Protective effect of copper II-albumin complex against aflatoxin B1- induced hepatocellular toxicity: The impact of Nrf2, PPAR-γ, and NF-kB in these protective effects

Copper II-Albumin complex (Cu-II-Albumin complex) is a novel therapeutic target that has been used as anti-inflammatory, antioxidant, and anti-gastrointestinal toxicity. In this study, 40 rats were divided into four groups, normal control (NC), aflatoxicosed group (AF) that received Aflatoxin B1 (AFB1) (50 μg/kg of the AFB1 daily for 3 weeks), AFB1-Cu-II-Albumin prophylactic group (AF/CUC-P) that subjected to intermittent treatment between AFB1 and Cu-II-Albumin complex (0.05 g/kg Cu-II-Albumin complex) day after day for 3 weeks and AFB1-Cu-II-albumin treatment group (AF/CUC-T) that received AFB1 for 3 weeks and Cu-II-albumin complex for another 3 weeks. The hepatocellular protective effect of the Cu-II-albumin complex was assessed by evaluating the liver functions markers, hepatic histopathology, reactive oxygen species (ROS) levels (Nitric Oxide (NO) and malondialdehyde (MDA)), apoptotic genes (caspase-3 and tumor necrosis factor receptor 1 [TNF-R1]) expressions, and serological and molecular biomarkers of hepatocellular carcinoma (histamine and Glucose-Regulated Protein 78 [GRP78], respectively). Our finding showed that Cu-II-Albumin Complex administration had restored liver function, oxidative stress levels, enhanced liver tissue recovery, and reduced the expression of the apoptotic genes of the aflatoxicosed rats. In conclusion, the current study results demonstrated the protective effect of Cu-II-albumin complex against AFB1-induced hepatocellular toxicity. PRACTICAL APPLICATIONS: The protective effect of Cu-II-Albumin Complex against AFB1-induced hepatocellular toxicity by assessing oxidative stress, liver biomarkers, inflammation, and histological changes of liver tissues. The protective mechanism of the Cu-II-albumin complex was also investigated. More clinical studies are required to evaluate the potential of using the Cu-II-albumin complex as a therapeutic agent against hepatocellular toxicity.

HEPATOCELLULAR TOXICITY OF THE METABOLITE EMODIN PRODUCED BY THE COMMON BUCKTHORN (RHAMNUS CATHARTICA) IN GREEN FROG (LITHOBATES CLAMITANS) TADPOLES

The secondary metabolite emodin, produced by the widely distributed invasive shrub known as the common buckthorn (Rhamnus cathartica), has been shown to produce deformities and mortality in invertebrates, fish, and amphibian larvae. Here, we describe the effects on the liver of green frog (Lithobates clamitans) tadpoles after 21 d of exposure to high concentrations of emodin in a controlled environment. Histopathologic analysis showed fibrosis, bile duct proliferation, hepatocellular swelling, and accumulations of flocculent material consistent with emodin within the gall bladder and bile ducts of exposed individuals. The extensive fibrosis produced probably impeded the blood flow within the portal triads, limiting the detoxification function of the liver and resulting in hepatocellular necrosis and premature death for the individuals exposed. Exposure to emodin in the environment could represent a significant threat to developing amphibian larvae and contribute to local declines of populations.

Inhalation exposure to silver nanoparticles induces hepatic inflammation and oxidative stress, associated with altered renin-angiotensin system signaling, in Wistar rats

Silver nanoparticles (AgNPs) have become increasingly popular in the biomedical field over the last few decades due to its proven antibacterial property. Previous scientific studies have reported that one of the major organs responsible for detoxification of AgNPs is the liver. The liver is also the primary organ responsible for secretion of angiotensinogen (AGT), a key signaling molecule involved in the renin-angiotensin system (RAS), which plays an important role in maintaining cardiac output and vascular pressure. The aim of this study was to assess any potential changes in the RAS-associated gene signaling, inflammatory response, and hepatocellular toxicity resulting from AgNP exposure. To do this, 6-week-old, male Wistar rats were exposed to a subacute inhalation exposure of AgNP (200 ppb/days over 4 h/days exposure, for 5 d) and their livers were analyzed for alterations in RAS components, inflammation, and oxidative stress. Real time qPCR analysis showed that AgNP-exposure resulted in a significant increase in hepatic AGT, angiotensin converting enzyme (ACE)-1, and ACE-2 mRNA expression. Expression of inflammatory markers interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α were also upregulated with AgNP-exposure, compared to controls. Furthermore AgNP-exposure mediated a significant increase in hepatic expression of catalase, and superoxide dismutase, and oxidative stress, as assessed via 8-Oxo-2'-deoxyguanosine staining. Increased oxidative stress was associated with increased monocyte/macrophage-2 staining in the liver of AgNP-exposed rats. Such findings indicate that subacute inhalation exposure to AgNPs mediate increased hepatic RAS signaling, associated with inflammation, macrophage infiltration, and oxidative stress.

