RESUMO
Drug conjugates are obtained from tumor-located vectors connected to cytotoxic agents via linkers, which are designed to deliver hyper-toxic payloads directly to targeted cancer cells. These drug conjugates include antibody-drug conjugates (ADCs), peptide-drug conjugates (PDCs), small molecule-drug conjugates (SMDCs), nucleic acid aptamer-drug conjugates (ApDCs), and virus-like drug conjugate (VDCs), which show great therapeutic value in the clinic. Drug conjugates consist of a targeting carrier, a linker, and a payload. Payloads are key therapy components. Cytotoxic molecules and their derivatives derived from natural products are commonly used in the payload portion of conjugates. The ideal payload should have sufficient toxicity, stability, coupling sites, and the ability to be released under specific conditions to kill tumor cells. Microtubule protein inhibitors, DNA damage agents, and RNA inhibitors are common cytotoxic molecules. Among these conjugates, cytotoxic molecules of natural origin are summarized based on their mechanism of action, conformational relationships, and the discovery of new derivatives. This paper also mentions some cytotoxic molecules that have the potential to be payloads. It also summarizes the latest technologies and novel conjugates developed in recent years to overcome the shortcomings of ADCs, PDCs, SMDCs, ApDCs, and VDCs. In addition, this paper summarizes the clinical trials conducted on conjugates of these cytotoxic molecules over the last five years. It provides a reference for designing and developing safer and more efficient conjugates.
Assuntos
Antineoplásicos , Produtos Biológicos , Imunoconjugados , Neoplasias , Humanos , Neoplasias/tratamento farmacológico , Animais , Produtos Biológicos/uso terapêutico , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Antineoplásicos/uso terapêutico , Antineoplásicos/química , Antineoplásicos/farmacologia , Imunoconjugados/uso terapêutico , Imunoconjugados/química , Imunoconjugados/farmacologiaRESUMO
Amanita phalloides is the primary species responsible for fatal mushroom poisoning, as its main toxin, α-amanitin, irreversibly and potently inhibits eukaryotic RNA polymerase II (RNAP II), leading to cell death. There is no specific antidote for α-amanitin, which hinders its clinical application. However, with the advancement of precision medicine in oncology, including the development of antibody-drug conjugates (ADCs), the potential value of various toxic small molecules has been explored. These ADCs ingeniously combine the targeting precision of antibodies with the cytotoxicity of small-molecule payloads to precisely kill tumor cells. We searched PubMed for studies in this area using these MeSH terms "Amanitins, Alpha-Amanitin, Therapeutic use, Immunotherapy, Immunoconjugates, Antibodies" and did not limit the time interval. Recent studies have conducted preclinical experiments on ADCs based on α-amanitin, showing promising therapeutic effects and good tolerance in primates. The current challenges include the not fully understood toxicological mechanism of α-amanitin and the lack of clinical studies to evaluate the therapeutic efficacy of ADCs developed based on α-amanitin. In this article, we will discuss the role and therapeutic efficacy of α-amanitin as an effective payload in ADCs for the treatment of various cancers, providing background information for the research and application strategies of current and future drugs.
Assuntos
Alfa-Amanitina , Imunoconjugados , Neoplasias , Humanos , Neoplasias/tratamento farmacológico , Animais , Imunoconjugados/uso terapêutico , Imunoconjugados/farmacologia , Antineoplásicos/uso terapêutico , Antineoplásicos/farmacologia , RNA Polimerase II/metabolismo , Intoxicação Alimentar por Cogumelos/tratamento farmacológicoRESUMO
In many species, centromere identity is specified epigenetically by special nucleosomes containing a centromere-specific histone H3 variant, designated as CENP-A in humans and CID in Drosophila melanogaster. After partitioning of centromere-specific nucleosomes onto newly replicated sister centromeres, loading of additional CENP-A/CID into centromeric chromatin is required for centromere maintenance in proliferating cells. Analyses with cultured cells have indicated that transcription of centromeric DNA by RNA polymerase II is required for deposition of new CID into centromere chromatin. However, a dependence of centromeric CID loading on transcription is difficult to reconcile with the notion that the initial embryonic stages appear to proceed in the absence of transcription in Drosophila, as also in many other animal species. To address the role of RNA polymerase II-mediated transcription for CID loading in early Drosophila embryos, we have quantified the effects of alpha-amanitin and triptolide on centromeric CID-EGFP levels. Our analyses demonstrate that microinjection of these two potent inhibitors of RNA polymerase II-mediated transcription has at most a marginal effect on centromeric CID deposition during progression through the early embryonic cleavage cycles. Thus, we conclude that at least during early Drosophila embryogenesis, incorporation of CID into centromeres does not depend on RNA polymerase II-mediated transcription.
