Factors affecting drug-induced liver injury: antithyroid drugs as instances

Methimazole and propylthiouracil have been used in the management of hyperthyroidism for more than half a century. However, hepatotoxicity is one of the most deleterious side effects associated with these medications. The mechanism(s) of hepatic injury induced by antithyroid agents is not fully recognized yet. Furthermore, there are no specific tools for predicting the occurrence of hepatotoxicity induced by these drugs. The purpose of this article is to give an overview on possible susceptibility factors in liver injury induced by antithyroid agents. Age, gender, metabolism characteristics, alcohol consumption, underlying diseases, immunologic mechanisms, and drug interactions are involved in enhancing antithyroid drugs-induced hepatic damage. An outline on the clinically used treatments for antithyroid drugs-induced hepatotoxicity and the potential therapeutic strategies found to be effective against this complication are also discussed

Protective Effect of Captopril against Doxorubicin-Induced Oxidative Stress in Isolated Rat Liver Mitochondria

Abstract Doxorubicin (DOX) is an anthracycline antibiotic that has been used for a long time in therapy of an array of human malignancies either alone or in combination with other cytotoxic agents. The dose-dependent cardiotoxicity of DOX significantly limits its anticancer efficacies. Oxidative stress caused by enhanced production of reactive oxygen species is an important contributor to DOX mitochondrial toxicity. In the present study, DOX produced a significant elevation in TBARS, which is an indicator of lipid peroxidation, and significantly inhibited the activity of superoxide dismutase in rat liver mitochondria. Mitochondrial GSH dramatically decreased while GSSG was increased upon treatment of mitochondria by DOX. Co-treatment with captopril significantly reduced the lipid peroxidation in mitochondria and prevented the inhibition of superoxide dismutase activity induced by DOX. Captopril also significantly increased the level of GSH in DOX-treated mitochondria. These results, therefore, suggest that captopril acts as an antioxidant and can protect the mitochondria against DOX-induced oxidative stress. This effect appears to be due to the sulfhydryl groups of captopril which may act as antioxidant or scavenger of reactive oxygen species

A comparative study of pharmaceutical institutions in Iran and abroad

Introduction: In different countries, various organizations and associations are active in the field of pharmacy. These activities mainly consist of policy-making, implementation, training and supervision. In Iran, different tasks are concentrated in one or two institutions; and the active presence of the private sector is not tangible. On the other hand, in developed countries, tasks are divided between public and private institutions. In this article, by investigating and comparing these institutions in different countries and drawing conclusions, systems for dividing tasks with greater efficiency will be achieved. Methods and Results: The workgroup on "Investigating Pharmaceutical Institutions" of Pharmaceutical-Strategic-Studies-Office conducted a study on the responsibilities of each of these institutions, their target population, efficiency rate on the defined objectives in policy, implementation, monitoring and education areas in Iran, neighboring countries and developed countries, as well as their different and similar duties with each other. In this review article, several searches have been done in databases such as PubMed, Google Scholar, Scopus, specialized books as well as websites related to each of these institutions. The results show that in developed countries an average of six pharmaceutical associations exist, all of which are active in the field of education. In the United States, an organization that approves the competency of pharmacists and issues pharmacy establishment permits has been separated from overseeing organizations. In Japan, other than the Health Ministry as a policy-maker and a special council for legislative purposes, a formal overseeing institution, an Office of Health Assessment and two associations with a scientific-trade and research approach are active. In Australia, one third of the associations are active in the area of law enforcement; and the organization which is active in the field of policy-making and supervision does not have any executive activities. In the European Union, one institution has a role in the field of macro policy-making and two associations are involved in micro policy-making. In India and Pakistan, practically all affairs are carried out in the governmental format; NGOs operate in the field of education, research and government consultation. Overall, China is the most similar to Iran

Amino Acid-Containing Krebs-Henseleit Buffer Protects Rat Liver in a Long-Term Organ Perfusion Model

Background: The liver is vulnerable to the toxicity induced by xenobiotics. On the other hand, it has been found that several endogenously-found amino acids have hepatoprotective properties. The current study was designed to evaluate the effect of taurine, glycine, and histidine on the liver function in an ex vivo model of prolonged organ perfusion. Methods: Rat liver was isolated and perfused with a hemoglobin- and albumin-free Krebs-Henseleit buffer (KBH). Liver injury biomarkers were monitored at scheduled time intervals. Results: The perfusate level of lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and the potassium ion (K+) were gradually increased in control (Only KBH) group. The histopathological evaluation also revealed significant necrosis, sinusoidal dilation, and pyknosis in control liver. Moreover, significant increase in lipid peroxidation and depletion of hepatic glutathione stores were detected in the control group. It was found that taurine (5, 10 and 20 mM) and glycine (5, 10 and 20 mM)-containing KBH buffer significantly decreased the perfusate level of liver injury biomarkers. Furthermore, lower liver tissue pathological changes, decreased lipid peroxidation, and higher glutathione content was detected in amino acid-treated groups. Histidine administration showed no significant protective effect on liver injury in the current study. On the other hand, combination amino acid administration (glycine and taurine) showed a better hepatoprotective profile. Conclusion: The data obtained from the current study might help to provide safe hepatoprotective agents against xenobiotics-induced hepatotoxicity or preserve liver functionality outside the body

