Animal models of hepatotoxicity

An Insight into Different Experimental Models used for Hepatoprotective Studies: A Review

Numerous factors, including exposure to harmful substances, drinking too much alcohol, contracting certain hepatitis serotypes, and using specific medicines, contribute to the development of liver illnesses. Lipid peroxidation and other forms of oxidative stress are the main mechanisms by which hepatotoxic substances harm liver cells. Pathological changes in the liver include a rise in the levels of blood serum, a decrease in antioxidant enzymes, as well as the formation of free radical radicals. It is necessary to find pharmaceutical alternatives to treat liver diseases to increase their efficacy and decrease their toxicity. For the development of new therapeutic medications, a greater knowledge of primary mechanisms is required. In order to mimic human liver diseases, animal models are developed. Animal models have been used for several decades to study the pathogenesis of liver disorders and related toxicities. For many years, animal models have been utilized to investigate the pathophysiology of liver illness and associated toxicity. The animal models are created to imitate human hepatic disorders. This review enlisted numerous hepatic damage in vitro and in vivo models using various toxicants, their probable biochemical pathways and numerous metabolic pathways via oxidative stressors, different serum biomarkers enzymes are discussed, which will help to identify the most accurate and suitable model to test any plant preparations to check and evaluate their hepatoprotective properties.

Biofabricated Palladium Nanoparticle-Decorated Reduced Graphene Oxide Nanocomposite Using the Punica granatum (Pomegranate) Peel Extract: Investigation of Potent In Vivo Hepatoprotective Activity against Acetaminophen-Induced Liver Injury in Wistar Albino Rats

Acute acetaminophen (APAP) toxicity is a predominant clinical problem, which causes serious liver injury in both humans and experimental animals. This study presents the histological and biochemical factor and antioxidant enzyme level changes induced by an acute acetaminophen overdose in Wistar albino rat livers to elucidate the effective hepatoprotective potential of biofabricated palladium nanoparticle-decorated reduced graphene oxide nanocomposites (rGO/PdNPs-NC) compared to silymarin. After detailed characterization of the hepatoprotective potential of the synthesized rGO/PdNPs-NC, the rats were divided into eight groups (n = 6): control group (normal saline, 1 mL/kg b.w.), silymarin, Punica granatum (pomegranate) peel extract, PdNPs, reduced graphene oxide (rGO-PG), and reduced graphene oxide palladium nanocomposites (rGO/PdNPs-NC, low and high doses) for 7 successive days. The acetaminophen (APAP)-treated group was administered a single dose of acetaminophen (2 g/kg b.w.) on the 8th day. The histopathological results showed that the acetaminophen overdose group exhibited massive intrahepatic hemorrhagic necrosis around the centrilobular region with hepatocytes with vacuolization and swollen cytoplasm found in the liver architecture. This hepatopotential was further assessed by various biochemical parameters such as SGOT, SGPT, ALB, ALP, LDH, direct bilirubin, total bilirubin, and total protein. Also, the antioxidant parameters such as SOD, CAT, MDA, GSH, GRD, and GST were assayed. Rats of groups 7 and 8 showed a significant decrease in SGOT, SGPT, ALP, LDH, direct bilirubin, and total bilirubin (p < 0.001), while a significant increase in the final total protein and ALB as compared to group 2 rats (p < 0.001) was observed. The antioxidant parameters exhibited that rats of groups 7 and 8 showed a significant (p < 0.001) increase in the level of SOD, CAT, GSH, GRD, and GST without affecting the MDA as compared to group 2 rats. Also, the hepatoprotective potential of rGO/PdNPs-NC (low and high doses) was comparable to that of the standard reference drug silymarin. The present study reveals that the rGO/PdNPs-NC possesses significant hepatoprotective activity and acts as an effective and promising curative agent against acetaminophen-induced hepatotoxicity.