Assuntos
Proteínas de Drosophila , Drosophila , Animais , Centrômero/genética , Centrômero/metabolismo , Proteína Centromérica A/metabolismo , Cromatina/metabolismo , Proteínas de Ligação a DNA/metabolismo , Drosophila/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Desenvolvimento Embrionário/genética , Nucleossomos/metabolismo , RNA Polimerase II/genética , RNA Polimerase II/metabolismoRESUMO
The well-known hepatotoxicity mechanism resulting from alpha-amanitin (α-AMA) exposure arises from RNA polymerase II (RNAP II) inhibition. RNAP â ¡ inhibition occurs through the dysregulation of mRNA synthesis. However, the signaling pathways in hepatocytes that arise from α-AMA have not yet been fully elucidated. Here, we identified that the RAS/RAF/ERK signaling pathway was activated through quantitative phosphoproteomic and molecular biological analyses in Huh-7 cells. Bioinformatics analysis showed that α-AMA exposure increased protein phosphorylation in a time-dependent α-AMA exposure. In addition, phosphorylation increased not only the components of the ERK signaling pathway but also U2AF65 and SPF45, known splicing factors. Therefore, we propose a novel mechanism of α-AMA as follows. The RAS/RAF/ERK signaling pathway involved in aberrant splicing events is activated by α-AMA exposure followed by aberrant splicing events leading to cell death in Huh-7 cells.
Assuntos
Alfa-Amanitina , RNA Polimerase II , Alfa-Amanitina/farmacologia , Sistema de Sinalização das MAP Quinases/fisiologia , Fosforilação , Fatores de Processamento de RNA , RNA MensageiroRESUMO
Amatoxins are produced primarily by 3 species of mushrooms: Amanita, Lepiota, and Galerina. Because amatoxin poisonings are increasing, the objective of this review was to identify all amatoxin-containing mushroom species, present a toxidromic approach to earlier diagnoses, and compare the efficacies and outcomes of therapies. To meet these objectives, Internet search engines were queried with keywords to select peer-reviewed scientific articles on amatoxin-containing mushroom poisoning and management. Descriptive epidemiological analyses have documented that most mushroom poisonings are caused by unknown mushrooms, and most fatal mushroom poisonings are caused by amatoxin-containing mushrooms. Amanita species cause more fatal mushroom poisonings than other amatoxin-containing species, such as Galerina and Lepiota. Amanita phalloides is responsible for most fatalities, followed by Amanita virosa and Amanita verna. The most frequently reported fatal Lepiota ingestions are due to Lepiota brunneoincarnata, and the most frequently reported fatal Galerina species ingestions are due to Galerina marginata. With the exception of liver transplantation, the current treatment strategies for amatoxin poisoning are all supportive and have not been subjected to rigorous efficacy testing in randomized controlled trials. All patients with symptoms of late-appearing gastrointestinal toxicity with or without false recovery or quiescent periods preceding acute liver insufficiency should be referred to centers providing liver transplantation. Patients with amatoxin-induced acute liver insufficiency that does not progress to liver failure will have a more favorable survival profile with supportive care than patients with amatoxin-induced acute liver failure, about half of whom will require liver transplantation.
