The priority of mesenchymal stem cells treated with melatonin in ameliorating thyroid impairment induced by amiodarone. Thorough look on the apoptotic pathway.

Amiodarone treatment has been associated with thyroid alterations. This work was planned to consider therapeutic outcome of MSCs versus MSCs treated with melatonin in minimizing amiodarone -induced deviations in thyroid. We handed-down 50 male Wistar rats, then distributed them into 5 groups; I, II, III, IV, V; control, sham control, amiodarone treated, amiodarone and MSCs treated, and amiodarone, MSCs and melatonin treated groups respectively. Light microscopic examination; levels of T3, T4 and TSH, Oxidative/antioxidative tissue markers, immune-histochemical staining (Bcl2, BAX, iNOS) and real time PCR (IL-6 and VEGF and Caspase 3) were done. Results of group III showed degenerated follicles, decreased follicular cell count and diminished colloid. Some of the follicles were dilated with signs of inflammatory response and apoptosis. Increased collagen deposition in group III was marked. The positive immune-reactive cells of Bcl-2 was decreased and that of BAX and iNOS was increased, also T3 and T4 levels were significantly decreased, but TSH was significantly increased in group III comparing it to the group I. There were highly significant diminution in both SOD and GPx and upsurge in MDA intensities in groups III, IV when correlated to the control. In group IV and V the aforementioned values were restored. The PCR results showed significant increase in IL-6 and VEGF and Caspase 3 in group III compared to the control one, whereas, their values in groups IV and V were reestablished. It is concluded that stem cells can to a great extent ameliorate the thyroid damage induced by amiodarone.But, Adding melatonin to the stem cells culture was found to have auxiliary beneficial effect in the improving the thyroid structure and function.

Protective effect of isoliquiritigenin in amiodarone-induced damage of human umbilical vein endothelial cells.

OBJECTIVE: Amiodarone (AM) is a drug commonly used in patients with ventricular arrhythmias. It can damage vascular endothelial cells and easily cause phlebitis. At present, the prevention and treatment of phlebitis induced by the use of AM is not clear due to the lack of corresponding primary research. Isoliquiritigenin (ISL) has an anti-inflammatory effect, but until now, has not been explored much in the field of research in primary care nursing. The purpose of this study is to investigate the efficacy and mechanism of action of ISL in treating phlebitis induced by AM. METHODS: In our study, we used human umbilical vein endothelial cells (HUVECs) that were divided into three groups: the NC group (normal), the AM group (AM 30 µmol/L for 24 h), and the ISL pretreatment group (isoliquiritigenin 10 µmol/L after 1 h of pretreatment with amiodarone for 24 h). We used CCK-8 to detect cell proliferation, cell scratch assay to detect the migration capability of cells, flow cytometry to measure apoptosis, angiogenesis assay to check the total length and total branches of angiogenesis, and PCR and WB to detect the expression of PCNA, casepase-3, and VEGFA. WB was used to detect NF-κBp65 and p-NF-κBp65 expression. RESULTS: Compared with the AM group, the ISL pretreatment promoted cell proliferation and migration, inhibited cell apoptosis, increased the total length and total branches of angiogenesis, and downregulated p-NF-κBp65 expression. CONCLUSION: ISL shows promise in the prevention and treatment of clinical phlebitis and can be used as a potential therapeutic drug to prevent phlebitis.

Toxicidad pulmonar por amiodarona. No olvidemos lo aprendido / Pulmonary toxicity by amiodarone. Let's not forget what we learned

La toxicidad pulmonar es un efecto adverso poco frecuente de la amiodarona cuyo diagnóstico es una tarea complicada ya que debe tenerse una alta sospecha clínica y descartar otras patologías que pueden confundirse con este proceso. Es importante que el diagnóstico sea precoz para poder instaurar un tratamiento temprano y evitar la progresión a fibrosis pulmonar. Presentamos un caso que manifiesta la importancia de un diagnóstico preciso y la buena evolución del mismo tras la retirada del fármaco y la instauración de tratamiento. (AU)

Pulmonary toxicity is a rare adverse effect of amiodarone, the diagnosis of which is a complicated task since a high clinical suspicion must be maintained and other pathologies that may be confused with this process must be ruled out. It is important that the diagnosis is early to be able to establish early treatmentand avoid progression to pulmonary fibrosis. We present a case that shows the importance of an accurate diagnosis and its good evolution after drug withdrawal and treatment initiation. (AU)

Effect of adenosine triphosphate on amiodarone-induced optic neuropathy in rats: biochemical and histopathological evaluation.

