Caffeine protects against alcohol-induced liver fibrosis by dampening the cAMP/PKA/CREB pathway in rat hepatic stellate cells

Combining proteomics and Phosphoproteomics to investigate radiation-induced rectal fibrosis in rats and the effects of pSTAT3 inhibitor S3I-201 on human intestinal fibroblasts

OBJECTIVE

To investigate the regulatory mechanisms of radiation-induced rectal fibrosis (RIRF) and assess the therapeutic potential of S3I-201.

METHODS

Sprague-Dawley rats were divided into control and radiation groups, with the latter exposed to 20 Gray pelvic X-rays. After 10 weeks, rectal tissues were analyzed using tandem mass tag (TMT) proteomics and phosphoproteomics. Pathway enrichment was performed via Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, with secondary annotation using Cluego. Representative proteins and their phosphorylated counterparts were validated through immunoblotting in another cohort. STAT3 levels in rectal tissues from irradiated and non-irradiated colorectal cancer patients were examined, and the effects of S3I-201 on human rectal fibroblasts were evaluated.

RESULTS

The radiation group showed significant inflammatory responses and collagen deposition in the rat rectal walls. Enrichment analysis revealed that radiation-induced proteins and phosphoproteins were primarily involved in extracellular matrix-receptor interaction and the MAPK signaling pathway. Immunoblotting indicated increased expression of p-CAMKII, p-MRACKS, p-Cfl1, p-Myl9, and p-STAT3 in the radiation group compared to the control, while p-AKT1 expression decreased. Elevated phosphorylation of STAT3 was observed in submucosal fibroblasts of the post-radiation human rectum. S3I-201 specifically inhibited STAT3 phosphorylation and suppressed activation of human rectal fibroblasts, also inhibiting the pro-fibrotic effects of the classical TGF-β/Smad/CTGF pathway.

CONCLUSION

By integrating phosphoproteomics and proteomics, this study elucidated the protein regulatory network of RIRF and identified the potential therapeutic targets, including phosphoproteins such as STAT3 in managing RIRF.

SIGNIFICANCE

In our research, we employed TMT labeling alongside LC-MS/MS techniques to comprehensively explore the proteomic and phosphoproteomic landscapes in rat models of radiation-induced intestinal fibrosis (RIRF). Our analysis revealed the function and pathways of proteins and phosphorylated proteins triggered by radiation, as well as those with protective roles. We mapped a network of interactions among these proteins and validated key protein expression levels using quantitative methods. Furthermore, we investigated STAT3 as a potential therapeutic target, assessing the efficacy of the inhibitor S3I-201 in laboratory settings, and highlighting its potential for RIRF treatment. Overall, our findings provide groundbreaking insights into the mechanisms underlying RIRF, paving the way for the development of future antifibrotic therapies.

Purinergic Signaling in Non-Parenchymal Liver Cells

Purinergic signaling has emerged as an important paracrine-autocrine intercellular system that regulates physiological and pathological processes in practically all organs of the body. Although this system has been thoroughly defined since the nineties, recent research has made substantial advances regarding its role in aspects of liver physiology. However, most studies have mainly targeted the entire organ, 70% of which is made up of parenchymal cells or hepatocytes. Because of its physiological role, the liver is exposed to toxic metabolites, such as xenobiotics, drugs, and fatty acids, as well as to pathogens such as viruses and bacteria. Under injury conditions, all cell types within the liver undergo adaptive changes. In this context, the concentration of extracellular ATP has the potential to increase dramatically. Indeed, this purinergic response has not been studied in sufficient detail in non-parenchymal liver cells. In the present review, we systematize the physiopathological adaptations related to the purinergic system in chronic liver diseases of non-parenchymal liver cells, such as hepatic stellate cells, Kupffer cells, sinusoidal endothelial cells, and cholangiocytes. The role played by non-parenchymal liver cells in these circumstances will undoubtedly be strategic in understanding the regenerative activities that support the viability of this organ under stressful conditions.

Kasai Portoenterostomy, Successful Liver Transplantation, and Immunosuppressive Therapy for Biliary Atresia in a Female Baby: A Case Report

Background

Biliary atresia (BA) is a severe neonatal progressive cholangiopathy of unknown etiology. A timely Kasai portoenterostomy (KPE) improves survival of the native liver in patients with BA, although liver transplantation remains the ultimate treatment for most (60%-80%) patients. However, postoperative adverse effects of liver transplantation may be significant. In addition, patients require lifelong immunosuppressive therapy after liver transplantation.

Case Summary

Here, we report a case of a newborn female baby (birthday: 10-03-2018) with congenital BA (confirmed at 76 days of life) who survived KPE (first surgery at 85 days of life) and underwent successful living-related liver transplantation (LRLT) (second surgery at 194 days of life). Additionally, we reviewed the existing literature on BA. After KPE (at 85 days of life), the liver function of the baby did not improve, and the indicators of liver and kidney function showed a trend of aggravation, indicating that the liver function had been seriously damaged before KPE (at 85 days of life), demonstrating the urgent need for liver transplantation surgery. The female baby survived after part of her father's liver was successfully transplanted into her body (at 194 days of life). The patient recovered successfully. No other diseases were found at the 4-year follow-up, and all indices of liver and kidney functions tended to be normal.

Conclusion

This case highlights the following. Postoperative alkaline phosphatase was consistently above the normal range, although the reason for this was unclear; neither tacrolimus nor cyclosporine A has formulations designed specifically for infants, which does not meet the needs of clinical individualized medication, suggesting that these anti-rejection drugs are future development directions. Only one case of congenital BA has been found thus far in Hefei, and this case has extremely important reference significance for the prevention, treatment, and diagnosis of BA in Hefei, Anhui province.

Exploring the impact of coffee consumption on liver health: A comprehensive bibliometric analysis

The study indicates that while research has demonstrated the potential of coffee to mitigate liver damage, a comprehensive quantitative analysis of its effects has yet to be conducted. This study seeks to explore the current landscape and focal points of research on coffee consumption's impact on the liver from 2013 to 2023. Articles published within this timeframe were retrieved from the Web of Science database and subjected to analysis using R software, VOSviewer, and CiteSpace software. A total of 1106 articles primarily focused on coffee's impact on liver health were analyzed. The frequency of publication exhibited a significant increase from 2013 to 2023. The United States emerged as the leading contributor in publications and international collaborations, particularly with institutions such as Harvard Medical School and Harvard T.H. Chan School of Public Health. Noteworthy journals in this domain included "Nutrients" and "Hepatology" Commonly occurring keywords encompassed components, chlorogenic acids, oxidative stress, and liver. The study highlighted coffee's potential benefits in preventing cardiovascular and liver diseases, attributed to mechanisms such as antioxidant activity and modulation of hepatic cells. Through bibliometric analysis, this study offers valuable insights into the research status and emphasis on coffee's effects on liver health, serving as a significant reference for future investigations in this area.

Microbial metabolism of caffeine and potential applications in bioremediation

With increasing global consumption of caffeine-rich products, such as coffee, tea, and energy drinks, there is also an increase in urban and processing waste full of residual caffeine with limited disposal options. This waste caffeine has been found to leach into the surrounding environment where it poses a threat to microorganisms, insects, small animals, and entire ecosystems. Growing interest in harnessing this environmental contaminant has led to the discovery of 79 bacterial strains, eight yeast strains, and 32 fungal strains capable of metabolizing caffeine by N-demethylation and/or C-8 oxidation. Recently observed promiscuity of caffeine-degrading enzymes in vivo has opened up the possibility of engineering bacterial strains capable of producing a wide variety of caffeine derivatives from a renewable resource. These engineered strains can be used to reduce the negative environmental impact of leached caffeine-rich waste through bioremediation efforts supplemented by our increasing understanding of new techniques such as cell immobilization. Here, we compile all of the known caffeine-degrading microbial strains, discuss their metabolism and related enzymology, and investigate their potential application in bioremediation.