Assuntos
Agaricales/química , Amanitinas/intoxicação , Intoxicação Alimentar por Cogumelos/diagnóstico , Intoxicação Alimentar por Cogumelos/terapia , Amanita/química , Insuficiência Hepática/diagnóstico , Insuficiência Hepática/microbiologia , Insuficiência Hepática/terapia , Humanos , Falência Hepática Aguda/diagnóstico , Falência Hepática Aguda/microbiologia , Falência Hepática Aguda/terapia , Transplante de Fígado/estatística & dados numéricos , Intoxicação Alimentar por Cogumelos/microbiologiaRESUMO
The fungus Amanita phalloides is known to contain two main groups of toxins: amanitins and phallotoxins. The amanitins group effectively blocks the RNA polymerase II enzyme found in eukaryotic cells. As alpha amanitin has a lethal effect on the majority of eukaryotic cells, it can be valuable as an antiparasitic or antifungal drug. It can be used externally against ectoparasites. It is critical that percutaneous applications of the alpha amanitin toxin are not harmful to the recipient. In this study, the absorption and the toxicity of percutaneous and intraperitoneal (ip) applications of 1 mg/kg alpha amanitin to mice were compared. Potential skin, liver and kidney toxicities were investigated through pathological examination. HPLC analysis was used to determine the amount of the toxin. No toxicity or toxin were found in the skin, liver, or kidneys of the mice in the control group. Interestingly, the percutaneous application group also showed no toxicity, and the toxin was not present in this group. After 24 h, Councilman-like bodies and pyknotic cells were observed in the mice in which alpha amanitin was applied intraperitoneally, demonstrating the presence of toxicity. Peak levels of alpha amanitin (µg/mL) in the liver, kidney, and blood in the ip application group were measured at 3.3 (6 h), 0.2 (6 h) and 1.2 (1 h), respectively. The results demonstrated that the toxin was not absorbed through the skin of the mice and that the percutaneous application of alpha amanitin did not have any toxic effects. Thus, alpha amanitin may be administered percutaneously for therapeutic purposes.
Assuntos
Alfa-Amanitina/farmacocinética , Alfa-Amanitina/toxicidade , Anti-Infecciosos/farmacocinética , Anti-Infecciosos/toxicidade , Absorção Cutânea , Administração Cutânea , Alfa-Amanitina/sangue , Animais , Anti-Infecciosos/sangue , Injeções Intraperitoneais , Rim/anatomia & histologia , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Camundongos Endogâmicos BALB C , Pele/anatomia & histologia , Pele/efeitos dos fármacos , Pele/metabolismoRESUMO
Mushroom poisonings caused by Amanita phalloides are the leading cause of mushroom-related deaths worldwide. Alpha-Amanitin (α-AMA), a toxic substance present in these mushrooms, is responsible for the resulting hepatotoxicity and nephrotoxicity. The objective of our study was to determine the distribution of α-AMA in Balb/c mice by labeling with Iodine-131. Mice were injected with a toxic dose (1.4 mg/kg) of α-AMA labeled with Iodine-131. The mice were sacrificed at the 1st, 2nd, 4th, 8th, 24th, and 48th hours under anesthesia. The organs of the mice were removed, and their biodistribution was assessed in all experiments. The percent injected dose per gram (ID/g %) value for kidney, liver, lung, and heart tissues at 1st hour were 1.59 ± 0.07, 1.25 ± 0.33, 3.67 ± 0.80 and 1.07 ± 0.01 respectively. This study provides insights into the potential long-term effects of α-AMA accumulation in specific organs. Additionally, this study has generated essential data that can be used to demonstrate the impact of antidotes on the biological distribution of α-AMA in future toxicity models.
Assuntos
Alfa-Amanitina , Intoxicação Alimentar por Cogumelos , Animais , Camundongos , Alfa-Amanitina/toxicidade , Distribuição Tecidual , Radioisótopos do Iodo , AmanitaRESUMO
Behavioural adaptations of hosts to their parasites form an important component of the evolutionary dynamics of host-parasite interactions. As mushroom-feeding Drosophila can tolerate deadly mycotoxins, but their Howardula nematode parasites cannot, we asked how consuming the potent mycotoxin α-amanitin has affected this host-parasite interaction. We used the fly D. putrida and its parasite H. aoronymphium, which is both highly virulent and at high prevalence in some populations, and investigated whether adult flies utilize food with toxin to prevent infection in the next generation or consume the toxin to reduce the virulence of an already established infection. First, we found that uninfected females did not prefer to eat or lay their eggs on toxic food, indicating that selection has not acted on the flies to alter their behaviour towards α-amanitin to prevent their offspring from becoming infected by Howardula. However, we cannot rule out that flies use an alternate cue that is associated with toxin presence in the wild. Second, we found that infected females did not prefer to eat food with α-amanitin and that consuming α-amanitin did not cure or reduce the virulence of the parasite in adults that were already infected. In sum, our results indicate there are no direct effects of eating α-amanitin on this host-parasite interaction, and we suggest that toxin tolerance is more likely maintained by selection due to competition for resources than as a mechanism to avoid parasite infection or to reduce the virulence of infection.
