Quercetin attenuates the activation of hepatic stellate cells and liver fibrosis in mice through modulation of HMGB1-TLR2/4-NF-κB signaling pathways

Enhancing the Therapeutic Efficacy of Berberine and Quercetin Through Salt Formulation for Liver Fibrosis Treatment

Liver fibrosis, caused by chronic hepatic injury, is a major threat to human health worldwide, as there are no specific drugs available for its treatment. Natural compounds, such as berberine (BBR) and quercetin (QR), have shown the ability to regulate energy metabolism and protect the liver without significant adverse effects. Additionally, combination therapy (the cocktail therapy approach), using multiple drugs, has shown promise in treating complicated conditions, including liver injury. In this study, we prepared a salt formulation of BBR and QR (BQS) to enhance their combined effect on liver fibrosis. The formation of BQS was confirmed using various analytical techniques, including nuclear magnetic resonance spectroscopy (NMR), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffractometry (PXRD), and scanning electron microscopy (SEM). The results demonstrated that the dissolution efficiency and bioavailability of QR significantly increased in the BQS form, aligning with that of BBR, compared to the physically mixed (BQP) form. Moreover, BQS exhibited a superior inhibitory effect on fibrosis compared to BQP in the human hepatic stellate cell line LX-2 by modulating lipid accumulation, inflammation, apoptosis, and the cell cycle. Furthermore, in a mouse model of hepatic fibrosis induced by methionine and choline-deficient (MCD) diets, BQS demonstrated enhanced anti-fibrotic activities compared to BQP. These findings suggest that BQS holds promise as a potential alternative treatment for liver fibrosis. Importantly, this study provides novel insights into achieving a cocktail effect through the salt formation of two or more drugs. The results highlight the potential of salt formulations in enhancing the therapeutic efficacy and consistent biological processes of drug combinations.

Quercetin inhibits mitophagy-mediated apoptosis and inflammatory response by targeting the PPARγ/PGC-1α/NF-κB axis to improve acute liver failure

BACKGROUND

Reactive oxygen species (ROS) from mitochondrial dysfunction are critical in triggering apoptosis and inflammation in acute liver failure (ALF). Quercetin (QUE), an antioxidant, is renowned for its therapeutic effects onliverdiseases. There are no studies on whether QUE regulates mitophagy level in hepatocytes to inhibit ALF.

OBJECTIVE

This study investigates QUE's protective effects on ALF and elucidates the mechanisms involved.

METHODS

The ALF and hepatocyte inflammatory injury model was established using LPS and D-Galn. To predict potential targets and mechanisms of QUE in ALF treatment, transcriptomics, network pharmacology, molecular docking techniques, and ChIP were employed. The expression level related to mitophagy, apoptosis, and signaling pathways were detected by CCK8, IHC, IF staining, TUNEL, RT-qPCR, TEM, Western blotting, ELISA, and flow cytometry.

RESULTS

Network pharmacology and transcriptomics revealed common targets between QUE and ALF. Enrichment analysis showed that the anti-ALF targets of QUE were significantly associated with mitochondria and NF-κB-related pathways. Subsequent experiments showed that QUE pretreatment significantly alleviated the loss of hepatocyte viability, enhanced mitochondrial membrane potential, activated mitophagy, and promoted the clearance of damaged mitochondria, thereby reducing ROS accumulation, significantly reducing cell apoptosis and inflammatory responses, reducing ALT and AST levels, and improving liver tissue pathology. Mechanistically, molecular docking, DARTS, and CETSA analyses confirmed that QUE directly binds to the PPARγ molecule, which reduced binding to IκB and significantly inhibit the NF-κB pathway to exert its protective effects.

CONCLUSION

In short, our results provide the first evidence that QUE improves acute liver failure by promoting mitophagy through regulating the PPARγ/PGC-1α/NF-κB axis and inhibiting apoptosis and inflammatory responses mediated by mitochondrial dysfunction, which provides evidence for the potential of QUE in the treatment of ALF.

Sequential system based on ferritin delivery system and cell therapy for modulating the pathological microenvironment and promoting recovery

The vicious crosstalk among capillarization of hepatic sinusoidal endothelial cells (LSECs), activation of hepatic stellate cells (aHSCs), and hepatocyte damage poses a significant impediment to the successful treatment of liver fibrosis. In this study, we propose a sequential combination therapy aimed at disrupting the malignant crosstalk and reshaping the benign microenvironment while repairing damaged hepatocytes to achieve effective treatment of liver fibrosis. Firstly, H-subunit apoferrin (Ferritin) was adopted to load platycodonin D (PLD) and MnO2, forming ferritin@MnO2/PLD (FMP) nanoparticles, which exploited the high affinity of ferritin for the highly expressed transferrin receptor 1 (TfR1) to achieve the precise targeted delivery of FMP in the liver. Upon PLD intervention, restoration of the fenestration pores in capillarized LSECs was facilitated by modulating the phosphatidyl inositol 3-kinase/protein kinase B (PI3K/AKT) and Kruppel Like Factor 2 (KLF2) signaling pathways both in vitro and in vivo, enabling efficient entry of FMP into the Disse space. Subsequently, FMP NPs effectively inhibited HSC activation by modulating the TLR2/TLR4/NF-κB-p65 signaling pathway. Moreover, FMP NPs efficiently scavenged reactive oxygen species (ROS) and mitigated the expression of inflammatory mediators, thereby reshaping the microenvironment to support hepatocyte repair. Finally, administration of bone marrow mesenchymal stem cells (BMMSCs) was employed to promote the regeneration and functional recovery of damaged hepatocytes. In conclusion, the combined sequential therapy involving FMP and BMMSCs effectively attenuated liver fibrosis induced by CCl4 administration, resulting in significant amelioration of the fibrotic condition. The therapeutic strategy outlined in this study underscores the significance of disrupting the deleterious cellular interactions and remodeling the microenvironment, thereby presenting a promising avenue for clinical intervention in liver fibrosis.

Flavonoids in natural products for the therapy of liver diseases: progress and future opportunities

The liver is the largest, important organ and the site for essential biochemical reactions in the human body. It has the function to detoxify toxic substances and synthesize useful biomolecules. Liver diseases related complications represent a significant source of morbidity and mortality worldwide, creating a substantial economic burden. Oxidative stress, excessive inflammation, and dysregulated energy metabolism significantly contributed to liver diseases. Therefore, discovery of novel therapeutic drugs for the treatment of liver diseases are urgently required. For centuries, flavonoids and their preparations which have the beneficial health effects in chronic diseases have been used to treat various human illnesses. Flavonoids mainly include flavones, isoflavones, flavanols, dihydroflavones, dihydroflavonols, anthocyanins and chalcones. The primary objective of this review is to assess the efficacy and safety of flavonoids, mainly from a clinical point of view and considering clinically relevant end-points. We summarized the recent progress in the research of hepatoprotective and molecular mechanisms of different flavonoids bioactive ingredients and also outlined the networks of underlying molecular signaling pathways. Further pharmacology and toxicology research will contribute to the development of natural products in flavonoids and their derivatives as medicines with alluring prospect in the clinical application.

Vincamine alleviates intrahepatic cholestasis in rats through modulation of NF-kB/PDGF/klf6/PPARγ and PI3K/Akt pathways

The defect in the hepatobiliary transport system results in an impairment of bile flow, leading to accumulation of toxic compounds with subsequent liver disorders. Vincamine, a plant indole alkaloid that is utilized as a dietary supplement, has been known for its promising pharmacological activities. For the first time, the present study was planned to estimate, at the molecular level, the potentiality of vincamine against alfa-naphthyl isothiocyanate (ANIT)-induced hepatic cholestasis. Liver function tests were analyzed. Hepatic activity of SOD and levels of GSH and MDA were assessed. Hepatic contents of bax, bcl2, NF-kB, PPARγ, catalase, heme-oxygenase-1, NTCP, and BSEP were evaluated using ELISA. mRNA levels of NF-kB, IL-1β, IL-6, TNFα, PDGF, klf6, PPARγ, and P53 were examined using qRT-PCR. PI3K, Akt and cleaved caspase-3 proteins were assessed using western blotting. Histopathological analyses were performed using hematoxylin & eosin staining. ANIT-induced hepatic cholestasis elevated liver function tests, including AST, ALT, GGT, ALP, and total bilirubin. ANIT reduced the protein expression of NTCP and BSEP hepatic transporters. It induced the expression of the inflammatory genes, TNFα, IL-6, IL-1β, and PDGF, and the expression of NF-kB at the genetic and protein level and suppressed the anti-inflammatory genes, klf6 and PPARγ. Also, antioxidant markers were reduced during ANIT induction such as GSH, SOD, catalase, heme-oxygenase-1 and PI3K/Akt pathway, while MDA levels were elevated. Furthermore, the expression of P53 gene, bax and cleaved caspase 3 proteins were activated, while bcl2 was inhibited. Also, the histopathological analysis showed degeneration of hepatocytes and inflammatory cellular infiltrates. However, vincamine treatment modulated all these markers. It improved liver function tests. It inhibited the expression of NF-kB, TNFα, IL-6, IL-1β and PDGF and activated the expression of klf6 and PPARγ. Furthermore, vincamine reduced MDA levels and induced GSH, SOD, catalase, heme-oxygenase-1 and PI3K/Akt pathway. Additionally, it inhibited expression of P53 gene, bax and cleaved caspase 3 proteins. More interestingly, vincamine showed better outcomes on the hepatic histopathological analysis and improved the alterations induced by ANIT. Vincamine alleviated hepatic dysfunction during ANIT-induced intrahepatic cholestasis through its anti-inflammatory and antioxidant efficacies by the modulation of NF-kB/PDGF/klf6/PPARγ and PI3K/Akt pathways.