OBJECTIVE: This study aims to investigate possible preventive effect of ATP on optic nerve damage caused by amiodarone in rats. MATERIAL AND METHOD: Thirty albino male Wistar rats weighing between 265 and 278 g were used in the study. Before the experiment, the rats were housed at 22 °C in a 12-h light/dark cycle under appropriate condition. The rats were equally divided into five groups of six animals each: healthy group, 50 mg/kg amiodarone (AMD-50), 100 mg/kg amiodarone (AMD-100), 25 mg/kg ATP + 50 mg/kg amiodarone (ATAD-50), and 25 mg/kg ATP + 100 mg/kg amiodarone (ATAD-100). At the end of 14th day, the animals were sacrificed using cardiac puncture under deep thiopental anaesthesia, and optic nerve tissues were harvested to measure superoxide dismutase (SOD), total glutathione (tGSH), malondialdehyde (MDA), and catalase (CAT) levels. RESULTS: The MDA levels were found to be significantly higher in the AMD-50 and AMD-100 groups compared to the healthy group (p ˂ 0.001). There was also a significant difference between the AMD-50 and ATAD-50 groups, and between the AMD-100 and ATAD-100 groups regarding MDA levels (p ˂ 0.001). tGSH, SOD, and CAT levels were significantly lower in the AMD-50 and AMD-100 groups compared to the healthy group (p ˂ 0.001). ATP was found to partially inhibit amiodarone-induced optic neuropathy. CONCLUSION: The biochemical and histopathological results of this study demonstrated that amiodarone at high doses caused more severe optic neuropathy inducing oxidative damage, but ATP could relatively antagonise these negative effects on the optic nerve. Therefore, we believe that ATP may be beneficial in preventing amiodarone-induced optic neuropathy.

Single and joint toxic effects of thyroid hormone, levothyroxine, and amiodarone on embryo-larval stages of zebrafish (Danio rerio).

This study evaluates single and joint endocrine disruptor toxicities of thyroid hormone, levothyroxine, and amiodarone in the embryo-larval stages of Danio rerio. Single toxicity experiments were carried out in concentrations based on the environmental concentration and increasing concentrations of 10, 100, and 1000 times the environmental concentration. Joint toxicity experiments evaluated the combined effects of these compounds. Toxic effects were examined during zebrafish embryonic development, and the parameters analyzed were apical sublethal, teratogenicity, mortality endpoints, and morphometry. Thyroid hormone exhibited the highest toxicity. However, the results showed that the environmental concentrations for all 3 compounds had low risk in relation to the parameters studied, such as teratogenic effects and morphometry. The larvae were more affected than embryos, where embryos needed higher concentrations in all experiments, possibly due to the absence of the chorion. The same type of effects were observed in the joint toxicity test, except that a possible antagonistic effect was detected. However, high concentrations showed stronger effects of these toxic compounds on fish development.

Nicorandil mitigates amiodarone-induced pulmonary toxicity and fibrosis in association with the inhibition of lung TGF-ß1/PI3K/Akt1-p/mTOR axis in rats.