Assuntos
Alfa-Amanitina , Drosophila/parasitologia , Comportamento Alimentar , Interações Hospedeiro-Parasita , Tylenchida/fisiologia , Animais , Feminino , MasculinoRESUMO
In the human body, proteins secreted into peripheral blood vessels are known as the secretome, and they represent the physiological or pathological status of cells. The unique response of cells to toxin exposure can be confirmed via secretome analysis, which can be used to discover toxic mechanisms or exposure markers. Alpha-amanitin (α-AMA) is the most widely studied amatoxin and inhibits transcription and protein synthesis by directly interacting with RNA polymerase II. However, secretory proteins released during hepatic failure caused by α-AMA have not been fully characterized. In this study, we analyzed the secretome of α-AMA-treated Huh-7 cells and mice using a comparative proteomics technique. Overall, 1440 and 208 proteins were quantified in cell media and mouse serum, respectively. Based on the bioinformatics results for the commonly downregulated proteins in cell media and mouse serum, we identified complement component 3 (C3) as a marker for α-AMA-induced hepatotoxicity. Through western blot in cell secretome and C3 ELISA assays in mouse serum, we validated α-AMA-induced downregulation of C3. In conclusion, using comparative proteomics and molecular biology techniques, we found that α-AMA-induced hepatotoxicity reduced C3 levels in the secretome. We expect that this study will aid in identifying new toxic mechanisms, therapeutic targets, and exposure markers of α-AMA-induced hepatotoxicity. Supplementary Information: The online version contains supplementary material available at 10.1007/s43188-022-00163-z.
RESUMO
A 10-year-old, female spayed Labrador Retriever was referred for acute hepatopathy and urinary retention. Blood work from the initial presentation (day 0) revealed a severe, mixed hepatopathy. Over the course of the patient's hospitalization, the patient developed liver insufficiency. Urine was submitted for toxicological screening and revealed detection of a trace concentration of alpha-amanitin. The patient was treated supportively for alpha-amanitin intoxication and was discharged from the hospital on day 8, with most biochemical parameters being markedly improved. The patient was persistently hyporexic at the time of discharge. On day 15, at a recheck appointment, the patient had lost 2.4 kg and liver enzymology revealed improved values. On day 24, the patient was presented for anorexia and vomiting and had lost another 2.3 kg. Blood work and endocrinological testing at that time were consistent with hypoadrenocorticism. The patient was started on glucocorticoids and mineralocorticoids. At day 106, the patient was doing well clinically while receiving monthly mineralocorticoids and daily glucocorticoids. This case report is the first to describe the chronological association between alpha-amanitin-induced liver dysfunction and the subsequent development of adrenal insufficiency in a dog.
RESUMO
The misuse of poisonous mushrooms containing amatoxins causes acute liver failure (ALF) in patients and is a cause of significant mortality. Although the toxic mechanisms of α-amanitin (α-AMA) and its interactions with RNA polymerase II (RNAP II) have been studied, α-AMA effector proteins that can interact with α-AMA in hepatocytes have not been systematically studied. Limited proteolysis-coupled mass spectrometry (LiP-MS) is an advanced technology that can quickly identify protein-ligand interactions based on global comparative proteomics. This study identified the α-AMA effector proteins found in human hepatocytes, following the detection of conformotypic peptides using LiP-MS coupled with tandem mass tag (TMT) technology. Proteins that are classified into protein processing in the endoplasmic reticulum and the ribosome during the KEGG pathway can be identified through affinity evaluation, according to α-AMA concentration-dependent LiP-MS and LiP-MS in hepatocytes derived from humans and mice, respectively. The possibility of interaction between α-AMA and proteins containing conformotypic peptides was evaluated through molecular docking studies. The results of this study suggest a novel path for α-AMA to induce hepatotoxicity through interactions with various proteins involved in protein synthesis, as well as with RNAP II.
