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King J, Kelly B, Rhein N, Rosengren R. Post-COVID-19 approach to teaching an undergraduate laboratory class focused on experimental design and data interpretation. BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION : A BIMONTHLY PUBLICATION OF THE INTERNATIONAL UNION OF BIOCHEMISTRY AND MOLECULAR BIOLOGY 2024; 52:442-452. [PMID: 38546208 DOI: 10.1002/bmb.21833] [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: 07/16/2023] [Revised: 02/27/2024] [Accepted: 03/17/2024] [Indexed: 07/13/2024]
Abstract
To best prepare students for the real-world research environment, key skills, including experimental design, data analysis, communication of results, and critical thinking, should be key components of undergraduate science courses. Furthermore, the impact of the COVID-19 pandemic on in-person teaching has resulted in a need to develop courses that enable flexible learning. This paper details the laboratory component of a senior-level toxicology class that was developed to emphasize all these skills and allow for flexible learning. The aim of the laboratory class was for students to determine how curcumin protected against acetaminophen-induced hepatoxicity. To stimulate critical thinking, students were required to choose a maximum of four experiments from the six on offer. Before conducting an experiment, students stated a hypothesis and selected the appropriate treatment groups. Once an experiment was completed, students were given access to a complete dataset, on which they performed statistical analysis and drew conclusions. Students who were unable to attend the laboratory session in person were able to complete the required pre-lab work and access the dataset. Following each experiment, students could write a lab summary, and receive thorough feedback. The final assessment was a written manuscript of their findings as well as a chance to respond to reviewer comments. This teaching approach prioritized the critical thinking, analysis, and experimental design aspects of scientific research. Overall, this structure was well received by students and it could easily be adapted for use on other life science courses.
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Affiliation(s)
- Jessie King
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Barnaby Kelly
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Nayla Rhein
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Rhonda Rosengren
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
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Tan YZ, Thomsen LR, Shrestha N, Camisasca A, Giordani S, Rosengren R. Short-Term Intravenous Administration of Carbon Nano-Onions is Non-Toxic in Female Mice. Int J Nanomedicine 2023; 18:3897-3912. [PMID: 37483316 PMCID: PMC10361275 DOI: 10.2147/ijn.s414438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 07/13/2023] [Indexed: 07/25/2023] Open
Abstract
Background A nanoscale drug carrier could have a variety of therapeutic and diagnostic uses provided that the carrier is biocompatible in vivo. Carbon nano-onions (CNOs) have shown promising results as a nanocarrier for drug delivery. However, the systemic effect of CNOs in rodents is unknown. Therefore, we investigated the toxicity of CNOs following intravenous administration in female BALB/c mice. Results Single or repeated administration of oxi-CNOs (125, 250 or 500 µg) did not affect mouse behavior or organ weight and there was also no evidence of hepatotoxicity or nephrotoxicity. Histological examination of organ slices revealed a significant dose-dependent accumulation of CNO aggregates in the spleen, liver and lungs (p<0.05, ANOVA), with a trace amount of aggregates appearing in the kidneys. However, CNO aggregates in the liver did not affect CYP450 enzymes, as total hepatic CYP450 as well as CYP3A catalytic activity, as meased by erythromycin N-demethylation, and protein levels showed no significant changes between the treatment groups compared to vehicle control. CNOs also failed to act as competitive inhibitors of CYP3A in vitro in both mouse and human liver microsomes. Furthermore, CNOs did not cause oxidative stress, as indicated by the unchanged malondialdehyde levels and superoxide dismutase activity in liver microsomes and organ homogenates. Conclusion This study provides the first evidence that short-term intravenous administration of oxi-CNOs is non-toxic to female mice and thus could be a promising novel and safe drug carrier.