The long-term side effect of the antiarrhythmic drug, amiodarone (AMIO), such as lung toxicity, remains a critical clinical issue. The previous knowledge denotes diverse antioxidant, anti-inflammatory, and antifibrotic properties of the anti-anginal drug, nicorandil (NI). Therefore, we aimed to investigate the possible protective effect of NI on pulmonary tissue remodelling following AMIO-induced lung toxicity. The included rats were assigned into four equal groups (n = 8): (1) control, (2) control group that received NI 10 mg kg-1  day-1 , (3) model group that received AMIO in a dose of 60 mg kg-1  day-1 , and (4) treated group (AMIO-NI) that were treated with AMIO plus NI as shown above. Drug administration continued for 10 weeks. AMIO resulted in deteriorated (p < 0.001) pulmonary functions accompanied by respiratory acidosis. AMIO showed an obvious histological injury score with intense collagen deposition, disturbed nitric oxide synthase enzymes (NOS/iNOS), and increased alpha smooth muscle actin expression. Furthermore, AMIO upregulated the transforming growth factor (TGF-ß1)/phosphoinositide-3 kinase (PI3K)-Akt1-p/mammalian target of rapamycin (mTOR) axis, which determined the possible mechanism of AMIO on pulmonary remodelling. NI treatment significantly (p < 0.001) prevented the AMIO-induced lung toxicity, as well as inhibited the TGF-ß1/PI3K/Akt1-p/mTOR axis in the lung tissue of rats. The results were confirmed by an in-vitro study. CONCLUSION: The current results revealed that NI was effective in preserving the lung structure and functions. Amelioration of the oxidative stress and modulation of TGF-ß1/PI3K/Akt1-p/mTOR have been achieved. This study suggests NI administration as a preventive therapy from the serious pulmonary fibrosis side effect of AMIO.

Cigarette smoke interacts with amiodarone toxicity in Saccharomyces cerevisiae.

Amiodarone (AMD) is an antiarrhythmic drug prescribed to treat ventricular tachycardia and fibrillation. However, it causes an unpredictable toxicity (idiosyncratic), which may depend on co-exposure to pollutants. AMD toxicity involves calcium homeostasis alteration and oxidative stress, which are also affected by cigarette smoke (CS). We investigated the interaction of CS-condensate (CSC), phenanthrene, and benzo(a)pyrene with AMD toxicity on Saccharomyces cerevisiae. AMD toxicity was reduced by CSC or phenanthrene. Benzo(a)pyrene mildly decreased AMD toxicity on the wild-type strain, but not on the catalase-CTT1 mutant. This latter and other mutants in glucose receptor-GPR1 or calcium transporter-PMR1 showed lower antagonistic effect to AMD by CSC or phenanthrene relative to the wild type, suggesting roles of oxidative stress, calcium homeostasis, and hexose-sensing in this interaction.

Dose-dependent interaction of two heavy metals with amiodarone toxicity in Saccharomyces cerevisiae.

Amiodarone (AMD) is an antiarrhythmic drug that induces idiosyncratic toxicity. Environmental pollutants, including heavy metals, could interact with its toxicity by affecting pharmacokinetics and pharmacodynamics. Other levels of interaction could exist in yeast, such as oxidative stress and the general stress response. In this study, we investigated the interaction of mercury chloride (HgCl2) and cadmium chloride (CdCl2) with AMD toxicity on Saccharomyces cerevisiae. Interaction type - synergistic, additive, or antagonistic - was determined by median drug effect analysis using "CompuSyn". HgCl2 potentiated AMD toxicity at high doses (≥ 71.4 µm, which yielded more than 60% inhibition). CdCl2 acted similarly at high doses (≥ 57.9 µm). An antagonistic effect appeared at lower doses with both heavy metals (≤ 49.4 µm for HgCl2 and AMD; ≤ 18.9 µm for CdCl2 and AMD). The threshold concentrations (HgCl2 or CdCl2 combined with AMD) that switched the interaction from antagonistic to additive, and then to synergistic, were decreased in the yeast strain mutant in catalase (CTT1), suggesting an important role for this enzyme. Moreover, mutation of the nutrient sensing receptor gene GPR1 caused the synergistic interaction of CdCl2, but not HgCl2, with AMD to occur at the lowest tested concentrations (1.2 µm). The reverse was obtained with the mutant strain in calcium-manganese transporter gene PMR1, where the synergistic interaction of HgCl2 with AMD occurred at concentrations (20.7 µm) lower than that of the wild type (71.4 µm). These results demonstrated a dose-dependent interaction between the two heavy metals with AMD toxicity, and the involvement of oxidative stress, calcium homeostasis, and nutrient sensing in the observed interaction.