Assuntos
Alfa-Amanitina , Hepatócitos , Humanos , Camundongos , Animais , Alfa-Amanitina/metabolismo , Alfa-Amanitina/toxicidade , Proteólise , Simulação de Acoplamento Molecular , Hepatócitos/metabolismo , Espectrometria de MassasRESUMO
Amanitin poisoning still has no particular, effective antidote. Erdosteine has been shown to protect numerous tissues, particularly those in the liver. This study investigates the potential therapeutic effects of erdosteine on alpha-, beta- and gamma-amanitin-induced hepatotoxicity in in vitro models. Three hours after administering amatoxins at various concentrations (1-50 µg/mL) to the cells of the C3A human hepatocyte cell line, erdosteine was administered in different concentrations (i.e., 1, 10, 50, 100 and 250 µg/mL). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was selected to determine cell viability. When concentrations of 1, 10, 50, 100 and 250 µg/mL of erdosteine were applied to cell lines, the following cell viability rates were obtained: 106%,99%,93%,86% and 86%, respectively, at a 10 µg/mL alpha-amanitin-induced toxicity; 43%,41%,41%,37% and 35%, respectively, at a 25 µg/mL alpha-amanitin-induced toxicity; 44%,42%,41%,39% and 41%, respectively, at a 50 µg/mL alpha-amanitin-induced toxicity; 136%,142%,143%,137% and 120%, respectively, at a 10 µg/mL beta-amanitin-induced toxicity; 113%,107%,107%,106% and 86%, respectively, at a 25 µg/mL beta-amanitin-induced toxicity; 78%,77%,77%,74% and 70%, respectively, at a 10 µg/mL gamma-amanitin-induced toxicity; and 39%,40%,39%,35% and 31%, respectively, at a 25 µg/mL gamma-amanitin-induced toxicity. This study was the first to evaluate the in vitro efficacy of erdosteine in cytotoxicity induced by alpha-, beta- and gamma-amanitin. Non-high (low and medium) doses of erdosteine are capable of nearly entirely preventing toxicity at mild hepatotoxic concentrations caused by amatoxin and partially preventing toxicity at moderate and severe concentrations. The beneficial effects of erdosteine, especially on the toxicity of alpha- and beta-amanitin, are promising.
Assuntos
Alfa-Amanitina , Amanitinas , Alfa-Amanitina/toxicidade , Amanitinas/toxicidade , Hepatócitos , Humanos , Tioglicolatos , TiofenosRESUMO
Alpha-amanitin (α-AMA) is a cyclic peptide and one of the most lethal mushroom amatoxins found in Amanita phalloides. α-AMA is known to cause hepatotoxicity through RNA polymerase II inhibition, which acts in RNA and DNA translocation. To investigate the toxic signature of α-AMA beyond known mechanisms, we used quantitative nanoflow liquid chromatography-tandem mass spectrometry analysis coupled with tandem mass tag labeling to examine proteome dynamics in Huh-7 human hepatoma cells treated with toxic concentrations of α-AMA. Among the 1828 proteins identified, we quantified 1563 proteins, which revealed that four subunits in the T-complex protein 1-ring complex protein decreased depending on the α-AMA concentration. We conducted bioinformatics analyses of the quantified proteins to characterize the toxic signature of α-AMA in hepatoma cells. This is the first report of global changes in proteome abundance with variations in α-AMA concentration, and our findings suggest a novel molecular regulation mechanism for hepatotoxicity.