Caffeine in Hepatocellular Carcinoma: Cellular Assays, Animal Experiments, and Epidemiological Investigation

The use of caffeine in treating various liver diseases has made substantial progress in the past decade owing to advances in science, technology, and medicine. However, whether caffeine has a preventive effect on hepatocellular carcinoma (HCC) and its mechanism are still worth further investigation. In this review, we summarize and analyze the efficacy and safety of caffeine in the prevention of HCC. We conducted a review of articles published in PubMed and Web of Science in the past 2 decades until December 6, 2023, which were searched for using the terms "Caffeine" and "Hepatocellular Carcinoma." Studies have found that coffee intake is negatively correlated with HCC risk, especially caffeinated coffee. Recent studies have found that caffeine has beneficial effects on liver health, decreasing levels of enzymes responsible for liver damaging and slowing the progression of hepatic fibrosis and cirrhosis. Caffeine also acts against liver fibrosis through adenosine receptors (ARs), which promote tissue remodeling by inducing fibrin and collagen production. Additionally, new studies have found that moderate consumption of caffeinated beverages can decrease various the levels of various collagens in patients with chronic hepatitis C. Furthermore, polyphenolic compounds in coffee can improve fat homeostasis, reduce oxidative stress, and prevent liver steatosis and fibrosis. Moreover, many in vitro studies have shown that caffeine can protect liver cells and inhibit the activation and proliferation of hepatic stellate cells. Taken together, we describe the benefits of caffeine for liver health and highlight its potential values as a drug to prevent various hepatic diseases. As a protective agent of liver inflammation, non-selective AR inhibitor caffeine can inhibit the growth of HCC cells by inhibiting adenosine and AR binding to initiate immune response, providing a basis for the future development of caffeine as an adjuvant drug against HCC.

Transcriptomic screening of novel targets of sericin in human hepatocellular carcinoma cells

Sericin, a natural protein derived from Bombyx mori, is known to ameliorate liver tissue damage; however, its molecular mechanism remains unclear. Herein, we aimed to identify the possible novel targets of sericin in hepatocytes and related cellular pathways. RNA sequencing analysis indicated that a low dose of sericin resulted in 18 differentially expressed genes (DEGs) being upregulated and 68 DEGs being downregulated, while 61 DEGs were upregulated and 265 DEGs were downregulated in response to a high dose of sericin (FDR ≤ 0.05, fold change > 1.50). Functional analysis revealed that a low dose of sericin regulated pathways associated with the complement and coagulation cascade, metallothionine, and histone demethylate (HDMs), whereas a high dose of sericin was associated with pathways involved in lipid metabolism, mitogen-activated protein kinase (MAPK) signaling and autophagy. The gene network analysis highlighted twelve genes, A2M, SERPINA5, MT2A, MT1G, MT1E, ARID5B, POU2F1, APOB, TRAF6, HSPA8, FGFR1, and OGT, as novel targets of sericin. Network analysis of transcription factor activity revealed that sericin affects NFE2L2, TFAP2C, STAT1, GATA3, CREB1 and CEBPA. Additionally, the protective effects of sericin depended on the counterregulation of APOB, POU2F1, OGT, TRAF6, and HSPA5. These findings suggest that sericin exerts hepatoprotective effects through diverse pathways at different doses, providing novel potential targets for the treatment of liver diseases.

Water extract of earthworms mitigates mouse liver fibrosis by potentiating hepatic LKB1/Nrf2 axis to inhibit HSC activation and hepatocyte death

ETHNOPHARMACOLOGICAL RELEVANCE

When left untreated, liver fibrosis (LF) causes various chronic liver diseases. Earthworms (Pheretima aspergillum) are widely used in traditional medicine because of their capacity to relieve hepatic diseases.

AIM OF THE STUDY

This study aimed to explore the anti-LF effects of water extract of earthworms (WEE) and the underlying molecular mechanisms.

MATERIALS AND METHODS

A CCl4-induced mouse model of LF was used to study the impact of WEE on LF in vivo. The anti-LF activity of WEE in mice was compared with that of silybin, which can be clinically applied in LF intervention and was used as a positive control. Activation of LX-2 hepatic stellate cells (HSCs) and apoptosis and ferroptosis of AML-12 hepatocytes induced by TGFβ1 were used as in vitro models.

RESULTS

WEE drastically improved LF in mice. WEE reduced markers of activated HSCs in mice and inhibited TGFβ1-induced activation of LX-2 HSCs in vitro. Additionally, WEE suppressed CCl4-induced apoptosis and ferroptosis in mouse hepatocytes. Mechanistically, WEE induced Nrf2 to enter the nuclei of the mouse liver cells, and the hepatic levels of Nrf2-downstream antioxidative factors increased. LKB1/AMPK/GSK3β is an upstream regulatory cascade of Nrf2. In the LF mouse model, WEE increased hepatic phosphorylated LKB1, AMPK, and GSK3β levels. Similar results were obtained for the LX-2 cells. In AML-12 hepatocytes and LX-2 HSCs, WEE elevated intracellular Nrf2 levels, promoted its nuclear translocation, and inhibited TGFβ1-induced ROS accumulation. Knocking down LKB1 abolished the impact of WEE on the AMPK/GSK3β/Nrf2 cascade and eliminated its protective effects against TGFβ1.

CONCLUSIONS

Our findings reveal that WEE improves mouse LF triggered by CCl4 and supports its application as a promising hepatoprotective agent against LF. The potentiation of the hepatic antioxidative AMPK/GSK3β/Nrf2 cascade by activating LKB1 and the subsequent suppression of HSC activation and hepatocyte apoptosis and ferroptosis are implicated in WEE-mediated alleviation of LF.

Urinary caffeine and its metabolites in association with advanced liver fibrosis and liver steatosis: a nationwide cross-sectional study

Aim: This study used urinary caffeine and its metabolites to evaluate their relationships with liver steatosis and advanced liver fibrosis. Methods: A total of 2068 adult participants with required data were filtered from the 2009-2014 National Health and Nutrition Examination Survey (NHANES) cycles. Non-invasive scores were applied to define liver steatosis and advanced liver fibrosis. Logistic regression models, weighted quantile sum (WQS) regression models, quantile-based g-computation (QG-Comp) models, and restricted cubic spline (RCS) regression models were used to assess the associations of urinary caffeine and its metabolites with liver steatosis and advanced liver fibrosis. A series of additional analyses were conducted to examine the subgroup-specific differences and test the robustness of the observed results. Results: The major caffeine metabolite mixture and most individual caffeine metabolites were found to be negatively associated with the risk of advanced liver fibrosis with subgroup-specific variations. Only 7-MX consistently showed a negative association with liver steatosis in all analyses, while no association was observed between the major caffeine metabolite mixture and liver steatosis. Conclusion: The major caffeine metabolite mixture and most individual urinary caffeine metabolites exhibited inverse associations with advanced liver fibrosis with subgroup differences. Further prospective and experimental studies are urgently needed to verify our results and further identify the possible mechanisms.

Current therapeutic targets and multifaceted physiological impacts of caffeine

Caffeine, which shares consubstantial structural similarity with purine adenosine, has been demonstrated as a nonselective adenosine receptor antagonist for eliciting most of the biological functions at physiologically relevant dosages. Accumulating evidence supports caffeine's beneficial effects against different disorders, such as total cardiovascular diseases and type 2 diabetes. Conversely, paradoxical effects are also linked to caffeine ingestion in humans including hypertension-hypotension and tachycardia-bradycardia. These observations suggest the association of caffeine action with its ingested concentration and/or concurrent interaction with preferential molecular targets to direct explicit events in the human body. Thus, a coherent analysis of the functional targets of caffeine, relevant to normal physiology, and disease pathophysiology, is required to understand the pharmacology of caffeine. This review provides a broad overview of the experimentally validated targets of caffeine, particularly those of therapeutic interest, and the impacts of caffeine on organ-specific physiology and pathophysiology. Overall, the available empirical and epidemiological evidence supports the dose-dependent functional activities of caffeine and advocates for further studies to get insights into the caffeine-induced changes under specific conditions, such as asthma, DNA repair, and cancer, in view of its therapeutic applications.

Protective effects of caffeine against palmitate-induced lipid toxicity in primary rat hepatocytes is associated with modulation of adenosine receptor A1 signaling

BACKGROUND

Epidemiological evidence has shown an association between coffee consumption and reduced risk for chronic liver diseases, including metabolic-dysfunction-associated liver disease (MALFD). Lipotoxicity is a key cause of hepatocyte injury during MAFLD. The coffee component caffeine is known to modulate adenosine receptor signaling via the antagonism of adenosine receptors. The involvement of these receptors in the prevention of hepatic lipotoxicity has not yet been explored. The aim of this study was to explore whether caffeine protects against palmitate-induced lipotoxicity by modulating adenosine receptor signaling.

METHODS

Primary hepatocytes were isolated from male rats. Hepatocytes were treated with palmitate with or without caffeine or 1,7DMX. Lipotoxicity was verified using Sytox viability staining and mitochondrial JC-10 staining. PKA activation was verified by Western blotting. Selective (ant)agonists of A1AR (DPCPX and CPA, respectively) and A2AR (istradefyline and regadenoson, respectively), the AMPK inhibitor compound C, and the Protein Kinase A (PKA) inhibitor Rp8CTP were used. Lipid accumulation was verified by ORO and BODIPY 453/50 staining.

