Dexamethasone counteracts hepatic inflammation and oxidative stress in cholestatic rats via CAR activation

Evolution of therapeutic strategy based on oxidant-antioxidant balance for fuchs endothelial corneal dystrophy

Fuchs endothelial corneal dystrophy (FECD) stands as the most prevalent primary corneal endothelial dystrophy worldwide, posing a significant risk to corneal homeostasis and clarity. Corneal endothelial cells exhibit susceptibility to oxidative stress, suggesting a nuanced relationship between oxidant-antioxidant imbalance and FECD pathogenesis, irrespective of FECD genotype. Given the constrained availability of corneal transplants, exploration into non-surgical interventions becomes crucial. This encompasses traditional antioxidants, small molecule compounds, biologics, and diverse non-drug therapies, such as gene-related therapy, hydrogen therapy and near infrared light therapy. This review concentrates on elucidating the mechanisms behind oxidant-antioxidant imbalance and the evolution of strategies to restore oxidant-antioxidant balance in FECD. It provides a comprehensive overview of both conventional and emerging therapeutic approaches, offering valuable insights for the advancement of non-surgical treatment modalities. The findings herein might establish a robust foundation for future research and the therapeutic strategy of FECD.

Anti-HER2 Super Stealth Immunoliposomes for Targeted-Chemotherapy

Liposomes play an important role in the field of drug delivery by virtue of their biocompatibility and versatility as carriers. Stealth liposomes, obtained by surface decoration with hydrophilic polyethylene glycol (PEG) molecules, represent an important turning point in liposome technology, leading to significant improvements in the pharmacokinetic profile compared to naked liposomes. Nevertheless, the generation of effective targeted liposomes-a central issue for cancer therapy-has faced several difficulties and clinical phase failures. Active targeting remains a challenge for liposomes. In this direction, a new Super Stealth Immunoliposomes (SSIL2) composed of a PEG-bi-phospholipids derivative is designed that stabilizes the polymer shielding over the liposomes. Furthermore, its counterpart, conjugated to the fragment antigen-binding of trastuzumab (Fab'TRZ -PEG-bi-phospholipids), is firmly anchored on the liposomes surface and correctly orients outward the targeting moiety. Throughout this study, the performances of SSIL2 are evaluated and compared to classic stealth liposomes and stealth immunoliposomes in vitro in a panel of cell lines and in vivo studies in zebrafish larvae and rodent models. Overall, SSIL2 shows superior in vitro and in vivo outcomes, both in terms of safety and anticancer efficacy, thus representing a step forward in targeted cancer therapy, and valuable for future development.

Ketogenic Diet Alleviates Brain Iron Deposition and Cognitive Dysfunction via Nrf2-mediated Ferroptosis pathway in APP/PS1 Mouse

Progressive cognitive decline and increased brain iron deposition with age are important features of Alzheimer's disease. Previous studies have found that the short-term ketogenic diet has neuroprotective effects in a variety of neurodegenerative diseases, but the effects of an early and long-term ketogenic diet on brain iron content and cognition of Alzheimer's disease have not been reported. In our study, 8-week-old APP/PS1 mice were given a 12-month ketogenic or standard diet, while C57BL/6 mice matched with the age and genetic background of APP/PS1 mice were used as normal controls to be given a standard diet for the same length of time. We found that 12 months of an early ketogenic diet improved the impaired learning and memory ability of APP/PS1 mice. The improvement of cognitive function may be related to the reduction of amyloid-beta deposition and neuronal ferroptosis. The mechanism was achieved by the regulation of ferroptosis-related pathways after activation of nuclear factor erythroid 2-related factor 2 by ketogenic diet-induced elevated β-hydroxybutyrate. In addition, blood biochemical results showed that compared with the standard diet group of the disease, although the early and long-term ketogenic diet increased blood lipids to some extent, it seemed to reduce liver, renal, and myocardial damage caused by genetic differences. This will provide a piece of positive evidence for the early and long-term use of ketogenic diets in people at risk of Alzheimer's disease.

Non-alcoholic Fatty Liver Disease (NAFLD), Type 2 Diabetes, and Non-viral Hepatocarcinoma: Pathophysiological Mechanisms and New Therapeutic Strategies

In recent years, the incidence of non-viral hepatocellular carcinoma (HCC) has increased dramatically, which is probably related to the increased prevalence of metabolic syndrome, together with obesity and type 2 diabetes mellitus (T2DM). Several epidemiological studies have established the association between T2DM and the incidence of HCC and have demonstrated the role of diabetes mellitus as an independent risk factor for the development of HCC. The pathophysiological mechanisms underlying the development of Non-alcoholic fatty liver disease (NAFLD) and its progression to Non-alcoholic steatohepatitis (NASH) and cirrhosis are various and involve pro-inflammatory agents, oxidative stress, apoptosis, adipokines, JNK-1 activation, increased IGF-1 activity, immunomodulation, and alteration of the gut microbiota. Moreover, these mechanisms are thought to play a significant role in the development of NAFLD-related hepatocellular carcinoma. Early diagnosis and the timely correction of risk factors are essential to prevent the onset of liver fibrosis and HCC. The purpose of this review is to summarize the current evidence on the association among obesity, NASH/NAFLD, T2DM, and HCC, with an emphasis on clinical impact. In addition, we will examine the main mechanisms underlying this complex relationship, and the promising strategies that have recently emerged for these diseases' treatments.

Grape seed meal by-product is able to counteract oxidative stress induced by lipopolysaccharide and dextran sulphate in IPEC cells and piglets after weaning

Oxidative stress is a pivotal factor in the pathogenesis of intestinal inflammation, leading to cellular damage and tissue injury. Natural antioxidants compounds found in agro-industrial by-products have proven their effectiveness in treatment of intestinal inflammation and oxidative stress, exhibiting many favourable effects. The aim of this study was to evaluate the capacity of a grape seed meal byproduct (GSM) to counteract the effects induced by E. coli lipopolysaccharide (LPS, 5μg/ml) in vitro on IPEC-1 cells and by dextran sulphate sodium (DSS, 1g/b.w./day) in vivo on piglets after weaning. Reactive oxygen species (ROS), pro-oxidant markers (malondialdehyde MDA, thiobarbituric acid reactive substances TBARS, protein carbonyl, DNA oxidative damage) antioxidant enzymes (catalase -CAT, superoxide dismutase -SOD, glutathione peroxidase -GPx, endothelial and inducible nitric oxide synthases -eNOS and iNOS) and several important components of Keap1/Nrf2 signalling pathway were analysed in IPEC-1 cells as well as in piglet's colon and lymph nodes. Our results demonstrated that GSM extract or 8% dietary GSM showed anti-oxidant properties counteracting the pro-oxidant response (ROS, MDA-TBARS, protein carbonyl, DNA/RNA damage) induced by LPS or DSS and restoring the levels of endogenous antioxidant enzymes, including CAT, SOD, GPx, eNOS and iNOS in colon and mesenteric lymph nodes. These beneficial effects were modulated via Nrf2 signalling pathway in both in vitro and in vivo studies.

