Chlorogenic acid alleviated liver fibrosis in methionine and choline deficient diet-induced nonalcoholic steatohepatitis in mice and its mechanism

Extract of Silphium perfoliatum L. improve lipid accumulation in NAFLD mice by regulating AMPK/FXR signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Globally, the incidence rate and number of patients with nonalcoholic fatty liver disease are increasing, which has become one of the greatest threats to human health. However, there is still no effective therapy and medicine so far. Silphium perfoliatum L. is a perennial herb native to North America, which is used to improve physical fitness and treat liver and spleen related diseases in the traditional medicinal herbs of Indian tribes. This herb is rich in chlorogenic acids, which have the functions of reducing blood lipids, losing weight and protecting liver. However, the effect of these compounds on nonalcoholic fatty liver disease remains unclear.

AIM OF THE STUDY

Clarify the therapeutic effects and mechanism of the extract (CY-10) rich in chlorogenic acid and its analogues from Silphium perfoliatum L. on non-alcoholic fatty liver disease, and to determine the active compounds.

MATERIALS AND METHODS

A free fatty acid-induced steatosis model of HepG2 cells was established to evaluate the in vitro activity of CY-10 in promoting lipid metabolism. Further, a high-fat diet-induced NAFLD model in C57BL/6 mice was established to detect the effects of CY-10 on various physiological and biochemical indexes in mice, and to elucidate the in vivo effects of the extract on regulating lipid metabolism, anti-inflammation and hepatoprotection, and nontarget lipid metabolomics was performed to analyze differential metabolites of fatty acids in the liver. Subsequently, western blotting and immunohistochemistry were used to analyze the target of the extract and elucidate its mechanism of action. Finally, the active compounds in CY-10 were elucidated through in vitro activity screening.

RESULTS

The results indicated that CY-10 significantly attenuated lipid droplet deposition in HepG2 cells. The results of in vivo experiments showed that CY-10 significantly reduce HFD-induced mouse body weight and organ index, improve biochemical indexes, oxidation levels and inflammatory responses in the liver and serum, thereby protecting the liver tissue. It can promote the metabolism of unsaturated fatty acids in the liver and reduce the generation of saturated fatty acids. Furthermore, it is clarified that CY-10 can promote lipid metabolism balance by regulating AMPK/FXR/SREPB-1c/PPAR-γ signal pathway. Ultimately, the main active compound was proved to be cryptochlorogenic acid, which has a strong promoting effect on the metabolism of fatty acids in cells. Impressively, the activities of CY-10 and cryptochlorogenic acid were stronger than simvastatin in vitro and in vivo.

CONCLUSION

For the first time, it is clarified that the extract rich in chlorogenic acids and its analogues in Silphium perfoliatum L. have good therapeutic effects on non-alcoholic fatty liver disease. It is confirmed that cryptochlorogenic acid is the main active compound and has good potential for medicine.

Mitochondrial dysfunction: A promising therapeutic target for liver diseases

The liver is an important metabolic and detoxification organ and hence demands a large amount of energy, which is mainly produced by the mitochondria. Liver tissues of patients with alcohol-related or non-alcohol-related liver diseases contain ultrastructural mitochondrial lesions, mitochondrial DNA damage, disturbed mitochondrial dynamics, and compromised ATP production. Overproduction of mitochondrial reactive oxygen species induces oxidative damage to mitochondrial proteins and mitochondrial DNA, decreases mitochondrial membrane potential, triggers hepatocyte inflammation, and promotes programmed cell death, all of which impair liver function. Mitochondrial DNA may be a potential novel non-invasive biomarker of the risk of progression to liver cirrhosis and hepatocellular carcinoma in patients infected with the hepatitis B virus. We herein present a review of the mechanisms of mitochondrial dysfunction in the development of acute liver injury and chronic liver diseases, such as hepatocellular carcinoma, viral hepatitis, drug-induced liver injury, alcoholic liver disease, and non-alcoholic fatty liver disease. This review also discusses mitochondrion-centric therapies for treating liver diseases.