RESULTS

Caffeine and its metabolite 1,7DMX prevented palmitate-induced toxicity in hepatocytes. The A1AR antagonist DPCPX also prevented lipotoxicity, whereas both the inhibition of PKA and the A1AR agonist CPA (partially) abolished the protective effect. Caffeine and DPCPX increased lipid droplet formation only in palmitate-treated hepatocytes and decreased mitochondrial ROS production.

CONCLUSIONS

The protective effect of caffeine against palmitate lipotoxicity was shown to be dependent on A1AR receptor and PKA activation. Antagonism of A1AR also protects against lipotoxicity. Targeting A1AR receptor may be a potential therapeutic intervention with which to treat MAFLD.

Blocking ATP-P1Rs axis attenuate alcohol-related liver fibrosis

AIMS

The aim of this study was to explore the fibrogenic effects of ATP-P1Rs axis and ATP-P2Rs axis on alcohol-related liver fibrosis (ALF).

MATERIALS AND METHODS

C57BL/6J CD73 knock out (KO) mice were used in our study. 8-12 weeks male mice were used as an ALF model in vivo. In conclusion, after one week of adaptive feeding, 5 % alcohol liquid diet was given for 8 weeks. High-concentration alcohol (31.5 %, 5 g/kg) was administered by gavage twice weekly, and 10 % CCl4 intraperitoneal injections (1 ml/kg) were administered twice weekly for the last two weeks. The mice in the control group were injected intraperitoneally with an equivalent volume of normal saline. Fasting for 9 h after the last injection, blood samples were collected, and related indicators were tested. In vitro, rat hepatic stellate cells (HSCs) were treated with 200 μM acetaldehyde to establish an alcoholic liver fibrosis for 48 h, then tested related indicators.

KEY FINDINGS

We found that both adenosine receptors including adenosine A1, A2A, A2B, A3 receptors (A1R, A2AR, A2BR, A3R) and ATP receptors including P2X7, P2Y2 receptors (P2X7R, P2Y2R) were expressed increased in ALF. After CD73 was knocked out, we found that adenosine receptors expression decreased, ATP expression increased, and fibrosis degree decreased.

SIGNIFICANCE

Based on the research, we discovered that adenosine plays a more important role in ALF. Therefore, blocking the ATP-P1Rs axis represented a potential treatment for ALF, and CD73 will become a potential therapeutic target.

A review of edible plant-derived natural compounds for the therapy of liver fibrosis

Liver fibrosis has a high incidence worldwide and is the common pathological basis of many chronic liver diseases. Liver fibrosis is caused by the excessive deposition of extracellular matrix and concomitant collagen accumulation in livers and can lead to the development of liver cirrhosis and even liver cancer. A large number of studies have provided evidence that liver fibrosis can be blocked or even reversed by appropriate medical interventions. However, the antifibrosis drugs with ideal clinical efficacy are still insufficient. The edible plant-derived natural compounds have been reported to exert effective antifibrotic effects with few side-effects, representing a kind of promising source for the treatment of liver fibrosis. In this article, we reviewed the current progress of the natural compounds derived from dietary plants in the treatment of liver fibrosis, including phenolic compounds (capsaicin, chlorogenic acid, curcumin, ellagic acid, epigallocatechin-3-gallate, resveratrol, sinapic acid, syringic acid, vanillic acid and vitamin E), flavonoid compounds (genistein, hesperidin, hesperetin, naringenin, naringin and quercetin), sulfur-containing compounds (S-allylcysteine, ergothioneine, lipoic acid and sulforaphane) and other compounds (betaine, caffeine, cucurbitacin B, lycopene, α-mangostin, γ-mangostin, ursolic acid, vitamin C and yangonin). The pharmacological effects and related mechanisms of these compounds in in-vivo and in-vitro models of liver fibrosis are focused.

Metabolomics analysis of urine from patients with alcohol-associated liver disease reveals dysregulated caffeine metabolism

Excess alcohol intake causes millions of deaths annually worldwide. Asymptomatic early-stage, alcohol-associated liver disease (ALD) is easily overlooked, and ALD is usually only diagnosed in more advanced stages. We explored the possibility of using polar urine metabolites as biomarkers of ALD for early-stage diagnosis and functional assessment of disease severity by quantifying the abundance of polar metabolites in the urine samples of healthy controls (n = 18), patients with mild or moderate liver injury (n = 21), and patients with severe alcohol-associated hepatitis (n = 25). The polar metabolites in human urine were first analyzed by untargeted metabolomics, showing that 209 urine metabolites are significantly changed in patients, and 17 of these are highly correlated with patients' model for end-stage liver disease (MELD) score. Pathway enrichment analysis reveals that the caffeine metabolic pathway is the most affected in ALD. We then developed a targeted metabolomics method and measured the concentration of caffeine and its metabolites in urine using internal and external standard calibration, respectively. The described method can quantify caffeine and its 14 metabolites in 35 min. The results of targeted metabolomics analysis agree with the results of untargeted metabolomics, showing that 13 caffeine metabolites are significantly decreased in patients. In particular, the concentrations of 1-methylxanthine, paraxanthine, and 5-acetylamino-6-amino-3-methyluracil are markedly decreased with increased disease severity. We suggest that these three metabolites could serve as functional biomarkers for differentiating early-stage ALD from more advanced liver injury.NEW & NOTEWORTHY Our study using both untargeted and targeted metabolomics reveals the caffeine metabolic pathway is dysregulated in ALD. Three caffeine metabolites, 1-methylxanthine, paraxanthine, and 5-acetylamino-6-amino-3-methyluracil, can differentiate the severity of early-stage ALD.

Synergistic toxicity of ethanol and 2,4-dichlorophenoxyacetic acid enhances oxidant status, DNA damage, inflammation, and apoptosis in rats

Clarifying the interactions between substances as a result of exposure to multiple xenobiotics and determining the impacts on health are important from the toxicological point of view. Therefore, the aim of the study was to investigate the synergistic toxic effects of ethanol and 2,4-dichlorophenoxyacetic acid (2,4-D) in male albino rats. A total number of 28 Wistar male rats were divided into 4 groups (7/each), and 2,4-D (5 mg/kg) and ethanol (3 g/kg) were administered orally to rats for 60 days, either alone or in combination. Co-administration of ethanol and 2,4-D increased liver functional enzyme levels and lipid peroxidation in blood and tissues while decreased glutathione and antioxidant enzyme activities when compared to individual applications. Furthermore, co-administration of ethanol and 2,4-D caused DNA damage as well as the increase in apoptotic and proinflammatory cytokine gene expressions. Furthermore, histopathological examination of the tissues especially liver and kidney revealed that these two substances induced more serious damage. In conclusion, co-administration of ethanol and 2,4-D resulted in strong toxic effects on tissues (especially liver) with a synergistic interaction and give rise to serious toxicological drawbacks.

Increased Intake of Both Caffeine and Non-Caffeine Coffee Components Is Associated with Reduced NAFLD Severity in Subjects with Type 2 Diabetes

Coffee may protect against non-alcoholic fatty liver disease (NAFLD), but the roles of the caffeine and non-caffeine components are unclear. Coffee intake by 156 overweight subjects (87% with Type-2-Diabetes, T2D) was assessed via a questionnaire, with 98 subjects (all T2D) also providing a 24 h urine sample for quantification of coffee metabolites by LC-MS/MS. NAFLD was characterized by the fatty liver index (FLI) and by Fibroscan^® assessment of fibrosis. No associations were found between self-reported coffee intake and NAFLD parameters; however, total urine caffeine metabolites, defined as Σ_caffeine (caffeine + paraxanthine + theophylline), and adjusted for fat-free body mass, were significantly higher for subjects with no liver fibrosis than for those with fibrosis. Total non-caffeine metabolites, defined as Σ_ncm (trigonelline + caffeic acid + p-coumaric acid), showed a significant negative association with the FLI. Multiple regression analyses for overweight/obese T2D subjects (n = 89) showed that both Σ_caffeine and Σ_ncm were negatively associated with the FLI, after adjusting for age, sex, Hb_A1c, ethanol intake and glomerular filtration rate. The theophylline fraction of Σ_caffeine was significantly increased with both fibrosis and the FLI, possibly reflecting elevated CYP2E1 activity-a hallmark of NAFLD worsening. Thus, for overweight/obese T2D patients, higher intake of both caffeine and non-caffeine coffee components is associated with less severe NAFLD. Caffeine metabolites represent novel markers of NAFLD progression.