The possible effects of α-tocopherol against amiodarone-treated lungs in rats: vimentin detection, lipid peroxidation assay, and histological and ultrastructural evaluations.

The purpose of this study was to learn more about the pathogenesis of amiodarone (AD) on alveoli and also the possible preventive effect of α-tocopherol (α-T) against these hazards. Rats were divided into 4 groups, one of which acted as a control, the second received α-T, the third AD, and the fourth AD and α-T for 2 weeks. Light microscopy (LM), immunohistochemistry, transmission electron microscopy (TEM), and malondialdehyde (MDA) activity were analyzed in sections of lung tissue. Alveoli of lung tissue AD examined with LM showed dilatation of alveolar spaces, aggregation of red blood cells, and narrowing of alveolar septa. When stained with vimentin (VIM), alveoli showed a positive reaction in the majority and a moderate reaction in others. In the pneumocytes of the type II, some cytoplasmic vesicles had been deflated, whereas others contained lamellar bodies, a damaged nucleus, and vesicles in their heterochromatin. In the interstitial space, collagen fibers with aggregation of red blood cells and a disrupted blood-air barrier were detected. In rat lung alveoli treated with AD and α-T, the alveolar septum thickened and the alveolar spaces expanded as estimated. The alveoli of this group had more or less intact type I and II pneumocytes and a better appearance of the blood-air barrier. In the cells of the alveolar lining, the VIM staining leads to a diffuse positive response. Finally, lung parenchyma also improved, suggesting that α-T may help minimize the effects of AD.

Comparative analysis of in vivo and in silico toxicity evaluation of the organoiodine compounds towards D.magna using multivariate chemometric approach: A study on the example of amiodarone phototransformation products.

In the present study the photochemical fate of organoiodine compound - amiodarone was performed. The drug turned out to be highly susceptible to UV-Vis irradiation, especially in the presence of humic substances and organic matrix. Qualitative LC-MS analysis revealed formation of twelve - mainly previously unreported - transformation products (TPs). Four major TPs were submitted to the toxicity analysis with the use of D. magna. All of the tested TPs presented higher toxic potential than the parent compound. The phenolic TPs were approximately 100 times more toxic than amiodarone. Toxic properties of the major TPs resulted in steadily increasing toxic potential of the photo-generated mixture over the time of irradiation. Moreover, the experimental toxicity data, concerning the TPs, were compared with results estimated by 6 in silico models with the use of a multivariate chemometric analysis. The results showed that the applied computational methods were able neither to correctly predict toxic properties of the studied compounds, nor the trends in change of their toxic parameters. Additional validation of in silico models ability to predict toxicity of iodinated organic compounds showed that the studied computational methods do not present sufficient prediction ability. Therefore their estimations concerning organoiodines should be verified using experimental tests.

Cell-Permeable Succinate Rescues Mitochondrial Respiration in Cellular Models of Amiodarone Toxicity.

Amiodarone is a potent antiarrhythmic drug and displays substantial liver toxicity in humans. It has previously been demonstrated that amiodarone and its metabolite (desethylamiodarone, DEA) can inhibit mitochondrial function, particularly complexes I (CI) and II (CII) of the electron transport system in various animal tissues and cell types. The present study, performed in human peripheral blood cells, and one liver-derived human cell line, is primarily aimed at assessing the concentration-dependent effects of these drugs on mitochondrial function (respiration and cellular ATP levels). Furthermore, we explore the efficacy of a novel cell-permeable succinate prodrug in alleviating the drug-induced acute mitochondrial dysfunction. Amiodarone and DEA elicit a concentration-dependent impairment of mitochondrial respiration in both intact and permeabilized platelets via the inhibition of both CI- and CII-supported respiration. The inhibitory effect seen in human platelets is also confirmed in mononuclear cells (PBMCs) and HepG2 cells. Additionally, amiodarone elicits a severe concentration-dependent ATP depletion in PBMCs, which cannot be explained solely by mitochondrial inhibition. The succinate prodrug NV118 alleviates the respiratory deficit in platelets and HepG2 cells acutely exposed to amiodarone. In conclusion, amiodarone severely inhibits metabolism in primary human mitochondria, which can be counteracted by increasing mitochondrial function using intracellular delivery of succinate.