The phenolic compounds tyrosol and hydroxytyrosol counteract liver fibrogenesis via the transcriptional modulation of NADPH oxidases and oxidative stress-related miRNAs

Liver fibrosis is the result of a chronic pathological condition caused by the activation of hepatic stellate cells (HSCs), which induces the excessive deposition of extracellular matrix. Fibrogenesis is sustained by an exaggerated production of reactive oxidative species (ROS) by NADPH oxidases (NOXs), which are overactivated in hepatic inflammation. In this study, we investigated the antifibrotic properties of two phenolic compounds of natural origin, tyrosol (Tyr) and hydroxytyrosol (HTyr), known for their antioxidant and anti-inflammatory effects. We assessed Tyr and HTyr antifibrotic and antioxidant activity both in vitro, by a co-culture of LX2, HepG2 and THP1-derived Mϕ macrophages, set up to simulate the hepatic microenvironment, and in vivo, in a mouse model of liver fibrosis obtained by carbon tetrachloride treatment. We evaluated the mRNA and protein expression of profibrotic and oxidative markers (α-SMA, COL1A1, NOX1/4) by qPCR and/or immunocytochemistry or immunohistochemistry. The expression of selected miRNAs in mouse livers were measured by qPCR. Tyr and HTyr reduces fibrogenesis in vitro and in vivo, by downregulating all fibrotic markers. Notably, they also modulated oxidative stress by restoring the physiological levels of NOX1 and NOX4. In vivo, this effect was accompanied by a transcriptional regulation of inflammatory genes and of 2 miRNAs involved in the control of oxidative stress damage (miR-181-5p and miR-29b-3p). In conclusion, Tyr and HTyr exert antifibrotic and anti-inflammatory effects in preclinical in vitro and in vivo models of liver fibrosis, by modulating hepatic oxidative stress, representing promising candidates for further development.

Investigating the possible mechanisms of pirfenidone to be targeted as a promising anti-inflammatory, anti-fibrotic, anti-oxidant, anti-apoptotic, anti-tumor, and/or anti-SARS-CoV-2

Pirfenidone (PFD) is a non-peptide synthetic chemical that inhibits the production of transforming growth factor-beta 1 (TGF-β1), tumor necrosis factor-alpha (TNF-α), platelet-derived growth factor (PDGF), Interleukin 1 beta (IL-1β), and collagen 1 (COL1A1), all of which have been linked to the prevention or removal of excessive scar tissue deposition in many organs. PFD has been demonstrated to decrease apoptosis, downregulate angiotensin-converting enzyme (ACE) receptor expression, reduce inflammation through many routes, and alleviate oxidative stress in pneumocytes and other cells while protecting them from COVID-19 invasion and cytokine storm. Based on the mechanism of action of PFD and the known pathophysiology of COVID-19, it was recommended to treat COVID-19 patients. The use of PFD as a treatment for a range of disorders is currently being studied, with an emphasis on outcomes related to reduced inflammation and fibrogenesis. As a result, rather than exploring the molecule's chemical characteristics, this review focuses on innovative PFD efficacy data. Briefly, herein we tried to investigate, discuss, and illustrate the possible mechanisms of actions for PFD to be targeted as a promising anti-inflammatory, anti-fibrotic, anti-oxidant, anti-apoptotic, anti-tumor, and/or anti-SARS-CoV-2 candidate.

Rosmarinic Acid Prevents Cisplatin-Induced Liver and Kidney Injury by Inhibiting Inflammatory Responses and Enhancing Total Antioxidant Capacity, Thereby Activating the Nrf2 Signaling Pathway

Drug-induced liver and kidney damage is an emergent clinical issue that should be addressed. Rosmarinic acid (RA) has obvious anti-inflammatory and antioxidant effects, so we evaluated the anti-inflammatory and antioxidant effects of RA pretreatment on serum and liver and kidney tissues of cisplatin (CP)-treated mice and explored the possible mechanisms. The results showed that RA pretreatment effectively downregulated the serum, liver, and kidney levels of ALT, AST, BUN, and CRE and the inflammatory factors IL-1β, IL-6, and TNF-α, and simultaneously enhanced the total antioxidant capacity of the liver and kidney. RA pretreatment significantly reduced the levels of MPO, MDA, and NO in liver and kidney tissue, inhibited the mRNA expression of IL-1β, IL-6, and TNF-α in liver and kidney tissue, activated the Nrf2 signaling pathway, and upregulated the mRNA expression of downstream target genes. Our findings show that RA could effectively prevent and alleviate acute liver and kidney injury caused by CP.

Activation of Alternative Bilirubin Clearance Pathways Partially Reduces Hyperbilirubinemia in a Mouse Model Lacking Functional Ugt1a1 Activity

Bilirubin is a heme catabolite and Ugt1a1 is the only enzyme involved in the biological elimination of bilirubin. Partially functional or non-functional Ugt1a1 may result in neuronal damage and death due to the accumulation of unconjugated bilirubin in the brain. The understanding of the role of alternative bilirubin detoxification mechanisms that can reduce bilirubin toxicity risk is crucial for developing novel therapeutic strategies. To provide a proof-of-principle showing whether activation of alternative detoxification pathways could lead to life-compatible bilirubin levels in the absence of Ugt1a1 activity, we used Ugt1^−/− hyperbilirubinemic mice devoid of bilirubin glucuronidation activity. We treated adult Ugt1^−/− mice with TCPOBOP, a strong agonist of the constitutive androstane receptor (CAR). TCPOBOP treatment decreased plasma and liver tissue bilirubin levels by about 38%, and resulted in the transcriptional activation of a vast array of genes involved in bilirubin transport and metabolism. However, brain bilirubin level was unaltered. We observed ~40% degradation of bilirubin in the liver microsomes from TCPOBOP treated Ugt1^−/− mice. Our findings suggest that, in the absence of Ugt1a1, the activation of alternative bilirubin clearance pathways can partially improve hyperbilirubinemic conditions. This therapeutic approach may only be considered in a combinatorial manner along with other treatments.

Epigallocatechin-3-gallate ameliorates liver injury secondary to Pseudomonas aeruginosa pneumonia

Pseudomonas aeruginosa is a dangerous pathogen causing nosocomial pneumonia. P. aeruginosa infection-induced liver damage is another fatal threat, and antibiotic treatment is not effective in relieving P. aeruginosa virulence-triggered damage. We here evaluated the protective effect of epigallocatechin gallate (EGCG), a substance that inhibits virulence of P. aeruginosa through quorum quenching, on liver damage secondary to P. aeruginosa infection. Mice were pretreated with EGCG (20, 40, and 80 mg/kg) for 3 days, and then infected with P. aeruginosa through intratracheal instillation to model acute pneumonia. The mice were sacrificed after 24 h of infection, and samples were harvested for subsequent analysis. EGCG significantly decreased the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Histopathological changes of liver were significantly ameliorated by EGCG. It also significantly reduced oxidative stress that induced liver damage in P. aeruginosa infection, which relied not on the activation of the Nrf₂-HO-1 pathway but on the upregulation of the activity of antioxidative enzymes. Then, the inflammatory response in the liver was tested. EGCG inhibited the release of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) by blocking the inflammation regulating signaling of the TLR4-myD88-NF-κB pathway. EGCG upregulated the activation of nuclear receptors to stronger the liver protective activity against P. aeruginosa infection. Conclusively, EGCG exhibited a significant hepatoprotective effective against P. aeruginosa infection.