Hematological and Biochemical Responses of Newly Formulated Primary Root Canal Obturating Material: An In Vivo Study

Background and objective Any drug or medicinal agent, when implanted into the body, gets biotransformed by various organ systems and the toxic byproducts of this process alter the normal physiological process. In this experimental study, we aimed to quantify the safety of newly formulated primary root canal obturating material by investigating the hematological and biochemical parameters related to liver function. Methodology Forty-eight Wistar rats (weighing 250-350 grams) were classified into three groups (n=16) through random allocation. Preoperative blood samples were collected by puncturing the orbital venous plexus, the values of which were used as control. Zinc oxide eugenol (ZOE), calcium hydroxide iodoform paste (Metapex), and newly formulated triple antibiotic obturating paste (TAOP) were implanted (100 µg) into dorsal connective tissues. Blood samples on the seventh, 15th, and 30th postoperative days were evaluated respectively by analyzing hematological, hepatic, and, renal function tests for acute and chronic inflammatory responses. Results  The intra-group and inter-group comparisons among all the test materials after seven days exhibited high significance in terms of hemoglobin (Hb), mean corpuscular volume (MCV), neutrophils, and serum glutamic-oxaloacetic transaminase (SGOT) (p<0.001), while others showed mixed responses (p<0.05 to p>0.05). After 15 days, the comparisons showed high significance with respect to packed cell volume (PCV), mean cell volume (MCV), and serum creatinine (p<0.001), while others showed significant to nonsignificant differences (p<0.05 to p>0.05). At the end of 30 days, all the parameters showed mixed responses (p<0.001 to p>0.05). Conclusion The newly formulated obturating material TAOP showed lower adverse hematological, hepatic, and renal effects in experimental animals compared to other test materials, with most parameters reverting to normal after 30 days.

Mesenchymal stem cells protect against ferroptosis via exosome-mediated stabilization of SLC7A11 in acute liver injury

Mesenchymal stem cells (MSCs) have attracted interest for their potential to alleviate liver injury. Here, the protective effect of MSCs on carbon tetrachloride (CCl₄)-induced acute liver injury (ALI) was investigated. In this study, we illustrated a novel mechanism that ferroptosis, a newly recognized form of regulated cell death, contributed to CCl₄-induced ALI. Subsequently, based on the in vitro and in vivo evidence that MSCs and MSC-derived exosomes (MSC-Exo) treatment achieved pathological remission and inhibited the production of lipid peroxidation, we proposed an MSC-based therapy for CCl₄-induced ALI. More intriguingly, treatment with MSCs and MSC-Exo downregulated the mRNA level of prostaglandin-endoperoxide synthase 2 (Ptgs2) and lipoxygenases (LOXs) while it restored the protein level of SLC7A11 in primary hepatocytes and mouse liver, indicating that the inhibition of ferroptosis partly accounted for the protective effect of MSCs and MSC-Exo on ALI. We further revealed that MSC-Exo-induced expression of SLC7A11 protein was accompanied by increasing of CD44 and OTUB1. The aberrant expression of ubiquitinated SLC7A11 triggered by CCl₄ could be rescued with OTUB1-mediated deubiquitination, thus strengthening SLC7A11 stability and thereby leading to the activation of system X_C⁻ to prevent CCl₄-induced hepatocyte ferroptosis. In conclusion, we showed that MSC-Exo had a protective role against ferroptosis by maintaining SLC7A11 function, thus proposing a novel therapeutic strategy for ferroptosis-induced ALI.

Schematic diagram of the protective effect of MSC-derived exosomes on maintaining SLC7A11 function during ferroptosis involved in CCl₄-induced ALI.

Mitochondria as the Target of Hepatotoxicity and Drug-Induced Liver Injury: Molecular Mechanisms and Detection Methods

One of the major mechanisms of drug-induced liver injury includes mitochondrial perturbation and dysfunction. This is not a surprise, given that mitochondria are essential organelles in most cells, which are responsible for energy homeostasis and the regulation of cellular metabolism. Drug-induced mitochondrial dysfunction can be influenced by various factors and conditions, such as genetic predisposition, the presence of metabolic disorders and obesity, viral infections, as well as drugs. Despite the fact that many methods have been developed for studying mitochondrial function, there is still a need for advanced and integrative models and approaches more closely resembling liver physiology, which would take into account predisposing factors. This could reduce the costs of drug development by the early prediction of potential mitochondrial toxicity during pre-clinical tests and, especially, prevent serious complications observed in clinical settings.