Chlorogenic Acid: A Systematic Review on the Biological Functions, Mechanistic Actions, and Therapeutic Potentials

Chlorogenic acid (CGA) is a type of polyphenol compound found in rich concentrations in many plants such as green coffee beans. As an active natural substance, CGA exerts diverse therapeutic effects in response to a variety of pathological challenges, particularly conditions associated with chronic metabolic diseases and age-related disorders. It shows multidimensional functions, including neuroprotection for neurodegenerative disorders and diabetic peripheral neuropathy, anti-inflammation, anti-oxidation, anti-pathogens, mitigation of cardiovascular disorders, skin diseases, diabetes mellitus, liver and kidney injuries, and anti-tumor activities. Mechanistically, its integrative functions act through the modulation of anti-inflammation/oxidation and metabolic homeostasis. It can thwart inflammatory constituents at multiple levels such as curtailing NF-kB pathways to neutralize primitive inflammatory factors, hindering inflammatory propagation, and alleviating inflammation-related tissue injury. It concurrently raises pivotal antioxidants by activating the Nrf2 pathway, thus scavenging excessive cellular free radicals. It elevates AMPK pathways for the maintenance and restoration of metabolic homeostasis of glucose and lipids. Additionally, CGA shows functions of neuromodulation by targeting neuroreceptors and ion channels. In this review, we systematically recapitulate CGA's pharmacological activities, medicinal properties, and mechanistic actions as a potential therapeutic agent. Further studies for defining its specific targeting molecules, improving its bioavailability, and validating its clinical efficacy are required to corroborate the therapeutic effects of CGA.

Bioactive functions of chlorogenic acid and its research progress in pig industry

Chlorogenic acid (CGA), also known as 3-caffeioylquinic acid or coffee tannin, is a water-soluble polyphenol phenylacrylate compound produced through the shikimate pathway by plants during aerobic respiration. CGA widely exists in higher dicotyledons, ferns and many Chinese medicinal materials, and enjoys the reputation of 'plant gold'. Here, we summarized the source, chemical structure, biological activity functions of CGA and its research progress in pigs, aiming to provide a more comprehensive understanding and theoretical basis for the prospect of CGA replacing antibiotics as a pig feed additive.

Yanggan Jiangmei Formula alleviates hepatic inflammation and lipid accumulation in non-alcoholic steatohepatitis by inhibiting the NF-κB/NLRP3 signaling pathway

The role of NF-κB and the NLRP3 inflammasome in the chronic inflammatory microenvironment of non-alcoholic steatohepatitis (NASH) has been posited as crucial. The Yanggan Jiangmei Formula (YGJMF) has shown promise in ameliorating hepatic steatosis in NASH patients, yet its pharmacological mechanisms remain largely unexplored. This study was conducted to investigate the efficacy of YGJMF in NASH and to elucidate its pharmacological underpinnings. To simulate NASH both in vivo and in vitro, high-fat-diet (HFD) rats and HepG2 cells stimulated with free fatty acids (FFAs) were utilized. The severity of liver injury and lipid deposition was assessed using serum indicators, histopathological staining, micro-magnetic resonance imaging (MRI), and the liver-to-muscle signal intensity ratio (SIRL/M). Furthermore, a combination of enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC), immunofluorescence, real-time quantitative polymerase chain reaction (RT-qPCR), and Western blotting analyses was employed to investigate the NF-κB/NLRP3 signaling pathway and associated cytokine levels. The results from liver pathology, MRI assessments, and biochemical tests in rat models demonstrated YGJMF's significant effectiveness in reducing liver damage and lipid accumulation. Additionally, YGJMF markedly reduced hepatocyte inflammation by downregulating inflammatory cytokines in both liver tissue and serum. Furthermore, YGJMF was found to disrupt NF-κB activation, consequently inhibiting the assembly of the NLRP3 inflammasome in both the in vitro and in vivo models. The preliminary findings of this study suggest that YGJMF may alleviate hepatic steatosis and inhibit the NF-κB/NLRP3 signaling pathway, thereby exerting anti-inflammatory effects in NASH.