Clinical Relevance of the Constitutive Androstane Receptor

Constitutive androstane receptor (CAR) (NR1I3), a xenobiotic receptor, has long been considered a master mediator of drug disposition and detoxification. Accumulating evidence indicates that CAR also participates in various physiologic and pathophysiological pathways regulating the homeostasis of glucose, lipid, and bile acids, and contributing to cell proliferation, tissue regeneration and repair, as well as cancer development. The expression and activity of CAR can be regulated by various factors, including small molecular modulators, CAR interaction with other transcription factors, and naturally occurring genetic variants. Given that the influence of CAR has extended beyond the realm of drug metabolism and disposition and has expanded into a potential modulator of human diseases, growing efforts have centered on understanding its clinical relevance and impact on human pathophysiology. This review highlights the current information available regarding the contribution of CAR to various metabolic disorders and cancers and ponders the possible challenges that might arise from pursuing CAR as a potential therapeutic target for these diseases. SIGNIFICANCE STATEMENT: The growing importance of the constitutive androstane receptor (CAR) in glucose and lipid metabolism as well as its potential implication in cell proliferation emphasizes a need to keenly understand the biological function and clinical impact of CAR. This minireview captures the clinical relevance of CAR by highlighting its role in metabolic disorders and cancer development.

Chronic exposure to nonylphenol induces oxidative stress and liver damage in male zebrafish (Danio rerio): Mechanistic insight into cellular energy sensors, lipid accumulation and immune modulation

Nonylphenol (NP), an environmentally persistent and toxic endocrine-disrupting chemical with estrogenic properties, has severe implications on humans and wildlife. Accumulating evidence demonstrates the toxic response of NP on the developmental process, nervous system, and reproductive parameters. Although NP exposure has been implicated in chronic liver injury, the underlying events associated with hepatic pathophysiology remain less investigated. Using male zebrafish (Danio rerio) as the model, the present study investigates the impact of environmentally relevant concentrations of NP (50 and 100 μg/L, 21 days) on hepatic redox homeostasis vis-à-vis cellular energy sensors, inflammatory response, and cell death involving a mechanistic insight into estrogen receptor (ER) modulation. Our results demonstrate that congruent with significant alteration in transcript abundance of antioxidant enzymes (SOD1, SOD2, Catalase, GPx1a, GSTα1), chronic exposure to NP promotes ROS synthesis, more specifically superoxide anions and H₂O₂ levels, and lipid peroxidation potentially through elevated NOX4 expression. Importantly, NP perturbation of markers associated with fatty acid biosynthesis (srebf1/fasn) and cellular energy-sensing network (sirt1/ampkα/pgc1α) indicates dysregulated energy homeostasis, metabolic disruption, and macrovesicular steatosis, albeit with differential sensitivity at the dose level tested. Besides, elevated p38-MAPK phosphorylation (activation) together with loss of ER homeostasis at both mRNA (esr1, esr2a, esr2b) and protein (ERα, ERβ) levels suggest that NP modulation of ER abundance may have a significant influence on hepatic events. Elevated expression of inflammatory markers (TLR4, p-NF-κB, TNF-α, IL-6, IL-1β, and NOS2) and pro-apoptotic and necrotic regulators, e.g., Bax, caspase- 8, -9 and cleaved PARP1 (50 kDa), indicate chronic inflammation and hepatotoxicity in NP-exposed males. Collectively, elevated oxidative stress, metabolic dysregulation and immune modulation may lead to chronic liver injury in organisms exposed to metabolic disrupting chemicals.

Dexamethasone may affect the occurrence of parenteral nutrition-associated cholestasis in preterm neonates

INTRODUCTION

Glucocorticoids are currently used for the co-therapeutic management of autoimmune hepatitis and some cholestatic diseases. Thus far, we do not know the efficacy of glucocorticoids in the treatment of parenteral nutrition-associated cholestasis. We aimed to analyze whether the administration of late postnatal dexamethasone for treating bronchopulmonary dysplasia influence the occurrence of parenteral nutrition-associated cholestasis in preterm neonates.

METHODS

A retrospective study was conducted for 78 preterm neonates without major anomalies (gestational age was <30 weeks, and birthweight was ≤1000 g) hospitalized in a neonatal unit. Total and direct serum bilirubin levels were measured about every two weeks for all neonates. Data including the administration of dexamethasone, intravenous nutrition, and enteral feeding were collected by at least three audits.

RESULTS

A total of 15 preterm neonates were diagnosed with parenteral nutrition-associated cholestasis, and after stopping parenteral nutrition, the direct bilirubin value decreased to the normal level for no longer than 150 days. The prolonged duration of parenteral nutrition was a risk factor, and late postnatal dexamethasone treatment was a protective factor in reducing the incidence of parenteral nutrition-associated cholestasis.

CONCLUSION

Dexamethasone treatment may reduce the occurrence of parenteral nutrition-associated cholestasis in preterm neonates.

The Nuclear Receptor PXR in Chronic Liver Disease

Pregnane X receptor (PXR), a nuclear receptor known for modulating the transcription of drug metabolizing enzymes and transporters (DMETs), such as cytochrome P450 3A4 and P-glycoprotein, is functionally involved in chronic liver diseases of different etiologies. Furthermore, PXR activity relates to that of other NRs, such as constitutive androstane receptor (CAR), through a crosstalk that in turn orchestrates a complex network of responses. Thus, besides regulating DMETs, PXR signaling is involved in both liver damage progression and repair and in the neoplastic transition to hepatocellular carcinoma. We here summarize the present knowledge about PXR expression and function in chronic liver diseases characterized by different etiologies and clinical outcome, focusing on the molecular pathways involved in PXR activity. Although many molecular details of these finely tuned networks still need to be fully understood, we conclude that PXR and its modulation could represent a promising pharmacological target for the identification of novel therapeutical approaches to chronic liver diseases.