Investigations of the antipyretic effect and safety of Prasachandaeng, a traditional remedy from Thailand national list of essential medicines

Prasachandaeng (PSD) remedy from the Thailand National List of Essential Medicines (NLEM) has been used as an antipyretic for chronic fever in both adults and children for centuries. Its therapeutic effect in treating fever and its safety have not been studied in animal models. We evaluated its antipyretic activity on lipopolysaccharide (LPS)-induced fever and safety in the liver in comparison with acetaminophen (ACP). Correlation between biochemistry of liver function and the level of cytochrome P450 (CYP2E1) was also evaluated using an ELISA kit. All doses of PSD powder (PSDP) and a 95% ethanol extract of PSD (PSDE) (50, 200, and 400 mg/kg) showed a significant antipyretic effect (* p < 0.05) as compared to ACP. We investigated clinical biochemistry of liver and kidney functions, histopathology, and concentrations of CYP2E1. All treatment groups demonstrated a normal range of clinical biochemistry of liver and kidney functions in comparison with ACP on days 1, 3, 7, and 10. Serum AST, ALP, and LDH levels of PSDE and PSDP showed mean values less than that of ACP on the corresponding days (* p < 0.05). None of the treatment groups showed evidence of hepatocellular damage, nor did they affect CYPE21. The results of histopathology on liver tissue correlated with the biochemistry of liver functions which indicated no hepatotoxicity effect in liver tissue during the seven day treatment. These findings suggest that both forms of PSD remedy possessed marked antipyretic activity and were not hepatotoxic during the seven days of administration in rats.

Chlorogenic acid alleviates thioacetamide-induced toxicity and promotes liver development in zebrafish (Danio rerio) through the Wnt signaling pathway

Chlorogenic acid (CGA) is a phenylpropanoid compound that is well known to improve the antioxidant capacity and other biological activities. However, the roles of CGA in the liver development of organisms are unclear. In the present study, we aimed to investigate the function of CGA in the hepatic development in thioacetamide (TAA)-induced zebrafish embryos. We found that CGA exerted certain beneficial effects on zebrafish larvae from TAA-exposed zebrafish embryos, such as increasing the liver size, body length, heart rate, acetylcholinesterase activity, and motor ability. In addition, CGA displayed an antioxidant effect on TAA-induced zebrafish embryos by enhancing the activities of superoxide dismutase (SOD), catalase (CAT), and glucose-6-phosphate dehydrogenase (G6PDH), and decreasing of the contents of malondialdehyde (MDA), reactive oxygen species (ROS), and nitric oxide (NO). The results of western blotting analysis showed that CGA inhibited cell apoptosis by increasing the levels of Bcl2 apoptosis regulator and decreasing the levels of Bcl2 associated X (Bax), apoptosis regulator and tumor protein P53. Moreover, CGA promoted cell proliferation in TAA-induced zebrafish larvae, as detected using proliferating cell nuclear antigen fluorescence immunostaining. In addition, CGA inhibited the expression of Wnt signaling pathway genes Dkk1 (encoding Dickkopf Wnt signaling pathway inhibitors), and promoted the expression of Lef1 (encoding lymphoid enhancer binding factor 1) and Wnt2bb (encoding wingless-type MMTV integration site family, member 2Bb). When the Wnt signal inhibitor IWR-1 was added, there was no significant change in liver development in the IWR-1 + TAA group compared with the IWR-1 + TAA + CGA group (p <0.05), which suggested that CGA regulates liver development via Wnt signaling pathway. Overall, our results suggested that CGA might alleviate TAA-induced toxicity in zebrafish and promote liver development through the Wnt signaling pathway, which provides a basis for the therapeutic effect of CGA on liver dysplasia.

Docetaxel and Lidocaine Co-Loaded (NLC-in-Hydrogel) Hybrid System Designed for the Treatment of Melanoma

Melanoma is the most aggressive skin carcinoma and nanotechnology can bring new options for its pharmacological treatment. Nanostructured lipid carriers (NLC) are ideal drug-delivery carriers for hydrophobic drugs, such as the antineoplastic docetaxel (DTX), and hybrid (NLC-in-hydrogel) systems are suitable for topical application. This work describes a formulation of NLC_DTX in xanthan-chitosan hydrogel containing lidocaine (LDC) with anticancer and analgesia effects. The optimized nanoparticles encapsulated 96% DTX and rheological analysis revealed inherent viscoelastic properties of the hydrogel. In vitro assays over murine fibroblasts (NIH/3T3) and melanoma cells (B16-F10), human keratinocytes (HaCaT) and melanoma cells (SK-MEL-103) showed reduction of docetaxel cytotoxicity after encapsulation in NLC_DTX and HGel-NLC_DTX. Addition of LDC to the hybrid system (HGel-NLC_DTX-LDC) increased cell death in tumor and normal cells. In vivo tests on C57BL/6J mice with B16-F10-induced melanoma indicated that LDC, NLC_DTX, HGel-NLC_DTX-LDC and NLC_DTX + HGel-LDC significantly inhibited tumor growth while microPET/SPECT/CT data suggest better prognosis with the hybrid treatment. No adverse effects were observed in cell survival, weight/feed-consumption or serum biochemical markers (ALT, AST, creatinine, urea) of animals treated with NLC_DTX or the hybrid system. These results confirm the adjuvant antitumor effect of lidocaine and endorse HGel-NLC_DTX-LDC as a promising formulation for the topical treatment of melanoma.