Quantitative proteomics reveals the protective effects of Yinchenzhufu decoction against cholestatic liver fibrosis in mice by inhibiting the PDGFRβ/PI3K/AKT pathway

Introduction: Yinchenzhufu decoction (YCZFD) is a traditional Chinese medicine formula with hepatoprotective effects. In this study, the protective effects of YCZFD against cholestatic liver fibrosis (CLF) and its underlying mechanisms were evaluated. Methods: A 3, 5-diethoxycarbonyl-1, 4-dihydro-collidine (DDC)-induced cholestatic mouse model was used to investigate the amelioration of YCZFD on CLF. Data-independent acquisition-based mass spectrometry was performed to investigate proteomic changes in the livers of mice in three groups: control, model, and model treated with high-dose YCZFD. The effects of YCZFD on the expression of key proteins were confirmed in mice and cell models. Results: YCZFD significantly decreased the levels of serum biochemical, liver injury, and fibrosis indicators of cholestatic mice. The proteomics indicated that 460 differentially expressed proteins (DEPs) were identified among control, model, and model treated with high-dose YCZFD groups. Enrichment analyses of these DEPs revealed that YCZFD influenced multiple pathways, including PI3K-Akt, focal adhesion, ECM-receptor interaction, glutathione metabolism, and steroid biosynthesis pathways. The expression of platelet derived growth factor receptor beta (PDGFRβ), a receptor associated with the PI3K/AKT and focal adhesion pathways, was upregulated in the livers of cholestatic mice but downregulated by YCZFD. The effects of YCZFD on the expression of key proteins in the PDGFRβ/PI3K/AKT pathway were further confirmed in mice and transforming growth factor-β-induced hepatic stellate cells. We uncovered seven plant metabolites (chlorogenic acid, scoparone, isoliquiritigenin, glycyrrhetinic acid, formononetin, atractylenolide I, and benzoylaconitine) of YCZFD that may regulate PDGFRβ expression. Conclusion: YCZFD substantially protects against DDC-induced CLF mainly through regulating the PDGFRβ/PI3K/AKT signaling pathway.

Human diet-derived polyphenolic compounds and hepatic diseases: From therapeutic mechanisms to clinical utilization

This review focuses on the potential ameliorative effects of polyphenolic compounds derived from human diet on hepatic diseases. It discusses the molecular mechanisms and recent advancements in clinical applications. Edible polyphenols have been found to play a therapeutic role, particularly in liver injury, liver fibrosis, NAFLD/NASH, and HCC. In the regulation of liver injury, polyphenols exhibit anti-inflammatory and antioxidant effects, primarily targeting the TGF-β, NF-κB/TLR4, PI3K/AKT, and Nrf2/HO-1 signaling pathways. In the regulation of liver fibrosis, polyphenolic compounds effectively reverse the fibrotic process by inhibiting the activation of hepatic stellate cells (HSC). Furthermore, polyphenolic compounds show efficacy against NAFLD/NASH by inhibiting lipid oxidation and accumulation, mediated through the AMPK, SIRT, and PPARγ pathways. Moreover, several polyphenolic compounds exhibit anti-HCC activity by suppressing tumor cell proliferation and metastasis. This inhibition primarily involves blocking Akt and Wnt signaling, as well as inhibiting the epithelial-mesenchymal transition (EMT). Additionally, clinical trials and nutritional evidence support the notion that certain polyphenols can improve liver disease and associated metabolic disorders. However, further fundamental research and clinical trials are warranted to validate the efficacy of dietary polyphenols.

Preventive Effects of Apple Polyphenol Extract on High-Fat-Diet-Induced Hepatic Steatosis Are Related to the Regulation of Hepatic Lipid Metabolism, Autophagy, and Gut Microbiota in Aged Mice

Our previous study confirmed that the ameliorated effects of an intervention with an apple polyphenol extract (APE) on hepatic steatosis induced by a high-fat diet (HFD) are dependent on SIRT1. Since SIRT1 expression decreases with age, it remains unclear whether APE intervention is effective against hepatic steatosis in aged mice. Thus, 12-month-old C57BL/6 male mice were fed with an HFD to establish an aging model of hepatic steatosis and treated with 500 mg/(kg·bw·d) APE for 12 weeks. Young mice (two months old) and baseline mice were used as controls to examine the effects of natural aging on hepatic steatosis. Compared with baseline mice, no obvious difference in hepatic histopathological assessment was observed for both young and aged mice on normal diets. Meanwhile, HFD induced much higher nonalcoholic fatty liver disease (NAFLD) activity scores in aged mice than in young mice. APE intervention ameliorated lipid and glucose metabolic disorders and liver injury in HFD-fed aged mice, improved hepatic steatosis, and reduced NAFLD activity scores. The upregulated expressions of SIRT1, HSL, ATG5, Ulk1, and Becn1 and downregulated expressions of HMGCR and FOXO1 suggested improved lipid metabolism and activated autophagy. APE intervention decreased the ratio of Firmicutes/Bacteroidetes and elevated the Akkermansia probiotics abundance. In summary, HFD showed a more significant effect on hepatic steatosis compared to the natural aging process in aged mice, and APE might be a promising dietary ingredient for alleviating hepatic steatosis.