Activation of activator protein-1-fibroblast growth factor 21 signaling attenuates Cisplatin hepatotoxicity

Fibroblast growth factor (Fgf/FGF) 21, which plays important roles in sugar, lipid and energy metabolism, has been accepted as a mito-stress marker gene. We recently reported that FGF21 expression can be up-regulated via activation of aryl hydrocarbon receptor (AhR) or glucocorticoid receptor (GR) and that FGF21 plays important cytoprotective roles. Cisplatin (cis-diamminedichloroplatinum, CDDP) is a widely used chemotherapeutic drug. Numerous adverse effects including hepatotoxicity have been noted during CDDP therapy. It is known that CDDP can induce mitochondrial dysfunction. The studies were designed to determine the regulation of Fgf/FGF21 expression by CDDP, and to characterize the underlying mechanisms of its regulation, as well as to determine the impact of gain or loss of Fgf/FGF21 function on the progression of CDDP hepatotoxicity. Our results showed that CDDP and phorbol ester induced mRNA and protein expression of Fgf/FGF21 and β-Klotho, two essential components of Fgf21 signaling, in mouse livers and cultured mouse/human hepatocytes. Luciferase reporter assays and ChIP-qPCR assays demonstrated that the cJun-AP-1 activation is responsible for CDDP- and phorbol ester-induced Fgf/FGF21 expression. Such induction is abolished after cotreated with AP-1 inhibitor SR11302. In addition, CDDP produces more severe liver injury in Fgf21-null than wild-type mice. Pre-treatment of GR activator dexamethasone or AhR activator β-Naphthoflavone, both of which can induce Fgf21 expression, attenuated CDDP-induced hepatotoxicity in vivo and in vitro. In conclusion, Fgf/FGF21-β-Klotho signaling can be activated via AP-1 activation. Gain of Fgf/FGF21 function attenuates the progression of CDDP hepatotoxicity, which may be considered clinically to improve CDDP therapy.

The Extra Virgin Olive Oil Polyphenol Oleocanthal Exerts Antifibrotic Effects in the Liver

Liver fibrosis, which is the outcome of wound-healing response to chronic liver damage, represents an unmet clinical need. This study evaluated the anti-fibrotic and anti-inflammatory effects of the polyphenol oleocanthal (OC) extracted from extra virgin olive oil (EVOO) by an in vitro/in vivo approach. The hepatic cell lines LX2 and HepG2 were used as in vitro models. The mRNA expression of pro-fibrogenic markers, namely alpha-smooth muscle actin (α-SMA), collagen type I alpha 1 chain (COL1A1), a panel of metalloproteinases (MMP1, MMP2, MMP3, MMP7, MMP9) and vascular endothelial growth factor A (VEGFA) as well as the pro-oxidant genes NADPH oxidases (NOXs) 1 and 4 were evaluated in TGF-β activated LX2 cells by qRT-PCR. α-SMA and COL1A1 protein expression was assessed by immunofluorescence coupled to confocal microscopy. VEGFA release from LX2 was measured by ELISA. We also evaluated the amount of reactive oxygen species (ROS) produced by H₂O₂ activated- HepG2 cells. In vivo, OC was administered daily by oral gavage to Balb/C mice with CCl₄-induced liver fibrosis. In this model, we measured the mRNA hepatic expression of the three pro-inflammatory interleukins (IL) IL6, IL17, IL23, chemokines such as C-C Motif Chemokine Ligand 2 (CCL2) and C-X-C Motif Chemokine Ligand 12 (CXCL12), and selected miRNAs (miR-181-5p, miR-221-3p, miR-29b-3p and miR-101b-3p) by qRT-PCR. We demonstrated that OC significantly downregulated the gene/protein expression of α-SMA, COL1A1, MMP2, MMP3, MMP7 and VEGF as well as the oxidative enzymes NOX1 and 4 in TGFβ1-activated LX2 cells, and reduced the production of ROS by HepG2. In vivo OC, beside causing a significant reduction of fibrosis at histological assessment, counteracted the CCl₄-induced upregulation of pro-fibrotic and inflammatory genes. Moreover, OC upregulated the anti-fibrotic miRNAs (miR-29b-3p and miR-101b-3p) reduced in fibrotic mice, while downregulated the pro-fibrotic miRNAs (miR-221-3p and miR-181-5p), which were dramatically upregulated in fibrotic mice. In conclusion, OC exerts a promising antifibrotic effect via a combined reduction of oxidative stress and inflammation involving putative miRNAs, which in turn reduces hepatic stellate cells activation and liver fibrosis.

COVID-19 Is a Multi-Organ Aggressor: Epigenetic and Clinical Marks

The progression of coronavirus disease 2019 (COVID-19), resulting from a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, may be influenced by both genetic and environmental factors. Several viruses hijack the host genome machinery for their own advantage and survival, and similar phenomena might occur upon SARS-CoV-2 infection. Severe cases of COVID-19 may be driven by metabolic and epigenetic driven mechanisms, including DNA methylation and histone/chromatin alterations. These epigenetic phenomena may respond to enhanced viral replication and mediate persistent long-term infection and clinical phenotypes associated with severe COVID-19 cases and fatalities. Understanding the epigenetic events involved, and their clinical significance, may provide novel insights valuable for the therapeutic control and management of the COVID-19 pandemic. This review highlights different epigenetic marks potentially associated with COVID-19 development, clinical manifestation, and progression.

Jekyll and Hyde: nuclear receptors ignite and extinguish hepatic oxidative milieu

Nuclear receptors (NRs) are ligand-binding transcription factors that regulate gene networks and physiological responses. Often oxidative stress precedes the onset of liver diseases, and Nrf2 is a key regulator of antioxidant pathways. NRs crosstalk with Nrf2, since NR activation can influence the oxidative milieu by modulating reductive cellular processes. Diet and xenobiotics also regulate NR expression and activity, suggesting a feedback loop. Depending on the tissue context and cues, NRs either increase or decrease toxicity and oxidative damage. Many FDA-approved drugs target NRs, and one could potentially repurpose them to ameliorate reactive oxygen species (ROS). Here, we discuss how several NRs modulate oxidative stress subsequent to diet, organic pollutants, and drug-induced injury to the liver.

In vivo demonstration of a novel non-invasive model for inducing localized hypothermia to ameliorate hepatotoxicity

Moderate hypothermia (32 °C) has been previously shown to ameliorate drug-induced liver injuries in vitro. However, there are concerns regarding its clinical relevance as it remains a challenge to perform selective liver cooling in a non-invasive manner. To reconcile this dilemma, we propose the use of pulsed cooling for regional hypothermic conditioning in liver. This involves intermittent cooling applied in pulses of 15 min each, with a one-hour recovery interval between pulses. Cooling is achieved by applying ice packs to the cutaneous region overlying the liver. Through an in vivo C57BL/6NTac mouse study, we demonstrated the feasibility of attaining localized hypothermia close to the liver while maintaining core body temperature. This has successfully ameliorated acetaminophen-induced liver injury based on the liver function tests, liver histology and total weight change. Collectively, we provide a proof of concept for pulsed external localized cooling as being clinically actionable to perform induced selective hypothermia.