Hepatoprotective Effect of Apigenin Against Liver Injury via the Non-canonical NF-κB Pathway In Vivo and In Vitro

Apigenin, a flavonoid found in many plants, has various biological properties. We aimed to investigate the anti-inflammatory and anti-oxidative activity of apigenin against carbon tetrachloride (CCl₄)-induced acute liver injury in mice and hydrogen peroxide (H₂O₂)-induced oxidative stress in HepG2 cells and possible mechanism. In vivo, apigenin significantly reduced alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity in serum of mice challenged by CCl₄ and markedly alleviated the lipid peroxidation as indicated by the increased level of superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidases (GSH-Px) and catalase (CAT), and the decreased malondialdehyde (MDA) in liver tissue. Apigenin also ameliorated inflammation by downregulating tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and upregulating IL-10. Consistently, the elevated ALT and AST level; the impaired balance between SOD, GSH activity, and excessive ROS; and the increased gene expression of TNF-α and IL-6 resulting from H₂O₂-induced oxidative stress were restored by apigenin. Moreover, the results from Western blot, real-time qPCR, and immunofluorescence assay indicated that apigenin enhanced the activity of TNF receptor-associated factor (TRAF) 2/3 and cellular inhibitor of apoptosis protein (c-IAP) 1, ameliorated NF-κB-inducing kinase (NIK), and mediated the nuclear translocation of NF-κB2, therefore had an inhibitory effect on the non-canonical NF-κB pathway which was activated in both models. siNIK canceled the protective effect of apigenin on H₂O₂-induced HepG2 cells. Altogether, our results demonstrated that apigenin mitigated liver injury by ameliorating inflammation and oxidative stress through suppression of the non-canonical NF-κB pathway, indicating the potential of apigenin for treatment of the liver injury.

Effects of C60 Fullerene on Thioacetamide-Induced Rat Liver Toxicity and Gut Microbiome Changes

Thioacetamide (TAA) is widely used to study liver toxicity accompanied by oxidative stress, inflammation, cell necrosis, fibrosis, cholestasis, and hepatocellular carcinoma. As an efficient free radical's scavenger, C60 fullerene is considered a potential liver-protective agent in chemically-induced liver injury. In the present work, we examined the hepatoprotective effects of two C60 doses dissolved in virgin olive oil against TAA-induced hepatotoxicity in rats. We showed that TAA-induced increase in liver oxidative stress, judged by the changes in the activities of SOD, CAT, GPx, GR, GST, the content of GSH and 4-HNE, and expression of HO-1, MnSOD, and CuZnSOD, was more effectively ameliorated with a lower C60 dose. Improvement in liver antioxidative status caused by C60 was accompanied by a decrease in liver HMGB1 expression and an increase in nuclear Nrf2/NF-κB p65 ratio, suggesting a reduction in inflammation, necrosis and fibrosis. These results were in accordance with liver histology analysis, liver comet assay, and changes in serum levels of ALT, AST, and AP. The changes observed in gut microbiome support detrimental effects of TAA and hepatoprotective effects of low C60 dose. Less protective effects of a higher C60 dose could be a consequence of its enhanced aggregation and related pro-oxidant role.