Chlorogenic acids: A pharmacological systematic review on their hepatoprotective effects

BACKGROUND

Liver diseases have a negative impact on global health and are a leading cause of death worldwide. Chlorogenic acids (CGAs), a family of esters formed between certain trans-cinnamic acids and quinic acid, are natural polyphenols abundant in coffee, tea, and a variety of traditional Chinese medicines (TCMs). They are reported to have good hepatoprotective effects against various liver diseases.

PURPOSE

This review aims to analyze the available literature on the hepatoprotective effect of CGAs, with particular emphasis on their mechanisms.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. PubMed and Web of Science databases were adopted to retrieve all relevant literature on CGAs for liver disease from 2013 to March 2023.

RESULTS

Research has indicated that CGAs play a crucial role in improving different types of liver diseases, including drug-induced liver injury (DILI), alcoholic liver disease (ALD), metabolic (dysfunction)-associated fatty liver disease (MAFLD), cholestatic liver disease (CLD), liver fibrosis, and liver cancer. CGAs display remarkable antioxidant and anti-inflammatory effects by activating erythroid 2-related factor 2 (Nrf2) and inhibiting toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathways. Some important molecules such as AMP-activated protein kinase (AMPK) and extracellular signal-regulated kinases 1 and 2 (ERK1/2), and other key physiological processes like intestinal barrier and gut microbiota have also been discovered to participate in CGAs-provided amelioration on various liver diseases.

CONCLUSION

In this review, different studies indicate that CGAs have an excellent protective effect against various liver diseases associated with various signaling pathways.

Phytochemical Profiling and Anti-Fibrotic Activities of the Gemmotherapy Bud Extract of Corylus avellana in a Model of Liver Fibrosis on Diabetic Mice

In this study, we aimed to explore the hepatoprotective effects of the gemmotherapy bud extract of Corylus avellana in a model of liver fibrosis on diabetic mice. An evaluation of total flavonoids and polyphenols contents and LC/MS analyses were performed. Experimental fibrosis was induced with CCl₄ (2 mL/kg by i.p. injections twice a week for 7 weeks) in streptozotocin-induced diabetic mice. Our results showed a content of 6-7% flavonoids, while hyperoside and chlorogenic acids were highlighted in the bud extract. Toxic administration of CCl₄ increased oxidative stress, mRNA expression of the transforming growth factor-β1 (TGF-β1) and Smad 2/3, and reduced Smad 7 expression. Furthermore, up-regulation of α-smooth muscle actin (α-SMA) revealed an activation of hepatic stellate cells (HSCs), while collagen I (Col I) up-regulation and matrix metalloproteinases (MMPs) unbalance led to an altered extracellular matrix enriched in collagen, confirmed as well by a trichrome stain and electron microscopy analysis. Treatment with gemmotherapy extract significantly restored the liver architecture and the antioxidant balance, and significantly decreased collagen deposits in the liver and improved the liver function. Our results suggest that Corylus avellana gemmotherapy extract may have anti-fibrotic effects and could be useful in the prevention and treatment of liver fibrosis. The hepatoprotective mechanism is based on HSC inhibition, a reduction in oxidative stress and liver damage, a downregulation of the TGF-β1/Smad signaling pathway and a MMPs/TIMP rebalance.

Small-molecule natural plants for reversing liver fibrosis based on modulation of hepatic stellate cells activation: An update

BACKGROUND

Liver fibrosis (LF) is a trauma repair process carried out by the liver in response to various acute and chronic liver injuries. Its primary pathological characteristics are excessive proliferation and improper dismissal of the extracellular matrix, and if left untreated, it will progress into cirrhosis, liver cancer, and other diseases. Hepatic stellate cells (HSCs) activation is intimately associated to the onset of LF, and it is anticipated that addressing HSCs proliferation can reverse LF. Plant-based small-molecule medications have anti-LF properties, and their mechanisms of action involve suppression of extracellular matrix abnormally accumulating as well as anti-inflammation and anti-oxidative stress. New targeting HSC agents will therefore be needed to provide a potential curative response.