Activation of the Constitutive Androstane Receptor Inhibits Leukocyte Adhesiveness to Dysfunctional Endothelium

Leukocyte cell recruitment into the vascular subendothelium constitutes an early event in the atherogenic process. As the effect of the constitutive androstane receptor (CAR) on leukocyte recruitment and endothelial dysfunction is poorly understood, this study investigated whether the role of CAR activation can affect this response and the underlying mechanisms involved. Under physiological flow conditions, TNFα-induced endothelial adhesion of human leukocyte cells was concentration-dependently inhibited by preincubation of human umbilical arterial endothelial cells with the selective human CAR ligand CITCO. CAR agonism also prevented TNFα induced VCAM-1 expression, as well as MCP-1/CCL-2 and RANTES/CCL-5 release in endothelial cells. Suppression of CAR expression with a small interfering RNA abrogated the inhibitory effects of CITCO on these responses. Furthermore, CITCO increased interaction of CAR with Retinoid X Receptor (RXR) and reduced TNFα-induced p38-MAPK/NF-κB activation. In vivo, using intravital microscopy in the mouse cremasteric microcirculation treatment with the selective mouse CAR ligand TCPOBOP inhibited TNFα-induced leukocyte rolling flux, adhesion, and emigration and decreased VCAM-1 in endothelium. These results reveal that CAR agonists can inhibit the initial inflammatory response that precedes the atherogenic process by targeting different steps in the leukocyte recruitment cascade. Therefore, CAR agonists may constitute a new therapeutic tool in controlling cardiovascular disease-associated inflammatory processes.

Anti-inflammatory effects of three withanolides isolated from Physalis angulata L. in LPS-activated RAW 264.7 cells through blocking NF-κB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Physalis angulata L. is commonly used in many countries as popular medicine for the treatment of a variety of diseases such as malaria, hepatitis, dermatitis and rheumatism. But the anti-inflammatory active constituents of this medicinal plant and their molecular mechanism are still not elucidated clearly.

AIM OF THE STUDY

The aim of the study is to isolate and identify a series of compounds from the ethanolic extract of Physalis angulata L., and to investigate the anti-inflammatory activities in vitro and the molecular mechanism of physagulin A, physagulin C, and physagulin H.

MATERIALS AND METHODS

In order to further understand the anti-inflammatory mechanism of the three compounds, their potential anti-inflammatory activities were investigated in vitro in LPS-activated RAW 264.7 macrophage cells by Griess assay, ELISA, Western blot and immunofluorescence methods in the present study.

RESULTS

Physagulin A, physagulin C, and physagulin H could not only inhibit the release of NO, PGE₂, IL-6 and TNF-α, but also could down-regulate the expression of iNOS and COX-2 proteins. Furthermore, physagulin A, physagulin C, and physagulin H could remarkably block the degradation of IκB-α and the nuclear translocation of NF-κB/p65 in LPS-activated RAW 264.7 cells. However, none of them could inhibit the phosphorylation of MAPKs family proteins ERK, JNK and p38. Thus, the anti-inflammatory actions of physagulin A, physagulin C, and physagulin H were mainly due to the significant inhibition of NF-κB signaling pathway rather than MAPKs signaling pathway.

CONCLUSIONS

All the results clearly showed that physagulin A, physagulin C, and physagulin H demonstrated potent anti-inflammatory activity and can be used as novel NF-κB inhibitors. They are potential to be developed as an alternative or complementary agents for inflammatory diseases.

Tomatoes consumed in-season prevent oxidative stress in Fischer 344 rats: impact of geographical origin

Tomatoes (Lycopersicon esculentum Mill.) constitute an important source of health-promoting compounds including bioactive antioxidants, such as flavonoids, that can differ in terms of composition and quantity depending on the conditions that tomatoes are cultivated. Otherwise, biological rhythms modulate oxidative stress. Therefore, the aim of this study was to evaluate the antioxidant properties of seasonally consumed tomatoes from two different geographical origins (local LT or non-local NLT) in Fischer 344 rats. The results show that LT and NLT have a specific phenolic signature and that each tomato gives a particular response toward biomarkers evaluated, which in turn showed a photoperiod-dependent effect. Remarkably, when tomatoes were administered in-season they improved or sustained antioxidant biomarkers, thus reducing oxidative stress values. It is noteworthy that the protective effect of tomatoes against oxidative stress depends on the geographical origin of the crop. Therefore, tomatoes consumed in-season may improve health by preventing oxidative stress.

Protective Effects of Spermidine Against Cirrhotic Cardiomyopathy in Bile Duct-Ligated Rats

Cirrhotic cardiomyopathy is a critical factor that causes morbidity and mortality in crucial conditions such as liver transplantation. In animal model, the common pathophysiologic mechanisms of cirrhotic cardiomyopathy are similar to those associated with bile duct ligation (BDL). Overproduction of inflammatory and oxidant markers plays a crucial role in cirrhotic cardiomyopathy. Spermidine, a multifunctional polyamine, is known for its antioxidant and anti-inflammatory effects. In this study, we investigated the effects of spermidine on development of cirrhotic cardiomyopathy in BDL rats. Rats were randomly housed in 6 groups. Except the normal and sham groups, BDL was performed for all the control and spermidine groups. Seven days after operation, 3 different doses of spermidine (5, 10 and 50 mg/kg) were administrated until day 28, in spermidine groups. At the end of the fourth week, the electrocardiography (ECG) and papillary muscle isolation were performed. The serum level of tumor necrosis factor-a (TNF-α), interleukin-1β (IL-1β), and IL-10 and cardiac level of superoxide dismutase, glutathione (GSH). and malondialdehyde (MDA) were assessed. Furthermore, the nuclear factor-κB (NF-κB) expression was assessed by western blot. Cardiac histopathological changes were monitored. The serum levels of magnesium (Mg) and potassium (K) were investigated. Control group, exhibited exaggerated signs of cirrhotic cardiomyopathy in comparison with the sham group. Co-administration of spermidine at the dose of 10 mg/kg in BDL rats significantly improved the cardiac condition, reduced the inflammatory mediators, and increased antioxidant enzymes. In addition, the histopathologic findings were in accordance with the other results of the study. Besides, there was no significant alteration in serum levels of Mg and K. This study demonstrates that spermidine at the dose of 10 mg/kg significantly improved the cirrhotic cardiomyopathy in BDL model in rats.

Folic Acid-Targeted Paclitaxel-Polymer Conjugates Exert Selective Cytotoxicity and Modulate Invasiveness of Colon Cancer Cells

Although selective tumor delivery of anticancer drugs has been sought by exploiting either passive targeting or by ligand-mediated targeting, a selective anticancer therapy remains an unmet medical need. Despite the advances which have been achieved by nanomedicines, nanosystems such as polymer-drug conjugates still miss the goal of clinical efficacy. In this study, we demonstrated that polymer-drug conjugates require a thoroughly chemical design and the right targeting agent/polymer ratio to be selective and effective towards cancer cells. In particular, two PEG conjugates carrying paclitaxel and targeted with different folic acid (FA)/PEG ratios (one or three) were investigated. The cytotoxicity study in positive (HT-29) and negative (HCT-15) FA receptor (FR)-cell lines demonstrated that the conjugates with one or three FAs were 4- or 28-fold more active in HT-29 cells, respectively. The higher activity of the 3-FA conjugate was confirmed by its strong impact on cell cycle arrest. Furthermore, FA targeting had a clear effect on migration and invasiveness of HT-29 cells, which were significantly reduced by both conjugates. Interestingly, the 3-FA conjugate showed also an improved pharmacokinetic profile in mice. The results of this study indicate that thorough investigations are needed to optimize and tune drug delivery and achieve the desired selectivity and activity towards cancer cells.