Molecular mechanism of heavy metals (Lead, Chromium, Arsenic, Mercury, Nickel and Cadmium) - induced hepatotoxicity - A review

Heavy metals pose a serious threat if they go beyond permissible limits in our bodies. Much heavy metal's viz. Lead, Chromium, Arsenic, Mercury, Nickel, and Cadmium pose a serious threat when they go beyond permissible limits and cause hepatotoxicity. They cause the generation of ROS which in turn causes numerous injuries and undesirable changes in the liver. Epidemiological studies have shown an increase in the levels of such heavy metals in the environment posing a serious threat to human health. Epigenetic alterations have been seen in the event of exposure to such heavy metals. Apoptosis, caspase activation as well as ultrastructural changes in the hepatocytes have also been seen due to heavy metals. Inflammation involving TNF-alpha, pro-inflammatory cytokines, MAPK, ERK pathways have been seen in the event of heavy metal hepatotoxicity. All these have shown that these heavy metals pose a serious threat to human health in particular and the environment as a whole.

Elevated cAMP Protects against Diclofenac-Induced Toxicity in Primary Rat Hepatocytes: A Protective Effect Mediated by the Exchange Protein Directly Activated by cAMP/cAMP-Regulated Guanine Nucleotide Exchange Factors

Chronic consumption of the nonsteroidal anti-inflammatory drug diclofenac may induce drug-induced liver injury (DILI). The mechanism of diclofenac-induced liver injury is partially elucidated and involves mitochondrial damage. Elevated cAMP protects hepatocytes against bile acid-induced injury. However, it is unknown whether cAMP protects against DILI and, if so, which downstream targets of cAMP are implicated in the protective mechanism, including the classic protein kinase A (PKA) pathway or alternative pathways like the exchange protein directly activated by cAMP (EPAC). The aim of this study was to investigate whether cAMP and/or its downstream targets protect against diclofenac-induced injury in hepatocytes. Rat hepatocytes were exposed to 400 µmol/l diclofenac. Apoptosis and necrosis were measured by caspase-3 activity assay and Sytox green staining, respectively. Mitochondrial membrane potential (MMP) was measured by JC-10 staining. mRNA and protein expression were assessed by quantitative polymerase chain reaction (qPCR) and Western blot, respectively. The cAMP-elevating agent 7β-acetoxy-8,13-epoxy-1α,6β,9α-trihydroxylabd-14-en-11-one (forskolin), the pan-phosphodiesterase inhibitor IBMX, and EPAC inhibitors 5,7-dibromo-6-fluoro-3,4-dihydro-2-methyl-1(2H)-quinoline carboxaldehyde (CE3F4) and ESI-O5 were used to assess the role of cAMP and its effectors, PKA or EPAC. Diclofenac exposure induced apoptotic cell death and loss of MMP in hepatocytes. Both forskolin and IBMX prevented diclofenac-induced apoptosis. EPAC inhibition but not PKA inhibition abolished the protective effect of forskolin and IBMX. Forskolin and IBMX preserved the MMP, whereas both EPAC inhibitors diminished this effect. Both EPAC1 and EPAC2 were expressed in hepatocytes and localized in mitochondria. cAMP elevation protects hepatocytes against diclofenac-induced cell death, a process primarily involving EPACs. The cAMP/EPAC pathway may be a novel target for treatment of DILI. SIGNIFICANCE STATEMENT: This study shows two main highlights. First, elevated cAMP levels protect against diclofenac-induced apoptosis in primary hepatocytes via maintenance of mitochondrial integrity. In addition, this study proposes the existence of mitochondrial cAMP-EPAC microdomains in rat hepatocytes, opening new avenues for targeted therapy in drug-induced liver injury (DILI). Both EPAC1 and EPAC2, but not protein kinase A, are responsible for this protective effect. Our findings present cAMP-EPAC as a potential target for the treatment of DILI and liver injury involving mitochondrial dysfunction.

Devices and techniques used to obtain and analyze three-dimensional cell cultures

Cell cultures are indispensable for both basic and applied research. Advancements in cell culture and analysis increase their utility for basic research and translational applications. A marked development in this direction is advent of three-dimensional (3D) cultures. The extent of advancement in 3D cell culture methods over the past decade has warranted referring to a single cell type being cultured as an aggregate or spheroid using simple scaffolds as "traditional." In recent years, the development of "next-generation" devices has enabled cultured cells to mimic their natural environments much better than the traditional 3D culture systems. Automated platforms like chip-based devices, magnetic- and acoustics-based assembly devices, di-electrophoresis (DEP), micro pocket cultures (MPoC), and 3D bio-printing provide a dynamic environment compared to the rather static conditions of the traditional simple scaffold-based 3D cultures. Chip-based technologies, which are centered on principles of microfluidics, are revolutionizing the ways in which cell culture and analysis can be compacted into table-top instruments. A parallel evolution in analytical devices enabled efficient assessment of various complex physiological and pathological endpoints. This is augmented by concurrent development of software enabling rapid large-scale automated data acquisition and analysis like image cytometry, elastography, optical coherence tomography, surface-enhanced Raman scattering (SERS), and biosensors. The techniques and devices utilized for the purpose of 3D cell culture and subsequent analysis depend primarily on the requirement of the study. We present here an in-depth account of the devices for obtaining and analyzing 3D cell cultures.