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Affiliation(s)
- Yi Zhen Tan
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, 9016, New Zealand
| | - Lucy R Thomsen
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, 9016, New Zealand
| | - Nensi Shrestha
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, 9016, New Zealand
| | - Adalberto Camisasca
- School of Chemical Sciences, Dublin City University, Glasnevin, Dublin, D09 NA55, Ireland
| | - Silvia Giordani
- School of Chemical Sciences, Dublin City University, Glasnevin, Dublin, D09 NA55, Ireland
| | - Rhonda Rosengren
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, 9016, New Zealand
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Chilvery S, Yelne A, Khurana A, Saifi MA, Bansod S, Anchi P, Godugu C. Acetaminophen induced hepatotoxicity: An overview of the promising protective effects of natural products and herbal formulations. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 108:154510. [PMID: 36332383 DOI: 10.1016/j.phymed.2022.154510] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 08/06/2022] [Accepted: 10/16/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND The liver plays an important role in regulating the metabolic processes and is the most frequently targeted organ by toxic chemicals. Acetaminophen (APAP) is a well-known anti-allergic, anti-pyretic, non-steroidal anti-inflammatory drug (NSAID), which upon overdose leads to hepatotoxicity, the major adverse event of this over-the-counter drug. PURPOSE APAP overdose induced acute liver injury is the second most common cause that often requires liver transplantation worldwide, for which N-acetyl cysteine is the only synthetic drug clinically approved as an antidote. So, it was felt that there is a need for the novel therapeutic approach for the treatment of liver diseases with less adverse effects. This review provides detailed analysis of the different plant extracts; phytochemicals and herbal formulations for the amelioration of APAP-induced liver injury. METHOD The data was collected using different online resources including PubMed, ScienceDirect, Google Scholar, Springer, and Web of Science using keywords given below. RESULTS Over the past decades various reports have revealed that plant-based approaches may be a better treatment choice for the APAP-induced hepatotoxicity in pre-clinical experimental conditions. Moreover, herbal compounds provide several advantages over the synthetic drugs with fewer side effects, easy availability and less cost for the treatment of life-threatening diseases. CONCLUSION The current review summarizes the hepatoprotective effects and therapeutic mechanisms of various plant extracts, active phytoconstituents and herbal formulations with potential application against APAP induced hepatotoxicity as the numbers of hepatoprotective natural products are more without clinical relativity. Further, pre-clinical pharmacological research will contribute to the designing of natural products as medicines with encouraging prospects for clinical application.
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Affiliation(s)
- Shrilekha Chilvery
- Department of Regulatory Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Balanagar, Hyderabad, Telangana, India
| | - Amit Yelne
- Department of Regulatory Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Balanagar, Hyderabad, Telangana, India
| | - Amit Khurana
- Department of Regulatory Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Balanagar, Hyderabad, Telangana, India
| | - Mohd Aslam Saifi
- Department of Regulatory Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Balanagar, Hyderabad, Telangana, India
| | - Sapana Bansod
- Department of Regulatory Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Balanagar, Hyderabad, Telangana, India
| | - Pratibha Anchi
- Department of Regulatory Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Balanagar, Hyderabad, Telangana, India
| | - Chandraiah Godugu
- Department of Regulatory Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Balanagar, Hyderabad, Telangana, India.
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Wang Y, Song X, Geng Y. Effects of IC 50 dose of retinol on metabolomics of RAW264.7 cells. J Food Biochem 2020; 44:e13327. [PMID: 32539219 DOI: 10.1111/jfbc.13327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 12/01/2022]
Abstract
Vitamin A is one of the most multifunctional vitamins in normal human physiology and is involved in several basic physiological processes from embryonic development to adulthood, such as embryogenesis, vision, immunity, cell differentiation, and proliferation. In this study, we conducted 1 H- NMR to evaluate the metabolomic changes in RAW264.7 cells after treatment with retinol at an IC50 dose to identify its effects on the differential metabolites and main metabolic pathways. Our results showed that the IC50 dose (140 μM) of retinol affected the metabolism of RAW264.7 cells, with a total of 22 differential metabolites identified via 1 H-NMR, including amino acids, sugars, organic acids, glutathione, glycerin, and creatine. Additionally, multiple metabolic pathways were affected by retinol treatment, including downregulation of amino acid biosynthesis, protein synthesis, and pyruvate metabolism. We speculate that the cytotoxicity of retinol at the IC50 dose is attributed to mitochondrial dysfunction as a result of oxidative stress or lipid peroxidation. PRACTICAL APPLICATIONS: With the general improvement of people's living standards, people use dietary supplements to improve the level of retinol to prevent non-specific diseases. But there are more and more cases of acute or chronic poisoning caused by excessive intake of vitamin A. Therefore, it is necessary to study the toxicity of vitamin A, and more attention should be paid to the excessive intake of vitamin A. From the perspective of metabolomics, this experiment studies the adverse effects of high dose retinol through the changes of metabolites and metabolic pathways at the cellular level. This study will assist further analyses of the toxic mechanism of excessive retinol as fortified foods and nutrient supplementation.