Mechanisms of toxicity associated with six tyrosine kinase inhibitors in human hepatocyte cell lines

Tyrosine kinase inhibitors have revolutionized the treatment of certain cancers. They are usually well tolerated, but can cause adverse reactions including liver injury. Currently, mechanisms of hepatotoxicity associated with tyrosine kinase inhibitors are only partially clarified. We therefore aimed at investigating the toxicity of regorafenib, sorafenib, ponatinib, crizotinib, dasatinib and pazopanib on HepG2 and partially on HepaRG cells. Regorafenib and sorafenib strongly inhibited oxidative metabolism (measured by the Seahorse-XF24 analyzer) and glycolysis, decreased the mitochondrial membrane potential and induced apoptosis and/or necrosis of HepG2 cells at concentrations similar to steady-state plasma concentrations in humans. In HepaRG cells, pretreatment with rifampicin decreased membrane toxicity (measured as adenylate kinase release) and dissipation of adenosine triphosphate stores, indicating that toxicity was associated mainly with the parent drugs. Ponatinib strongly impaired oxidative metabolism but only weakly glycolysis, and induced apoptosis of HepG2 cells at concentrations higher than steady-state plasma concentrations in humans. Crizotinib and dasatinib did not significantly affect mitochondrial functions and inhibited glycolysis only weakly, but induced apoptosis of HepG2 cells. Pazopanib was associated with a weak increase in mitochondrial reactive oxygen species accumulation and inhibition of glycolysis without being cytotoxic. In conclusion, regorafenib and sorafenib are strong mitochondrial toxicants and inhibitors of glycolysis at clinically relevant concentrations. Ponatinib affects mitochondria and glycolysis at higher concentrations than reached in plasma (but possibly in liver), whereas crizotinib, dasatinib and pazopanib showed no relevant toxicity. Mitochondrial toxicity and inhibition of glycolysis most likely explain hepatotoxicity associated with regorafenib, sorafenib and possibly pazopanib, but not for the other compounds investigated.

Hepatoprotective and antioxidant effects of wheat, carrot, and mango as nutraceutical agents against CCl4-induced hepatocellular toxicity

BACKGROUND AND AIMS

During the last decade, there has been a growing interest in replacing synthetic antioxidants by natural ones because they are cheaper and safe. The main aim of this work was to investigate the possible role of carrot, mango, and wheat extracts against carbon tetrachloride (CCl4)-induced oxidative stress and hepatotoxicity.

METHODS

Forty albino rats were recruited and divided into 5 groups. Group 1 was fed a basal diet and group 2 was fed a basal diet and CCl4. Groups 3, 4, and 5 were treated with carrot, mango, and wheat extracts, respectively, in addition to a basal diet and CCl4.

RESULTS

Hepatocellular toxicity decreased significantly following treatment. Lipid profile and liver enzymes markers decreased remarkably and total protein and high-density lipoprotein (HDL) increased dramatically. The oxidative stress has decreased noticeably through the decrease in Malondialdehyde (MDA). Microscopic examination of the treated rats exhibited a normal histopathological structure.

CONCLUSION

These data suggest that carrot, mango, and wheat extracts could be used as nutraceuticals for the prophylaxis and treatment against hepatotoxicity and oxidative stress. This is the first study of its kind that highlights the importance of including such plants in the dairy and food industry for the prevention of hepatocellular toxicity and oxidative stress.

Azithromycin induced hepatocellular toxicity and hepatic encephalopathy in asymptomatic dilated cardiomyopathy

Azithromycin is a widely used macrolide derivative and has generally been considered to be a very safe medication. Though gastrointestinal symptoms and reversible hearing loss are common, potentially serious side effects including angioedema and cholestatic jaundice occurred in less than one percent of patients. We report a case of asymptomatic dilated cardiomyopathy with Azithromycin induced severe hepatocellular toxicity and hepatic encephalopathy.