Gigantol ameliorates CCl4-induced liver injury via preventing activation of JNK/cPLA2/12-LOX inflammatory pathway

Arachidonic acid (AA) signaling pathway is an important constituent of inflammatory processes. In our previous study, it was found that dihydro-stilbene gigantol relieved hepatic inflammation in mice with CCl₄-induced acute liver injury. This study aimed to investigate the involvement of arachidonate metabolic cascade in this process. Our results showed CCl₄ activated AA metabolism with the evidence of cPLA2 phosphorylation, which was dependent on the MAPK/JNK activation. Pretreatment with JNK inhibitor SU3327 or gigantol abolished the cPLA2 activation, along with the attenuation of liver damage. Besides, gigantol markedly decreased immune cells activation. Metabolomic analysis revealed that gigantol universally reversed the upregulation of major AA metabolites in injured mouse livers induced by CCl₄, especially 12-hydroxyeicosatetraenoic acid (12-HETE). Gigantol also decreased the mRNA and protein expression of platelet-, and leukocyte-type 12-lipoxxygenase (LOX) in the liver. Furthermore, pan-LOX inhibitor nordihydroguaiaretic acid (NDGA) and specific 12-LOX inhibitors baicalein and ML351 attenuated the liver injury to the same extent as gigantol. Overall, our study elucidated a comprehensive profile of AA metabolites during hepatic inflammation caused by CCl₄, highlighting the role of 12-LOX-12-HETE pathway in this process. And gigantol alleviated liver inflammation partly through inhibiting the JNK/cPLA2/12-LOX pathway.

Nicorandil and atorvastatin attenuate carbon tetrachloride - induced liver fibrosis in rats

PURPOSE

The present study aimed to evaluate the possible hepatoprotective effects of nicorandil and atorvastatin against experimentally induced liver fibrosis.

MATERIALS AND METHODS

Wistar male rats wereassigned tofivegroups; control group, fibrosis group, the remaining three groups received in addition to CCl₄, N-acetyl cysteine (300 mg/kg), nicorandil(15 mg/kg) and atorvastatin (20 mg/kg), respectively. Liver fibrosis was induced by intraperitoneal injection of rats with CCl₄ (2 ml/kg), twice weekly for five consecutive weeks. All treatments were administered daily starting from the first day of fibrosis induction for five consecutive weeks. By the end of the experiment, fibrosis biomarkers [hepatic transforming growth factor β1 (TGF-β₁) and hydroxyproline (HYP)], liver function [serum alanine transaminase (ALT), aspartate transaminase (AST), albumin and total bilirubin] were assessed. Moreover, lipid profile [total cholesterol, serum triglycerides, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C)], inflammatory biomarkers [hepatic myeloperoxidase (MPO), serum tumor necrosis factor alpha (TNF-α)], relative liver weight] and oxidative stress biomarkers [malondialdehyde (MDA), glutathione (GSH) and catalase (CAT)] were evaluated. In support, histopathological and immunohistochemical examination of liver alpha smooth muscle actin (α-SMA) were performed.

RESULTS

Nicorandil and atorvastatin effectively reduced fibrosis and liver function biomarkers. They both restored serum lipid profile, TNF-α, MPO, relative liver weight, and hepatic MDA content. Alternatively, they markedly elevated albumin, HDL-C and hepatic content of GSH and CAT. Additionally, a marked histopathological and immunohistochemical improvement of α-SMA was observed.

CONCLUSION

Nicorandil and atorvastatin might be promising protective agents against liver fibrosis through amelioration of liver function, modulation of fibrous formation, anti-inflammatory and antioxidant potentials.