Network Analysis of Gut Microbial Communities Reveals Key Reason for Quercetin Protects against Colitis

As one of the most representative natural products among flavonoids, quercetin (QUE) has been reported to exhibit beneficial effects on gut health in recent years. In this study, we utilized a dextran sulfate sodium (DSS)-induced colitis mice model to explore the protective effects and underlying mechanisms of QUE on colitis. Our data demonstrated that QUE oral gavage administration significantly ameliorates the symptoms and histopathological changes associated with colitis. Additionally, the concentration of mucin-2, the number of goblet cells, and the expression of tight junction proteins (such as ZO-1, Occludin, and Claudin-1) were all found to be increased. Furthermore, QUE treatment regulated the levels of inflammatory cytokines and macrophage polarization, as well as the oxidative stress-related pathway (Nrf2/HO-1) and associated enzymes. Additionally, 16S rDNA sequencing revealed that QUE treatment rebalances the alterations in colon microbiota composition (inlcuding Bacteroidaceae, Bacteroides, and Odoribacter) in DSS-induced colitis mice. The analysis of network dynamics reveals a significant correlation between gut microbial communities and microenvironmental factors associated with inflammation and oxidative stress, in conjunction with the previously mentioned findings. Collectively, our results suggest that QUE has the potential to treat colitis by maintaining the mucosal barrier, modulating inflammation, and reducing oxidation stress, which may depend on the reversal of gut microbiota dysbiosis.

Advancements in Plant-Based Therapeutics for Hepatic Fibrosis: Molecular Mechanisms and Nanoparticulate Drug Delivery Systems

Chronic liver injuries often lead to hepatic fibrosis, a condition characterized by excessive extracellular matrix accumulation and abnormal connective tissue hyperplasia. Without effective treatment, hepatic fibrosis can progress to cirrhosis or hepatocellular carcinoma. Current treatments, including liver transplantation, are limited by donor shortages and high costs. As such, there is an urgent need for effective therapeutic strategies. This review focuses on the potential of plant-based therapeutics, particularly polyphenols, phenolic acids, and flavonoids, in treating hepatic fibrosis. These compounds have demonstrated anti-fibrotic activities through various signaling pathways, including TGF-β/Smad, AMPK/mTOR, Wnt/β-catenin, NF-κB, PI3K/AKT/mTOR, and hedgehog pathways. Additionally, this review highlights the advancements in nanoparticulate drug delivery systems that enhance the pharmacokinetics, bioavailability, and therapeutic efficacy of these bioactive compounds. Methodologically, this review synthesizes findings from recent studies, providing a comprehensive analysis of the mechanisms and benefits of these plant-based treatments. The integration of novel drug delivery systems with plant-based therapeutics holds significant promise for developing effective treatments for hepatic fibrosis.

A review of Phyllanthus urinaria L. in the treatment of liver disease: viral hepatitis, liver fibrosis/cirrhosis and hepatocellular carcinoma

Due to the pathological production of liver disease in utility particularly complexity, the morbidity and mortality of liver disease including viral hepatitis, liver fibrosis/cirrhosis and hepatocellular carcinoma (HCC) are rapidly increasing worldwide. Considering its insidious onset, rapid progression and drug resistance, finding an effective therapy is particularly worthwhile. Phyllanthus urinaria L. (P. urinaria), an ethnic medicine, can be applied at the stages of viral hepatitis, liver fibrosis/cirrhosis and HCC, which demonstrates great potential in the treatment of liver disease. Currently, there are numerous reports on the application of P. urinaria in treating liver diseases, but a detailed analysis of its metabolites and a complete summary of its pharmacological mechanism are still scarce. In this review, the phytochemical metabolites and ethnopharmacological applications of P. urinaria are summarized. Briefly, P. urinaria mainly contains flavonoids, lignans, tannins, phenolic acids, terpenoids and other metabolites. The mechanisms of P. urinaria are mainly reflected in reducing surface antigen secretion and interfering with DNA polymerase synthesis for anti-viral hepatitis activity, reducing hepatic stellate cells activity, inflammation and oxidative stress for anti-liver fibrosis/cirrhosis activity, as well as preventing tumor proliferation, invasion and angiogenesis for anti-HCC activity via relevant signaling pathways. Accordingly, this review provides insights into the future application of natural products in the trilogy of liver diseases and will provide a scientific basis for further research and rational utilization of P. urinaria.

HMGB1 as an extracellular pro-inflammatory cytokine: Implications for drug-induced organic damage

Drug-induced organic damage encompasses various intricate mechanisms, wherein HMGB1, a non-histone chromosome-binding protein, assumes a significant role as a pivotal hub gene. The regulatory functions of HMGB1 within the nucleus and extracellular milieu are interlinked. HMGB1 exerts a crucial regulatory influence on key biological processes including cell survival, inflammatory regulation, and immune response. HMGB1 can be released extracellularly from the cell during these processes, where it functions as a pro-inflammation cytokine. HMGB1 interacts with multiple cell membrane receptors, primarily Toll-like receptors (TLRs) and receptor for advanced glycation end products (RAGE), to stimulate immune cells and trigger inflammatory response. The excessive or uncontrolled HMGB1 release leads to heightened inflammatory responses and cellular demise, instigating inflammatory damage or exacerbating inflammation and cellular demise in different diseases. Therefore, a thorough review on the significance of HMGB1 in drug-induced organic damage is highly important for the advancement of pharmaceuticals, ensuring their effectiveness and safety in treating inflammation as well as immune-related diseases. In this review, we initially outline the characteristics and functions of HMGB1, emphasizing their relevance in disease pathology. Then, we comprehensively summarize the prospect of HMGB1 as a promising therapeutic target for treating drug-induced toxicity. Lastly, we discuss major challenges and propose potential avenues for advancing the development of HMGB1-based therapeutics.

Plant-derived flavonoids are a potential source of drugs for the treatment of liver fibrosis

Liver fibrosis is a dynamic pathological process that can be triggered by any chronic liver injury. If left unaddressed, it will inevitably progress to the severe outcomes of liver cirrhosis or even hepatocellular carcinoma. In the past few years, the prevalence and fatality of hepatic fibrosis have been steadily rising on a global scale. As a result of its intricate pathogenesis, the quest for pharmacological interventions targeting liver fibrosis has remained a formidable challenge. Currently, no pharmaceuticals are exhibiting substantial clinical efficacy in the management of hepatic fibrosis. Hence, it is of utmost importance to expedite the development of novel therapeutics for the treatment of this condition. Various research studies have revealed the ability of different natural flavonoid compounds to alleviate or reverse hepatic fibrosis through a range of mechanisms, which are related to the regulation of liver inflammation, oxidative stress, synthesis and secretion of fibrosis-related factors, hepatic stellate cells activation, and proliferation, and extracellular matrix synthesis and degradation by these compounds. This review summarizes the progress of research on different sources of natural flavonoids with inhibitory effects on liver fibrosis over the last decades. The anti-fibrotic effects of natural flavonoids have been increasingly studied, making them a potential source of drugs for the treatment of liver fibrosis due to their good efficacy and biosafety.

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.

Recent Advances in Research on Active Compounds Against Hepatic Fibrosis

BACKGROUND

Almost all chronic liver diseases cause fibrosis, which can lead to cirrhosis and eventually liver cancer. Liver fibrosis is now considered to be a reversible pathophysiological process and suppression of fibrosis is necessary to prevent liver cancer. At present, no specific drugs have been found that have hepatic anti-fibrotic activity.

OBJECTIVE

The research progress of anti-hepatic fibrosis compounds in recent ten years was reviewed to provide a reference for the design and development of anti-hepatic fibrosis drugs.

METHODS

According to the structure of the compounds, they are divided into monocyclic compounds, fused-heterocyclic compounds, and acyclic compounds.

RESULTS

In this article, the natural products and synthetic compounds with anti-fibrotic activity in recent ten years were reviewed, with emphasis on their pharmacological activity and structure-activity relationship (SAR).

CONCLUSION

Most of these compounds are natural active products and their derivatives, and there are few researches on synthetic compounds and SAR studies on natural product.

Unveiling the hub genes associated with aflatoxin B1-induced hepatotoxicity in chicken

Aflatoxin B1 (AFB1), a ubiquitous and toxic mycotoxin in human food and animal feedstuff, can impair the function and health of some organs, especially the liver. However, the knowledge about the potential mechanisms of AFB1-induced hepatotoxicity in chickens is limited. Therefore, we analyzed the gene expression data of chicken embryo primary hepatocytes (CEPHs) treated with and without AFB1 at the dose of 0.1 μg/mL which were cultured at 37 °C in Medium 199 (Life Technologies, Shanghai, China) with 5.0% CO2 for 48 h. Totally 1,711 differentially expressed genes (DEGs) were identified, in which 1,170 and 541 genes were up- and down-regulated in AFB1-administrated CEPHs compared to the control, respectively. Biological process analysis suggested that these DEGs might take part in angiogenesis, cell adhesion, immune response, cell differentiation, inflammatory response, cell migration regulation, and blood coagulation. Signaling pathways analysis revealed that these DEGs were mainly linked to metabolic pathways, MAPK, TLR2, and actin cytoskeleton regulation pathways. Moreover, the hub genes, including GYS2, NR1H4, ALDH8A1, and ANGPTL3, might participate in AFB1-induced hepatotoxicity. Taken together, our study offers a new insight into the mechanisms of the AFB1-induced hepatotoxicity.

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.