PURPOSE

The most recent HSC routes and small molecule natural plants that target HSC described domestically and internationally in recent years were examined in this review.

METHODS

The data was looked up using resources including ScienceDirect, CNKI, Web of Science, and PubMed. Keyword searches for information on hepatic stellate cells included "liver fibrosis", "natural plant", "hepatic stellate cells", "adverse reaction", "toxicity", etc. RESULTS: We discovered that plant monomers can target and control various pathways to prevent the activation and proliferation of HSC and promote the apoptosis of HSC in order to achieve the anti-LF effect in this work by compiling the plant monomers that influence many common pathways of HSC in recent years. It demonstrates the wide-ranging potential of plant monomers targeting different routes to combat LF, with a view to supplying new concepts and new strategies for natural plant therapy of LF as well as research and development of novel pharmaceuticals. The investigation of kaempferol, physalin B, and other plant monomers additionally motivated researchers to focus on the structure-activity link between the main chemicals and LF.

CONCLUSION

The creation of novel pharmaceuticals can benefit greatly from the use of natural components. They are often harmless for people, non-target creatures, and the environment because they are found in nature, and they can be employed as the starting chemicals for the creation of novel medications. Natural plants are valuable resources for creating new medications with fresh action targets because they feature original and distinctive action mechanisms.

Chlorogenic acid ameliorated non-alcoholic steatohepatitis via alleviating hepatic inflammation initiated by LPS/TLR4/MyD88 signaling pathway

Non-alcoholic steatohepatitis (NASH) is a severe pathological stage in non-alcoholic fatty liver disease (NAFLD) and is generally recognized to be induced by chronic inflammation. Natural compound chlorogenic acid (CGA) is well-known for its anti-inflammatory capacity. This study aimed at evaluating the alleviation of CGA on NASH and further exploring its engaged mechanism via focusing on abrogating hepatic inflammation. Our results showed that CGA had a good amelioration on NASH in vivo. CGA alleviated liver oxidative injury by inducing nuclear factor erythroid 2-related factor 2 (Nrf2) activation and reduced liver steatosis via up-regulating peroxisome proliferator-activated receptor-alpha (PPARα). CGA attenuated hepatic inflammation in vivo, but didn't decrease the elevated lipopolysaccharide (LPS) content. CGA blocked the activation of nuclear factor kappa-B (NFκB) or inflammasome both in MCDD-fed mice and in LPS-stimulated macrophages. CGA was found to directly bind to myeloid differentiation primary response 88 (MyD88), and thus competitively blocked the interaction between toll-like receptor 4 (TLR4) and MyD88, thereby abrogating hepatic inflammation initiated by LPS-TLR4-MyD88. Moreover, the CGA-provided anti-inflammatory effect was obviously disappeared in macrophages overexpressed MyD88. Hence, CGA has an excellent efficacy in improving NASH. CGA alleviated liver inflammation during NASH progression through blocking LPS-TLR4-MyD88 signaling pathway via directly binding to MyD88.

Quality Markers’ Discovery and Quality Evaluation of Jigucao Capsule Using UPLC-MS/MS Method

Jigucao capsules (JGCC) have the effects of soothing the liver and gallbladder and clearing heat and detoxification. It is a good medicine for treating acute and chronic hepatitis cholecystitis with damp heat of the liver and gallbladder. However, the existing quality standard of JGCC does not have content determination items, which is not conducive to quality control. In this study, serum pharmacochemistry technology and UNIFI data processing software were used to identify the blood prototype components and metabolites under the condition of the obvious drug effects of JGCC, and the referenced literature reports and the results from in vitro analysis of JGCC in the early stage revealed a total of 43 prototype blood components and 33 metabolites in JGCC. Quality markers (Q-markers) were discovered, such as abrine, trigonelline, hypaphorine and isoschaftoside. In addition, ultra-high-performance liquid chromatography–triple quadrupole mass spectrometry (UPLC-QQQ-MS) was used to determine the active ingredients in JGCC. The components of quantitative analysis have good correlation in the linear range with R2 ≥ 0.9993. The recovery rate is 93.15%~108.92% and the relative standard deviation (RSD) is less than 9.48%. The established UPLC-MS/MS quantitative analysis method has high sensitivity and accuracy, and can be used for the quality evaluation of JGCC.