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Affiliation(s)
- Yali Wang
- Key Laboratory of Food Nutrition and Safety of SDNU, Provincial Key Laboratory of Animal Resistant Biology, College of Life Science, Shandong Normal University, Jinan, China
| | - Xiao Song
- Key Laboratory of Food Nutrition and Safety of SDNU, Provincial Key Laboratory of Animal Resistant Biology, College of Life Science, Shandong Normal University, Jinan, China
| | - Yue Geng
- Key Laboratory of Food Nutrition and Safety of SDNU, Provincial Key Laboratory of Animal Resistant Biology, College of Life Science, Shandong Normal University, Jinan, China
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Shmarakov IO, Borschovetska VL, Ivanishchuk LP, Marchenko MM. Hepatotoxicity of bisphenol A under conditions of differential supplementation with retinoids. UKRAINIAN BIOCHEMICAL JOURNAL 2018; 88:99-105. [PMID: 29235335 DOI: 10.15407/ubj88.03.099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Classical xenoestrogenic in vivo effects of bisphenol A (2,2-bis(4-hydroxyphenyl)propane, BPA) are well-described in the literature, however the molecular mechanisms of BPA-induced hepatotoxicity are not fully characterized. The work is aimed to assess biochemical markers of BPA induced hepatotoxicity under conditions of differential supplementation with retinoids. We demonstrate that the absence of hepatic retinyl esters as the main form of vitamin A storage provides for a resistance to BPA induced liver damage. Retinoid supplementation increases the hepatotoxic effects of bisphenol A, evidenced in higher indexes of oxidative damage of lipids, proteins and non-protein thiol groups as well as increase of serum alanine aminotransferase activity and myeloperoxidase activity in liver parenchyma. The absence of hepatotoxicity signs when hepatic retinoid stores are depleted and their presence during normal or excessive retinoid supplementation suggest that hepatic retinoid availability is one of the factors determining the hepatotoxicity of bisphenol A.
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Thiagarajan D, Ananthakrishnan R, Zhang J, O'Shea KM, Quadri N, Li Q, Sas K, Jing X, Rosario R, Pennathur S, Schmidt AM, Ramasamy R. Aldose Reductase Acts as a Selective Derepressor of PPARγ and the Retinoic Acid Receptor. Cell Rep 2016; 15:181-196. [PMID: 27052179 DOI: 10.1016/j.celrep.2016.02.086] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 01/13/2016] [Accepted: 02/24/2016] [Indexed: 01/04/2023] Open
Abstract
Histone deacetylase 3 (HDAC3), a chromatin-modifying enzyme, requires association with the deacetylase-containing domain (DAD) of the nuclear receptor corepressors NCOR1 and SMRT for its stability and activity. Here, we show that aldose reductase (AR), the rate-limiting enzyme of the polyol pathway, competes with HDAC3 to bind the NCOR1/SMRT DAD. Increased AR expression leads to HDAC3 degradation followed by increased PPARγ signaling, resulting in lipid accumulation in the heart. AR also downregulates expression of nuclear corepressor complex cofactors including Gps2 and Tblr1, thus affecting activity of the nuclear corepressor complex itself. Though AR reduces HDAC3-corepressor complex formation, it specifically derepresses the retinoic acid receptor (RAR), but not other nuclear receptors such as the thyroid receptor (TR) and liver X receptor (LXR). In summary, this work defines a distinct role for AR in lipid and retinoid metabolism through HDAC3 regulation and consequent derepression of PPARγ and RAR.
