The role of the immune system in nevirapine-induced subclinical liver injury of a rat model

Lymphocyte Index of Peripheral Blood in Rats at Different Stages of the Post-Stress Period under Conditions of Antigenic Exposure and Injection of Lipopolysaccharide

Changes in the Shaganin lymphocyte index (ratio of the number of lymphocytes to segmented neutrophils) in the peripheral blood of rats after intraperitoneal administration of LPS (100 μg/kg) at the end of a single stress exposure in a model of 24-h restraint stress were studied. The lymphocyte index was analyzed 3 h later, on the 1st and 8th days after the stress load. Immobilization was accompanied by a decrease in this parameter 3 h after exposure. One day after the stress load, an increase in the lymphocyte index was noted, which remained on the 8th day of observation. LPS injection did not affect the changes in this parameter caused by 24-h immobilization on the 1st and 8th days of the study, but prevented a pronounced increase in the lymphocyte index on the 1st day after the stress load. The data obtained expand the existing scientific understanding of the specificity of the involvement of immunomodulatory substances in the implementation of adaptive-compensatory processes in mammals under conditions of emotional stress.

NNRTI and Liver Damage: Evidence of Their Association and the Mechanisms Involved

Due to the improved effectiveness and safety of combined antiretroviral therapy, human immunodeficiency virus (HIV) infection has become a manageable, chronic condition rather than a mortal disease. However, HIV patients are at increased risk of experiencing non-AIDS-defining illnesses, with liver-related injury standing out as one of the leading causes of death among these patients. In addition to more HIV-specific processes, such as antiretroviral drug-related toxicity and direct injury to the liver by the virus itself, its pathogenesis is related to conditions that are also common in the general population, such as alcoholic and non-alcoholic fatty liver disease, viral hepatitis, and ageing. Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are essential components of combined anti-HIV treatment due to their unique antiviral activity, high specificity, and acceptable toxicity. While first-generation NNRTIs (nevirapine and efavirenz) have been related largely to liver toxicity, those belonging to the second generation (etravirine, rilpivirine and doravirine) seem to be generally safe for the liver. Indeed, there is preclinical evidence of rilpivirine being hepatoprotective in different models of liver injury, independently of the presence of HIV. The present study aims to review the mechanisms by which currently available anti-HIV drugs belonging to the NNRTI family may participate in the development of liver disease.

Rosmarinic Acid Protects Mice from Concanavalin A-Induced Hepatic Injury through AMPK Signaling

Rosmarinic acid (RA) is extensively utilized in herbal medicine in China. The AMP-activated protein kinase (AMPK) signaling can be activated by RA and inhibited by the synthetic, reversible AMP-competitive inhibitor, Compound C (CC). The objective of this study was to investigate the role of AMPK signaling involving the protective effects of RA on concanavalin A (Con A)-induced autoimmune hepatitis (AIH) in mice. BALB/c mice were treated with RA, with or without CC, followed by the pretreatment with Con A. Analysis of serum aminotransferases and cytokines were conducted and liver tissue histology was performed to evaluate hepatic injury. Cytokine levels in serum and hepatic tissue were respectively measured by enzyme-linked immunoassay (ELISA) and used quantitative (q)PCR. Levels of phosphorylated acetyl CoA carboxylase in the liver, representing AMPK activation, were detected by Western blotting. Compared with the Con A group, serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in RA group (100 and 150 mg/kg/d) were significantly reduced. RA also reduced hepatocyte swelling, cell death, and infiltration of leukocytes in the liver of Con A-treated mice. Serum levels of cytokines, such as interferon-γ (IFN-γ), interleukin-2 (IL-2) and interleukin-1β (IL-1β), were reduced by RA pretreatment, while the levels of serum interleukin-10 (IL-10), an anti-inflammatory cytokine, was elevated. These protective effects were reversed by treatment with CC. RA treatment reduced the hepatic damage via the activation of AMPK in the mice of Con A-induced. So RA acts as a potential part in the therapy of autoimmune hepatitis.