Protective Effects of Sophorae tonkinensis Gagnep. (Fabaceae) Radix et Rhizoma Water Extract on Carbon Tetrachloride-Induced Acute Liver Injury

Sophorae tonkinensis Radix et Rhizoma (STR) is a traditional Chinese herbal medicine. STR can reduce aminotransferase activity; however, the specific mechanism remains unclear. Here, we explored the potential therapeutic effects and hepatoprotective mechanism of STR on liver damage in mice. The chemical characteristics of the extract were characterized using ultra-high-performance liquid chromatography-tandem mass spectrometry fingerprinting, and its antioxidant capacity was verified using free radical scavenging tests. Forty-eight Kunming mice were randomly assigned into six groups. The model was made after the corresponding drug was given. The results showed that the STR water extract pretreatment significantly reduced serum aminotransferase and related liver function indicators compared with that in the model group. Furthermore, the STR water extract pretreatment significantly inhibited the apoptosis of liver cells, the level of liver high-mobility group box 1 (HMGB1), and inflammatory factors in hepatic tissue compared with that in the model group, and significantly downregulated the levels of toll-like receptor 4 (TLR4), Myeloid differentiation factor 88 (MyD88), and nuclear factor kappa B (NF-κB) compared with those in the model group. Overall, the STR water extract exerted a significant protective effect on CCL₄-induced acute liver injury in this study, and the accurate active ingredients of the STR water extract will be explored in the near future.

Mechanisms of Xiaochaihu Decoction on Treating Hepatic Fibrosis Explored by Network Pharmacology

Purpose. To explore the material basis and pharmacological mechanism of Xiaochaihu Decoction (XCHD), the classic Traditional Chinese Medicine (TCM) formula in inhibiting hepatic fibrosis (HF). Methods. The main components in XCHD were screened from the TCMSP database, ETCM database, and literature, and their potential targets were detected and predicted using the Swiss Target Prediction platform. The HF-related targets were retrieved and screened through GeneCard database and OMIM database, combined with GEO gene chips. The XCHD targets and HF targets were mapped to search common targets. The protein-protein interaction (PPI) network was acquired via the STRING11.0 database and analyzed visually using Cytoscape 3.8.0 software. The potential mechanisms of the common targets identified through GO and KEGG pathway enrichment analysis were analyzed by using Metascape database. The results were visualized through OmicShare Tools. The “XCHD compound-HF target” network was visually constructed by Cytoscape 3.8.0 software. AutoDockVina1.1.2 and PyMoL software were used to verify the molecular docking of XCHD main active compounds and HF key targets. Results. A total of 164 potential active compounds from XCHD were screened to act on 95 HF-related targets. Bioinformatics analysis revealed that quercetin, β-sitosterol, and kaempferol may be candidate agents, which acted on multiple targets like PTGS2, HSP90AA1, and PTGS1 and regulate multiple key biological pathways like IL-17 signaling pathway, TNF signaling pathway and PI3K-Akt signaling pathway to relieve HF. Moreover, molecular docking suggested that quercetin and PTGS2 could statically bind and interact with each other through amino acid residues val-349, LEU-352, PHE-381, etc. Conclusion. This work provides a systems perspective to study the relationship between Chinese medicines and diseases. The therapeutic efficacy of XCHD on HF was the sum of multitarget and multi-approach effects from the bioactive ingredients. This study could be one of the cornerstones for further research.

Hawk Tea Flavonoids as Natural Hepatoprotective Agents Alleviate Acute Liver Damage by Reshaping the Intestinal Microbiota and Modulating the Nrf2 and NF-κB Signaling Pathways

Hawk tea (Litsea coreana Levl. var. lanuginosa) is a traditional herbal tea in southwestern China, and was found to possess hepatoprotective effects in our previous study. However, it is unclear whether hawk tea flavonoids (HTF) can alleviate alcoholic liver damage (ALD). Firstly, we extracted and identified the presence of 191 molecules categorized as HTFs, with reynoutrin, avicularin, guaijaverin, cynaroside, and kaempferol-7-O-glucoside being the most prevalent. After taking bioavailability into consideration and conducting comprehensive sorting, the contribution of guaijaverin was the highest (0.016 mg/mice). Then, by daily intragastric administration of HTF (100 mg/kg/day) to the ALD mice, we found that HTF alleviated liver lipid deposition (inhibition of TG, TC, LDL-C) by reducing liver oxidative-stress-mediated inflammation (up-regulation NRF2/HO-1 and down-regulation TLR4/MyD88/NF-κB pathway) and reshaping the gut microbiota (Lactobacillus, Bifidobacterium, Bacillus increased). Overall, we found HTF could be a potential protective natural compound for treating ALD via the gut–liver axis and guaijaverin might be the key substance involved.

The construction of preclinical evidence for the treatment of liver fibrosis with quercetin: A systematic review and meta-analysis

Quercetin (3,3',4',5,7-pentahydroxyflavone), a flavonoid, is widely found in fruits and vegetables and exerts broad-spectrum pharmacological effects in the liver. Many studies have explored the bioactivity of quercetin in the treatment of liver fibrosis. Hence, through a systematic review and biological mechanism evaluation, this study aimed to construct a body of preclinical evidence for the treatment of liver fibrosis using quercetin. The literature used in this study was mainly obtained from four databases, and the SYRCLE list (10 items) was used to evaluate the quality of the included literature. A meta-analysis of HA, LN, and other indicators was performed via STATA 15.0 software. Subgroup analyses based on animal species and model protocol were performed to further obtain detailed results. Moreover, the therapeutic mechanism of quercetin was summarized in a directed network form based on a comprehensive search of the literature. After screening, a total of 14 articles (comprising 15 studies) involving 254 animals were included. The results from the analysis showed that the corresponding liver function indexes, such as the levels of HA and LN, were significantly improved in the quercetin group compared with the model group, and liver function, such as the levels of AST and ALT, were also improved in the quercetin group. The species- and model-based subgroup analyses of AST and ALT revealed that quercetin exerts a significant effect. The therapeutic mechanism of quercetin was shown to be related to multiple pathways involving anti-inflammatory and antioxidant activities and lipid accumulation, including regulation of the TGF-β, α-SMA, ROS, and P-AMPK pathways. The results showed that quercetin exerts an obvious effect on liver fibrosis, and more prominent improvement effects on liver function and liver fibrosis indicators were obtained with a dose of 5-200 mg during a treatment course ranging from 4 to 8 weeks. Quercetin might be a promising therapeutic for liver fibrosis.

Deficiency of PKCλ/ι alleviates the liver pathologic impairment of Schistosoma japonicum infection by thwarting Th2 response

BACKGROUND

The activation of immune response driven by the eggs of Schistosoma japonicum and the subsequent secretions is the culprit behind granulomatous inflammation and liver fibrosis. Evidence suggests that PKCλ/ι participates in a variety of physiological and pathological processes, including the regulation of metabolism, growth, proliferation and differentiation of cells. However, the role of PKCλ/ι in liver disease caused by Schistosoma japonicum remains unclear.

METHODS

In the present study, we observe the pathological changes of egg-induced granulomatous inflammation and fibrosis in the liver of mice infected by Schistosoma japonicum by using conditional PKCλ/ι-knockout mice and wild-type control. Immune cytokines and fibrogenic factors were analyzed by performing flow cytometry and real-time fluorescence quantitative PCR.

RESULTS

The results of H&E and Masson staining show that the degree of granulomatous lesions and fibrosis in the liver of the infected PKCλ/ι-knockout mice was significantly reduced compared with those of the infected wild-type mice. The mean area of single granuloma and hepatic fibrosis in the PKCλ/ι-knockout mice was significantly lower than that of the wild-type mice (85,295.10 ± 5399.30 μm² vs. 1,433,702.04 ± 16,294.01 μm², P < 0.001; 93,778.20 ± 8949.05 μm² vs. 163,103.01 ± 11,103.20 μm², P < 0.001), respectively. Serological analysis showed that the ALT content was significantly reduced in the infected knockout mice compared with infected wild-type mice. RT-PCR analysis showed that IL-4 content in knockout mice was significantly increased after Schistosoma japonicum infection, yet the increase was less than that in infected wild-type mice (P < 0.05). PKCλ/ι deficiency led to reduced expression of fibrosis-related factors, including TGF-β1, Col-1, Col-3, α-SMA and liver DAMP factor HMGB1. Flow cytometry analysis showed that the increasing percentage of Th2 cells, which mainly secrete IL-4 cytokines in spleen cells, was significantly lower in PKCλ/ι-deficient mice compared with wild-type mice after infection (P < 0.05).

CONCLUSIONS

Our data demonstrate that PKCλ/ι deficiency alleviating granulomatous inflammation and fibrosis in the liver of mice with S. japonicum infection by downregulating Th2 immune response is the potential molecular mechanism behind the role of PKCλ/ι in schistosomiasis.

The Yin and Yang of epigenetics in the field of nanoparticles

Nanoparticles (NPs) have become a very exciting research avenue, with multitudinous applications in various fields, including the biomedical one, whereby they have been gaining considerable interest as drug carriers able to increase bioavailability, therapeutic efficiency and specificity of drugs. Epigenetics, a complex network of molecular mechanisms involved in gene expression regulation, play a key role in mediating the effect of environmental factors on organisms and in the etiology of several diseases (e.g., cancers, neurological disorders and cardiovascular diseases). For many of these diseases, epigenetic therapies have been proposed, whose application is however limited by the toxicity of epigenetic drugs. In this review, we will analyze two aspects of epigenetics in the field of NPs: the first is the role that epigenetics play in mediating nanotoxicity, and the second is the possibility of using NPs for delivery of "epi-drugs" to overcome their limitations. We aim to stimulate discussion among specialists, specifically on the potential contribution of epigenetics to the field of NPs, and to inspire newcomers to this exciting technology.