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Affiliation(s)
- Devi Thiagarajan
- Diabetes Research Program, Department of Medicine, New York University Langone Medical Center, New York, NY 10016, USA
| | - Radha Ananthakrishnan
- Diabetes Research Program, Department of Medicine, New York University Langone Medical Center, New York, NY 10016, USA
| | - Jinghua Zhang
- Diabetes Research Program, Department of Medicine, New York University Langone Medical Center, New York, NY 10016, USA
| | - Karen M O'Shea
- Diabetes Research Program, Department of Medicine, New York University Langone Medical Center, New York, NY 10016, USA
| | - Nosirudeen Quadri
- Diabetes Research Program, Department of Medicine, New York University Langone Medical Center, New York, NY 10016, USA
| | - Qing Li
- Columbia University Medical Center, New York, NY 10032, USA
| | - Kelli Sas
- Division of Nephrology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Xiao Jing
- Diabetes Research Program, Department of Medicine, New York University Langone Medical Center, New York, NY 10016, USA
| | - Rosa Rosario
- Diabetes Research Program, Department of Medicine, New York University Langone Medical Center, New York, NY 10016, USA
| | - Subramaniam Pennathur
- Division of Nephrology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Ann Marie Schmidt
- Diabetes Research Program, Department of Medicine, New York University Langone Medical Center, New York, NY 10016, USA
| | - Ravichandran Ramasamy
- Diabetes Research Program, Department of Medicine, New York University Langone Medical Center, New York, NY 10016, USA.
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The Alterations in the Expression and Function of P-Glycoprotein in Vitamin A-Deficient Rats as well as the Effect of Drug Disposition in Vivo. Molecules 2015; 21:E46. [PMID: 26729079 PMCID: PMC6273054 DOI: 10.3390/molecules21010046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 12/22/2015] [Accepted: 12/23/2015] [Indexed: 11/24/2022] Open
Abstract
This study was aimed to investigate whether vitamin A deficiency could alter P-GP expression and function in tissues of rats and whether such effects affected the drug distribution in vivo of vitamin A-deficient rats. We induced vitamin A-deficient rats by giving them a vitamin A-free diet for 12 weeks. Then, Abcb1/P-GP expression was evaluated by qRT-PCR and Western blot. qRT-PCR analysis revealed that Abcb1a mRNA levels were increased in hippocampus and liver. In kidney, it only showed an upward trend. Abcb1b mRNA levels were increased in hippocampus, but decreased in cerebral cortex, liver and kidney. Western blot results were in good accordance with the alterations of Abcb1b mRNA levels. P-GP function was investigated through tissue distribution and body fluid excretion of rhodamine 123 (Rho123), and the results proclaimed that P-GP activities were also in good accordance with P-GP expression in cerebral cortex, liver and kidney. The change of drug distribution was also investigated through the tissue distribution of vincristine, and the results showed a significantly upward trend in all indicated tissues of vitamin A-deficient rats. In conclusion, vitamin A deficiency may alter Abcb1/P-GP expression and function in rat tissues, and the alterations may increase drug activity/toxicity through the increase of tissue accumulation.
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Shmarakov IO. Retinoid-xenobiotic interactions: the Ying and the Yang. Hepatobiliary Surg Nutr 2015; 4:243-67. [PMID: 26311625 DOI: 10.3978/j.issn.2304-3881.2015.05.05] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 05/13/2015] [Indexed: 12/20/2022]
Abstract
The literature provides compelling evidence pointing to tight metabolic interactions between retinoids and xenobiotics. These are extensive and important for understanding xenobiotic actions in the body. Within the body, retinoids affect xenobiotic metabolism and actions and conversely, xenobiotics affect retinoid metabolism and actions. This article summarizes data that establish the importance of retinoid-dependent metabolic pathways for sustaining the body's responses to xenobiotic exposure, including the roles of all-trans- and 9-cis-retinoic acid for protecting mammals from harmful xenobiotic effects and for ensuring xenobiotic elimination from the body. This review will also consider molecular mechanisms underlying xenobiotic toxicity focusing on how this may contribute to retinoid deficiency and disruption of normal retinoid homeostasis. Special attention is paid to xenobiotic molecular targets (nuclear receptors, regulatory proteins, enzymes, and transporters) which affect retinoid metabolism and signaling.