Clinical and genetic factors associated with increased risk of severe liver toxicity in a monocentric cohort of HIV positive patients receiving nevirapine-based antiretroviral therapy

Background

Nevirapine has been used as antiretroviral agent since early ‘90. Although nevirapine is not currently recommended in initial anti-HIV regimens, its use remains consistent in a certain number of HIV-1-positive subjects. Thus, our aim was to determine clinical and genetic factors involved in the development of severe nevirapine induced liver toxicity.

Methods

We retrospectively analyzed all HIV positive patients who were followed at the Infectious Diseases Unit, DIBIC Luigi Sacco, University of Milan from May 2011 to December 2015. All patients treated with nevirapine who underwent a genotyping for the functional variants mapping into ABCB1, CYP2B6, CYP3A4 and CYP3A5 genes were included in the analysis. Severe hepatotoxicity was defined as ACTG grade 3–4 AST/ALT increase during the first three months of nevirapine treatment. The causality assessment between NVP exposure and drug-induced liver injury was performed by using the updated Roussel Uclaf Causality Assessment Methods. Hardy Weinberg equilibrium was tested by χ² test. A multivariable logistic regression model was constructed using a backward elimination method.

Results

Three hundred and sixty-two patients were included in the analysis, of which 8 (2.2%) experienced a severe liver toxicity. We observed no differences between patients with and without liver toxicity as regards gender, ethnicity, age and immune-virological status. A higher prevalence of HCV coinfection (75.0% vs 30.2%; p = .0013) and higher baseline AST (58 IU/L vs 26 IU/L; p = 0.041) and ALT (82 IU/L vs 27 IU/L; p = 0.047) median levels were observed in patients with liver toxicity vs those without toxicity. The genotypes CT/TT at ABCB1 rs1045642 single nucleotide polymorphism (SNP), showed a protective effect for liver toxicity when compared with genotype CC (OR = 0.18, 95%CI 0.04–0.76; p = 0.020) in univariate analysis. In the multivariate model, HCV coinfection was independently associated with higher risk of developing liver toxicity (aOR = 8.00, 95%CI 1.27–50.29; p = 0.027), whereas ABCB1 rs1045642 CT/TT genotypes (aOR = 0.10, 95%CI 0.02–0.47; p = 0.004) was associated with a lower risk.

Conclusions

According to our findings HCV coinfection and ABCB1 rs1045642 SNP represent independent determinants of severe liver toxicity related to nevirapine. This genetic evaluation could be included as toxicity assessment in HIV-1-positive subjects treated with nevirapine.

Herbal Compound "Jiedu Huayu" Reduces Liver Injury in Rats via Regulation of IL-2, TLR4, and PCNA Expression Levels

Aim of the Study. To investigate the preventative effects of Jiedu Huayu (JDHY) on D-galactosamine (D-GalN) and lipopolysaccharide-induced acute liver failure (ALF) and to evaluate the possible mechanisms of action. Materials and Methods. ALF was induced in Wistar rats by administrating D-GalN (900 mg/kg) and lipopolysaccharide (10 μg/kg). After treatment with JDHY granules, the levels of blood alanine aminotransferase, aspartate aminotransferase, total bilirubin, and prothrombin time were determined. Proliferating cell nuclear antigen was detected by immunohistochemistry staining. The expression of interleukin-2 (IL-2) and toll-like receptor 4 (TLR4) was examined by fluorescence quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot. Results. JDHY treatment dramatically improved liver function and increased survival rates in an ALF model in rats. We observed a decrease in IL-2 and TLR4 expression following treatment with JDHY in liver cells from ALF rats using qRT-PCR and Western blot analysis. Conclusion. We hypothesize that the therapeutic potential of JDHY for treating ALF is due to its modulatory effect on the suppression of inflammation and by promoting hepatocyte regeneration. Our results contribute towards validation of the traditional use of JDHY in the treatment of liver disease.