The Role of Oxidative Stress in NAFLD-NASH-HCC Transition-Focus on NADPH Oxidases

A peculiar role for oxidative stress in non-alcoholic fatty liver disease (NAFLD) and its transition to the inflammatory complication non-alcoholic steatohepatitis (NASH), as well as in its threatening evolution to hepatocellular carcinoma (HCC), is supported by numerous experimental and clinical studies. NADPH oxidases (NOXs) are enzymes producing reactive oxygen species (ROS), whose abundance in liver cells is closely related to inflammation and immune responses. Here, we reviewed recent findings regarding this topic, focusing on the role of NOXs in the different stages of fatty liver disease and describing the current knowledge about their mechanisms of action. We conclude that, although there is a consensus that NOX-produced ROS are toxic in non-neoplastic conditions due to their role in the inflammatory vicious cycle sustaining the transition of NAFLD to NASH, their effect is controversial in the neoplastic transition towards HCC. In this regard, there are indications of a differential effect of NOX isoforms, since NOX1 and NOX2 play a detrimental role, whereas increased NOX4 expression appears to be correlated with better HCC prognosis in some studies. Further studies are needed to fully unravel the mechanisms of action of NOXs and their relationships with the signaling pathways modulating steatosis and liver cancer development.

Blood Pressure-Lowering Effect of Wine Lees: Dose-Response Study, Effect of Dealcoholization and Possible Mechanisms of Action

The antihypertensive effect of wine lees (WL) has been previously evidenced. In this study, the antihypertensive properties of different doses of WL were evaluated in spontaneously hypertensive rats (SHR). In addition, the blood pressure (BP)-lowering effect of dried (dealcoholized) WL powder (WLPW) and the mechanisms involved in its functionality were investigated. Furthermore, a possible hypotensive effect of WLPW was discarded in Wistar-Kyoto (WKY) rats. The administration of WL at different doses caused a dose-dependent decrease in BP of SHR up to 5.0 mL/kg bw, exhibiting the maximum decrease at 6 h post-administration. WLPW caused a greater drop in BP than WL, showing an antihypertensive effect higher and more prolonged than the drug Captopril. Moreover, the BP-lowering effect of WLPW was specific to the hypertensive state since an undesirable hypotensive effect in normotensive WKY rats was ruled out. Finally, WLPW improved oxidative stress and increased the activity of the antioxidant endogen system of SHR. These results suggest that WLPW could be used as functional ingredient for foods or nutraceuticals to ameliorate hypertension. Nevertheless, further clinical studies are needed to evaluate its long-term antihypertensive efficiency.

Inflammation-induced cholestasis in cancer cachexia

BACKGROUND

Cancer cachexia is a debilitating metabolic syndrome contributing to cancer death. Organs other than the muscle may contribute to the pathogenesis of cancer cachexia. This work explores new mechanisms underlying hepatic alterations in cancer cachexia.

METHODS

We used transcriptomics to reveal the hepatic gene expression profile in the colon carcinoma 26 cachectic mouse model. We performed bile acid, tissue mRNA, histological, biochemical, and western blot analyses. Two interventional studies were performed using a neutralizing interleukin 6 antibody and a bile acid sequestrant, cholestyramine. Our findings were evaluated in a cohort of 94 colorectal cancer patients with or without cachexia (43/51).

RESULTS

In colon carcinoma 26 cachectic mice, we discovered alterations in five inflammatory pathways as well as in other pathways, including bile acid metabolism, fatty acid metabolism, and xenobiotic metabolism (normalized enrichment scores of -1.97, -2.16, and -1.34, respectively; all Padj < 0.05). The hepatobiliary transport system was deeply impaired in cachectic mice, leading to increased systemic and hepatic bile acid levels (+1512 ± 511.6 pmol/mg, P = 0.01) and increased hepatic inflammatory cytokines and neutrophil recruitment to the liver of cachectic mice (+43.36 ± 16.01 neutrophils per square millimetre, P = 0.001). Adaptive mechanisms were set up to counteract this bile acid accumulation by repressing bile acid synthesis and by enhancing alternative routes of basolateral bile acid efflux. Targeting bile acids using cholestyramine reduced hepatic inflammation, without affecting the hepatobiliary transporters (e.g. tumour necrosis factor α signalling via NFκB and inflammatory response pathways, normalized enrichment scores of -1.44 and -1.36, all Padj < 0.05). Reducing interleukin 6 levels counteracted the change in expression of genes involved in the hepatobiliary transport, bile acid synthesis, and inflammation. Serum bile acid levels were increased in cachectic vs. non-cachectic cancer patients (e.g. total bile acids, +5.409 ± 1.834 μM, P = 0.026) and were strongly correlated to systemic inflammation (taurochenodeoxycholic acid and C-reactive protein: ρ = 0.36, Padj = 0.017).

CONCLUSIONS

We show alterations in bile acid metabolism and hepatobiliary secretion in cancer cachexia. In this context, we demonstrate the contribution of systemic inflammation to the impairment of the hepatobiliary transport system and the role played by bile acids in the hepatic inflammation. This work paves the way to a better understanding of the role of the liver in cancer cachexia.

Nuclear Receptors in the Control of the NLRP3 Inflammasome Pathway

The innate immune system is the first line of defense specialized in the clearing of invaders whether foreign elements like microbes or self-elements that accumulate abnormally including cellular debris. Inflammasomes are master regulators of the innate immune system, especially in macrophages, and are key sensors involved in maintaining cellular health in response to cytolytic pathogens or stress signals. Inflammasomes are cytoplasmic complexes typically composed of a sensor molecule such as NOD-Like Receptors (NLRs), an adaptor protein including ASC and an effector protein such as caspase 1. Upon stimulation, inflammasome complex components associate to promote the cleavage of the pro-caspase 1 into active caspase-1 and the subsequent activation of pro-inflammatory cytokines including IL-18 and IL-1β. Deficiency or overactivation of such important sensors leads to critical diseases including Alzheimer diseases, chronic inflammatory diseases, cancers, acute liver diseases, and cardiometabolic diseases. Inflammasomes are tightly controlled by a two-step activation regulatory process consisting in a priming step, which activates the transcription of inflammasome components, and an activation step which leads to the inflammasome complex formation and the subsequent cleavage of pro-IL1 cytokines. Apart from the NF-κB pathway, nuclear receptors have recently been proposed as additional regulators of this pathway. This review will discuss the role of nuclear receptors in the control of the NLRP3 inflammasome and the putative beneficial effect of new modulators of inflammasomes in the treatment of inflammatory diseases including colitis, fulminant hepatitis, cardiac ischemia-reperfusion and brain diseases.