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Affiliation(s)
- Igor O Shmarakov
- Department of Biochemistry and Biotechnology, Chernivtsi National University, Chernivtsi, Ukraine
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Shmarakov IO, Borschovetska VL, Marchenko MM, Blaner WS. Retinoids modulate thioacetamide-induced acute hepatotoxicity. Toxicol Sci 2014; 139:284-92. [PMID: 24614237 DOI: 10.1093/toxsci/kfu045] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The literature indicates that retinoids can influence the metabolism and actions of xenobiotics and conversely that xenobiotics can influence the metabolism and actions of retinoids. We were interested in understanding the degree to which hepatic retinoid stores, accumulated over a lifetime, affect xenobiotic metabolism, and actions. To investigate this, we induced liver injury through administration of the hepatotoxin thioacetamide (TAA) to chow fed wild type (WT) mice and lecithin:retinol acyltransferase-deficient (Lrat(-/-)) mice that are genetically unable to accumulate hepatic retinoid stores. Within 48 h of TAA-treatment, WT mice develop liver injury as evidenced by focal necrotic areas and increases in serum ALT activity and myeloperoxidase activity in hepatic parenchyma. Simultaneously, features of hepatic encephalopathy develop, as evidenced by a 25% increase in blood ammonia and a threefold reduction of blood glucose levels. This is accompanied by reduced hepatic glutathione, and increased thiobarbituric acid reactive substances, protein carbonyl and sulfhydryl groups, and increased cytochrome P450-catalyzed hydroxylation activity and flavin-containing monooxygenase activity in microsomes prepared from WT liver. Strikingly, none of these TAA-induced effects were observed for matched Lrat(-/-) mice. To confirm that TAA hepatotoxicity depends on retinoid availability, we administered, over 48 h, four oral doses of 3000 IU retinyl acetate each to the mice. This led to the development of hepatotoxicity in Lrat(-/-) mice that was similar in extent to that observed in WT mice. Our findings establish that endogenous hepatic retinoid stores can modulate the toxicity of TAA in mice.
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Affiliation(s)
- Igor O Shmarakov
- Department of Biochemistry and Biotechnology, Chernivtsi National University, Chernivtsi 58000, Ukraine
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Chen Q, Cao M, Xiang WL, Sun Q, Zhang J, Hou RT, Yan ZY, Yang ZR, Liu J, Zhao J. Study on genes with altered expression in alpha-amanitin poisoned mice and evaluation on antagonistic effects of traditional Chinese medicines against toxicity of alpha-amanitin. ACTA BIOLOGICA HUNGARICA 2009; 60:281-91. [PMID: 19700387 DOI: 10.1556/abiol.60.2009.3.5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The forward and reverse cDNA subtractive libraries before and after the toxic effect of alpha-amanitin were constructed by suppression subtractive hybridization and randomly selected clones from each subtractive library were screened by PCR and dot blot hybridization. A total of 85 genes with altered expression were finally identified, with 41 genes from the forward library and 44 from the reverse library. Subsequently, the antagonistic effects of candidate traditional Chinese medicines were evaluated based on the genetic transcription levels of the genes with significant altered expression, including Catnbeta, Flt3-L, IL-7r and Rpo2-4. The results indicated that Silybum marianum (L.) Gaert and Ganoderma lucidum had significant down-regulated effects on the transcription level of Catnbeta that was up-regulated by alpha-amanitin, and the two herbs also up-regulated the transcription levels of Flt3-L and Rpo2-4. Silybum marianum (L.) had significant up-regulated effects on the IL-7r that was down-regulated by alpha-amanitin. These preliminary studies suggested that Silybum marianum (L.) and Ganoderma lucidum were effective antagonists against the toxicity of alpha-amanitin.