Idiosyncratic Drug-Induced Liver Injury (IDILI): Potential Mechanisms and Predictive Assays

Idiosyncratic drug-induced liver injury (IDILI) is a significant source of drug recall and acute liver failure (ALF) in the United States. While current drug development processes emphasize general toxicity and drug metabolizing enzyme- (DME-) mediated toxicity, it has been challenging to develop comprehensive models for assessing complete idiosyncratic potential. In this review, we describe the enzymes and proteins that contain polymorphisms believed to contribute to IDILI, including ones that affect phase I and phase II metabolism, antioxidant enzymes, drug transporters, inflammation, and human leukocyte antigen (HLA). We then describe the various assays that have been developed to detect individual reactions focusing on each of the mechanisms described in the background. Finally, we examine current trends in developing comprehensive models for examining these mechanisms. There is an urgent need to develop a panel of multiparametric assays for diagnosing individual toxicity potential.

Changes in IL-2 and IL-10 during Chronic Administration of Isoniazid, Nevirapine, and Paracetamol in Rats

The aim of this study was to illustrate the initial subclinical drug-induced liver injury and the associated adaptive immune response by monitoring for the changes in plasma IL-2, IL-10, and some cytochrome P450 activity during chronic administration of nevirapine (NVP), isoniazid (INH), and paracetamol (PAR) in rats without clinical hepatotoxicity. Male Sprague-Dawley (SD) rats were divided into four groups (saline (S), NVP, INH, and PAR) of 25 animals each. The drugs were administered daily for 42 days at therapeutic doses (NVP 200 mg/kg, PAR 500 mg/kg, and INH 20 mg/kg) to the respective groups by oral gavage and five rats per group were sacrificed weekly. All the three drugs induced a subclinical liver injury in the first 2-3 weeks followed by healing, indicating adaption. The liver injury was pathologically similar and was associated with immune stimulation and increased cytochrome P450 activity. NVP- and PAR-induced liver injury lasted up to 14 days while that for INH lasted for 28 days. NVP-induced liver injury was associated with increased IL-2, CD4 count, and CYP3A2 activity, followed by increased IL-10 during the healing phase. In conclusion, the initial drug-induced subclinical liver injury, its spontaneous healing, and the associated adaptive immune response have been demonstrated.

Dynamics of changes in nociceptive reactions of rats after peripheral administration of lipopolysaccharide

The type of changes in nociceptive reactions of rats was studied at various time intervals after intraperitoneal injection of LPS in a dose of 30 μg/kg. The perceptual component of nociception in animals was evaluated from the tail-flick latency in response to light-heat stimulation. The emotional component of nociception in rats was determined from the vocalization threshold during electrocutaneous stimulation of the tail. The tail-flick latency of animals under conditions of light-heat stimulation was shown to decrease 1 day after peripheral administration of LPS, which illustrates an increase in the perceptual component of nociception at the relatively early stage of antigenic stimulation. A significant decrease in the tail-flick latency and vocalization threshold in rats in response to nociceptive stimulation was observed on day 7 after LPS injection. These changes demonstrate an increase in the perceptual and emotional components of nociception at the late period after antigen exposure. Our results indicate that antigenic stimulation due to peripheral administration of LPS is followed by the increase in nociceptive sensitivity of rats. LPS-induced variations in the emotional and perceptual components of nociception in animals suggest the existence of specific mechanisms for systemic regulation of pain. They probably depend on the period of study and type of immune reactions during antigenic stimulation.

Cytokine levels in rat blood and brain structures after administration of lipopolysaccharide

We compared cytokine profile of rat serum and brain structures after immune status modulation by LPS (30 μg/kg intraperitoneally). The content of inflammatory (IL-1α, IL-1β, IL-2, IL-6, IFN-γ, and TNF-α) and anti-inflammatory (IL-4 and IL-10) cytokines in biological samples of animals was measured on days 1 and 7 after antigenic stimulation. LPS administration reduced the levels of both inflammatory and anti-inflammatory cytokines in the peripheral blood of the rats, especially on the 1st day. LPS administration was also accompanied by specific changes in cytokine content in the dorsal hippocampus and anterior cingulate cortex. Antigenic stimulation increased the level of anti-inflammatory cytokines IL-4 and IL-10 in the examined brain tissues, the changes were most pronounced on day 1 after LPS injection. No significant changes in the levels of proinflammatory cytokines in the brain tissue of animals were found at the above terms after LPS injection. Thus, peripheral LPS administration to rats shifts the balance between the inflammatory and anti-inflammatory cytokines in the CNS structures towards the latter.