A simplified 3D liver microsphere tissue culture model for hepatic cell signaling and drug-induced hepatotoxicity studies

Although a number of experimental models have been developed for liver research, each has its own advantages and disadvantages. The present study attempted to develop a simple and effective 3‑dimensional mouse liver microsphere tissue culture (LMTC) model in vitro for the analysis of hepatic functions. Hepatic characteristics and potential applications of this model were compared with that of mouse model in vivo and mouse primary hepatocytes in vitro. Using freshly‑perfused mouse liver tissue passed through 80‑mesh sift strainer (sift80), it was demonstrated that under the optimal culture conditions, the sift80 microsphere tissue cultured in 2% bovine calf serum medium remained viable with marked proliferating cell nuclear antigen and anti‑Myc proto‑oncogene protein expression, exhibited normal hepatic functions including indocyanine green (ICG) uptake/release and periodic acid‑Schiff staining, and expressed hepatocyte‑specific genes for up to 2 weeks. The microsphere tissue was responsive to bone morphogenic protein 9 (BMP9) stimulation leading to upregulation of downstream targets of BMP9 signaling. Furthermore, 3 commonly‑used liver‑damaging drugs were indicated to effectively inhibit hepatic ICG uptake, and induce the expression of hepatotoxicity‑associated genes. Therefore, this simplified LMTC model may be a useful in vitro tissue culture model to investigate drug‑induced liver injury and metabolism, and hepatocyte‑based cell singling.

Histopathological and biochemical assessment of liver damage in albino Wistar rats treated with cytotoxic platinum compounds in combination with 5-fluorouracil

INTRODUCTION

Chemotherapy-induced hepatotoxicity in cancer patients often results in cessation of therapy and prevents completion of the treatment plan. The entire pathological description and comparison of hepatic damage induced by oxaliplatin or cisplatin in combination with 5-fluorouracil (5-FU) is not adequately reported. This study reports histopathological assessment of hepatotoxicity of a non-tumor bearing organ in rats treated with 5-FU, oxaliplatin and cisplatin (CDDP).

MATERIAL AND METHODS

Changes in hepatic biochemical profile of 36 albino Wistar rats equally divided into different treatment groups with cisplatin, oxaliplatin, 5-FU, cisplatin plus 5-FU and oxaliplatin plus 5-FU were compared with a group of rats treated with normal saline (control group). At the end of treatments, hepatic tissues were taken for blinded histopathological assessment by light microscopy.

RESULTS

Serum glutamate pyruvate transaminase and serum glutamic-oxaloacetic transaminase levels were disrupted in rats treated with 5-FU alone and in combination with cisplatin or oxaliplatin. Hepatocellular injuries, e.g. sinusoidal dilatation, venular fibrosis and centrilobular vein injury induced by oxaliplatin were intensified in treatment groups also receiving 5-FU, manifested as massive architectural distortion, periportal fibrosis, hepatic cord degeneration and cystic lesions with demarcated margins. Hepatocellular degenerative sequence and abnormally dilated central hepatic vein was shown in the cisplatin plus 5-FU treatment group with hemorrhage and blood filled sinusoids.

CONCLUSIONS

Oxaliplatin-associated cystic lesions were intensified in rats treated with a combination of 5-FU and oxaliplatin.

Mapping novel genetic loci associated with female liver weight variations using Collaborative Cross mice

BACKGROUND

Liver weight is a complex trait, controlled by polygenic factors and differs within populations. Dissecting the genetic architecture underlying these variations will facilitate the search for key role candidate genes involved directly in the hepatomegaly process and indirectly involved in related diseases etiology.

METHODS

Liver weight of 506 mice generated from 39 different Collaborative Cross (CC) lines with both sexes at age 20 weeks old was determined using an electronic balance. Genomic DNA of the CC lines was genotyped with high-density single nucleotide polymorphic markers.

RESULTS

Statistical analysis revealed a significant (P < 0.05) variation of liver weight between the CC lines, with broad sense heritability (H 2) of 0.32 and genetic coefficient of variation (CVG) of 0.28. Subsequently, quantitative trait locus (QTL) mapping was performed, and results showed a significant QTL only for females on chromosome 8 at genomic interval 88.61-93.38 Mb (4.77 Mb). Three suggestive QTL were mapped at chromosomes 4, 12 and 13. The four QTL were designated as LWL1-LWL4 referring to liver weight loci 1-4 on chromosomes 8, 4, 12 and 13, respectively.

CONCLUSION

To our knowledge, this report presents, for the first time, the utilization of the CC for mapping QTL associated with baseline liver weight in mice. Our findings demonstrate that liver weight is a complex trait controlled by multiple genetic factors that differ significantly between sexes.