Fructose Consumption Affects Glucocorticoid Signaling in the Liver of Young Female Rats

The effects of early-life fructose consumption on hepatic signaling pathways and their relation to the development of metabolic disorders in later life are not fully understood. To investigate whether fructose overconsumption at a young age induces alterations in glucocorticoid signaling that might contribute to development of metabolic disturbances, we analysed glucocorticoid receptor hormone-binding parameters and expression of its target genes involved in gluconeogenesis (phosphoenolpyruvate carboxykinase and glucose-6-phosphatase) and lipid metabolism (lipin-1), as well as redox and inflammatory status in the liver of female rats subjected to a fructose-rich diet immediately after weaning. The fructose diet increased hepatic corticosterone concentration, 11β-hydroxysteroid dehydrogenase type 1 level, glucocorticoid receptor protein level and hormone-binding activity, as well as lipin-1 level. The expression of glucose-6-phosphatase was reduced in fructose-fed rats, while phosphoenolpyruvate carboxykinase remained unaltered. The fructose-rich diet increased the level of fructose transporter GLUT2, while the expression of fructolytic enzymes fructokinase and aldolase B remained unaltered. The diet also affected pro-inflammatory pathways, but had no effect on the antioxidant defence system. In conclusion, a fructose-rich diet applied immediately after weaning promoted lipogenesis and enhanced hepatic glucocorticoid signaling, possibly to protect against inflammatory damage, but without an effect on gluconeogenesis and antioxidant enzymes. Yet, prolonged treatment might ultimately lead to more pronounced metabolic disturbances.

Regulation of CAR and PXR Expression in Health and Disease

Pregnane X receptor (PXR, NR1I2) and constitutive androstane receptor (CAR, NR1I3) are members of the nuclear receptor superfamily that mainly act as ligand-activated transcription factors. Their functions have long been associated with the regulation of drug metabolism and disposition, and it is now well established that they are implicated in physiological and pathological conditions. Considerable efforts have been made to understand the regulation of their activity by their cognate ligand; however, additional regulatory mechanisms, among which the regulation of their expression, modulate their pleiotropic effects. This review summarizes the current knowledge on CAR and PXR expression during development and adult life; tissue distribution; spatial, temporal, and metabolic regulations; as well as in pathological situations, including chronic diseases and cancers. The expression of CAR and PXR is modulated by complex regulatory mechanisms that involve the interplay of transcription factors and also post-transcriptional and epigenetic modifications. Moreover, many environmental stimuli affect CAR and PXR expression through mechanisms that have not been elucidated.

Oridonin Attenuates TNBS-induced Post-inflammatory Irritable Bowel Syndrome via PXR/NF-κB Signaling

To investigate the beneficial effects of oridonin, a diterpenoid compound isolated from Rabdosia rubescens, on the inflammatory response in TNBS-induced post-inflammatory irritable bowel syndrome (PI-IBS) model and the underlying mechanism. Using the PI-IBS rat model and Caco-2 cell lines, we found that intestinal barrier function reflected by lactulose/mannitol (L/M) ratio and tight junction protein level was significantly ameliorated by oridonin. We also demonstrated that oridonin abrogated inflammation through inhibiting the phosphorylation of NF-κBp65 as well as its downstream gene (iNOS, COX-2, IL-1β, and IL-6) level. Molecular docking studies confirmed the good binding activity between oridonin and PXR. In Caco-2 cell lines, oridonin markedly inhibited LPS-induced NF-κB activation in a PXR-dependent manner. Meanwhile, PXR and its target genes CYP3A4 and P-gp were induced by oridonin, which was associated with the decreased expression of NF-κB and the recovery of intestinal barrier. This study indicated that the therapeutic effect of oridonin on experimental PI-IBS through repairing intestinal barrier function may be closely associated with the regulatory role of PXR/NF-κB signaling pathway. Oridonin may serve as a PXR ligand for the development of drugs in the therapy for PI-IBS.

Oxidative Stress in Rats is Modulated by Seasonal Consumption of Sweet Cherries from Different Geographical Origins: Local vs. Non-Local

Sweet cherries (Prunus avium L.) are a source of bioactive compounds, including phenolic compounds, which are antioxidants that contribute to protection against oxidative stress. It is known that the composition of cherries is influenced by external conditions, such as the geographic origin of cultivation, and that biological rhythms have a significant effect on oxidative stress. Therefore, in this study, Fischer 344 rats were exposed to various photoperiods and were supplemented with Brooks sweet cherries from two different geographical origins, local (LC) and non-local (NLC), to evaluate the interaction of supplementation and biological rhythms with regard to the oxidative stress status. The results indicate that the two fruits generated specific effects and that these effects were modulated by the photoperiod. Consumption of sweet cherries in-season, independently of their origin, may promote health by preventing oxidative stress, tending to: enhance antioxidant status, decrease alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, reduce liver malondialdehyde (MDA) levels, and maintain constant serum MDA values and reactive oxygen species (ROS) generation.

Cuban Brown Propolis Interferes in the Crosstalk between Colorectal Cancer Cells and M2 Macrophages

Tumor-associated macrophages (TAMs), primarily the M2 phenotype, are involved in the progression and metastasis of colorectal cancer (CRC). Cuban brown propolis (Cp) and its main component Nemorosone (Nem) displays an antiproliferative effect on different cancer cells, including CRC cell lines. However, whether Cp and Nem could exploit its effect on CRC cells by targeting their relationship with TAMs remains to be elucidated. In this study, we differentiated the human monocytic THP-1 cells to M2 macrophages and confirmed this transition by immunofluorescence (IF) staining, qRT-PCR and zymography. An MTT assay was performed to determine the effect of Cp and Nem on the viability of CRC HT-29 cells co-cultured with M2 macrophages. Furthermore, the migration and invasion abilities of HT-29 cells were determined by Transwell assays and the expression levels of epithelial–mesenchymal transition (EMT) markers were analyzed by IF staining. We demonstrated that Cp and Nem reduced the viability of M2 macrophages and, accordingly, the activity of the MMP-9 metalloprotein. Moreover, we demonstrated that M2 macrophages produce soluble factors that positively regulate HT-29 cell growth, migration and invasion. These M2-mediated effects were counteracted by Cp and Nem treatments, which also played a role in regulating the expression of the EMT markers E-cadherin and vimentin. Taken together, our results indicate that Nem contained in Cp interferes in the crosstalk between CRC cells and TAMs, by targeting M2 macrophages.