Anti-Liver Fibrosis Activity and the Potential Mode of Action of Ruangan Granules: Integrated Network Pharmacology and Metabolomics

Ruangan granules (RGGs) have been used to treat liver fibrosis with good clinical efficacy for many years. However, the potential mechanism of action of RGGs against liver fibrosis is still unclear. In this study, we evaluated the quality and safety of this preparation and aimed to explore the anti-liver fibrosis activity and potential mode of action of RGGs using network pharmacology and metabolomics. The results showed that RGGs contained abundant ferulic acid, salvianolic acid B and paeoniflorin, and at the given contents and doses, RGGs were safe and presented anti-liver fibrosis activity. They presented anti-liver fibrosis activity by improving liver function (ALT and AST, p < 0.01) and pathology and decreasing fibrosis markers in the serum of rats caused by CCl₄, including HA, LN, PC III, HYP, CoII-V, and α-SMA, and the oxidant stress and inflammatory response were also alleviated in a dose-dependent manner, especially for high-dose RGGs (p < 0.01). Further studies showed that RGGs inhibited the activation of the PI3K-Akt signaling pathway in rats induced by CCl₄, regulated pyrimidine metabolism, improved oxidative stress and the inflammatory response by regulating mitochondrial morphology, and alleviated liver fibrosis. Luteolin, quercetin, morin and kaempferol were active compounds and presented the cytotoxicity toward to LX-02 cells. This study provides an overall view of the mechanism underlying the action of RGGs protecting against liver fibrosis.

Hepatic stellate cell activation by TGFβ induces hedgehog signaling and endoplasmic reticulum stress simultaneously

Activation of hepatic stellates (HSCs) is known as the major cause of initiation and progression of liver fibrosis. A wide array of events occurs during HSC activation including induction of hedgehog (Hh) signaling and endoplasmic reticulum (ER) stress. Targeting HSC activation may provide promising insights into liver fibrosis treatment. In this regard, establishing in vitro models which can mimic the molecular pathways of interest is very important. We aimed to activate HSC in which Hh signaling and ER stress are stimulated simultaneously. We used 5 ng/ml TGFβ to activate LX-2 cells, HSC cell line. Gene expression analysis using qRT-PCR, immunostaining and immunoblotting were performed to show HSC activation associated markers. Furthermore, the migration capacity of the TGFβ treated cells is evaluated. The results demonstrated that major fibrogenic markers including collagen1a, lysyl oxidase, and tissue inhibitor of matrix metalloproteinase 1 genes are up-regulated significantly. In addition, our immunofluorescence and immunoblotting results showed that protein levels of GLI-2 and XBP1, were enhanced. Moreover, we found that TGFβ treatment reduced the migration of LX-2 cells. Our results are compatible with high throughput data analysis with respect to differentially expressed genes of activated HSC compared to the quiescent ones. Moreover, our findings suggest that quercetin can reduce fibrogenic markers of activated HSCs as well as osteopontin expression, a target gene of hedgehog signaling.

Quercetin Reduces Oxidative Stress and Apoptosis by Inhibiting HMGB1 and Its Translocation, Thereby Alleviating Liver Injury in ACLF Rats

Background

Acute on chronic liver failure (ACLF) is a syndrome of acute liver failure that occurs on the basis of chronic liver disease, which is characterized by a rapid deterioration in a short period and high mortality. High mobility group box 1 (HMGB1) may be involved in the pathological process of ACLF; its specific role remains to be further elucidated. Our previous studies have shown that quercetin (Que) exerts anti-oxidant and anti-apoptotic effects by inhibiting HMGB1 in vitro. The present study aimed to investigate the effect of Que on liver injury in ACLF rats.

Methods

The contents of ALT, AST, TBiL, and PT time of rats in each group were observed. HE staining was used to detect liver pathology. The levels of oxidative stress indicators such as MDA, GSH, and 4-HNE in the rat liver were detected. TUNEL assay was used to detect apoptosis in rat hepatocytes. Immunofluorescence and western blot analysis were performed to explore the protective effect of Que on ACLF rats and the underlying mechanism.

Results

The results showed that Que could reduce the increase of serum biochemical indices, improve liver pathology, and reduce liver damage in ACLF rats. Further results confirmed that Que reduced the occurrence of oxidative stress and apoptosis of hepatocytes, and these reactions may aggravate the progress of ACLF. Meanwhile, the results of immunofluorescence and western blotting also confirmed that the expression of HMGB1 and extranuclear translocation in ACLF rat hepatocytes were significantly increased, which was alleviated by the treatment of Que. In addition, when cotreated with glycyrrhizin (Gly), an inhibitor of HMGB1, the inhibition of Que on HMGB1 and its translocation, apoptosis and oxidative stress, and the related proteins of HMGB1-mediated cellular pathway have been significantly enhanced.

Conclusion

Thus, Que alleviates liver injury in ACLF rats, and its mechanism may be related to oxidative stress and apoptosis caused by HMGB1 and its translocation.

Effects of hyperbaric oxygen therapy on patients with spinal cord injury: A systematic review and meta-analysis of Randomized Controlled Trials

BACKGROUND

The effects of hyperbaric oxygen therapy (HBO) for spinal cord injury (SCI) are controversial.

OBJECTIVE

The purpose of this study was to evaluate the effects of HBO therapy on motor function, sensory function, and psychology after SCI.

METHOD

We searched the following databases: Medline, Embase, PubMed, Ovid, Cochrane library, China National Knowledge Infrastructure (CNKI), Wan Fang, and VIP up to May 2020. We included Randomized Controlled Trials (RCTs) which investigated patients with SCI received HBO during hospitalization. Motor function, sensory function, and psychology status were measured by commonly used scales including American Spinal Injury Association (ASIA) motor score, Modified Barthel Index (MBI), ASIA sensory score, Hamilton Depression Scale (HAMD), and Hamilton Anxiety Scale (HAMA). We performed a meta-analysis by calculating mean difference (MD) to determine the effect of HBO on three levels of function on patients with SCI. We evaluated heterogeneity by I2 test, and I2> 50% was significant.

RESULTS

A total of 1746 studies were identified initially, and 11 studies were included, involving 875 participants. HBO therapy significantly improved the ASIA motor score (MD 15.84, 95% CI 9.04 to 22.64, I2= 87%). Six trails suggested that HBO therapy statistically promoted ASIA sensory score (MD 66.30, 95% CI 53.44 to 79.16, I2= 95%). The other four trails suggested that HBO therapy statistically increased the light touch score (MD 9.27, 95% CI 3.89 to 14.65, I2= 91%) and needling score (MD 10.01, 95% CI 8.60 to 11.43, I2= 95%), respectively. HBO therapy was implicated in the significant improvement of MBI (MD 13.80, 95% CI 10.65 to 16.94, I2= 0%). HBO therapy also decreased the HAMA (MD -2.37, 95% CI -2.72 to -2.02, I2= 0%) and HAMD (MD -3.74, 95% CI -5.82 to -1.65, I2= 90%).

CONCLUSIONS

HBO therapy may improve motor function, sensory function and psychology after SCI compared to conventional treatments. More high-quality, large sample size RCTs are needed to support these perspectives.

Effect of Quercetin on the Expression of NOXs and P-Smad3C in TGF-Β-Activated Hepatic Stellate Cell Line LX-2

Background: Hepatic stellate cells (HSCs) play a primary role in liver fibrogenesis. NOXs are the main origin of reactive oxygen species (ROS) in the liver. Among them, NOX1, NOX2, and NOX4 are expressed more in HSCs and are involved in the development of liver fibrosis. Quercetin, an abundant citrus flavonoid, is known to have beneficial effects on liver injury and hepatic fibrosis. Objectives: In this study, the effect of quercetin on NOX1, NOX2, and NOX4 expression and Smad3 phosphorylation induced by TGF-β in the human hepatic LX2 cell line was investigated. Methods: The cytotoxic effects of quercetin on the cells were determined by MTT assay. The cells were activated with 2 ng/mL of TGF-β for 24 h and then treated with different concentrations of Quercetin. The mRNA expression rates of NOX1, NOX2, NOX4, and phosphorylated Smad 3C (p-Smad3C) were analyzed using real-time polymerase chain reaction (PCR) and western blot assays. Results: TGF-β increased the mRNA expression of NOX1, NOX2, and NOX4 and the protein level of p-Smad3C in the LX2 cell line. Quercetin significantly decreased the mRNA expression of NOX1, NOX2, and NOX4 in the LX-2 cells. Moreover, quercetin significantly diminished the p-Smad3C level in the LX-2 cell line activated with TGF-β. Conclusions: Quercetin may be effective in improving hepatic fibrosis via the reduction of NOX1, NOX2, and NOX4 expression in activated HSCs. The main mechanism through which quercetin reduces the expression of these target genes may be related to the reduction of the p-Smad3C level.

Network Pharmacological Analysis and Experimental Validation of the Mechanisms of Action of Si-Ni-San Against Liver Fibrosis

Background: Si-Ni-San (SNS), a commonly used traditional Chinese medicine (TCM) formula, has potency against liver diseases, such as hepatitis and non-alcoholic fatty liver disease (NAFLD). However, the therapeutic efficacy and pharmacological mechanisms of action of SNS against liver fibrosis remain largely unclear. Methods: A carbon tetrachloride (CCl4)-induced liver fibrosis mouse model was adopted for the first time to investigate the beneficial effects of SNS on liver fibrosis. The potential mechanisms of action of SNS were explored using the network pharmacology-based strategy and validated with the aid of diverse assays. Results: SNS treatment reduced collagen and ECM deposition, downregulated fibrosis-related factor (hyaluronic acid and laminin) contents in serum, maintained the morphological structure of liver tissue, and improved liver function in the liver fibrosis model. Based on network pharmacology results, apoptosis, inflammation and angiogenesis, together with the associated pathways (including VEGF, TNF, caspase, PPAR-γ and NF-κB), were identified as the mechanisms underlying the effects of SNS on liver fibrosis. Further in vivo experiments validated the significant mitigatory effects of SNS on inflammatory infiltration and pro-inflammatory cytokine contents (IFNγ, IL-1β and TGF-β1) in liver tissues of mice with liver fibrosis. SNS suppressed pathologic neovascularization as well as levels of VEGFR1, VEGF and VEGFR2 in liver tissues. SNS treatment additionally inhibited hepatic parenchyma cell apoptosis in liver tissues of mice with liver fibrosis and regulated apoptin expression while protecting L02 cells against apoptosis induced by TNF-α and Act D in vitro. Activation of hepatic stellate cells was suppressed and the balance between MMP13 and TIMP1 maintained in vitro by SNS. These activities may be associated with SNS-induced NF-κB suppression and PPAR-γ activation. Conclusion: SNS effectively impedes liver fibrosis progression through alleviating inflammation, ECM accumulation, aberrant angiogenesis and apoptosis of hepatic parenchymal cells along with inhibiting activation of hepatic stellate cells through effects on multiple targets and may thus serve as a novel therapeutic regimen for this condition.