Laminarin ameliorates alcohol-induced liver damage and its molecular mechanism in mice

Alcoholic liver disease (ALD) has become a health issue globally. Laminarin, a low molecular weight marine-derived β-glucan, has been identified with multiple biological activities. In this study, the ameliorative effect on ALD of laminarin isolated from brown algae was investigated. Phenotypic, pathological alterations and biochemical characteristics indicated that laminarin administration (100 mg/kg/day) significantly alleviated liver injury and improved liver function in the alcohol-induced mice. Gene chip results indicated that laminarin treatment caused 52 up-regulated and 13 down-regulated genes in the hepatic tissues of alcohol-induced damage mice, and most of these genes are associated with regulation of oxidative stress (such as CYP450/glutathione-dependent antioxidation), Wnt signaling pathway, retinol metabolism, and cAMP pathway based on GO and KEGG analysis. PPI network analysis indicated that the downstream target genes lied in the hub of the net. Our experiments also confirmed the changed expressions of some target genes. Taken together, these results suggest that laminarin can ameliorate alcohol-induced damage in mice and its molecular mechanism lies in modulating anti-oxidation pathway, WNT pathway, and cAMP pathway, which regulate the expressions of downstream target genes and alleviate alcohol-induced damage. Our study provides new clue to prevent alcohol-induced damage and will be benefit to develop functional foods. PRACTICAL APPLICATIONS: This study verified the positive effect on alcoholic liver disease (ALD) of laminarin, a water-soluble brown algae-derived β-glucan, linked by β-(1,3) glycosidic bonds with β-(1,6) branches. Laminarin significantly alleviated liver injury and improved liver function of ALD mice. Moreover, transcriptomics and bioinformatics analysis further revealed the gene expression patterns, hub targets, and signalings including CYP450/glutathione, Wnt, retinol metabolism, cAMP pathways regulated by laminarin. This research is the first evidence for hepatoprotective effect of laminarin against ALD and its molecular mechanism, which will be advantage to develop functional foods or adjuvant therapy of ALD.

The upregulation of glutamate decarboxylase 67 against hippocampal excitability damage in male fetal rats by prenatal caffeine exposure

As a kind of xanthine alkaloid, caffeine is widely present in beverages, food, and analgesic drugs. Our previous studies have shown that prenatal caffeine exposure (PCE) can induce programmed hypersensitivity of the hypothalamic-pituitary-adrenal (HPA) axis in offspring rats, which is involved in developing many chronic adult diseases. The present study further examined the potential molecular mechanism and toxicity targets of hippocampal dysfunction, which might mediate the programmed hypersensitivity of the HPA axis in offspring. Pregnant rats were intragastrically administered with 0, 30, and 120 mg/kg/day caffeine from gestational days (GD) 9-20, and the fetal rats were extracted at GD20. Rat fetal hippocampal H19-7/IGF1R cell line was treated with caffeine, adenosine A2A receptor (A2AR) agonist (CGS-21680) or adenylate cyclase agonist (forskolin) plus caffeine. Compared with the control group, hippocampal neurons of male fetal rats by PCE displayed increased apoptosis and reduced synaptic plasticity, whereas glutamate decarboxylase 67 (GAD67) expression was increased. Moreover, the expression of A2AR was down-regulated, PCE inhibited the cAMP/PKA/CREB/BDNF/TrkB pathway. Furthermore, the results in vitro were consistent with the in vivo study. Both CGS21680 and forskolin could reverse the above alteration caused by caffeine. These results indicated that PCE inhibits the BDNF pathway and mediates the hippocampus's glutamate (Glu) excitotoxicity. The compensatory up-regulation of GAD67 unbalanced the Glu/gamma-aminobutyric acid (GABA)ergic output, leading to the impaired negative feedback to the hypothalamus and hypersensitivity of the HPA axis.

Caffeine in liver diseases: Pharmacology and toxicology

We have previously shown that adenosine A1AR antagonists, adenosine A2aAR antagonists, and caffeine have significant inhibitory effects on the activation and proliferation of hepatic stellate cells in alcoholic liver fibrosis. Many recent studies have found that moderate coffee consumption is beneficial for various liver diseases. The main active ingredient of coffee is caffeine, which is a natural non-selective adenosine receptor antagonist. Moreover, numerous preclinical epidemiological studies and clinical trials have examined the association between frequent coffee consumption and the risk of developing different liver diseases. In this review, we summarize and analyze the prophylactic and therapeutic effects of caffeine on various liver diseases, with an emphasis on cellular assays, animal experiments, and clinical trials. To review the prevention and treatment effects of caffeine on different liver diseases, we searched all literature before 19 July 2022, using “caffeine” and “liver disease” as keywords from the PubMed and ScienceDirect databases. We found that moderate coffee consumption has beneficial effects on various liver diseases, possibly by inhibiting adenosine binding to its receptors. Caffeine is a potential drug for the prevention and treatment of various liver diseases.

Natural polysaccharides as potential anti-fibrotic agents: A review of their progress

Fibrosis, as a common disease which could be found in nearly all organs, is normally initiated by organic injury and eventually ended in cellular dysfunction and organ failure. Currently, effective and safe therapeutic strategies targeting fibrogenesis still in highly demand. Natural polysaccharides derived from natural resources possess promising anti-fibrosis potential, with no deleterious side effects. Based on the etiology and pathogenesis of fibrosis, this review summarizes the intervention effects and mechanisms of natural polysaccharides in the prevention and treatment of fibrosis. Natural polysaccharides are able to regulate each phase of the fibrogenic response, including primary injury to organs, activation of effector cells, the elaboration of extracellular matrix (ECM) and dynamic deposition. In addition, polysaccharides significantly reduce fibrosis levels in multiple organs including heart, lung, liver and kidney. The investigation of the pathogenesis of fibrosis indicates that mechanisms including the inhibition of TGF-β/Smad, NF-κB, HMGB1/TLR4, cAMP/PKA signaling pathways, MMPs/TIMPs system as well as microRNAs are promising therapeutic targets. Natural polysaccharides can target these mediators or pathways to alleviate fibrosis. The information reviewed here offer new insights into the understanding the protective role of natural polysaccharides against fibrosis, help design further experimental studies related to polysaccharides and fibrotic responses, and shed light on a potential treatment for fibrosis.

Oxidative Stress in Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a challenging disease caused by multiple factors, which may partly explain why it still remains an orphan of adequate therapies. This review highlights the interaction between oxidative stress (OS) and disturbed lipid metabolism. Several reactive oxygen species generators, including those produced in the gastrointestinal tract, contribute to the lipotoxic hepatic (and extrahepatic) damage by fatty acids and a great variety of their biologically active metabolites in a “multiple parallel-hit model”. This leads to inflammation and fibrogenesis and contributes to NAFLD progression. The alterations of the oxidant/antioxidant balance affect also metabolism-related organelles, leading to lipid peroxidation, mitochondrial dysfunction, and endoplasmic reticulum stress. This OS-induced damage is at least partially counteracted by the physiological antioxidant response. Therefore, modulation of this defense system emerges as an interesting target to prevent NAFLD development and progression. For instance, probiotics, prebiotics, diet, and fecal microbiota transplantation represent new therapeutic approaches targeting the gut microbiota dysbiosis. The OS and its counter-regulation are under the influence of individual genetic and epigenetic factors as well. In the near future, precision medicine taking into consideration genetic or environmental epigenetic risk factors, coupled with new OS biomarkers, will likely assist in noninvasive diagnosis and monitoring of NAFLD progression and in further personalizing treatments.

Effects of Different Green Tea Extracts on Chronic Alcohol Induced-Fatty Liver Disease by Ameliorating Oxidative Stress and Inflammation in Mice

Alcoholic fatty liver disease (AFLD) is a common chronic liver disease and has become a critical global public health problem. Green tea is a popular drink worldwide and contains several bioactive compounds. Different green teas could contain diverse compounds and possess distinct bioactivities. In the present study, the effects of 10 green teas on chronic alcohol induced-fatty liver disease in mice were explored and compared. The results showed that several green teas significantly reduced triacylglycerol levels in serum and liver as well as the aminotransferase activities in mice at a dose of 200 mg/kg, suggesting that they possess hepatoprotective effects. Moreover, several green teas remarkably decreased the expression of cytochrome P450 2E1, the levels of malondialdehyde and 4-hydroxynonenoic acid, and the contents of proinflammatory cytokines, indicating that they could alleviate oxidation damage and inflammation induced by chronic alcohol exposure. In addition, Seven Star Matcha Tea and Selenium-Enriched Matcha Tea could increase glutathione level. Furthermore, the main phytochemical components in green teas were determined and quantified by high-performance liquid chromatography, and the correlation analysis showed that gallic acid, gallocatechin, catechin, chlorogenic acid, and epigallocatechin gallate might at least partially contribute to protective effects on AFLD. In conclusion, Selenium-Enriched Chaoqing Green Tea, Xihu Longjing Tea, Taiping Houkui Tea, and Selenium-Enriched Matcha Tea showed the strongest preventive effects on AFLD. This research also provides the public with new insights about the effects of different green teas on AFLD.