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Affiliation(s)
- Q Chen
- Key Laboratory of Biological Resource and Ecological Environment of the Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610041, PR China
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Hamzah J, Batty KT, Davis WA, Mori TA, Ching SYL, Croft KD, Davis TME. Retinol supplementation in murine Plasmodium berghei malaria: Effects on tissue levels, parasitaemia and lipid peroxidation. Int J Parasitol 2007; 37:525-37. [PMID: 17157853 DOI: 10.1016/j.ijpara.2006.10.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Revised: 10/15/2006] [Accepted: 10/17/2006] [Indexed: 11/20/2022]
Abstract
Reduced plasma retinol concentrations occur in human malaria but the benefits of supplementation remain uncertain. We assessed the in vivo efficacy of retinol administration, and its effect on lipid peroxidation, in a Plasmodium berghei murine model. Animals received vehicle (n=17) or retinol (i) before P. berghei inoculation (four doses), (ii) at parasitaemia 10-15% (three to four doses) or (iii) before and after inoculation (six to seven doses; n=15 in each group), with euthanasia on day 8 post-inoculation or when the parasitaemia exceeded 50%. Multiple-dose pre-inoculation retinol reduced endpoint parasitaemia by 24% (P=0.001 versus controls). A reduction of 18% (P=0.042) was observed when retinol was given to parasitaemic animals. Retinol was ineffective when given both before and after infection (11% reduction; P=0.47). Although retinol supplementation did not change plasma retinol concentrations, liver retinol content increased and correlated inversely with endpoint parasitaemia (r=-0.45, P=0.001). Malaria infection augmented concentrations of the free radical lipid peroxidation end-product F(2)-isoprostanes in plasma, erythrocytes and liver by 1.8-, 2.8- and 4.9-fold, respectively, but retinol supplementation had no effect on these increases. Consistent with some human malaria studies, prophylactic retinol reduces P. berghei parasitaemia. This effect relates to augmentation of tissue retinol stores rather than to retinol-associated changes in oxidant status.
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Affiliation(s)
- J Hamzah
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, Fremantle, Western Australia, Australia
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Wang K, Mendy AJ, Dai G, Luo HR, He L, Wan YJY. Retinoids activate the RXR/SXR-mediated pathway and induce the endogenous CYP3A4 activity in Huh7 human hepatoma cells. Toxicol Sci 2006; 92:51-60. [PMID: 16632523 DOI: 10.1093/toxsci/kfj207] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Steroid and xenobiotic receptor (SXR) or human pregnane X receptor (hPXR) dimerizes with retinoid X receptor (RXR) and regulates the transcription of genes encoding xenobiotic-metabolizing enzymes such as CYP3A4. Rifampin, the classical activator of CYP3A4, binds to SXR directly. It is unclear whether various natural and synthetic retinoids can regulate the expression of CYP3A4. To evaluate the effects of retinoids on the RXR/SXR-mediated pathway, transient transfection assays were performed on both CV-1 and human hepatoma Huh7 cells using a reporter construct containing multiple RXR/SXR consensus binding elements (an everted repeat with a 6-nucleotide spacer, ER-6). The results revealed that eight out of 13 retinoids screened significantly induced the RXR/SXR-mediated pathway in Huh7 cells. At an equal molar concentration, the acid forms (9-cis-RA, 13-cis-RA, and all-trans-RA) or aldehyde, the direct precursor of acid (9-cis-retinal and 13-cis-retinal), exhibited a greater or similar potency than rifampin. Depending on the ligands, RXR may serve as a silent or an active partner of SXR. Additionally, retinoids can increase CYP3A4 enzyme activity in Huh7 cells. To further evaluate the potential drug-drug interactions, which may be caused by retinoids, Huh7 cells were pretreated with 9-cis-RA and followed by acetaminophen. We showed that 9-cis-RA enhanced the covalent binding of N-acetyl-p-quinoneimine, a toxic intermediate of acetaminophen produced by phase I enzymes oxidation. This result suggested that drug-drug interaction might occur between 9-cis-RA and acetaminophen in human liver cells. Taken together, retinoids activate the RXR/SXR-mediated pathway and regulate the expression of CYP3A4. Thus, retinoids potentially can cause drug-drug interactions when they are administered with other CYP3A4 substrates.