Assuntos
Alfa-Amanitina/toxicidade , Chaperonina com TCP-1/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Fígado/efeitos dos fármacos , Intoxicação Alimentar por Cogumelos/metabolismo , Proteoma , Proteômica , Linhagem Celular Tumoral , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Cromatografia Líquida , Biologia Computacional , Humanos , Fígado/metabolismo , Mapas de Interação de Proteínas , Espectrometria de Massas em TandemRESUMO
Alpha-amanitin (α-AMA), the primary toxin of Amanita phalloides, is known to cause nephrotoxicity and hepatotoxicity. Resveratrol is an antioxidant that has shown efficacy in many nephrotoxicity models. The aim of this study was to investigate the effects of resveratrol against the early and late stages of α-AMA-induced nephrotoxicity, compared to those of silibinin, a well-known antidote for poisoning by α-AMA-containing mushrooms. Mice kidney tissues were obtained from five groups: (1) α-AMA + NS (simultaneous administration of α-AMA and normal saline), (2) α-AMA + SR (simultaneous administration of α-AMA and resveratrol), (3) α-AMA + 12R (resveratrol administration 12 h after α-AMA administration), (4) α-AMA + 24R (resveratrol administration 24 h after α-AMA administration), and (5) α-AMA + Sil (simultaneous administration of α-AMA and silibinin). Histomorphological and biochemical analyses were performed to evaluate kidney damage and oxidant-antioxidant status in the kidney. Scores of renal histomorphological damage decreased significantly in the early resveratrol treatment groups (α-AMA + SR and α-AMA + 12R), compared to those in the α-AMA + NS group (p < 0.05). Catalase levels increased significantly in the α-AMA + SR group, compared to those in the α-AMA + NS group (p < 0.001). Early resveratrol administration within 12 h after α-AMA ingestion may reverse the effects of α-AMA-induced nephrotoxicity, partly through its antioxidant action, thereby suggesting its potential as a treatment for poisoning by α-AMA-containing mushrooms.
Assuntos
Alfa-Amanitina/toxicidade , Nefropatias/induzido quimicamente , Nefropatias/tratamento farmacológico , Resveratrol/uso terapêutico , Animais , Antioxidantes/metabolismo , Antioxidantes/uso terapêutico , Glutationa Peroxidase , Rim/metabolismo , Malondialdeído , Camundongos , Camundongos Endogâmicos BALB C , Oxidantes/metabolismo , Superóxido DismutaseRESUMO
The bacterial gut microbiota of many animals is known to be important for many physiological functions including detoxification. The selective pressures imposed on insects by exposure to toxins may also be selective pressures on their symbiotic bacteria, who thus may contribute to the mechanism of toxin tolerance for the insect. Amatoxins are a class of cyclopeptide mushroom toxins that primarily act by binding to RNA polymerase II and inhibiting transcription. Several species of mycophagous Drosophila are tolerant to amatoxins found in mushrooms of the genus Amanita, despite these toxins being lethal to most other known eukaryotes. These species can tolerate amatoxins in natural concentrations to utilize toxic mushrooms as larval hosts, but the mechanism by which these species are tolerant remains unknown. Previous data have shown that a local population of D. tripunctata exhibits significant genetic variation in toxin tolerance. This study assesses the potential role of the microbiome in α-amanitin tolerance in six wild-derived strains of Drosophila tripunctata. Normal and antibiotic-treated samples of six strains were reared on diets with and without α-amanitin, and then scored for survival from the larval stage to adulthood and for development time to pupation. Our results show that a substantial reduction in bacterial load does not influence toxin tolerance in this system, while confirming genotype and toxin-specific effects on survival are independent of the microbiome composition. Thus, we conclude that this adaptation to exploit toxic mushrooms as a host is likely intrinsic to the fly's genome and not a property of their microbiome.
RESUMO
Amanitin-induced apoptosis is proposed to have a significant effect on the pathogenesis of liver damage. However, few reports have focused on proteome changes induced by α-amanitin (α-AMA). Here, we evaluated changes in mitochondrial proteins of hepatocytes in response to 2⯵M α-AMA, a concentration at which α-AMA-induced cell damage could be rescued at cellular level by common clinical drugs. We found 56 proteins were differentially expressed in an α-AMA-treated group. Among them, 38 proteins were downregulated and 18 were upregulated. Downregulated functional proteins included importer TOMM40, respiratory chain component cytochrome C, and metabolic enzymes of citrate acid cycle such as malate dehydrogenase, which localize on the mitochondrial outer membrane, inner membrane and matrix respectively. Immunoblot analysis showed that α-AMA decreased mitochondrial import receptor subunit TOMM40 and cytochrome c accompanied by an increase in the cytosol although their total protein levels were not affected significantly. The mitochondrial membrane potential was also destroyed by α-AMA and was restored by the clinical drug silibinin. Immunofluorescence suggested that mitochondrial morphology did not change. Taken together, our results provide further insights into the toxic mechanism of α-AMA on hepatocytes.