Novel Therapeutic Targets in Liver Fibrosis

Liver fibrosis is end-stage liver disease that can be rescued. If irritation continues due to viral infection, schistosomiasis and alcoholism, liver fibrosis can progress to liver cirrhosis and even cancer. The US Food and Drug Administration has not approved any drugs that act directly against liver fibrosis. The only treatments currently available are drugs that eliminate pathogenic factors, which show poor efficacy; and liver transplantation, which is expensive. This highlights the importance of clarifying the mechanism of liver fibrosis and searching for new treatments against it. This review summarizes how parenchymal, nonparenchymal cells, inflammatory cells and various processes (liver fibrosis, hepatic stellate cell activation, cell death and proliferation, deposition of extracellular matrix, cell metabolism, inflammation and epigenetics) contribute to liver fibrosis. We highlight discoveries of novel therapeutic targets, which may provide new insights into potential treatments for liver fibrosis.

The effect of coffee consumption on the non-alcoholic fatty liver disease and liver fibrosis: A meta-analysis of 11 epidemiological studies

INTRODUCTION AND OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD) is a widespread chronic liver disease. It is considered a multifactorial disorder that can progress to liver fibrosis and cause a worldwide public health concern. Coffee consumption may have a protective impact on NAFLD and liver fibrosis. However, the evidence from the previous studies is inconsistent. This meta-analysis summarizes available literature.

MATERIALS AND METHODS

This study comprises two meta-analyses. The first meta-analysis summarizes the effect of coffee consumption on NAFLD in those who did or did not drink coffee. The second analysis compares the risk of liver fibrosis development between NAFLD patients who did or did not drink coffee. Pooled risk ratios (RR) and confidence intervals (CI) of observational studies were estimated.

RESULTS

Of the total collected 321 articles, 11 met our eligibility criteria to be included in the analysis. The risk of NAFLD among those who drank coffee compared to those who did not was significantly lower with a pooled RR value of 0.77 (95% CI 0.60-0.98). Moreover, we also found a significantly reduced risk of liver fibrosis in those who drink coffee than those who did not drink in the NAFLD patients with the relative risk (RR) of 0.68 (95% CI 0.68-0.79).

CONCLUSIONS

Regular coffee consumption is significantly associated with a reduced risk of NAFLD. It is also significantly associated with decreased risk of liver fibrosis development in already diagnosed NAFLD patients. Although coffee consumption may be considered an essential preventive measure for NAFLD, this subject needs further epidemiological studies.

Caffeine-induced inversion of prostaglandin E2 effects on hepatic stellate cell activation

BACKGROUND AND AIMS

Liver inflammation leads to the activation of hepatic stellate cells (HSCs), resulting in the development of liver fibrosis. The present study aimed to investigate the effects of prostaglandin E₂ (PGE₂), which is biosynthesized by Kupffer cells, hepatocytes, and HSCs during inflammation, on HSC activation, including its combinatory effect with caffeine.

METHODS

HSCs isolated from mice were activated by culturing in a medium supplemented with 10% fetal bovine serum for 7 days on plastic plates. The activation of HSCs was evaluated by immunofluorescence of α-smooth muscle actin in HSCs. Comprehensive gene expression analysis was performed using mRNA-sequencing to compare HSCs cultured for 1 or 7 days, with or without PGE₂, caffeine, or both.

RESULTS

PGE₂ (1 μM) facilitated the activation of HSCs but inhibited the HSC activation in the presence of caffeine (3 mM). Comprehensive gene expression analysis revealed that HSCs treated with PGE₂ in the presence of caffeine were classified in the same class as HSCs cultured for 1 day, i.e., quiescent HSCs. In contrast, PGE₂ did not exhibit an inhibitory effect on HSC activation when co-treated with any isoform-specific phosphodiesterase inhibitors. Although the adenylate cyclase inhibitor 2',5'-dideoxyadenosine suppressed the elevation of intracellular cAMP level induced by PGE₂ in the presence of caffeine, it had no effect on the inhibition of HSC activation by PGE₂ plus caffeine.

CONCLUSION

The effect of PGE₂ on HSC activation is changed from facilitatory to inhibitory when combined with caffeine, suggesting that caffeine may effectively suppress liver fibrosis during inflammation.

Caffeine prevents oxalate-induced epithelial-mesenchymal transition of renal tubular cells by its anti-oxidative property through activation of Nrf2 signaling and suppression of Snail1 transcription factor

Caffeine is an active ingredient found in coffee and energy beverages. Its hepatoprotective effects against liver fibrosis are well-documented. Nonetheless, its renoprotective effects against renal fibrogenesis and epithelial-mesenchymal transition (EMT) processes remain unclear and under-investigated. In this study, the protective effects of caffeine against oxalate-induced EMT in renal tubular cells were evaluated by various assays to measure expression levels of epithelial and mesenchymal markers, cell migrating activity, level of oxidized proteins, and expression of Nrf2 and Snail1. Oxalate at sublethal dose significantly suppressed cell proliferation but increased cell elongation, spindle index and migration. Oxalate also decreased expression of epithelial markers (zonula occludens-1 (ZO-1) and E-cadherin) but increased expression of mesenchymal markers (fibronectin, vimentin and α-smooth muscle actin (α-SMA)). All of these EMT-inducing effects of oxalate could be prevented by pretreatment with caffeine. While oxalate increased oxidized proteins and Snail1 levels, it decreased Nrf2 expression. Caffeine could preserve all these molecules to their basal (control) levels. Finally, silencing of Nrf2 expression by small interfering RNA (siRNA) could abolish such protective effects of caffeine on oxalate-induced EMT. Our data indicate that the renoprotective effects of caffeine against oxalate-induced EMT is mediated, at least in part, by its anti-oxidative property through activation of Nrf2 signaling and suppression of Snail1 transcription factor.

Diagnosis and prevention of the vasodepressor type of neurally mediated syncope in Japanese patients

We investigated circulatory dynamics in patients with vasodepressor type neurally mediated syncope (VT-NMS) by performing high-resolution Holter electrocardiography and a correlation analysis of changes in adenylate cyclase activity, blood pressure, and pulse during the head-up tilt test. Holter electrocardiography was performed for 30 patients. Adenylate cyclase activity was evaluated in lymphocytes from blood samples taken at rest and during the head-up tilt test. There was no change in autonomic nerve fluctuation during electrocardiography in VT-NMS patients, but our results showed a significant difference in blood pressure and adenylate cyclase activity between VT-NMS patients and healthy volunteers; the systolic blood pressure of VT-NMS patients decreased after 5 min, while at 10 min, the adenylate cyclase activity was the highest (0.53%) and the systolic blood pressure was the lowest (111.8 mm Hg). Pulse rates increased after 10 min. VT-NMS patients showed higher blood pressure, pulse rate, and adenylate cyclase activity during the tilt test than did healthy volunteers. In patients with syncope, standing for longer than 10 minutes may increase the risk of VT-NMS. From our results, we consider it likely that high systolic blood pressure and adenylate cyclase activity at rest cause fainting in VT-NMS patients. Our findings may be helpful for identifying individuals with a high risk of developing NMS in the healthy population.

Knockdown of TRIM15 inhibits the activation of hepatic stellate cells

Liver fibrosis is a global public health problem, and the activation of hepatic stellate cells (HSCs) is the main driving force for liver fibrosis. However, the activation mechanism of HSCs is still not fully understood. In this study, we screened out 854 differentially expressed genes [Log₂ fold change absolute: log2 FC(abs) ≥ 1] in activated LX-2 cells. Subsequently, we performed functional analyses of these differentially expressed genes. Gene Ontology enrichment analysis showed that the target genes were mainly enriched in processes such as positive regulation of cell migration involved in sprouting angiogenesis, negative regulation of keratinocyte proliferation, and nuclear inclusion bodies. Kyoto Encyclopedia of Gene and Genome signaling pathway enrichment analysis revealed that dysregulated genes were involved in signaling pathways such as pantothenate and coenzyme A biosynthesis and riboflavin metabolism. The microarray results were validated by reverse transcription-quantitative polymerase chain reaction, which indicated that the microarray results were reliable and that the tripartite motif containing 15 (TRIM15) had the highest absolute value of Log₂FC. Additionally, the effect of TRIM15 on the proliferation, migration, and activation of LX-2 cells was assessed using overexpression plasmids and siRNA transfections. TRIM15 promoted the proliferation and migration of LX-2 cells and positively regulated the expression of α-smooth muscle actin and type I collagen. Collectively, the data revealed the gene expression profiles of quiescent and activated LX-2 cells and the involvement of TRIM15 in the activation of LX-2 cells. Hereby, TRIM15 could be a novel target of the HSC activation mechanism.