Evaluating the effects of different fractions obtained from Gundelia tournefortii extract against carbon tetrachloride-induced liver injury in rats

Xenobiotics-induced liver injury is a major challenge for clinicians and pharmaceutical industry. Hence, finding new therapeutic molecules against this complication has clinical value. The current investigation aimed to evaluate the potential protective effects of different fractions obtained from Gundelia tournefortii (GT) hydroalcoholic extract in a rat model of acute hepatic injury. Male Sprague-Dawley rats (200‑250 g) were treated with carbon tetrachloride (CCl4) (1.5 ml/kg, i.p), then ethanol, water, chloroform, ethyl acetate, and n-Butanol fractions of GT extract were administered. Biochemical and histopathological markers of hepatic injury were assessed and glutathione (GSH) and lipid peroxidation were monitored in liver samples. CCl4 administration caused hepatotoxicity as revealed by an increase in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) activity, as well as pathological changes of the liver. Furthermore, a significant reduction in hepatic glutathione content and an elevation in lipid peroxidation were observed in CCl4‑treated rats. It was found that the n‑butanol (200 mg/kg) and the ethyl acetate (300 mg/kg) fractions of GT extract protected liver against CCL4‑induced damage as judged by lower AST, ALT, LDH and lipid peroxidation, prevention of tissue glutathione depletion, and alleviation of histopathological damages of liver in extract‑treated animals. As n‑butanol and the ethyl acetate fractions of GT effectively alleviated the liver injury induced by CCl4 and provide antioxidant properties, we might be able to propose that the hepatoprotective chemicals of Gundelia extract are present in these fractions.</p

Boldine Supplementation Regulates Mitochondrial Function and Oxidative Stress in a Rat Model of Hepatotoxicity

Background: The xenobiotics-induced liver injury is a clinical complication. Hence, finding new hepatoprotective strategies has clinical value. Oxidative stress and its subsequent complications are major mechanisms involved in xenobiotics-induced hepatotoxicity. Boldine is one of the most potent antioxidant molecules widely investigated for its protective properties in different experimental models. In the current study, the hepatoprotective properties of boldine and its potential mechanisms of hepatoprotection have been investigated. Methods: Rats received thioacetamide (TAA; 200 mg/kg, i.p) as a model of acute liver injury. Boldine (5, 10, 1nd 20 mg/kg; 24 hours intervals; oral) was administered as the hepatoprotective agent. Results: Liver injury was evident in TAA-treated animals (48 hours after TAA exposure) as a severe increase in serum level of liver injury biomarkers and histopathological alterations. Moreover, markers of oxidative stress were increased in liver tissue of TAA-treated rats. Assessment of mitochondrial indices of functionality revealed a significant decrease in mitochondrial dehydrogenases activity, the collapse of mitochondrial membrane potential, mitochondrial swelling and depletion of ATP content. It was found that boldine supplementation mitigated liver tissue markers of oxidative stress and improved mitochondrial indices of functionality in TAA-treated animals. Conclusion: The hepatoprotective properties of boldine might primarily rely on antioxidant and mitochondria protecting effects of this alkaloid

The Hepatoprotective Role of Thiol Reductants against Mitoxantrone-Induced Liver Injury

Mitoxantrone is anthracycline antibiotic highly effective against various human cancers. Hepatotoxicity is associated with mitoxantrone administration. On the other hand, there is no effective therapeutic option against chemotherapy-induced liver injury. The current investigation was designed to evaluate the effect of thiol reductants on mitoxantrone-induced liver injury in two experimental models. As an ex vivo model, isolated rat liver was exposed to increasing concentrations of mitoxantrone (100, 250, 750, and 1000 µM) alone or in combination with thiol-reductants (Dithiothreitol; DTT, and N-acetyl cysteine; NAC). In addition, rats (in vivo) received mitoxantrone (2.5 mg/kg, i.p, at days 1, 10, and 20), NAC (100 and 300 mg/kg/day, i.p, for 20 consecutive days) and DTT (15 and 30 mg/kg/day, i.p, for 20 consecutive days), then liver and serum pathological changes were monitored. Mitoxantrone-induced liver injury was evident in both ex vivo and in vivo experiments as assessed by pathological changes in biomarkers of liver injury, along with tissue histopathological changes. Furthermore, an increase in liver tissue markers of oxidative stress was detected in the mitoxantrone-treated group. It was found that thiol reductants significantly mitigated mitoxantrone hepatotoxicity. The data indicate that thiol reductants might serve as hepatoprotective agents against chemotherapy-induced liver injury.</p

Taurine Alleviates Brain Tissue Markers of Oxidative Stress in a Rat Model of Hepatic Encephalopathy