Assuntos
Alfa-Amanitina/toxicidade , Hepatócitos/efeitos dos fármacos , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/metabolismo , Proteínas Mitocondriais/metabolismo , Proteoma/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Citocromos c/metabolismo , Hepatócitos/metabolismo , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Proteínas de Membrana Transportadoras/metabolismo , Proteínas do Complexo de Importação de Proteína Precursora MitocondrialRESUMO
Abstract Thymoquinone (TQ) has shown hepatoprotective effects in various experimental studies. We aimed to investigate the possible beneficial effects of TQ regarding its prevention of alpha-amanitin induced hepatotoxicity in human C3A hepatocytes. After administering alpha-amanitin in a concentrations of 1 and 10µg/mL on the cells in a hepatocyte cell line, TQ was administered in various concentrations (10, 5, 1, 0.5, 0.1, 0.05, 0.01, 0.005 µg/mL). The MTT test was used to determine cell viability. For the groups given only TQ at various concentrations, the cell viability rates at 48 hours post-administration were found at 82.6, 98.3, 102.1, 102.5, 99.4, 99.4, 101.9 and 106.3%, respectively. For the group with 1μg/mL alpha-amanitin and various TQ concentrations, the cell viability rates were found at 74.6, 88.5, 87.4, 88.7, 85.7, 86.8, 88.4, and 92.9%, respectively. For the group with 10μg/mL alpha-amanitin and various TQ concentrations, the cell viability rates for each TQ subgroup were found at 65.2, 79.2, 81.4, 81.1, 81.8, 81.8, 82.2 and 91.9%, respectively. Our study is the first in vitro study that investigates TQ's effects on alpha-amanitin induced hepatotoxicity. Although TQ had beneficial effect in low doses did not significantly increase cell viability in liver damage due to alpha-amanitin toxicity.
Assuntos
Linhagem Celular/classificação , Técnicas In Vitro/métodos , Alfa-Amanitina/administração & dosagem , Fígado/fisiopatologiaRESUMO
BACKGROUND: Alpha-amanitin (α-AMA) plays a major role in Amanita phalloides poisoning, showing toxic effects on multi-organs, particularly on the liver and kidneys. Studies have shown a relationship between α-AMA-related injuries and reactive oxygen species. OBJECTIVES: We aimed to investigate whether there is renal injury and its relationship with oxidative stress after intraperitoneal injection of α-AMA in mice experimental poisoning models. MATERIALS AND METHODS: There were 37 male BALB/c laboratory mice treated with α-AMA, according to the study groups: control group (n = 7); low dose (0.2 mg/kg) (n = 10); moderate dose (0.6 mg/kg) (n = 10), and high dose (1 mg/kg) (n = 10). The sample size was detected according to the ethical committee's decision as well as similar studies in the literature. After a 48-hour follow-up period, all the subjects were sacrificed for pathological and biochemical assays. The study was held in Turkey. RESULTS: α-AMA poisoning in mice results in inflammatory changes and necrosis in renal structures. There were statistically significant differences between the study groups regarding measured levels of catalase, superoxide dismutase, glutathione peroxidase, total antioxidant status (TAS), total oxidant status (TOS) and malonyl dialdehyde in renal homogenates of mice (P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, and P = 0.001, respectively). The TOS and TAS measurements helped to eliminate cumbersome analysis of diverse oxidant and antioxidant molecules. The TOS levels in renal homogenate of mice were significantly higher in all the intoxication groups compared to the control group (5.73, 7.02, 7.77, and 9.65 mmol trolox eq/g protein and P = 0.002, P = 0.001, and P = 0.001, respectively). The TAS levels in moderate and high-dose groups were significantly lower than all the other groups treated with α-AMA (0.130, 0.152, 0.065, and 0.087 mmol trolox eq/g protein and P = 0.031, P = 0.001, and P = 0.001, respectively). CONCLUSIONS: Our results indicated that α-AMA poisoning in mice led to inflammatory changes and necrosis in renal structures. Biochemical analysis showed a shift in the oxidative/anti-oxidative balance towards the oxidative status.