Plant-Based Foods and Their Bioactive Compounds on Fatty Liver Disease: Effects, Mechanisms, and Clinical Application

Fatty liver disease (FLD), including nonalcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD), is a serious chronic metabolic disease that affects a wide range of people. Lipid accumulation accompanied by oxidative stress and inflammation in the liver is the most important pathogenesis of FLD. The plant-based, high-fiber, and low-fat diet has been recommended to manage FLD for a long time. This review discusses the current state of the art into the effects, mechanisms, and clinical application of plant-based foods in NAFLD and AFLD, with highlighting related molecular mechanisms. Epidemiological evidence revealed that the consumption of several plant-based foods was beneficial to alleviating FLD. Further experimental studies found out that fruits, spices, teas, coffee, and other plants, as well as their bioactive compounds, such as resveratrol, anthocyanin, curcumin, and tea polyphenols, could alleviate FLD by ameliorating hepatic steatosis, oxidative stress, inflammation, gut dysbiosis, and apoptosis, as well as regulating autophagy and ethanol metabolism. More importantly, clinical trials confirmed the beneficial effects of plant-based foods on patients with fatty liver. However, several issues need to be further studied especially the safety and effective doses of plant-based foods and their bioactive compounds. Overall, certain plant-based foods are promising natural sources of bioactive compounds to prevent and alleviate fatty liver disease.

Role of Oxidative Stress in the Pathogenesis of Non-Alcoholic Fatty Liver Disease: Implications for Prevention and Therapy

Oxidative stress (OxS) is considered a major factor in the pathophysiology of inflammatory chronic liver diseases, including non-alcoholic liver disease (NAFLD). Chronic impairment of lipid metabolism is closely related to alterations of the oxidant/antioxidant balance, which affect metabolism-related organelles, leading to cellular lipotoxicity, lipid peroxidation, chronic endoplasmic reticulum (ER) stress, and mitochondrial dysfunction. Increased OxS also triggers hepatocytes stress pathways, leading to inflammation and fibrogenesis, contributing to the progression of non-alcoholic steatohepatitis (NASH). The antioxidant response, regulated by the Nrf2/ARE pathway, is a key component in this process and counteracts oxidative stress-induced damage, contributing to the restoration of normal lipid metabolism. Therefore, modulation of the antioxidant response emerges as an interesting target to prevent NAFLD development and progression. This review highlights the link between disturbed lipid metabolism and oxidative stress in the context of NAFLD. In addition, emerging potential therapies based on antioxidant effects and their likely molecular targets are discussed.

CD73 regulates hepatic stellate cells activation and proliferation through Wnt/β-catenin signaling pathway

Alcoholic liver fibrosis (ALF) is commonly associated with long-term alcohol consumption and the activation of hepatic stellate cells (HSCs). Inhibiting the activation and proliferation of HSCs is a critical step to alleviate liver fibrosis. Increasing evidence indicates that ecto-5'-nucleotidase (CD73) plays a vital role in liver disease as a critical component of extracellular adenosine pathway. However, the regulatory role of CD73 in ALF has not been elucidated. In this study, both ethanol plus CCl₄-induced liver fibrosis mice model and acetaldehyde-activated HSC-T6 cell model were employed and the expression of CD73 was consistently elevated in vivo and in vitro. C57BL/6 J mice were intraperitoneally injected with CD73 inhibitor Adenosine 5'-(α, β-methylene) diphosphate sodium salt (APCP) from 5th week to the 8th week in the development of ALF. The results showed APCP could inhibit the activation of HSCs, reduce fibrogenesis marker expression and thus alleviate ALF. Silencing of CD73 inhibited the activation of HSC-T6 cells and promoted apoptosis of activated HSC-T6 cells. What's more, the proliferation of HSC-T6 cells was inhibited, which was characterized by decreased cell viability and cycle arrest. Mechanistically, Wnt/β-catenin pathway was activated in acetaldehyde-activated HSC-T6 cells and CD73 silencing or overexpression could regulate Wnt/β-catenin signaling pathway. Collectively, our study unveils the role of CD73 in HSCs activation, and Wnt/β-catenin signaling pathway might be involved in this progression.

Industrial Elimination of Essential Oils from Rosmarinus Officinalis: In Support of the Synergic Antifibrotic Effect of Rosmarinic and Carnosic Acids in Bleomycin Model of Lung Fibrosis

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease characterized by collagen deposition as a consequence of excessive lung fibroblasts and myofibroblasts proliferation. We aimed to investigate for the first time the effect of rosemary leaf extract rich with carnosic acid (CA) or rosmarinic acid (RA), after industrial elimination of essential oils, against bleomycin (BLM)-induced lung fibrosis in rats. Male Wistar rats were given a single dose of BLM (4 mg/kg, intratracheal), while CA rich extract, RA rich extract or the combination RA/CA rich extracts (10, 75 and 150 mg/kg, intraperitoneal) were administered 3 day later and continued for 4 weeks. We reveled by HPLC an important similar amount of phenolic compounds such as pyrogallol, vanillic, gallic and ellagic acids in both rosemary extracts. BLM induced lung fibrotic foci and disturbance in superoxide dismutase, catalase and malondialdehyde levels. At 10 mg/kg, both rosemary extracts administrated alone or in combination alleviated synergistically lung fibrosis and ameliorated oxidative changes induced by BLM. In conclusion, industrial elimination of essential oils from rosemary allowed us to obtain two extracts with potent antifibrotic activities due to the large amount of RA and CA that appear much higher and effective than wild rosemary extract.

A comprehensive review of natural products to fight liver fibrosis: Alkaloids, terpenoids, glycosides, coumarins and other compounds

The discovery of drugs to treat liver fibrosis has long been a challenge over the past decades due to its complicated pathogenesis. As a primary approach for drug development, natural products account for 30% of clinical drugs used for disease treatment. Therefore, natural products are increasingly important for their medicinal value in liver fibrosis therapy. In this part of the review, special focus is placed on the effect and mechanism of natural compounds, including alkaloids, terpenoids, glycosides, coumarins and others. A total of 36 kinds of natural compounds demonstrate significant antifibrotic effects in various liver fibrosis models in vivo and in hepatic stellate cells (HSCs) in vitro. Revealing the mechanism will provide further basis for clinical conversion, as well as accelerate drug discovery. The mechanism was further summarized with the finding of network regulation by several natural products, such as oxymatrine, paeoniflorin, ginsenoside Rg1 and taurine. Moreover, there are still improvements needed in investigating clinical efficacy, determining mechanisms, and combining applications, as well as semisynthesis and modification. Therefore, natural products area promising resource for agents that protect against liver fibrosis.

Reversine and herbal Xiang-Sha-Liu-Jun-Zi decoction ameliorate thioacetamide-induced hepatic injury by regulating the RelA/NF-κB/caspase signaling pathway

This study investigated the anti-fibrotic effects of reversine and Chinese medicine Xiang–Sha–Liu–Jun–Zi decoction (XSLJZD) on thioacetamide (TAA)-induced hepatic injury. Sprague-Dawley rats were intraperitoneally administered with TAA, then injected with reversine intraperitoneally, and/or orally provided with XSLJZD. TAA resulted in liver injury with increases in the liver index and levels of serum aspartate aminotransferase (AST) and alanine aminotransferase. Reversine alleviated the liver index and AST level and improved TAA-induced pathological changes but decreased TAA-induced collagen deposition, and α-smooth muscle actin and transforming growth factor-β1 expression. Reversine also modulated the mRNA levels of inflammatory cytokines, such as RelA, interleukin (IL)-17A, IL-22, IL-1β, IL-6, NLR family pyrin domain containing 3, platelet-derived growth factor, and monocyte chemoattractant protein, and suppressed nuclear factor (NF)-κB (p65) phosphorylation and caspase 1 activation. Meanwhile, XSLJZD protected TAA-injured liver without increasing fibrosis and enhanced the regulating effect of reversine on RelA, IL-17A, IL-1β, and MCP-1 cytokines. In conclusion, reversine ameliorates liver injury and inhibits inflammation reaction by regulating NF-κB, and XSLJZD protects the liver through its synergistic effect with reversine on regulating inflammatory cytokines.