13-Weeks subchronic toxicity of isoquercitrin-γ-cyclodextrin (IQC-γCD) molecular inclusion complex in Sprague-Dawley rats

Flavonoids such as quercetin and its glycoside Isoquercitrin and are abundantly present in the diet and have various pharmacological effects. However, limited data about its potential toxicity is available. In this study, we aim to evaluate the subchronic toxicity of the isoquercitrin-γ-cyclodextrin (IQC-γCD) molecular inclusion complex (SunActive® QCD/EN) in Sprague-Dawley (SD) rats. The IQC-γCD was administrated orally to 40 male and 40 female SD rats at dietary doses up to 5.0 % for 13 consecutive weeks. During the experiment periods, the general clinical signs, mortality, hematological, urinalysis values, biochemical, and histopathological parameters were examined. All animals survived until the scheduled necropsy, and no statistically significant or clinical sign of toxicologically relevant differences including pathology parameters, and histopathological endpoints were observed in any of the IQC-γCD treatment groups, compared with the control group. However, certain observations were noted in the male rats treated with the highest concentration (5.0 %), but these were not seen in female rats. A slight inhibition of weight gain was observed, probably linked to a fall in red blood cells, and hematocrit index in female rats. Statistically significant changes were noted in some clinical measures, such as plasma bilirubin level, alkaline phosphatase total bile acid without evidence of systemic clinical toxicity. The results support no observed adverse effect level (NOAEL) of IQC-γCD of 5.0 % in the diet for males (3338.55 mg/kg/day), and 3.0 % in the diet for females (2177.33 mg/kg/day) SD rats. Therefore, in this 13 weeks repeated-dose SD rat study there were no treatment-related adverse clinical or pathological findings for IQC-γCD of 5.0 % in the diet for males, and 3.0 % in the diet for females SD rats. The results of the present study support the safe use of IQC-γCD as a functional food, food additive, and natural ingredient.

Elevated miR-129-5p attenuates hepatic fibrosis through the NF-κB signaling pathway via PEG3 in a carbon CCl4 rat model

Hepatic fibrosis is a reversible scaring response to chronic liver injury. MicroRNA (miR)-129-5p might regulate fibrosis-related gene expression. This study is performed to decipher, potential of miR-129-5p to influence the progression of hepatic fibrosis in a carbon tetrachloride (CCl4) rat model. Rat hepatic fibrosis was successfully established by subcutaneous injection of 50% CCl4. RT-qPCR revealed that miR-129-5p was poorly expressed and PEG3 was highly expressed in hepatic fibrosis tissues. As reflected by dual-luciferase reporter gene assay, miR-129-5p targeted and reduced the expression of PEG3. Thereafter, miR-129-5p antagomir or short hairpin RNA against paternally expressed gene 3 (PEG3) was adopted for gain- and loss-of-function assay to determine the molecular regulatory mechanism of miR-129-5p. Moreover, we detected the expression of nuclear factor kappa B (NF-κB) signaling pathway-related proteins and apoptosis-related factors, and made a serological analysis of the rat serum samples. Results showed that upregulated miR-129-5p or downregulated PEG3 led to reduction of the histological changes of liver cirrhosis and lowered the apoptosis rate, via downstream effects on the NF-κB signaling pathway. Thus, the hepatic fibrosis induced by CCl4 can be rescued by upregulated miR-129-5p or downregulated PEG3 expression.

Quercetin/Zinc complex and stem cells: A new drug therapy to ameliorate glycometabolic control and pulmonary dysfunction in diabetes mellitus: Structural characterization and genetic studies

Medicinal uses and applications of metals and their complexes are of increasing clinical and commercial importance. The ligation behavior of quercetin (Q), which is a flavonoid, and its Zn (II) (Q/Zn) complex were studied and characterized based on elemental analysis, molar conductance, Fourier-transform infrared (FTIR) spectra, electronic spectra, proton nuclear magnetic resonance (1H-NMR), thermogravimetric analysis, and transmission electron microscopy (TEM). FTIR spectral data revealed that Q acts as a bidentate ligand (chelating ligand) through carbonyl C(4) = O oxygen and phenolic C(3)-OH oxygen in conjugation with Zn. Electronic, FTIR, and 1H-NMR spectral data revealed that the Q/Zn complex has a distorted octahedral geometry, with the following chemical formula: [Zn(Q)(NO3)(H2O)2].5H2O. Diabetes was induced by streptozotocin (STZ) injection. A total of 70 male albino rats were divided into seven groups: control, diabetic untreated group and diabetic groups treated with either MSCs and/or Q and/or Q/Zn or their combination. Serum insulin, glucose, C-peptide, glycosylated hemoglobin, lipid profile, and enzymatic and non-enzymatic antioxidant levels were determined. Pancreatic and lung histology and TEM for pancreatic tissues in addition to gene expression of both SOD and CAT in pulmonary tissues were evaluated. MSCs in combination with Q/Zn therapy exhibited potent protective effects against STZ induced hyperglycemia and suppressed oxidative stress, genotoxicity, glycometabolic disturbances, and structural alterations. Engrafted MSCs were found inside pancreatic tissue at the end of the experiment. In conclusion, Q/Zn with MSC therapy produced a synergistic effect against oxidative stress and genotoxicity and can be considered potential ameliorative therapy against diabetes with pulmonary dysfunction, which may benefit against COVID-19.

Puerarin Alleviates Lipopolysaccharide-Induced Myocardial Fibrosis by Inhibiting PARP-1 to Prevent HMGB1-Mediated TLR4-NF-κB Signaling Pathway

Myocardial fibrosis (MFs) is a crucial pathological process that results in cardiac failure in the development of multiple cardiovascular diseases. Puerarin could reportedly be used to treat a variety of cardiovascular diseases. However, the exact mechanism of puerarin on MFs was not clear enough. The separated primary cardiac fibroblasts (CFs) were induced by lipopolysaccharide (LPS) and treated with puerarin. The levels of TNF-α, IL-6, HMGB1, PARP-1, α-SMA, collagen-1, collagen-3, NF-κB pathways were examined by ELISA, immunofluorescence, RT-qPCR, western blot and immunohistochemistry assays. In addition, MFs rats' model was established using transverse aortic constriction (TAC), and the degree of fibrosis was certified by masson staining. We successfully separated primary CFs, and certified that LPS induction could upregulate the levels of PARP-1, HMGB1, inflammatory cytokines and fibrosis-related proteins (α-SMA, collagen-1 and collagen-3). In addition, we proved that puerarin could weaken MFs, and PARP-1 and HMGB1 expressions, which were induced by LPS in primary CFs. In terms of mechanism, HMGB1 expression could be promoted by PARP-1, and PARP-1 could attenuate the therapeutic effect of puerarin on LPS-induced MFs. Besides, PARP-1-HMGB1-NF-κB pathway was related to the protective effect of puerarin on MFs. In vivo, we also verified the protective efficacy of puerarin on MFs induced by TAC, and puerarin also regulated HMGB1-mediated TLR4-NF-κB signaling pathway. We demonstrated that puerarin could ameliorate MFs by downregulating PARP-1 to inhibit HMGB1-mediated TLR4-NF-κB signaling pathway in LPS-induced primary CFs and TAC-induced MFs rats' model.

A Comprehensive Review of Natural Products against Liver Fibrosis: Flavonoids, Quinones, Lignans, Phenols, and Acids

Liver fibrosis resulting from continuous long-term hepatic damage represents a heavy burden worldwide. Liver fibrosis is recognized as a complicated pathogenic mechanism with extracellular matrix (ECM) accumulation and hepatic stellate cell (HSC) activation. A series of drugs demonstrate significant antifibrotic activity in vitro and in vivo. No specific agents with ideally clinical efficacy for liver fibrosis treatment have been developed. In this review, we summarized the antifibrotic effects and molecular mechanisms of 29 kinds of common natural products. The mechanism of these compounds is correlated with anti-inflammatory, antiapoptotic, and antifibrotic activities. Moreover, parenchymal hepatic cell survival, HSC deactivation, and ECM degradation by interfering with multiple targets and signaling pathways are also involved in the antifibrotic effects of these compounds. However, there remain two bottlenecks for clinical breakthroughs. The low bioavailability of natural products should be improved, and the combined application of two or more compounds should be investigated for more prominent pharmacological effects. In summary, exploration on natural products against liver fibrosis is becoming increasingly extensive. Therefore, natural products are potential resources for the development of agents to treat liver fibrosis.

Toll-like Receptors as a Novel Therapeutic Target for Natural Products Against Chronic Diseases

Toll-like receptors (TLR) are one among the initial responders of the immune system which participate in the activation inflammatory processes. Several different types of TLR such as TLR2, TLR4, TLR7 and TLR9 have been identified in various cell types, each having distinct ligands like lipids, lipoproteins, nucleic acids and proteins. Though its prime concern is xenobiotic defences, TLR signalling has also recognized as an activator of inflammation and associated development of chronic degenerative disorders (CDDs) including obesity, type 2 diabetes mellitus (T2DM), fatty liver disease, cardiovascular and neurodegenerative disorders as well as various types of cancers. Numerous drugs are in use to prevent these disorders, which specifically inhibit different pathways associated with the development of CDDs. Compared to these drug targets, inhibition of TLR, which specifically responsible for the inflammatory insults has proven to be a better drug target. Several natural products have emerged as inhibitors of CDDs, which specifically targets TLR signalling, among these, many are in the clinical trials. This review is intended to summarize the recent progress on TLR association with CDDs and to list possible use of natural products, their combinations and their synthetic derivative in the prevention of TLR-driven CDD development.