The inhibitory mechanisms of losartan and vitamin D on amiodarone-induced lung inflammation in rats: Role of mitogen-activated protein kinases/activator protein-1.

Amiodarone (AMD), an antiarrhythmic drug, is used cautiously due to its lung toxicity that is characterized by alveolar inflammation followed by fatal fibrosis. AMD induces lung inflammation via increasing the alveolar macrophages and disturbing the balance of T-helper-1 (Th1) and Th2 cells cytokines. In this study, the role of the mitogen-activated protein kinases (MAPKs)/activator protein-1 (AP-1) pathway in AMD-induced lung inflammation was evaluated. Also, the anti-inflammatory and antifibrotic effects of losartan and/or vitamin D were investigated following 7, 14, and 28 days of AMD administration. AMD resulted in lung injury, inflammatory infiltration, and increased pulmonary levels of inflammatory cytokines starting from Week 1 of exposure. A significant increase in serum levels of interleukin-4 along with a significant reduction of interferon-gamma, in addition to strong expression of CD68, were reported after 14 and 28 days of AMD administration reflecting Th1/Th2 cytokines imbalance and the accumulation of alveolar macrophages, respectively. The phosphorylation of MAPKs (ERK1/2, JNK, p38) and AP-1 was significantly enhanced starting from Week 1 of exposure. Marked expression of transforming growth factor beta-1 and massive deposition of collagen were detected after 28 days reflecting late fibrosis. All these abnormalities were significantly mitigated by vitamin D and its combination with losartan. Losartan alone has less prominent anti-inflammatory effects particularly after 28 days; however, it efficiently prevented late fibrosis. This study concludes that MAPKs/AP-1 pathway is involved in AMD-induced lung inflammation and that vitamin D and/or losartan could be used as a prophylactic agent to prevent AMD-induced lung toxicity.

Crucial Role of PLGA Nanoparticles in Mitigating the Amiodarone-Induced Pulmonary Toxicity.

BACKGROUND: Amiodarone (AMD) is a widely used anti-arrhythmic drug, but its administration could be associated with varying degrees of pulmonary toxicity. In attempting to circumvent this issue, AMD-loaded polymeric nanoparticles (AMD-loaded NPs) had been designed. MATERIALS AND METHODS: AMD was loaded in NPs by the nanoprecipitation method using two stabilizers: bovine serum albumin and Kolliphor® P 188. The physicochemical properties of the AMD-loaded NPs were determined. Among the prepared NPs, two ones were selected for further investigation of spectral and thermal analysis as well as morphological properties. Additionally, in vitro release patterns were studied and kinetically analyzed at different pH values. In vitro cytotoxicity of an optimized formula (NP4) was quantified using A549 and Hep-2 cell lines. In vivo assessment of the pulmonary toxicity on Sprague Dawley rats via histopathological and immunohistochemical evaluations was applied. RESULTS: The developed NPs achieved a size not more than 190 nm with an encapsulation efficiency of more than 88%. Satisfactory values of loading capacity and yield were also attained. The spectral and thermal analysis demonstrated homogeneous entrapment of AMD inside the polymeric matrix of NPs. Morphology revealed uniform, core-shell structured, and sphere-shaped particles with a smooth surface. Furthermore, the AMD-loaded NPs exhibited a pH-dependent and diffusion-controlled release over a significant period without an initial burst effect. NP4 demonstrated a superior cytoprotective efficiency by diminishing cell death and significantly increasing the IC50 by more than threefold above the pure AMD. Also, NP4 ameliorated AMD-induced pulmonary damage in rats. Significant downregulation of inflammatory mediators and free radicle production were noticed in the NP4-treated rats. CONCLUSION: The AMD-loaded NPs could ameliorate the pulmonary injury induced by the pure drug moieties. Cytoprotective, anti-fibrotic, anti-inflammatory, and antioxidant properties were presented by the optimized NPs (NP4). Future studies may be built on these findings for diminishing AMD-induced off-target toxicities.

The protective potential of alpha lipoic acid on amiodarone-induced pulmonary fibrosis and hepatic injury in rats.