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Affiliation(s)
- Kun Wang
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
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Bassi AM, Canepa C, Maloberti G, Casu A, Nanni G. Effect of a load of Vitamin A after acute thioacetamide intoxication on dolichol, dolichol isoprenoids and retinol content in isolated rat liver cells. Toxicology 2004; 199:97-107. [PMID: 15147784 DOI: 10.1016/j.tox.2004.02.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2003] [Revised: 11/06/2003] [Accepted: 02/02/2004] [Indexed: 12/18/2022]
Abstract
This study examines how treatment with a single dose of thioacetamide, a known experimental hepatotoxin, alters the content of dolichol, dolichol isoprene units and retinol in isolated rat parenchymal and non-parenchymal liver cells at different times and when the animals are supplemented with Vitamin A. Thioacetamide (300 mg/kg i.p.) was administered in a single injection to rats, sacrificed at intervals of 0.5, 1, 2, 3, 4, 15 and 30 days. Rats supplemented, following thioacetamide, with Vitamin A, 3 days before sacrifice showed increased mortality and cellular necrosis on the third and fourth days. Parameters indicating tissue necrosis returned to normal values in surviving animals. Dolichol and retinol content showed a variable, reversible decrease, with normal levels being restored in 15-30 days. After Vitamin A, dolichol content only in hepatic stellate cells (HSC) was lower then the controls 3 and 4 days after thioacetamide treatment, in parallel with the decrease of retinol storage. The percentage of dolichol-18 is not modified by thioacetamide alone. When supplemented with Vitamin A the percentage of dolichol-18 always decreased after thioacetamide, showing that damage was still present. Mechanisms that might be operative in liver cells are briefly discussed. This approach would provide an indication to investigate how the length of the dolichol chain is determined.
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Affiliation(s)
- Anna M Bassi
- Department of Experimental Medicine, Section of General Pathology, University of Genoa, Via L.B. Alberti 2, 16132 Genoa, Italy.
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Kawaii S, Lansky EP. Differentiation-Promoting Activity of Pomegranate (Punica granatum) Fruit Extracts in HL-60 Human Promyelocytic Leukemia Cells. J Med Food 2004; 7:13-8. [PMID: 15117547 DOI: 10.1089/109662004322984644] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Differentiation refers to the ability of cancer cells to revert to their normal counterparts, and its induction represents an important noncytotoxic therapy for leukemia, and also breast, prostate, and other solid malignancies. Flavonoids are a group of differentiation-inducing chemicals with a potentially lower toxicology profile than retinoids. Flavonoid-rich polyphenol fractions from the pomegranate (Punica granatum) fruit exert anti-proliferative, anti-invasive, anti-eicosanoid, and pro-apoptotic actions in breast and prostate cancer cells and anti-angiogenic activities in vitro and in vivo. Here we tested flavonoid-rich fractions from fresh (J) and fermented (W) pomegranate juice and from an aqueous extraction of pomegranate pericarps (P) as potential differentiation-promoting agents of human HL-60 promyelocytic leukemia cells. Four assays were used to assess differentiation: nitro blue tetrazolium reducing activity, nonspecific esterase activity, specific esterase activity, and phagocytic activity. In addition, the effect of these extracts on HL-60 proliferation was evaluated. Extracts W and P were strong promoters of differentiation in all settings, with extract J showing only a relatively mild differentiation-promoting effect. The extracts had proportional inhibitory effects on HL-60 cell proliferation. The results highlight an important, previously unknown, mechanism of the cancer preventive and suppressive potential of pomegranate fermented juice and pericarp extracts.