Antioxidative and Protective Actions of Apigenin in a Paracetamol-Induced Hepatotoxicity Rat Model

BACKGROUND AND OBJECTIVES

Apigenin is known to have various pharmacological properties without causing significant toxicity; however, hepatoprotective effect of apigenin is not often reported. The aim of our study was to investigate if the alterations in lipid peroxidation and antioxidant status are in favor to prove the efficacy of apigenin against paracetamol-induced hepatotoxicity.

METHODS

The effect of apigenin on paracetamol-induced hepatotoxicity in rats was examined by determining biochemical parameters, histological assessment and oxidative status in liver homogenates.

RESULTS

The treatment of animals with both apigenin and paracetamol attenuates the parameters of hepatotoxicity, especially for ALT and ALP activity which was significantly lower compared to groups of animals treated with saline and paracetamol. Hepatotoxicity induced by toxic dose of paracetamol was revealed also by notable histopathological alterations, which were not observed in the group treated with paracetamol together with apigenin. Apigenin also prevented paracetamol-induced increase in malondialdehyde (MDA) level. The activities of both CAT (catalase) and GR (glutathione reductase) enzymes after the toxic dose of paracetamol were significantly increased in the liver homogenates, compared to control group. Apigenin reversed these parameters near to values of control group.

CONCLUSIONS

The result of our study indicates that apigenin inhibits the level of lipid peroxidation and significantly increases the enzyme antioxidant defense mechanisms in paracetamol-induced hepatotoxicity in rats.

Microscale 3D Liver Bioreactor for In Vitro Hepatotoxicity Testing under Perfusion Conditions

The accurate prediction of hepatotoxicity demands validated human in vitro models that can close the gap between preclinical animal studies and clinical trials. In this study we investigated the response of primary human liver cells to toxic drug exposure in a perfused microscale 3D liver bioreactor. The cellularized bioreactors were treated with 5, 10, or 30 mM acetaminophen (APAP) used as a reference substance. Lactate production significantly decreased upon treatment with 30 mM APAP (p < 0.05) and ammonia release significantly increased in bioreactors treated with 10 or 30 mM APAP (p < 0.0001), indicating APAP-induced dose-dependent toxicity. The release of prostaglandin E2 showed a significant increase at 30 mM APAP (p < 0.05), suggesting an inflammatory reaction towards enhanced cellular stress. The expression of genes involved in drug metabolism, antioxidant reactions, urea synthesis, and apoptosis was differentially influenced by APAP exposure. Histological examinations revealed that primary human liver cells in untreated control bioreactors were reorganized in tissue-like cell aggregates. These aggregates were partly disintegrated upon APAP treatment, lacking expression of hepatocyte-specific proteins and transporters. In conclusion, our results validate the suitability of the microscale 3D liver bioreactor to detect hepatotoxic effects of drugs in vitro under perfusion conditions.

Expression of classical mediators in hearts of rats with hepatic dysfunction

Liver cirrhosis is associated with impairment of cardiovascular function including alterations of the heart innervation, humoral and nervous dysregulation, changes in systemic circulation and electrophysiological abnormalities. Choline acetyltransferase (ChAT), enzyme forming acetylcholine, tyrosine hydroxylase (TH), and dopamine-β-hydroxylase (DBH), enzymes participating in noradrenaline synthesis, are responsible for the production of classical neurotransmitters, and atrial natriuretic peptide (ANP) is produced by cardiomyocytes. The aim of this study was to evaluate the influence of experimentally induced hepatic dysfunction on the expression of proANP, ChAT, TH, and DBH in the heart. Hepatic dysfunction was induced by application of thioacetamide (TAA) or by ligation of bile duct. Biochemical parameters of hepatic injury and levels of peroxidation in the liver and heart were measured. Liver enzymes measured in the plasma were significantly elevated. Cardiac level of peroxidation was increased in operated but not TAA group animals. In the left atrium of operated rats, the expression of TH and DBH was lower, while expression of ChAT remained unchanged. In TAA group, no significant differences in the expression of the genes compared to controls were observed. Liver injury induced by ligation leads to an imbalance in the intracardiac innervation, which might impair nervous control of the heart.

Protective effects of theasinensin A against carbon tetrachloride-induced liver injury in mice

TSA markedly reduced the CCl₄-induced liver injury in mice.