herb-drug interactions and may potentially lead to hepatotoxicity.
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29
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Johnson TE, Kassie F, O'Sullivan MG, Negia M, Hanson TE, Upadhyaya P, Ruvolo PP, Hecht SS, Xing C. Chemopreventive Effect of Kava on 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone plus Benzo[a]pyrene–Induced Lung Tumorigenesis in A/J Mice. Cancer Prev Res (Phila) 2008; 1:430-8. [DOI: 10.1158/1940-6207.capr-08-0027] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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30
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Yamazaki Y, Hashida H, Arita A, Hamaguchi K, Shimura F. High dose of commercial products of kava (Piper methysticum) markedly enhanced hepatic cytochrome P450 1A1 mRNA expression with liver enlargement in rats. Food Chem Toxicol 2008; 46:3732-8. [PMID: 18930106 DOI: 10.1016/j.fct.2008.09.052] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 08/27/2008] [Accepted: 09/22/2008] [Indexed: 02/05/2023]
Abstract
Commercial products containing the kava plant (Piper methysticum), known to have the anxiolytic activity, are banned in several European countries and Canada because of the suspicion of a potential liver toxicity. In some reports, kava and kavalactones (major constituents of kava) inhibited activities of cytochrome P450 (CYP) isoforms including CYP1A2. On the other hand, a few studies showed that administration of kava to rats moderately increased CYP1A2 proteins in the liver. CYP1A isoforms are likely responsible for the metabolic activation of potent carcinogenic environmental toxins such as aflatoxins, benzo[a]pyrene, and others. On these bases, we have investigated the effects of administration of commercial kava products on gene expression of hepatic CYP1A isoforms in rats. A high dose (equivalent to approximately 380mg kavalactones/kg/day; 100 times of the suggested dosage for human use) of two different types of kava products for 8 days significantly increased liver weights. CYP1A2 mRNA expression was moderately increased (2.8-7.3 fold). More importantly, the high dose of kava markedly enhanced CYP1A1 mRNA expression (75-220 fold) as well as ethoxyresorufin O-deethylase activities and CYP1A1 immunoreactivities. Thus, no observed adverse effect levels of kavalactones would be lower than 380mg/kg/day. When the safety factor of kavalactones is assumed to be 100, a value most often used upon the risk analysis of chemicals and designed to account for interspecies and intraspecies variations, a number of kava product users likely ingest more kavalactones than acceptable daily intakes. Based on overall evidence, we should pay considerable attention to the possibility that kava products induce hepatic CYP1A1 expression in human especially in sensitive individuals.
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Affiliation(s)
- Yuko Yamazaki
- Department of Food and Nutritional Sciences, Jumonji University, 2-1-28 Sugasawa, Niiza, Saitama 352-8510, Japan
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31
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Gurley BJ, Swain A, Hubbard MA, Williams DK, Barone G, Hartsfield F, Tong Y, Carrier DJ, Cheboyina S, Battu SK. Clinical assessment of CYP2D6-mediated herb-drug interactions in humans: effects of milk thistle, black cohosh, goldenseal, kava kava, St. John's wort, and Echinacea. Mol Nutr Food Res 2008; 52:755-63. [PMID: 18214849 PMCID: PMC2562884 DOI: 10.1002/mnfr.200600300] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Cytochrome P450 2D6 (CYP2D6), an important CYP isoform with regard to drug-drug interactions, accounts for the metabolism of approximately 30% of all medications. To date, few studies have assessed the effects of botanical supplementation on human CYP2D6 activity in vivo. Six botanical extracts were evaluated in three separate studies (two extracts per study), each incorporating 16 healthy volunteers (eight females). Subjects were randomized to receive a standardized botanical extract for 14 days on separate occasions. A 30-day washout period was interposed between each supplementation phase. In study 1, subjects received milk thistle (Silybum marianum) and black cohosh (Cimicifuga racemosa). In study 2, kava kava (Piper methysticum) and goldenseal (Hydrastis canadensis) extracts were administered, and in study 3 subjects received St. John's wort (Hypericum perforatum) and Echinacea (Echinacea purpurea). The CYP2D6 substrate, debrisoquine (5 mg), was administered before and at the end of supplementation. Pre- and post-supplementation phenotypic trait measurements were determined for CYP2D6 using 8-h debrisoquine urinary recovery ratios (DURR). Comparisons of pre- and post-supplementation DURR revealed significant inhibition (approximately 50%) of CYP2D6 activity for goldenseal, but not for the other extracts. Accordingly, adverse herb-drug interactions may result with concomitant ingestion of goldenseal supplements and drugs that are CYP2D6 substrates.
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Affiliation(s)
- Bill J Gurley
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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32
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Fu PP, Xia Q, Guo L, Yu H, Chan PC. Toxicity of kava kava. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2008; 26:89-112. [PMID: 18322868 PMCID: PMC5868963 DOI: 10.1080/10590500801907407] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Kava is a traditional beverage of various Pacific Basin countries. Kava has been introduced into the mainstream U.S. market principally as an anti-anxiety preparation. The effects of the long-term consumption of kava have not been documented adequately. Preliminary studies suggest possible serious organ system effects. The potential carcinogenicity of kava and its principal constituents are unknown. As such, kava extract was nominated for the chronic tumorigenicity bioassay conducted by the National Toxicology Program (NTP). At present toxicological evaluation of kava extract is being conducted by the NTP. The present review focuses on the recent findings on kava toxicity and the mechanisms by which kava induces hepatotoxicity.
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Affiliation(s)
- Peter P Fu
- National Center for Toxicological Research, Jefferson, Arkansas 72079, USA.
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33
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Gurley BJ, Swain A, Hubbard MA, Hartsfield F, Thaden J, Williams DK, Gentry WB, Tong Y. Supplementation With Goldenseal (Hydrastis canadensis), but not Kava Kava (Piper methysticum), Inhibits Human CYP3A Activity In Vivo. Clin Pharmacol Ther 2007; 83:61-9. [PMID: 17495878 DOI: 10.1038/sj.clpt.6100222] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The effects of goldenseal (Hydrastis canadensis) and kava kava (Piper methysticum) supplementation on human CYP3A activity were evaluated using midazolam (MDZ) as a phenotypic probe. Sixteen healthy volunteers were randomly assigned to receive either goldenseal or kava kava for 14 days. Each supplementation phase was followed by a 30-day washout period. MDZ (8 mg, per os) was administered before and after each phase, and pharmacokinetic parameters were determined using standard non-compartmental methods. Comparisons of pre- and post-supplementation MDZ pharmacokinetic parameters revealed significant inhibition of CYP3A by goldenseal (AUC(0-infinity), 107.9+/-43.3 vs 175.3+/-74.8 ng x h/ml; Cl/F/kg, 1.26+/-0.59 vs 0.81+/-0.45 l/h/kg; T(1/2), 2.01+/-0.42 vs 3.15+/-1.12 h; Cmax, 50.6+/-26.9 vs 71.2+/-50.5 ng/ml). MDZ disposition was not affected by kava kava supplementation. These findings suggest that significant herb-drug interactions may result from the concomitant ingestion of goldenseal and CYP3A substrates.
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Affiliation(s)
- B J Gurley
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
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