The Cuban Propolis Component Nemorosone Inhibits Proliferation and Metastatic Properties of Human Colorectal Cancer Cells

The majority of deaths related to colorectal cancer (CRC) are associated with the metastatic process. Alternative therapeutic strategies, such as traditional folk remedies, deserve attention for their potential ability to attenuate the invasiveness of CRC cells. The aim of this study is to investigate the biological activity of brown Cuban propolis (CP) and its main component nemorosone (NEM) and to describe the molecular mechanism(s) by which they inhibit proliferation and metastatic potential of 2 CRC cell lines, i.e., HT-29 and LoVo. Our results show that CP and NEM significantly decreased cell viability and inhibited clonogenic capacity of CRC cells in a dose and time-dependent manner, by arresting the cell cycle in the G0/G1 phase and inducing apoptosis. Furthermore, CP and NEM downregulated BCL2 gene expression and upregulated the expression of the proapoptotic genes TP53 and BAX, with a consequent activation of caspase 3/7. They also attenuated cell migration and invasion by inhibiting MMP9 activity, increasing E-cadherin and decreasing β-catenin and vimentin expression, proteins involved in the epithelial–mesenchymal transition (EMT). In conclusion NEM, besides displaying antiproliferative activity on CRC cells, is able to decrease their metastatic potential by modulating EMT-related molecules. These finding provide new insight about the mechanism(s) of the antitumoral properties of CP, due to NEM content.

Fucus vesiculosus and Ascophyllum nodosum Ameliorate Liver Function by Reducing Diet-Induced Steatosis in Rats

The Asian coastal communities have used the brown seaweeds Fucus vesiculosus and Ascophyllum nodosum since ancient times. Recently, some in vitro and in vivo studies have demonstrated their abilities in reducing risk factors for metabolic syndrome. Here, we analyzed the protective effect of a phytocomplex extracted from these seaweeds on the deposition of fat in the liver after the administration of a high-fat diet (HFD) to rats for five weeks. The administration of F. vesiculosus and A. nodosum led to significant reductions in microvescicular steatosis and plasma biochemical and lipid parameters, such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total and conjugated bilirubin, and triglycerides. Furthermore, the postprandial glycemic peak was delayed and significantly reduced (p < 0.01) by the algal extract administration. In conclusion, this extract is effective in reducing microvescicular steatosis and improving glycemic control, thereby lowering the risk of nonalcoholic fatty liver disease, obesity, and diabetes, diseases related to the consumption of fat and sugar-enriched diets.

Nemorosone inhibits the proliferation and migration of hepatocellular carcinoma cells

AIMS

In the tumor microenvironment, dysregulated immune cells could promote tumor progression, invasion and metastasis, by establishing a symbiotic relationship with cancer cells. A pivotal role is played by monocyte recruitment and induction of tumor-associated macrophages (TAMs), which provide immunosuppression and tumorigenesis. The effect of nemorosone, an antiproliferative phytocomponent present in Cuban Propolis, on TAM-induced tumor progression remains to be elucidated. Here we investigated the symbiotic relationship between monocytic leukemia THP-1 and hepatocellular carcinoma HepG2 cells, and the role of nemorosone in preventing TAM-induced tumor growth.

MAIN METHODS

Macrophage differentiation induced by HepG2-conditioned medium was assessed by flow cytometry, analysis of secreted molecules and cytokine expression. The effect of nemorosone and/or conditioned THP-1-medium on HepG2 proliferation was evaluated by MTT assay, colony formation, cells cycle and migration assays.

KEY FINDINGS

HepG2 cells induced THP-1 recruitment and differentiation to macrophages. When compared with control THP-1 cells, differentiated THP-1 showed a significant increase of the matrix metalloproteinases MMP-2 and MMP-9 expression (P < 0.01), and slightly induced HepG2 cells growth. This effect was counteracted by nemorosone, which also significantly inhibited colony formation (P < 0.01) and migratory capacity of HepG2 cells, driving a high percentage of cells (80%) to the G0/G1 phase.

SIGNIFICANCE

HepG2-conditioned medium is a suitable model for THP-1 modulation and differentiation. Moreover, nemorosone significantly inhibits the proliferation of HepG2 cells, both in presence and absence of the soluble factors secreted by TAMs. Further studies are needed to elucidate the role of this natural compound in the HCC-TAM relationship.

Effects of dexamethasone to reverse decreased hepatic midazolam metabolism in rats with acute renal failure

The inductive effects of dexamethasone on hepatic midazolam metabolism were examined in Wistar rats with acute renal failure (ARF) to clarify whether the ARF-related decrease in the hepatic expression of drug-metabolizing enzymes is caused by an impairment in the translation/polypeptide formation process.ARF was induced with intramuscular glycerol injection. Dexamethasone was orally administered. Pooled liver microsomes from five rats were prepared with ultracentrifugation for each of four groups, namely, control and ARF rats, control rats with dexamethasone treatment and ARF rats with dexamethasone treatment.Hepatic drug-metabolizing activity was examined in an incubation study with the microsomes, where midazolam was employed as a substrate of cytochrome P450 (CYP) 3A enzymes. The hepatic protein and mRNA expressions of CYP3A23/3A1 and 3A2 enzymes were also evaluated.With dexamethasone treatment, the hepatic metabolic rate of midazolam increased 1.4 times in control rats, while it increased 19.6 times in ARF rats, reflecting the greater induction of hepatic protein expressions of CYP3A enzymes in ARF rats than in control rats.The hepatic protein expression process for CYP3A23/3A1 and 3A2 responds well to dexamethasone treatment in ARF rats, indicating that the translation/polypeptide formation process is not impaired in the presence of ARF.

Western Diet-Induced Metabolic Alterations Affect Circulating Markers of Liver Function before the Development of Steatosis

Since nutrition might have a significant impact on liver function, we analyzed the early effect of Western-type diet on hepatic tissue and lipid and drug metabolism in Wistar–Kyoto rats (n = 8); eight rats fed with a standard diet were used as controls. Histological analysis of liver tissue was performed, and plasma biochemical parameters were measured. Plasma concentration of six bile acids was determined by ultra-liquid chromatography-tandem mass spectrometry UHPLC-MS/MS. Hepatic gene expressions of enzymes involved in drug and lipid metabolism were assessed by means of real-time reverse transcription (qRT)-PCR. Liver of rats fed with a Western diet did not show macroscopic histological alterations, but number and diameter of lipid droplets increased, as well as DGAT1, GPAT4, SCD, FASN and SREBP2 expression. Furthermore, Western diet-fed animals showed an increase in the activation of hepatic stellate cells and macrophage number in liver tissue, as well as a significant increase in AST and bilirubin levels (p < 0.01), and in the LDL:HDL cholesterol ratio (p < 0.001). Plasma chenodeoxycholic acid concentration increased significantly, whereas cholic acid decreased (p < 0.05), and cytochrome P450 genes were generally downregulated. Significant changes in hepatic lipid and drug metabolism are early induced by the Western diet, prior to steatosis development. Such changes are associated with a peculiar alteration in circulating bile acids, which could represent an early marker of non-alcoholic fatty liver disease (NAFLD) development.