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Affiliation(s)
- Satoru Kawaii
- Laboratory of Bio-Organic Chemistry, Tokyo Denki University, Saitama, Japan
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Le Nedelec MJ, Rosengren RJ. Methylphenidate inhibits cytochrome P450 in the Swiss Webster mouse. Hum Exp Toxicol 2002; 21:273-80. [PMID: 12141399 DOI: 10.1191/0960327102ht245oa] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Drug interactions have previously been reported following the co-administration of methylphenidate (MPH) and drugs metabolized by the cytochrome P450 (CYP450) system such as imipramine. Therefore, this study used the Swiss Webster mouse to determine the effect of MPH on CYP450 isozymes likely to be important in the interaction between MPH and imipramine. Single high doses of MPH (25, 50 and 100 mg/kg, i.p.) were administered to simulate the abuse of MPH. Under these conditions, MPH decreased total hepatic CYP450 to 50% of control. Additionally, MPH inhibited the catalytic activity of CYP1A and CYP2E1 by 50%, and decreased the polypeptide levels of CYP3A by 30%. In a second study designed to simulate more closely therapeutic use, MPH was administered orally for two weeks at 10-fold lower doses (2.5, 5 and 10 mg/kg/day). MPH decreased total hepatic CYP450 at both 5 and 10 mg/ kg/day (0.96 +/- 0.01 and 0.96 +/- 0.06 nmol/mg versus 1.34 +/- 0.01 nmol/mg for saline control, P<0.05). The catalytic activity and protein levels of CYP1A were diminished by up to 50% of control, while catalytic activity and polypeptide levels for CYP2E1 and CYP3A remained unchanged. These results indicate that MPH inhibits the CYP450 system following both abuse and therapeutic scenarios. However, this effect was dependent on both the isoform of CYP450 and the duration of MPH administration.
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Affiliation(s)
- M J Le Nedelec
- Department of Pharmacology and Toxicology, School of Medical Sciences, University of Otago, Dunedin, New Zealand
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Bray BJ, Rosengren RJ. Retinol potentiates acetaminophen-induced hepatotoxicity in the mouse: mechanistic studies. Toxicol Appl Pharmacol 2001; 173:129-36. [PMID: 11437634 DOI: 10.1006/taap.2001.9170] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study was designed to elucidate the mechanism of retinol's potentiation of acetaminophen-induced hepatotoxicity. To accomplish this, the major bioactivation and detoxification pathways for acetaminophen were investigated following retinol (75 mg/kg/day, 4 days), acetaminophen (400 mg/kg), and retinol + acetaminophen treatment. Hepatic microsomes were used to determine the catalytic activity and polypeptide levels of cytochrome P450 enzymes involved in the murine metabolism of acetaminophen. Results showed that the catalytic activity and polypeptide levels of CYP1A2, CYP2E1, and CYP3A were unchanged in the treatment groups compared to vehicle and untreated controls. In combination, retinol + acetaminophen caused a significantly greater depletion of GSH compared to corn oil + acetaminophen (0.36 +/- 0.11 vs 0.89 +/- 0.19 micromol/g, respectively, p < 0.05). This greater GSH depletion correlated with a higher degree of hepatic injury in the retinol + acetaminophen-treated animals but is probably not the cause of the potentiated injury since the results showed that retinol treatment itself did not alter hepatic glutathione (3.34 +/- 0.43 vs 3.44 +/- 0.46 micromol/g for retinol vs vehicle, respectively). However, hepatic UDPGA stores were decreased in the retinol-treated group compared to untreated and corn oil controls (54.6 +/- 10.6 vs 200.6 +/- 17.6 nmol/g for retinol and untreated control, respectively, p < 0.001). This demonstrates that there is significantly less hepatic UDPGA available for conjugation following retinol administration. The results suggest that decreased hepatic UDPGA is likely the cause of retinol's potentiation of acetaminophen-induced hepatic injury.
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Affiliation(s)
- B J Bray
- Department of Pharmacology, University of Otago Medical School, Dunedin, New Zealand
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