HMGB1 Inhibits HNF1A to Modulate Liver Fibrogenesis via p65/miR-146b Signaling

High mobility group box 1 (HMGB1) is essential for the pathogenesis of liver injury and liver fibrosis. We previously revealed that miR-146b promotes hepatic stellate cells (HSCs) activation and proliferation. Nevertheless, the potential mechanisms are still unknown. Herein, HMGB1 increased HSCs proliferation and COL1A1 and α-SMA protein levels. However, the knockdown of miR-146b inhibited HSCs proliferation and COL1A1 and α-SMA protein levels induced via HMGB1 treatment. miR-146b was upregulated by HMGB1 and miR-146b targeted hepatocyte nuclear factor 1A (HNF1A) 3'-untranslated region (3'UTR) to modulate its expression negatively. Further, we confirmed that HMGB1 might elicit miR-146b expression via p65 within HSCs. Knockdown or block of HMGB1 relieved the CCl₄-induced liver fibrosis. In fibrotic liver tissues, miR-146b expression was positively correlated with p65 mRNA, but HNF1A mRNA was inversely correlated with p65, and miR-146b expression. In summary, our findings suggest that HMGB1/p65/miR-146b/HNF1A signaling exerts a crucial effect on liver fibrogenesis via the regulation of HSC function.

Expression of TLR-2 in hepatocellular carcinoma is associated with tumour proliferation, angiogenesis and Caspase-3 expression

AIMS

Unlike other Toll-like receptors (TLRs), the role of toll like receptor 2 (TLR-2) in the pathogenesis of chronic liver disease and hepatocellular carcinoma (HCC) is not well studied. We, therefore, set out to investigate the expression of TLR-2 in different chronic liver disease states along with other markers of cell death, cellular proliferation and tissue vascularisation METHODS AND RESULTS: Immunohistochemistry was performed on liver tissue microarrays comprising hepatitis, cirrhosis and HCC patient samples using antibodies against TLR-2, Ki-67, Caspase-3 and VEGF. This was done in order to characterise receptor expression and translocation, apoptosis, cell proliferation and vascularisation. Cytoplasmic TLR-2 expression was found to be weak in 5/8 normal liver cases, 10/19 hepatitis cases and 8/21 cirrhosis patients. Moderate to strong TLR-2 expression was observed in some cases of hepatitis and cirrhosis. Both, nuclear and cytoplasmic TLR-2 expression was present in HCC with weak intensity in 11/41 cases, and moderate to strong staining in 19/41 cases. Eleven HCC cases were TLR-2 negative. Surprisingly, both cytoplasmic and nuclear TLR-2 expression in HCC were found to significantly correlate with proliferative index (r = 0.24 and 0.37), Caspase-3 expression (r = 0.27 and 0.38) and vascularisation (r = 0.56 and 0.23). Further, nuclear TLR-2 localisation was predominant in HCC, whereas cytoplasmic expression was more prevalent in hepatitis and cirrhosis. Functionally, treatment of HUH7 HCC cells with a TLR-2 agonist induced the expression of cellular proliferation and vascularisation markers CD34 and VEGF.

CONCLUSIONS

Our results demonstrate a positive correlation between the expression of TLR-2 and other markers of proliferation and vascularisation in HCC which suggests a possible role for TLR-2 in HCC pathogenesis.

Isochlorogenic Acid A Attenuates the Progression of Liver Fibrosis Through Regulating HMGB1/TLR4/NF-κB Signaling Pathway

Liver fibrosis, a chronic damage process related to further progression of hepatic cirrhosis, has yet no truly effective treatment. Isochlorogenic acid A (ICQA), isolated from a traditional Chinese herbal medicine named Laggera alata (DC.) Sch.Bip. ex Oliv. (Asteraceae), is proved to exhibit anti-inflammatory, hepatoprotective and antiviral properties. However, the actions of ICQA on liver fibrosis are poorly understood. The purpose of this study was to evaluate the actions of ICQA on liver fibrosis and clarify the underlying mechanism. It was found that ICQA had significant protective actions on liver injury, inflammation as we as fibrosis in rats. Meanwhile, ICQA prevented hepatic stellate cells (HSC) activation, indicated by its inhibitory effect on the overexpression of α-smooth muscle actin (α-SMA). In addition, the reduced fibrosis was found to be associated with the decreased protein expression of high-mobility group box 1 (HMGB1) as well as toll like receptor (TLR) 4. Simultaneously, ICQA can suppress the cytoplasmic translocation of HMGB1 in rat liver. Further investigations indicated that ICQA treatment dramatically attenuated the nuclear translocation of the nuclear factor-kB (NF-κB) p65 and suppressed the hepatic expression of p−IκBα in rats with liver fibrosis. Taken together, our study indicated that ICQA could protect against CCl₄-induced liver fibrosis probably through suppressing the HMGB1/TLR4/NF-κB signaling pathways.

Myricetin Modulates Macrophage Polarization and Mitigates Liver Inflammation and Fibrosis in a Murine Model of Nonalcoholic Steatohepatitis

This study aimed to investigate the beneficial effects of myricetin in a diet-induced nonalcoholic steatohepatitis (NASH) model and the underlying mechanism. C57BL/6J mice were fed a standard chow or the choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) for 8 weeks with the treatment of myricetin (100 mg/kg) or vehicle by daily gavage. Hepatic inflammation, steatosis, fibrosis, and hepatic stellate cells (HSC) activation were assessed. We also analyzed M1 and M2 macrophages and its related markers in livers from NASH mice and in RAW264.7 macrophages stimulated by lipopolysaccharide (LPS) or interleukin 4 (IL-4) in vitro. Furthermore, we determined the effect of myricetin on the triggering receptor expressed on myeloid cells-1 (TREM-1), toll like receptor (TLR) 2 and 4, and myeloid differentiation factor 88 (MyD88) signaling both in livers from mice and in RAW264.7 cells stimulated by LPS. Our results revealed that myricetin remarkably ameliorated hepatic steatosis, inflammation, and inhibited hepatic macrophage infiltration in CDAHFD-fed mice. Myricetin-treated to CDAHFD-fed mice also inhibited liver fibrosis and HSC activation when compared with vehicle-treated to those mice. Moreover, myricetin inhibited M1 macrophage polarization and its relative markers in livers of NASH mice while induced M2 polarization. Similarly, in vitro study, myricetin inhibited the LPS-induced mRNA expression of M1 macrophages marker genes and induced IL-4-induced M2 macrophage marker genes in RAW264.7 macrophages. Mechanically, myricetin inhibited the expression of TREM-1 and TLR2/4-MyD88 signaling molecules in livers from NASH mice and in RAW264.7 macrophages stimulated by LPS in vitro. Additionally, myricetin inhibited the activation of nuclear factor (NF)-κB signaling and the phosphorylation of the signal transducer and activation of transcription 3 (STAT3) in LPS-stimulated RAW264.7 macrophages. Taken together, our data indicated that myricetin modulated the polarization of macrophages via inhibiting the TREM-1-TLR2/4-MyD88 signaling molecules in macrophages and therefore mitigated NASH and hepatic fibrosis in the CDAHFD-diet-induced NASH model in mice.

Intercellular crosstalk of hepatic stellate cells in liver fibrosis: New insights into therapy

Liver fibrosis is a dynamic wound-healing process characterized by the net accumulation of extracellular matrix. There is no efficient antifibrotic therapy other than liver transplantation to date. Activated hepatic stellate cells (HSCs) are the major cellular source of matrix-producing myofibroblasts, playing a central role in the initiation and progression of liver fibrosis. Paracrine signals from resident and inflammatory cells such as hepatocytes, liver sinusoidal endothelial cells, hepatic macrophages, natural killer/natural killer T cells, biliary epithelial cells, hepatic progenitor cells, and platelets can directly or indirectly regulate HSC differentiation and activation. Intercellular crosstalk between HSCs and those "responded" cells has been a critical event involved in HSC activation and fibrogenesis. This review summarizes recent advancement regarding intercellular communication between HSCs and other "responded cells" during liver fibrosis and experimental models of intercellular crosstalk systems, and provides novel ideas for potential antifibrotic therapeutic strategy.

Modeling Progressive Fibrosis with Pluripotent Stem Cells Identifies an Anti-fibrotic Small Molecule

Progressive organ fibrosis accounts for one-third of all deaths worldwide, yet preclinical models that mimic the complex, progressive nature of the disease are lacking, and hence, there are no curative therapies. Progressive fibrosis across organs shares common cellular and molecular pathways involving chronic injury, inflammation, and aberrant repair resulting in deposition of extracellular matrix, organ remodeling, and ultimately organ failure. We describe the generation and characterization of an in vitro progressive fibrosis model that uses cell types derived from induced pluripotent stem cells. Our model produces endogenous activated transforming growth factor β (TGF-β) and contains activated fibroblastic aggregates that progressively increase in size and stiffness with activation of known fibrotic molecular and cellular changes. We used this model as a phenotypic drug discovery platform for modulators of fibrosis. We validated this platform by identifying a compound that promotes resolution of fibrosis in in vivo and ex vivo models of ocular and lung fibrosis.