Research progress regarding the effect and mechanism of dietary phenolic acids for improving nonalcoholic fatty liver disease via gut microbiota

Phenolic acids (PAs), a class of small bioactive molecules widely distributed in food and mainly found as secondary plant metabolites, present significant advantages such as antioxidant activity and other health benefits. The global epidemic of nonalcoholic fatty liver disease (NAFLD) is becoming a serious public health problem. Existing studies showed that gut microbiota (GM) dysbiosis is highly associated with the occurrence and development of NAFLD. In recent years, progress has been made in the study of the relationship among PA compounds, GM, and NAFLD. PAs can regulate the composition and functions of the GM to promote human health, while GM can increase the dietary sources of PAs and improve its bioavailability. This paper discussed PAs, GM, and their interrelationship while introducing several representative dietary PA sources and examining the absorption and metabolism of PAs mediated by GM. It also summarizes the effect and mechanisms of PAs in improving and regulating NAFLD via GM and their metabolites. This helps to better evaluate the potential preventive effect of PAs on NAFLD via the regulation of GM and expands the utilization of PAs and PA-rich food resources.

Study on quality control of Zuojin pill by HPLC fingerprint with quantitative analysis of multi-components by single marker method and antioxidant activity analysis

Current quality control methods for Zuojin Pill (ZJP) lack comprehensiveness and practicability. This study aimed to develop a comprehensive strategy for the quality evaluation of ZJP and the prediction of potential bioactive components in ZJP. First, an HPLC method with excellent separation of main components was developed and was used to establish the chromatographic fingerprint of ZJP. Similarities were calculated by comparing 28 batches of ZJPs with the reference fingerprint and the resulting similarity values were all greater than 0.976. The 28 samples were classified into different groups according to their origins by Hierarchical Cluster Analysis, Principal component analysis, and orthogonal partial least squares discriminant analysis. Based on the classification, eight quality markers (Q-Markers) affecting the quality of ZJP were discovered. Then, using berberine as an internal standard substance, quantitative analysis of multi-components by single marker method (QAMS) for the determination of eight Q-markers was developed. The results showed that there was no significant difference between QAMS and external standard method (P＞0.05). Finally, using an off-line antioxidant system and partial least-squares model (PLS), the fingerprint-efficacy relationship of ZJP was constructed to explore and predict the bioactive components in ZJP. The present study strategy could be also applied to comprehensive quality study of other TCMs.

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.

Natural Foods for the Treatment of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide. The etiology of NAFLD is highly heterogeneous, which occurs and develops under the joint action of metabolism, inflammation, genetics, environment, and gut microbiota. At present, the principal therapeutic modalities targeting NAFLD are lifestyle interventions such as weight loss through diet and exercise. At present, there is no established therapy for the treatment of NAFLD, and many therapies are associated with a variety of side effects. A great number of in vitro and in vivo experiments have indicated that there are many natural foods that have therapeutic potential for NAFLD. This review summarizes the natural foods and their mechanisms that were found in recent years, furthermore, provides further information relevant to the treatment of NAFLD.

Utility of Human Relevant Preclinical Animal Models in Navigating NAFLD to MAFLD Paradigm

Fatty liver disease is an emerging contributor to disease burden worldwide. The past decades of work established the heterogeneous nature of non-alcoholic fatty liver disease (NAFLD) etiology and systemic contributions to the pathogenesis of the disease. This called for the proposal of a redefinition in 2020 to that of metabolic dysfunction-associated fatty liver disease (MAFLD) to better reflect the current understanding of the disease. To date, several clinical cohort studies comparing NAFLD and MAFLD hint at the relevancy of the new nomenclature in enriching for patients with more severe hepatic injury and extrahepatic comorbidities. However, the underlying systemic pathogenesis is still not fully understood. Preclinical animal models have been imperative in elucidating key biological mechanisms in various contexts, including intrahepatic disease progression, interorgan crosstalk and systemic dysregulation. Furthermore, they are integral in developing novel therapeutics against MAFLD. However, substantial contextual variabilities exist across different models due to the lack of standardization in several aspects. As such, it is crucial to understand the strengths and weaknesses of existing models to better align them to the human condition. In this review, we consolidate the implications arising from the change in nomenclature and summarize MAFLD pathogenesis. Subsequently, we provide an updated evaluation of existing MAFLD preclinical models in alignment with the new definitions and perspectives to improve their translational relevance.