Amiodarone (AMD) is a widely used antiarrhythmic drug prescribed to treat cardiac tachyarrhythmias; however, AMD has been reported to provoke pulmonary fibrosis (PF) and hepatotoxicity. This study aimed to investigate the influence of alpha lipoic acid (ALA) on AMD-induced PF and hepatotoxicity in male Wistar rats. AMD administration resulted in elevated lung contents of hydroxyproline (Hyp), malondialdehyde (MDA), and increased serum levels of transforming growth factor beta-1 (TGF-ß1), interferon-γ (IFN-γ), alanine amino transaminase (ALT), aspartate amino transaminase (AST), total cholesterol (TC), and glucose. On the other side, lung content of glutathione reduced (GSH) and serum levels of total anti-oxidant capacity (TAC) were significantly decreased. Histopathologically, AMD caused PF, produced a mild hepatic injury, and increased expression of alpha smooth muscle actin (α-SMA). Treatment with ALA produced a significant reversal of the oxidative stress, fibrosis, and inflammation parameters with reductions in α-SMA expressions, leading to amelioration of histopathological lesions. ALA might provide supportive therapy in AMD-receiving cardiovascular patients.

Silymarin's defensive role against hepatotoxicity induced by amiodarone in albino rats / El efecto defensivo de silimarin contra la hepatotoxicidad inducida por amiodarona en ratas albinas

SUMMARY: Amiodarone (AMD), an orally powerful antidysrhythmic medication that has caused hepatotoxicity on long-term administration, is commonly used across the world. Silymarin ameliorative effects (SLM); this research elucidated the magnitude of the damage to the liver tissue in AMD. We divided 24 albino rats evenly into four groups given daily doses by gastric tube for eight weeks as follows; the 1st group acted as a control group; the 2nd group received SLM; the 3rd group received AMD; and the 4th group received AMD parallel to SLM. Liver tissues prepared for light, electron microscopic and serum samples screened for biomarkers (I)liver injury enzymes, alanine aminotransferase (ALT) and aspartate aminotransferase (AST); (II) oxidative and antioxidant stress, malondialdehyde (MDA) and superoxide dismutase (SOD); and (III) inflammatory markers, tumor necrosis factor-alpha (TNF-a) and interleukin-6 (IL-6). The findings showed that AMD caused hepatic histological changes that included congestion of the blood vessels, leucocytic infiltration and cytoplasmic vacuolation. Ultrastructural degeneration of the mitochondria, endoplasmic reticulum swelling, nuclear pyknosis and increased fat droplets and lysosomes were observed. The biochemical findings showed an increase in the AMD group's ALT and AST activities. The group of rats treated with AMD and SLM, increased the improvements in histology and ultrastructure, while the ALT and AST levels were reduced. Our findings collectively agreed that SLM has a protective impact on AMD hepatotoxicity which can be due to its antioxidant properties.

RESUMEN: La amiodarona (AMD) es un fuerte medicamento antiarrítmico administrado por vía oral que ha causado hepatotoxicidad en la administración a largo plazo utilizado con frecuencia en todo el mundo. Efectos de mejora de la silimarina (SLM); esta investigación analizó la magnitud del daño al tejido hepático en la DMAE. Dividimos 24 ratas albinas de manera uniforme en cuatro grupos que recibieron dosis diarias por sonda gástrica durante ocho semanas de la siguiente manera; el primer grupo fue designado como grupo control; el segundo grupo recibió SLM; el tercer grupo recibió AMD; y el cuarto grupo recibió AMD en paralelo a SLM. Se prepararon tejidos hepáticos para muestras de suero, microscopía de luz y electrónica y se analizaron para biomarcadores (I) enzimas de daño hepático, alanina aminotransferasa (ALT) y aspartato aminotransferasa (AST); (II) estrés oxidativo y antioxidante, malondialdehído (MDA) y superóxido dismutasa (SOD); y (III) marcadores inflamatorios, factor de necrosis tumoral alfa (TNF-a) e interleucina-6 (IL-6). Los hallazgos mostraron que la DMAE genera cambios histológicos hepáticos que incluyen congestión de los vasos sanguíneos, infiltración leucocítica y vacuolación citoplásmica. Se observó una degeneración ultraestructural de las mitocondrias, aumento del retículo endoplásmico, picnosis nuclear y aumento de gotitas de grasa y lisosomas. Los hallazgos bioquímicos mostraron un aumento en las actividades de ALT y AST del grupo AMD. El grupo de ratas tratadas con AMD y SLM, aumentó las mejoras en histología y ultraestructura, mientras que se redujeron los niveles de ALT y AST. Nuestros hallazgos coincidieron colectivamente en que SLM tiene un impacto protector sobre la hepatotoxicidad de AMD debido a sus propiedades antioxidantes.