Quercetin administration post-weaning attenuates high-fructose, high-cholesterol diet-induced hepatic steatosis in growing, female, Sprague Dawley rat pups

BACKGROUND

Fructose and cholesterol-rich diets have been implicated in the upsurge of metabolic syndrome (MetS). Phytochemicals are being explored as alternatives for the prevention and management of MetS. Thirty-six 21-day-old, female Sprague Dawley rats fed a high-fructose, high-cholesterol diet post-weaning were used to investigate the prophylactic potential of quercetin. Group 1 was given standard rat chow (SRC); Group 2: SRC and quercetin (75 mg kg-1 daily); Group 3: SRC and fenofibrate (100 mg kg-1 daily); Group 4 was given a high cholesterol diet (HCD) (2% added dietary cholesterol in SRC), 20% fructose drinking solution (FS); Group 5 was given HCD, 20% FS and quercetin (75 mg kg-1 daily); Group 6: HCD, 20% FS and fenofibrate (100 mg kg-1 daily). Rats were fed ad libitum for 8 weeks, euthanized, and blood and liver samples were collected.

RESULTS

The HCD and FS significantly increased (P < 0.05) absolute and relative liver masses and serum cholesterol. Fasting blood glucose, serum triglycerides, alanine transaminase, creatinine, and urea were not significantly different (P > 0.05) between groups. The HCD and FS significantly increased liver lipid yield compared to the SRC and rats receiving SRC with fenofibrate (P < 0.05). Quercetin or fenofibrate together with HCD and FS attenuated the diet-induced increase in liver lipids by approximately 50%, although this was not statistically significant. Liver macro- and micro-steatosis scores were significantly increased (P < 0.05) in rats receiving HCD and FS. Quercetin or fenofibrate administration together with HCD and FS significantly decreased (P < 0.05) liver macro-steatosis scores.

CONCLUSION

The prophylactic effect of quercetin on fructose and cholesterol diet-induced liver lipid accumulation may be exploited in the fight against non-alcoholic fatty liver disease (NAFLD). © 2019 Society of Chemical Industry.

Morin Hydrate Inhibits TREM-1/TLR4-Mediated Inflammatory Response in Macrophages and Protects Against Carbon Tetrachloride-Induced Acute Liver Injury in Mice

This study aims to investigate the protective effects of morin hydrate (MH) against acute liver injury induced by carbon tetrachloride (CCl₄) in mice and to elucidate the possible molecular mechanism of action. Mice were pretreated with MH (50 mg/kg body weight) or vehicle by oral gavage once daily for 5 days, followed by intraperitoneal injection of a single dose of CCl₄ (1 ml/kg in olive oil). Mice were sacrificed 24 h later; the blood and liver samples were harvested for analysis. We also used the model of lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages in vitro and examined the effects of MH and its mechanism of action on the inflammatory response. Our results revealed that MH remarkably attenuated liver histopathological alterations, serum transaminases, hepatocytes death, and inflammatory response induced by CCl₄. Importantly, MH reduced expression of the triggering receptor expressed on myeloid cells-1 (TREM-1) and toll-like receptor 4 (TLR4) both in vivo and in vitro experiments. This inhibitory effect MH on expression of the TREM-1 and TLR4 in cell culture was further heightened after TREM-1 knockdown with small interfering RNA (siRNA). Moreover, MH dramatically suppressed the inhibitor of kappa B α (IκBα) degradation and subsequent nuclear factor-kappa B (NF-κB) p65 translocation into the nucleus and NF-κB-mediated cytokines, such as tumor necrosis factor α (TNF-α), interleukin (IL)-1β, and IL-6. Additionally, MH also ameliorated CCl₄-induced oxidative stress by enhancing the nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression in the injured livers. Taken together, MH has hepatoprotective activity, and this effect may be elicited by attenuating macrophage-mediated inflammatory responses via inhibition TREM-1/TLR4/NF-κB signaling and by regulating hepatic oxidative stress via enhancement Nrf2/HO-1 antioxidant pathway.

Modulatory effect of Prosopis juliflora leaves on hepatic fibrogenic and fibrolytic alterations induced in rats by thioacetamide

This study investigated the antifibrotic effect of Prosopis juliflora leaves crude methanolic extract (PJEL) against thioacetamide (TAA)-induced liver fibrosis. The phytochemical analysis of PJEL was performed via HPLC/MS in association with evaluating its free radical scavenging and cytotoxic activities. The antifibrotic activity of PJEL was assessed by dividing Wistar rats into 8 groups: normal control, PJEL1-administered rats (2 mg/ Kg b.w.), PJEL2-administered rats (4 mg/ Kg b.w.), PJEL3-administered rats (8 mg/Kg b.w.), TAA-induced hepatic fibrosis, TTA + PJEL1, TAA + PJEL2, and TAA + PJEL3. Results indicated that PJEL crude methanolic extract is rich in polyphenolic compounds and alkaloids. PJEL exerted free radical scavenging activity with IC₅₀ of 123.5 μg/mL and cytotoxic activity against a well-differentiated hepatocellular cell line (IC₅₀ = 11.1 μg/mL). PJEL at a dose of 4 mg/Kg b.w. ameliorated serum ALT activity and improved serum albumin level and hepatic hydroxyproline content in association with a reduction in the fibrosis stage. PJEL elevated hepatic tumor necrosis factor-α and interleukin-6 contents with less necrosis grade. PJEL post-therapy ameliorated the relative expression of Bcl-2, Col1A1, Mmp-9, and Mmp-2 genes in liver. CONCLUSION: PJEL possesses a good therapeutic activity against TAA-induced liver fibrosis via enhancing extracellular matrix removal and stimulating hepatic regeneration to decrease hepatic necrosis.

Quercetin ameliorates pulmonary fibrosis by inhibiting SphK1/S1P signaling

Idiopathic pulmonary fibrosis is an agnogenic chronic disorder with high morbidity and low survival rate. Quercetin is a flavonoid found in a variety of herbs with anti-fibrosis function. In this study, bleomycin was employed to induce a pulmonary fibrosis mouse model. The quercetin administration ameliorated bleomycin-induced pulmonary fibrosis, evidenced by the expression level changes of hydroxyproline, fibronectin, α-smooth muscle actin, Collagen I, and Collagen III. Similar results were observed in transforming growth factor (TGF)-β-treated human embryonic lung fibroblast (HELF). The bleomycin or TGF-β administration caused the increase of sphingosine-1-phosphate (S1P) level in pulmonary tissue and HELF cells, as well as its activation-required kinase, sphingosine kinase 1 (SphK1), and its degradation enzyme, sphinogosine-1-phosphate lyase (S1PL). However, the increase of S1P, SphK1, and S1PL was attenuated by application of quercetin. In addition, the effect of quercetin on fibrosis was abolished by the ectopic expression of SphK1. The colocalization of SphK1/S1PL and fibroblast specific protein 1 (FSP1) suggested the roles of fibroblasts in pulmonary fibrosis. In summary, we demonstrated that quercetin ameliorated pulmonary fibrosis in vivo and in vitro by inhibiting SphK1/S1P signaling.

Chloroquine ameliorates carbon tetrachloride-induced acute liver injury in mice via the concomitant inhibition of inflammation and induction of apoptosis

This is the first study to investigate the hepatoprotective effect of CQ on acute liver injury caused by carbon tetrachloride (CCl₄) in a murine model and the underlying molecular mechanisms. Ninety-six mice were randomly divided into the control (n = 8), CQ (n = 8), CCl₄ (n = 40), and CCl₄ + CQ (n = 40) treatment groups. In the CCl₄ group, mice were intraperitoneally (i.p) injected with 0.3% CCl₄ (10 mL/kg, dissolved in olive oil); in the CCl₄ + CQ group, mice were i.p injected with CQ at 50 mg/kg at 2, 24, and 48 h before CCl₄ administration. The mice in the control and CQ groups were administered with an equal vehicle or CQ (50 mg/kg). Mice were killed at 2, 6, 12, 24, 48 h post CCl₄ treatment and their livers were harvested for analysis. The results showed that CQ pre-treatment markedly inhibited CCl₄-induced acute liver injury, which was evidenced by decreased serum transaminase, aspartate transaminase and lower histological scores of liver injury. CQ pretreatment downregulated the CCl₄-induced hepatic tissue expression of high-mobility group box 1 (HMGB1) and the levels of serum HMGB1 as well as IL-6 and TNF-α. Furthermore, CQ pre-treatment inhibited autophagy, downregulated NF-kB expression, upregulated p53 expression, increased the ratio of Bax/Bcl-2, and increased the activation of caspase-3 in hepatic tissue. This is the first study to demonstrate that CQ ameliorates CCl₄-induced acute liver injury via the inhibition of HMGB1-mediated inflammatory responses and the stimulation of pro-apoptotic pathways to modulate the apoptotic and inflammatory responses associated with progress of liver damage.

Effect of hyperbaric oxygen therapy on HMGB1/NF-κB expression and prognosis of acute spinal cord injury: A randomized clinical trial

Although there are reports of the beneficial effects of hyperbaric oxygen (HBO) therapy in experimental settings, there are few clinical trials of HBO therapy for acute spinal cord injury (SCI). We investigated the effect of HBO in acute SCI by measuring plasma high mobility group box 1 (HMGB1) and nuclear factor kappa-B (NF-κB) levels, and by monitoring changes in electromyogram F-persistence (the percentage of discernible F-waves) and F-chronodispersion (the difference between minimal and maximal latency). We enrolled 79 acute SCI patients and randomly divided them into control (conventional treatment) and the treatment (conventional treatment plus HBO therapy) groups. Plasma was collected before treatment and after treatment on 1st, 3rd, 7th, 10th and 30th day for the measurement of HMGB1 and NF-κB. Electromyogram F-waves were detected before therapy and after therapy on the 10th and 30th days. Clinical profiles and neurological outcomes were evaluated using American Spinal Injury Association (ASIA) and Frankel Grade scores. Compared to the control group, HBO therapy down-regulated HMGB1 and NF-κB expression in patients with acute SCI on days 3, 7, 10 and 30 (p < 0.05). F-wave chronodispersion decreased at days 10 and 30 (p < 0.01) following HBO. ASIA and Frankel Grade motor/pain scores in the treatment group were significantly improved on day 30 (p < 0.01). There was a positive correlation between plasma NF-κB at day 7 and F-wave dispersion at day 30 (r = 0.76, p = 0.00). In summary, HBO therapy regulated the inflammatory reaction in secondary SCI by decreasing plasma HMGB1/NF-κB levels and reducing the dispersion of electromyogram F-waves of the lower limbs, thereby promoting neurological function recovery.