Alanyl-Glutamine Protects Mice against Methionine- and Choline-Deficient-Diet-Induced Steatohepatitis and Fibrosis by Modulating Oxidative Stress and Inflammation

Nonalcoholic steatohepatitis (NASH) is a common chronic liver disease with increasing prevalence rates over years and is associated with hepatic lipid accumulation, liver injury, oxidative stress, hepatic inflammation, and liver fibrosis and lack of approved pharmacological therapy. Alanyl-glutamine (Ala-Gln) is a recognized gut-trophic nutrient that has multiple pharmacological effects in the prevention of inflammation- and oxidative-stress-associated diseases. Nevertheless, whether Ala-Gln has a protective effect on NASH still lacks evidence. The aim of this study is to explore the influence of Ala-Gln on NASH and its underlying mechanisms. Here, C57BL/6 mice were fed a methionine- and choline-deficient (MCD) diet to establish the model of NASH, and Ala-Gln at doses of 500 and 1500 mg/kg were intraperitoneally administered to mice along with a MCD diet. The results showed that Ala-Gln treatment significantly attenuated MCD-induced hepatic pathological changes, lowered NAFLD activity score, and reduced plasma alanine transaminase (ALT), aspartate transaminase (AST) and lactate dehydrogenase (LDH) levels. Ala-Gln dramatically alleviated lipid accumulation in liver through modulating the expression levels of fatty acid translocase (FAT/CD36) and farnesoid X receptor (FXR). In addition, Ala-Gln exerted an anti-oxidant effect by elevating the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX). Moreover, Ala-Gln exhibited an anti-inflammatory effect via decreasing the accumulation of activated macrophages and suppressing the production of proinflammatory mediators. Notably, Ala-Gln suppressed the development of liver fibrosis in MCD-diet-fed mice, which may be due to the inhibition of hepatic stellate cells activation. In conclusion, these findings revealed that Ala-Gln prevents the progression of NASH through the modulation of oxidative stress and inflammation and provided the proof that Ala-Gln might be an effective pharmacological agent to treat NASH.

Jieduan–Niwan Formula Ameliorates Oxidative Stress and Apoptosis in Acute-on-Chronic Liver Failure by Suppressing HMGB1/TLR-4/NF-κB Signaling Pathway: A Study In Vivo and In Vitro

Jieduan-Niwan (JDNW) formula is a traditional Chinese medicine compound created by the famous Chinese medicine expert Professor Qian Ying, and has been used clinically for decades to treat acute-on-chronic liver failure (ACLF) and exhibits remarkable efficacy. However, the exact mechanism remains to be discovered. As an important hepatocyte damage-associated molecular patterns (DAMP) factor, high mobility group box 1 (HMGB1) is a potential therapeutic target as an accelerator of ACLF in the pathogenesis. Therefore, the present study investigated whether JDNW inhibits the overexpression and cytoplasmic translocation of HMGB1 in ACLF liver tissue and alleviates its mediated oxidative stress and apoptosis. In vivo, an immune-induced ACLF rat model was established, and then treated with JDNW for 5, 10, and 15 d. The results showed that a large number of cytoplasmic translocations of HMGB1 occurred in the ACLF group. And there was an increase in the expression of HMGB1 in the M-5 d group. After the intervention of JDNW, the overexpression and translocation of HMGB1 were inhibited. In vitro, D-GaLN caused an increase in the expression and translocation of HMGB1 in L02 cells. Similar to the inhibitor of HMGB1, JDNW serum alleviated this kind of increase. Further tests showed that JDNW attenuated ACLF-related oxidative stress and apoptosis, and the inhibition was associated with the regulation of TLR-4/NF-κB signaling pathway. In conclusion, our present findings suggest that the therapeutic effect of JDNW on ACLF was associated with the inhibition of high expression and cytoplasmic translocation of HMGB1 during the acute injury phase, thus, attenuating oxidative stress injury and apoptosis induced by HMGB1/TLR-4/NF-κB pathway.