Caffeine inhibits hypoxia-induced renal fibroblast activation by antioxidant mechanism

Caffeine has been demonstrated to possess anti-fibrotic activity against liver fibrosis. However, its role in renal fibrosis remained unclear. This study investigated the effects of caffeine on renal fibroblast activation induced by hypoxia (one of the inducers for renal fibrosis). BHK-21 fibroblasts were cultured under normoxia or hypoxia with or without caffeine treatment. Hypoxia increased levels of fibronectin, α-smooth muscle actin, actin stress fibers, intracellular reactive oxygen species (ROS), and oxidized proteins. However, caffeine successfully preserved all these activated fibroblast markers to their basal levels. Cellular catalase activity was dropped under hypoxic condition but could be reactivated by caffeine. Hif1a gene and stress-responsive Nrf2 signaling molecule were elevated/activated by hypoxia, but only Nrf2 could be partially recovered by caffeine. These data suggest that caffeine exhibits anti-fibrotic effect against hypoxia-induced renal fibroblast activation through its antioxidant property to eliminate intracellular ROS, at least in part, via downstream catalase and Nrf2 mechanisms.

Associations of Coffee Consumption with the Circulating Level of Alanine Aminotransferase and Aspartate Aminotransferase. A Meta-Analysis of Observational Studies

Background: The associations of coffee consumption with the circulating level of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) remains controversial. We conducted a meta-analysis of observational studies to sum up the existing evidence about this matter.Methods: A comprehensive literature-search up to January 2020, using PubMed, Embase and Web of Science databases, was conducted to identify the relevant observational studies that examined the associations of coffee consumption with the circulating level of ALT and AST. The standard mean difference (SMD) for the level of ALT and AST, odds ratio (OR) for the elevated ALT and AST and their corresponding 95% CIs for the highest versus lowest categories of coffee intake were determined.Results: A total of 19 observational studies, which involved 222,067 individuals, were included in this meta-analysis. The combined SMD suggested that coffee consumption was associated with a lower level of ALT (SMD = -0.14, 95% CI: -0.22 to -0.06; p = 0.001) and AST (SMD = -0.17, 95% CI: -0.20 to -0.13; p < 0.001), respectively. Meanwhile, the overall multivariable adjusted OR showed that coffee consumption was inversely associated with the elevated ALT (OR = 0.69, 95% CI: 0.60 to 0.79; p < 0.001) and AST (OR = 0.62, 95% CI: 0.48 to 0.81; p < 0.001), respectively.Conclusion: The results of this meta-analysis suggest that coffee consumption is inversely associated with the circulating level of ALT and AST, and elevated ALT and AST. More randomized controlled trials are needed to elaborate the concerned issues.

Beet root (Beta vulgaris) protects lipopolysaccharide and alcohol-induced liver damage in rat

The purpose of this study was to investigate the protective effects of beet root (Beta vulgaris var. rubra) in lipopolysaccharide (LPS) and alcohol induced liver damage. Beta vulgaris ethanol extract (BVEE) showed good antioxidant activity in the contents of polyphenol and flavonoid compounds, and the electron-donating ability and ABTS⁺ radical scavenging activity. As for anti-inflammatory effect in RAW 264.7 cells, inhibition rate of nitric oxide production was increased in dose dependent manner. In hepatotoxicity model induced by LPS and alcohol in rat, BVEE significantly decreased serum AST, ALT and γ-GTP concentrations in a dose-dependent manner. The histopathological changes after H&E staining showed that fat accumulation and inflammatory cell infiltration were decreased by BVEE. The collagen fibers around the central lobule observed by Masson's trichrome staining were also decreased by BVEE. In addition, as for the immunohistochemical staining and Transmission electron microscopy, BVEE improved morphological characteristics of damaged liver lesion. The increased mRNA expressions of NF-κB, MAPK1, MAPK3, CYP2E1, and α-SMA were significantly decreased in BVEE treated group. These results indicated that BVEE would have protective effects in hepatotoxicity by altering various indicators related to the liver damage induced by LPS or alcohol.

Purine signaling regulating HSCs inflammatory cytokines secretion, activation, and proliferation plays a critical role in alcoholic liver disease

Purine signaling pathway plays an important role in inflammation and tissue damage. To investigate the role of purine signaling pathway in acute alcoholic liver injury and chronic alcoholic liver fibrosis, we replicated two animal models and two cellular models. We found that body weights, liver indexes, serum biochemical parameters, serum fibrosis indexes, and pathological and immunohistochemical results had significant changes in two treatment groups compared with two control groups. In addition, gene expressions of purine receptors, inflammatory cytokines, fibrogenic cytokines, and inflammasomes increased obviously in two animal models and two cellular models. Furthermore, purine receptor inhibitors could significantly inhibit protein expressions of purine receptors and reduce protein expressions of inflammatory cytokines, fibrogenic cytokines, and inflammasomes. Besides, P2X7R small interfering ribonucleic acid (siRNA) had the same effects. Meanwhile, we detected protein expressions of inflammatory cytokines secreted by inflammasomes, and we found that purine receptor-mediated inflammasomes activation was a key event in the process of chronic alcoholic liver fibrosis. In summary, this study shows that inhibition of purine receptors can alleviate acute alcoholic liver injury and chronic alcoholic liver fibrosis in mice. Therefore, purine receptor is a potential new target for the treatment of acute alcoholic liver injury and chronic alcoholic fibrosis.

Methyl helicterilate ameliorates alcohol-induced hepatic fibrosis by modulating TGF-β1/Smads pathway and mitochondria-dependent pathway

This study aimed to investigate the effect and underlying mechanism of Methyl helicterilate from Helicteres angustifolia (MHHA) on alcohol-induced hepatic fibrosis. The results showed that MHHA treatment markedly alleviated alcohol-induced liver injury and notably reduced collagen deposition in liver tissue. It significantly enhanced the activity of alcohol dehydrogenase and aldehyde dehydrogenase. Moreover, MHHA treatment markedly decreased the content of inflammatory cytokines, alleviated collagen accumulation, and inhibited the expression of TGF-β1 and Smad2/3 in liver tissue. The experiments in cells showed that MHHA significantly inhibited HSC activation by blocking TGF-β1/Smads signaling pathway. Additionally, it notably induced HSC apoptosis by modulating the mitochondria-dependent pathway. The present study demonstrates that MHHA treatment significantly ameliorates alcoholic hepatic fibrosis and the underlying mechanism may be ascribed to the inhibition of the TGF-β1/Smads pathway and regulation of the mitochondria-mediated apoptotic pathway.

Research progress on the anti-hepatic fibrosis action and mechanism of natural products

Hepatic fibrosis is the most common pathological feature of most chronic liver diseases, and its continuous deterioration gradually develops into liver cirrhosis and eventually leads to liver cancer. At present, there are many kinds of drugs used to treat liver fibrosis. However, Western drugs tend to only target single genes/proteins and induce many adverse reactions. Most of the mechanisms and active ingredients of traditional Chinese medicine (TCM) are not clear, and there is a lack of unified diagnosis and treatment standards. Natural products, which are characterized by structural diversity, low toxicity, and origination from a wide range of sources, have unique advantages and great potential in anti-liver fibrosis. This article summarizes the work done over the previous decade, on the active ingredients in natural products that are reported to have anti-hepatic fibrosis effects. The effective anti-hepatic fibrosis ingredients identified can be generally divided into flavonoids, saponins, polysaccharides and alkaloids. Mechanisms of anti-liver fibrosis include inhibition of liver inflammation, anti-lipid peroxidation injury, inhibition of the activation and proliferation of hepatic stellate cells (HSCs), modulation of the synthesis and secretion of pro-fibrosis factors, and regulation of the synthesis and degradation of the extracellular matrix (ECM). This review provides suggestions for the development of anti-hepatic fibrosis drugs.

Drinking for protection? Epidemiological and experimental evidence on the beneficial effects of coffee or major coffee compounds against gastrointestinal and liver carcinogenesis

Recent meta-analyses indicate that coffee consumption reduces the risk for digestive tract (oral, esophageal, gastric and colorectal) and, especially, liver cancer. Coffee bean-derived beverages, as the widely-consumed espresso and "common" filtered brews, present remarkable historical, cultural and economic importance globally. These drinks have rich and variable chemical composition, depending on factors that vary from "seeding to serving". The alkaloids caffeine and trigonelline, as well as the polyphenol chlorogenic acid, are some of the most important bioactive organic compounds of these beverages, displaying high levels in both espresso and common brews and/or increased bioavailability after consumption. Thus, we performed a comprehensive literature overview of current knowledge on the effects of coffee beverages and their highly bioavailable compounds, describing: 1) recent epidemiological and experimental findings highlighting the beneficial effects against gastrointestinal/liver carcinogenesis, and 2) the main molecular mechanisms in these in vitro and in vivo bioassays. Findings predominantly address the protective effects of coffee beverages and their most common/bioavailable compounds individually on gastrointestinal and liver cancer development. Caffeine, trigonelline and chlorogenic acid modulate common molecular targets directly implicated in key cancer hallmarks, what could stimulate novel translational or population-based mechanistic investigations.