Hypothesis: Targeted Ikkβ deletion upregulates MIF signaling responsiveness and MHC class II expression in mouse hepatocytes

Macrophage migration inhibitory factor (MIF) is causally related to the pathogenesis of chronic liver disease but its hepatocellular mechanisms of action are largely unknown. Scattered reports in the literature hint at functional connections between the expression of MIF and major histocompatibility complex (MHC) Class II molecules. Not surprisingly, these relationships have not yet been explored in hepatocytes because MIF and MHC Class II cell surface receptors are commonly expressed by other cell types including various antigen presenting cells of the immune system. On the other hand, mounting evidence suggests that heteromeric MIF receptors share a common molecule with intracellular MHC Class II complexes, viz., CD74, which also serves as the MHC Class II chaperone; and, while it is unclear what cancer-related role(s) MHC Class II receptors might play, increasing evidence suggests that MIF and CD74 are also implicated in the biology of hepatocellular carcinoma. These reports are provocative for two reasons: firstly, Ikkβ^Δhep mice carrying hepatocyte-targeted deletions of Ikkβ, an IκB kinase complex subunit required for the activation of the transcription factor NF-κB (nuclear factor-κB), have been shown to display heightened susceptibilities to hepatotoxins and chemical hepatocarcinogens; secondly, microarray profiling observations indicate that Ikkβ^Δhep hepatocytes constitutively and “ectopically” overexpress genes, particularly CD74, CD44 (a MIF-receptor subunit) and MHC Class II I-A/E β and I-A α chains, and gene families that regulate host immune process and immune defense responses. These findings together suggest that Ikkβ^Δhep mice might express functional MIF and MHC Class II receptors, leading to increased hepatocellular sensitivity to MIF signaling as well as to the unusual property of antigen presentation; both functions might contribute to the heightened liver disease phenotypes of Ikkβ^Δhep mice. The findings raise questions about the potential existence of cohorts of human patients with genetic abnormalities of Ikkβ that might confer heightened susceptibility to liver disease including hepatocellular carcinoma.

Potential role for Duffy antigen chemokine-binding protein in angiogenesis and maintenance of homeostasis in response to stress

CXC chemokines, which induce angiogenesis, have glutamine-leucine-arginine amino acid residues (ELR motif) in the amino terminus and bind CXCR2 and the Duffy antigen chemokine-binding protein. Duffy, a seven transmembrane protein that binds CXC and CC chemokines, has not been shown to couple to trimeric G proteins or to transduce intracellular signals, although it is highly expressed on red blood cells, endothelial cells undergoing neovascularization, and neuronal cells. The binding of chemokines by Duffy could modulate chemokine responses positively or negatively. Positive regulation could come through the presentation of chemokine to functional receptors, and negative regulation could come through Duffy competition with functional chemokine receptors for chemokine binding, thus serving as a decoy receptor. To determine whether Duffy has a role in angiogenesis and/or maintenance of homeostasis, we developed transgenic mice expressing mDuffy under the control of the preproendothelin promoter/enhancer (PPEP), which directs expression of the transgene to the endothelium. Two PPEP-mDuffy-transgenic founders were identified, and expression of the transgene in the endothelium was verified by Northern blot, RT-PCR, and immunostaining of tissues. The phenotype of the mice carrying the transgene appeared normal by all visual parameters. However, careful comparison of transgenic and nontransgenic mice revealed two phenotypic differences: mDuffy-transgenic mice exhibited a diminished angiogenic response to MIP-2 in the corneal micropocket assay, and mDuffy-transgenic mice exhibited enhanced hepatocellular toxicity and necrosis as compared with nontransgenic littermates in response to overdose of acetaminophen (APAP; 400 mg/kg body weight). Morover, APAP treatment was lethal in 50% of the mDuffy-transgenic mice 24 h post challenge, and 100% of the nontransgenic littermates survived this treatment at the 24 h time point. Our data suggest that enhanced expression of mDuffy on endothelial cells can lead to impaired angiogenic response to chemokines and impaired maintenance of homeostasis in response to toxic stresses.