Human ES and iPS cells display less drug resistance than differentiated cells, and naïve-state induction further decreases drug resistance.

Pluripotent stem cells (PSCs) possess unique characteristics that distinguish them from other cell types. Human embryonic stem (ES) cells are recently gaining attention as a powerful tool for human toxicity assessment without the use of experimental animals, and an embryonic stem cell test (EST) was introduced for this purpose. However, human PSCs have not been thoroughly investigated in terms of drug resistance or compared with other cell types or cell states, such as naïve state, to date. Aiming to close this gap in research knowledge, we assessed and compared several human PSC lines for their resistance to drug exposure. Firstly, we report that RIKEN-2A human induced pluripotent stem (iPS) cells possessed approximately the same sensitivity to selected drugs as KhES-3 human ES cells. Secondly, both ES and iPS cells were several times less resistant to drug exposure than other non-pluripotent cell types. Finally, we showed that iPS cells subjected to naïve-state induction procedures exhibited a sharp increase in drug sensitivity. Upon passage of these naïve-like cells in non-naïve PSC culture medium, their sensitivity to drug exposure decreased. We thus revealed differences in sensitivity to drug exposure among different types or states of PSCs and, importantly, indicated that naïve-state induction could increase this sensitivity.

Prediction of the dose range for adverse neurological effects of amiodarone in patients from an in vitro toxicity test by in vitro-in vivo extrapolation.

Amiodarone is an antiarrhythmic agent inducing adverse effects on the nervous system, among others. We applied physiologically based pharmacokinetic (PBPK) modeling combined with benchmark dose modeling to predict, based on published in vitro data, the in vivo dose of amiodarone which may lead to adverse neurological effects in patients. We performed in vitro-in vivo extrapolation (IVIVE) from concentrations measured in the cell lysate of a rat brain 3D cell model using a validated human PBPK model. Among the observed in vitro effects, inhibition of choline acetyl transferase (ChAT) was selected as a marker for neurotoxicity. By reverse dosimetry, we transformed the in vitro concentration-effect relationship into in vivo effective human doses, using the calculated in vitro area under the curve (AUC) of amiodarone as the pharmacokinetic metric. The upper benchmark dose (BMDU) was calculated and compared with clinical doses eliciting neurological adverse effects in patients. The AUCs in the in vitro brain cell culture after 14-day repeated dosing of nominal concentration equal to 1.25 and 2.5 µM amiodarone were 1.00 and 1.99 µg*h/mL, respectively. The BMDU was 385.4 mg for intravenous converted to 593 mg for oral application using the bioavailability factor of 0.65 as reported in the literature. The predicted dose compares well with neurotoxic doses in patients supporting the hypothesis that impaired ChAT activity may be related to the molecular/cellular mechanisms of amiodarone neurotoxicity. Our study shows that predicting effects from in vitro data together with IVIVE can be used at the initial stage for the evaluation of potential adverse drug reactions and safety assessment in humans.

Grape seed extract protects against amiodarone - induced nephrotoxicity and ultrastructural alterations associated with the inhibition of biomarkers of inflammation and oxidative stress in rats.