Hepatic encephalopathy (HE) is a serious clinical complication, which could lead to coma and death if not appropriately managed. There is agreement on the predominant role of ammonia in the etiology of HE. Brain is one of the most critical organs affected by ammonia. The critical role of oxidative stress and its consequences in the pathogenesis of ammonia-induced brain injury have been revealed before. On the other hand, there is no promising therapeutic option against ammonia neurotoxicity. Taurine is one of the most abundant amino acids in the human body. Several pharmacological roles including brain protecting properties have been attributed to this amino acid. The current study was designed to evaluate the role of taurine supplementation on HE-induced oxidative stress in the brain tissue. Animals received thioacetamide (400 mg/kg, i.p, for three consecutive days at 24-hr intervals) as a model of acute liver failure and hyperammonemia. Several serum biochemical parameters, in addition to plasma and brain ammonia level, were monitored. Moreover, markers of oxidative stress in the brain of hyperammonemic animals were assessed. It was found that plasma and brain ammonia was increased, and serum markers of liver injury were significantly elevated in the thioacetamide-treated group. On the other hand, an increase in markers of oxidative stress, including reactive oxygen species formation, lipid peroxidation, glutathione depletion, and decreased tissue antioxidant capacity, was detected in the brain tissue of thioacetamide-treated animals. It was found that taurine treatment (250, 500, and 1000 mg/kg, i.p) alleviated brain tissue markers of oxidative stress and decreased serum biomarkers of liver injury. Furthermore, lower plasma and brain ammonia were detected in taurine-treated animals. These data suggest taurine as a potential protective agent with therapeutic capability against HE-associated central nervous system complications.</p

Carnosine Supplementation Mitigates Brain Tissue Markers of Oxidative Stress in a Rat Model of Fulminant Hepatic Failure

Fulminant hepatic failure is a deleterious clinical complication, which leads to hyperammonemia. Ammonia is a noxious neurotoxic agent, which affects brain tissue through different mechanisms. On the other hand, it is well-known that oxidative stress and its consequences play a major role in the pathogenesis of ammonia-induced brain injury. Carnosine is a dipeptide abundantly found in the human central nervous system (CNS). This peptide is widely investigated for its neuroprotective properties. The current study aimed to evaluate the effect of carnosine supplementation on oxidative stress markers in the brain tissue of a rat model of fulminant hepatic failure and hyperammonemia. Animals received thioacetamide (400 mg/kg, i.p, for three consecutive days at 24-hr intervals) as a model of acute liver failure and hyperammonemia. Several serum biochemical parameters, in addition to plasma and brain ammonia level, were monitored. On the other hand, brain tissue markers of oxidative stress including reactive oxygen species (ROS) formation, lipid peroxidation, tissue glutathione content, and total antioxidant capacity were measured. It was found that plasma and brain ammonia was increased, and serum markers of liver injury were significantly elevated in the thioacetamide-treated group. On the other hand, an increase in markers of oxidative stress, including ROS formation, lipid peroxidation, glutathione depletion, and decreased tissue antioxidant capacity, was evident in the brain of thioacetamide-treated animals. It was found that carnosine supplementation (250, 500, and 1000 mg/kg) decreased serum markers of liver injury, mitigated brain, and plasma ammonia level, and alleviated brain tissue markers of oxidative stress. These data suggest carnosine as a potential neuroprotective agent with therapeutic capability against ammonia-induced CNS injury.</p

Sildenafil Blunts Lung Inflammation and Oxidative Stress in a Rat Model of Cholestasis

Background: Cholestasis is a multifaceted disease that influences not only the function of the liver but also affects many other organs. In this context, cholestasis-induced lung injury is a significant clinical complication. Unfortunately, there is no precise therapeutic option against cholestasis-associated lung injury. It has been revealed that oxidative stress and inflammatory response play a role in cholestasis-induced pulmonary damage. Sildenafil is a phosphodiesterase enzyme inhibitor used in the management of erectile dysfunction. Meanwhile, several experiments revealed the effects of sildenafil on oxidative stress and inflammation. This study aimed to evaluate the effect of sildenafil on cholestasis-induced oxidative stress and inflammation in cholestasis-induced lung injury. Methods: Rats underwent bile duct ligation (BDL) to induce cholestasis. Bronchoalveolar lavage fluid (BALF) levels of inflammatory cells, cytokine, and immunoglobulin were monitored at (3, 7, and 14 days after BDL surgery). Moreover, lung tissue histopathological alterations and biomarkers of oxidative stress were evaluated. Results: A significant increase in BALF inflammatory cells, TNF-α, and immunoglobulin G (IgG) was evident in BDL animals. Moreover, the infiltration of inflammatory cells, vascular congestion, and hemorrhage were detected in the lung of BDL rats. Increased markers of oxidative stress were also evident in the lung of BDL animals. Sildenafil (10 and 20 mg/kg) significantly blunted inflammatory response, oxidative stress, and histopathological alterations in the lung of cholestatic animals. Conclusion: The effects of sildenafil on inflammatory response and oxidative stress biomarkers seems to play a crucial role in its protective properties in the lung of cholestatic animals