CREB family: A significant role in liver fibrosis

Liver fibrosis (LF) is known as a result of the progressive accumulation of extracellular matrix (ECM), and always ascribed to chronic liver diseases. Advanced liver fibrosis results in cirrhosis, liver failure, portal hypertension, and even multi-organ dysfunction and will bring up a health care burden worldwide. Cyclic AMP response-element binding protein (CREB), as a critical transcriptional factor, binds with conserved cAMP response-element (CRE), which is located in the promoter of targeted genes, to regulate the transcription. In the past decades, numerous studies have contributed to improved understanding of the links between CREB and liver fibrosis. In this review, we will summarize molecular mechanisms of CREB pathways and discuss contributions of CREB to liver fibrosis, focusing on activation and proliferation of hepatic stellate cells (HSCs), proliferation of cholangiocytes, deposition of extracellular matrix (ECM) and inflammation, for the development of antifibrotic therapies.

A Compound of Chinese Herbs Protects against Alcoholic Liver Fibrosis in Rats via the TGF-β1/Smad Signaling Pathway

Alcoholic liver fibrosis (ALF) has become a major public health concern owing to its health impacts and the lack of effective treatment strategies for the disease. In this study, we investigated the effect of a compound composed of Chinese herbs Pueraria lobata (Willd.), Salvia miltiorrhiza, Schisandra chinensis, and Silybum marianum on ALF. An ALF model was established. Rats were fed with modified Lieber-Decarli alcohol liquid diet and injected with trace CCl4 at late stage. The rats were then treated with several doses of the compound. Biochemical and fibrosis-relevant parameters were measured from the sera obtained from the rats. Liver tissues were obtained for hematoxylin and eosin and Masson's trichrome staining. Matrix metalloproteinase-13 and tissue inhibitor of metalloproteinase-1 were determined by immunohistochemistry assays. The mRNA and protein expression levels of transforming growth factor-β1 (TGF-β1), Smad2, Smad3, and Smad7 on the livers were also measured by quantitative polymerase chain reaction and Western blot. Results showed that the compound treatment alleviated pathological lesions in the liver, decreased the serum levels of hyaluronan, laminin, and hydroxyproline, and diminished the expression of hepatic tissue inhibitor of metalloproteinase-1. Compound treatment also increased hepatic matrix metalloproteinase-13 expression and inhibited the TGF-β1/Smad signaling pathway. In conclusion, the compound has a protective effect against ALF in rats, and an underlying mechanism is involved in the TGF-β1/Smad signaling pathway.

Neurally mediated syncope diagnosis based on adenylate cyclase activity in Japanese patients

The study aims to clarify the mechanism in patients with neurally mediated syncope (NMS), focusing on the adenylate cyclase (AC) activity level in lymphocytes. This study included 40 subjects: 22 healthy volunteers and 18 NMS patients. We investigated the changes in AC activity that occur during of syncope at rest and during the head-up tilt (HUT) test. We obtained 8 mL of blood at rest time and four times during the HUT test. Then, we measured the AC activity and the test reagent was added to the lymphocytes (10,000) and reacted for 30 min at room temperature. We were able to determine the standard value of AC activity when adrenaline (AD) and isoproterenol (IP) were added to lymphocytes. The results of our study showed one of the causes of NMS has a difference in AC activity level and classification of the patients into two different types of NMS was possible: either the vasodepressor type (VT) or mixed type (MT). At rest time, VT patients showed significantly higher AC activity (AD; 100 μM: p = 0.005, IP; 50 μM: p = 0.02) and MT patients showed significantly lower AC activity (AD; 10 μM: p = 0.02, IP; 50 μM: p = 0.004) than the average AC activity in healthy volunteers. Moreover, VT patients had significantly higher AC activity than healthy volunteers at the four points of the HUT test. MT patients had significantly lower AC activity (AD: p = 0.04 and IP: p = 0.04) than healthy volunteers at the rest time of HUT. Our study showed a significant difference in AC activities between NMS patients and healthy volunteers at rest. Therefore, a detailed NMS diagnosis can be made by examining AC activity levels in blood taken at rest time.

Supplementation of okra seed oil ameliorates ethanol-induced liver injury and modulates gut microbiota dysbiosis in mice

This study assesses the possible effects of dietary okra seed oil (OSO) consumption on attenuation of alcohol-induced liver damage and gut microbiota dysbiosis, and associated mechanisms in mice.

A systematic review and a dose-response meta-analysis of coffee dose and nonalcoholic fatty liver disease

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) is the most predominant chronic liver disease worldwide. Effect of coffee on NAFLD risk and its potential dose-response patterns were explored in the study.

DESIGN

PubMed, Web of Science, MEDLINE, Cochrane and Embase were searched up to 10 April 2018. We performed pair-wise meta-analysis of <1 cup per day vs. 1-2 cups per days or >2 cups per day to pool the relative risks (RRs) and corresponding 95% confidence intervals (CIs). And dose-response analysis was used to estimate relationship of NAFLD occurrence with coffee intake.

RESULTS

Seven articles were included with 4825 cases and 49,616 non-cases. Compared with <1 cup, 1-2 cups or >2 cups of coffee consumption per day were not significantly associated with NAFLD occurrence, and RR were 0.97 (95% CI: 0.85-1.11) and 0.88 (95%CI: 0.72-1.06). However, the summary RR of the highest versus lowest coffee consumption was 0.94 (95% CI: 0.92-0.97). Dose-response meta-analysis presented a non-linearity curve relationship of coffee and NAFLD occurrence while coffee consumption >3 cups per day reduced NAFLD significantly.

CONCLUSION

Coffee intake level more than 3 cups was observed lower risk of NAFLD than <2 cups per day. Although the risk of NAFLD was inversely associated with coffee consumption, while relevance may not be very close and more observational studies would be needed to verify the relationship of coffee and NAFLD.

Enhancement of Silymarin Anti-fibrotic Effects by Complexation With Hydroxypropyl (HPBCD) and Randomly Methylated (RAMEB) β-Cyclodextrins in a Mouse Model of Liver Fibrosis

Silymarin (Sy) shows limited water solubility and poor oral bioavailability. Water-soluble hydroxypropyl (HPBCD) and randomly methylated (RAMEB) β-cyclodextrins were designed to enhance anti-fibrotic efficiency of silymarin in CCl₄-induced liver fibrosis in mice. Experimental fibrosis was induced by intraperitoneal injection with 2 ml/kg CCl₄ (20% v/v) twice a week, for 7 weeks. Mice were orally treated with 50 mg/kg of Sy-HPBCD, Sy-RAMEB and free silymarin. For assessment of the spontaneous reversion of fibrosis, CCl₄ treated animals were investigated after 2 weeks of recovery time. The CCl₄ administration increased hepatic oxidative stress, augmented the expression of transforming growth factor-β1 (TGF-β1) and Smad 2/3, and decreased Smad 7 expression. Furthermore, increased α-smooth muscle actin (α-SMA) expression indicated activation of hepatic stellate cells (HSCs), while up-regulation of collagen I (Col I) and matrix metalloproteinases (MMPs) expression led to an altered extracellular matrix enriched in collagen, confirmed as well by trichrome staining and electron microscopy analysis. Treatment with Sy-HPBCD and Sy-RAMEB significantly reduced liver injury, attenuating oxidative stress, restoring antioxidant balance in the hepatic tissue, and significantly decreasing collagen deposits in the liver. The levels of pro-fibrogenic markers' expression were also significantly down-regulated, whereas in the group for spontaneous regression of fibrosis, they remained significantly higher, even at 2 weeks after CCl₄ administration was discontinued. The recovery was significantly lower for free silymarin group compared to silymarin/β cyclodextrins co-treatments. Sy-HPBCD was found to be the most potent anti-fibrotic complex. We demonstrated that Sy-HPBCD and Sy-RAMEB complexes decreased extracellular matrix accumulation by inhibiting HSC activation and diminished the oxidative damage. This might occur via the inhibition of TGF-β1/Smad signal transduction and MMP/tissue inhibitor of MMPs (TIMP) rebalance, by blocking the synthesis of Col I and decreasing collagen deposition. These results suggest that complexation of silymarin with HPBCD or RAMEB represent viable options for the its oral delivery, of the flavonoid as a potential therapeutic entity candidate, with applications in the treatment of liver fibrosis.