Amiodarone (AMD) is one of the highly effective antiarrhythmic agents used for treating refractory arrhythmias. It is well known to have long-term administration side effects such as nephrotoxicity. The possible ameliorative effects of antioxidant grape seed extract; on the extent of tissue damage in AMD-induced nephrotoxicity has not been investigated before. Twenty-four albino rats were used in this study and divided into four groups (n = 6). The 1st group served as an untreated control group, under the same laboratory conditions, the 2nd group received (100 mg/kg/day) of grape seed extract (GSE), the 3rd group, AMD-treated group, received AMD (40 mg/kg/day) and the 4th group received both AMD and GSE in the same doses as the previous groups. AMD-treated group showed abnormal glomerular capillaries with wrinkling basement membranes damaged mesangial cells and distorted proximal tubules with plenty of lysosomes. Ultrastructural alterations were also observed in this group. This was also associated with a significant increase in biomarkers of kidney injury (creatinine), oxidative stress ((Decreased SOD and increased MDA) and biomarkers of inflammation IL-6) in comparison to the control group. Supplementation of GSE to AMD group for eight weeks counteracted these effects. It caused an improvement in histological and t ultrastructure changes of the renal tissues associated with decreased creatinine and biomarkers of oxidative stress and inflammation in comparison to AMD-treated group. We conclude that GSE protects against AMD-induced kidney injuries in rats, which is associated with the inhibition of biomarkers of inflammation and oxidative stress.

Hydroxypropyl Cyclodextrin Improves Amiodarone-induced Aberrant Lipid Homeostasis of Alveolar Cells.

Alveolar epithelial type II (AT2) cells secrete pulmonary surfactant via lamellar bodies (LBs). Abnormalities in LBs are associated with pulmonary disorders, including fibrosis. However, high-content screening (HCS) for LB abnormalities is limited by the lack of understanding of AT2 cell functions. In the present study, we have developed LB cells harboring LB-like organelles that secrete surfactant proteins. These cells were more similar to AT2 cells than to parental A549 cells. LB cells recapitulated amiodarone (AMD)-induced LB enlargement, similar to AT2 cells of patients exposed to AMD. To reverse AMD-induced LB abnormalities, we performed HCS of approved drugs and identified 2-hydroxypropyl-ß-cyclodextrin (HPßCD), a cyclic oligosaccharide, as a potential therapeutic agent. A transcriptome analysis revealed that HPßCD modulates lipid homeostasis. In addition, HPßCD inhibited AMD-induced LB abnormalities in human induced pluripotent stem cell-derived AT2 cells. Our results demonstrate that LB cells are useful for HCS and suggest that HPßCD is a candidate therapeutic agent for AMD-induced interstitial pneumonia.

Amiodarone bioconcentration and suppression of metamorphosis in Xenopus.

Trace concentrations of a number of pharmaceutically active compounds have been detected in the aquatic environment in many countries, where they are thought to have the potential to exert adverse effects on non-target organisms. Amiodarone (AMD) is one such high-risk compound commonly used in general hospitals. AMD is known to alter normal thyroid hormone (TH) function, although little information is available regarding the specific mechanism by which this disruption occurs. Anuran tadpole metamorphosis is a TH-controlled developmental process and has proven to be useful as a screening tool for environmental pollutants suspected of disrupting TH functions. In the present study, our objective was to clarify the effects of AMD on Xenopus metamorphosis as well as to assess the bioconcentration of this pharmaceutical in the liver. We found that AMD suppressed spontaneous metamorphosis, including tail regression and hindlimb elongation in pro-metamorphic stage tadpoles, which is controlled by endogenous circulating TH, indicating that AMD is a TH antagonist. In transgenic X. laevis tadpoles carrying plasmid DNA containing TH-responsive element (TRE) and a 5'-upstream promoter region of the TH receptor (TR) ßA1 gene linked to a green fluorescent protein (EGFP) gene, triiodothyronine (T3) exposure induced a strong EGFP expression in the hind limbs, whereas the addition of AMD to T3 suppressed EGFP expression, suggesting that this drug interferes with the binding of T3 to TR, leading to the inhibition of TR-mediated gene expression. We also found AMD to be highly bioconcentrated in the liver of pro-metamorphic X. tropicalis tadpoles, and we monitored hepatic accumulation of this drug using mass spectrometry imaging (MSI). Our findings suggest that AMD imposes potential risk to aquatic wildlife by disrupting TH homeostasis, with further possibility of accumulating in organisms higher up in the food chain.