Profibrogenic effect of high-mobility group box protein-1 in human dermal fibroblasts and its excess in keloid tissues

High-mobility group box 1 (HMGB1) protein acts as a DNA chaperone for nuclear homeostasis. It translocates into the cytosol and is secreted into extracellular spaces, triggering proinflammatory cytokines and acting as a mediator in fibrosis. We determined whether HMGB1 plays a role in normal dermal fibrosis and keloid, and is involved with transforming growth factor β. We investigated the translocation and active release of HMGB1 from normal dermal fibroblasts under lipopolysaccharide stimuli, and the redistribution of nuclear HMGB1 into the cytoplasm of keloid fibroblasts. HMGB1 and its effector toll-like receptors and receptors for advanced glycation end product proteins are actively expressed in keloid tissues. Exogenous HMGB1 can induce the proliferation of human dermal fibroblasts, and could act as a profibrogenic molecule to produce collagen, decrease MMP-1, and increase TIMP-1 mRNA expression. Moreover, administration of HMGB1 increased the expression level of TGF-β1 and internal signaling molecules, such as Smad 2 and 3, phosphorylated Smad 2/3 complex, Erk 1/2, Akt, and NF-κB. Collectively, we demonstrate that HMGB1 treatment increases the expression level of collagen types I and III, elastin, and fibronectin in dermal spheroid cultures, thus making HMGB1 a promising therapeutic target for treatment of profibrogenic diseases.

Autophagy inhibition attenuates the induction of anti-inflammatory effect of catalpol in liver fibrosis

Autophagy has been regarded as an inflammation-associated defensive mechanism against chronic liver disease, which has been highlighted as a novel therapeutic target for the treatment of liver fibrosis. We herein aimed to study the effects of catalpol on liver fibrosis in vivo and in vitro, and to elucidate the role of autophagy in catalpol-induced anti-inflammation. Catalpol protected the liver against CCl₄-induced injury, as evidenced by mitigated hepatic steatosis, necrosis, and fibrotic septa. Catalpol decreased the serum levels of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase and bilirubin as well as the liver/body weight ratio. Masson and sirius red staining along with hydroxyproline detection showed that catalpol decreased collagen deposition significantly compared to that of the model group. Catalpol inhibited CCl₄-induced liver fibrosis, manifested as decreased expressions of α-SMA, fibronectin and α1(I)-procollagen at both transcriptional and translational levels. Inflammatory factors, such as IL-1β, TNF-α, IL-18, IL-6 and COX-2, were significantly elevated in rats receiving CCl₄ and down-regulated by catalpol in a dose-dependent manner in vivo. Western blot and immunofluorescence assay revealed that catalpol activated the autophagy of rats with CCl₄-caused liver fibrosis, as indicated by up-regulation of LC3-II and beclin1 and down-regulation of P62. The results of in vitro experiments were consistent. Interestingly, inhibition or depletion of autophagy by LY294002 or Atg5 siRNA significantly attenuated catalpol-induced anti-inflammatory effects on activated hepatic stellate cells in vitro. In conclusion, catalpol relieved liver fibrosis mainly by inhibiting inflammation, and autophagy inhibition attenuated the catalpol-induced anti-inflammatory effect on liver fibrosis.

The Flavonoid Quercetin Ameliorates Liver Inflammation and Fibrosis by Regulating Hepatic Macrophages Activation and Polarization in Mice

At present, there are no effective antifibrotic drugs for patients with chronic liver disease; hence, the development of antifibrotic therapies is urgently needed. Here, we performed an experimental and translational study to investigate the potential and underlying mechanism of quercetin treatment in liver fibrosis, mainly focusing on the impact of quercetin on macrophages activation and polarization. BALB/c mice were induced liver fibrosis by carbon tetrachloride (CCl₄) for 8 weeks and concomitantly treated with quercetin (50 mg/kg) or vehicle by daily gavage. Liver inflammation, fibrosis, and hepatic stellate cells (HSCs) activation were examined. Moreover, massive macrophages accumulation, M1 macrophages and their related markers, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and monocyte chemotactic protein-1 (MCP-1) in livers were analyzed. In vitro, we used Raw 264.7 cells to examine the effect of quercetin on M1-polarized macrophages activation. Our results showed that quercetin dramatically ameliorated liver inflammation, fibrosis, and inhibited HSCs activation. These results were attributed to the reductive recruitment of macrophages (F4/80⁺ and CD68⁺) into the liver in quercetin-treated fibrotic mice confirmed by immunostaining and expression levels of marker molecules. Importantly, quercetin strongly inhibited M1 polarization and M1-related inflammatory cytokines in fibrotic livers when compared with vehicle-treated mice. In vitro, studies further revealed that quercetin efficiently inhibited macrophages activation and M1 polarization, as well as decreased the mRNA expression of M1 macrophage markers such as TNF-α, IL-1β, IL-6, and nitric oxide synthase 2. Mechanistically, the inhibition of M1 macrophages by quercetin was associated with the decreased levels of Notch1 expression on macrophages both in vivo and in vitro. Taken together, our data indicated that quercetin attenuated CCl₄-induced liver inflammation and fibrosis in mice through inhibiting macrophages infiltration and modulating M1 macrophages polarization via targeting Notch1 pathway. Hence, quercetin holds promise as potential therapeutic agent for human fibrotic liver disease.

Synergistic Anti-tumour Effects of Quercetin and Oncolytic Adenovirus expressing TRAIL in Human Hepatocellular Carcinoma

The combination of oncolytic adenoviruses and specific chemotherapy agents is fast emerging as a novel therapeutic approach for resistan the patocellular carcinoma (HCC) cells. A detailed analysis of the network between adenovirus and chemotherapeutic agents can help design an effective strategy to combat HCC. We sought to investigate whether a combined treatment of ZD55-TRAIL and quercetin can have an enhanced cell-killing effect on HCC cells. In-vitro experiments showed that quercetin can enhance ZD55-TRAIL mediated growth inhibition and apoptosis in HCC cells. In addition, we showed that quercetin reduced ZD55-TRAIL mediated NF-κB activation and down-regulated its downstream targets, which in turn promoted the pro-apoptotic action of ZD55-TRAIL. Furthermore, in-vivo experiments in mice injected with HuH-7 cells resulted in significantly greater reduction in tumour growth and volume following combined ZD55-TRAIL and quercetin treatment. In conclusion, we demonstrated that quercetin could sensitize human HCC cells to apoptosis via ZD55-TRAIL in-vitro and in-vivo and presented ZD55-TRAIL and quercetin combination as a suitable anti-HCC therapy.

HMGB1 mediates microglia activation via the TLR4/NF-κB pathway in coriaria lactone induced epilepsy

Epilepsy is a chronic and recurrent disease of the central nervous system, with a complex pathology. Recent studies have demonstrated that the activation of glial cells serve an important role in the development of epilepsy. The objective of the present study was to investigate the role of high‑mobility group box‑1 (HMGB1) in mediating the activation of glial cells through the toll‑like receptor 4 (TLR4)/nuclear factor (NF)‑κB signaling pathway in seizure, and the underlying mechanism. The brain tissue of post‑surgery patients with intractable epilepsy after resection and the normal control brain tissue of patients with craniocerebral trauma induced intracranial hypertension were collected. The expression level and distribution pattern of HMGB1, OX42 and NF‑κB p65 were detected by immunohistochemistry. HMGB1, TLR4, receptor for advanced glycation end products (RAGE), NF‑κB p65 and inducible nitric oxide synthase (iNOS) expression levels were detected by western blotting, and serum cytokine levels of interleukin (IL)‑1, IL‑6, tumor necrosis factor (TNF)‑α, transforming growth factor (TGF)‑β and IL‑10 in patients with epilepsy and craniocerebral trauma were detected by ELISA. And cell model of epilepsy was established by coriaria lactone (CL)‑stimulated HM cell, and the same factors were measured. The potential toxic effect of HMGB1 on HM cells was evaluated by MTT and 5‑ethynyl‑2‑deoxyuridine assays. The results demonstrated that compared with the control group, levels of HMGB1, TLR4, RAGE, NF‑κB p65 and iNOS in the brain of the epilepsy group were significantly increased, and increased cytokine levels of IL‑1, IL‑6, TNF‑α, TGF‑β and IL‑10 in patients with epilepsy were also observed. At the same time, the above results were also observed in HM cells stimulated with CL. Overexpression of HMGB1 enhanced the results, while HMGB1 small interfering RNA blocked the function of CL. There was no significant toxic effect of HMGB1 on HM cells. In conclusion, overexpression of HMGB1 potentially promoted epileptogenesis. CL‑induced activation of glial cells may act via up‑regulation of HMGB1 and TLR4/RAGE receptors, and the downstream transcription factor NF‑κB.

Carnosic Acid Alleviates BDL-Induced Liver Fibrosis through miR-29b-3p-Mediated Inhibition of the High-Mobility Group Box 1/Toll-Like Receptor 4 Signaling Pathway in Rats

Fibrosis reflects a progression to liver cancer or cirrhosis of the liver. Recent studies have shown that high-mobility group box-1 (HMGB1) plays a major role in hepatic injury and fibrosis. Carnosic acid (CA), a compound extracted from rosemary, has been reported to alleviate alcoholic and non-alcoholic fatty liver injury. CA can also alleviate renal fibrosis. We hypothesized that CA might exert anti-liver fibrosis properties through an HMGB1-related pathway, and the results of the present study showed that CA treatment significantly protected against hepatic fibrosis in a bile duct ligation (BDL) rat model. CA reduced the liver expression of α-smooth muscle actin (α-SMA) and collagen 1 (Col-1). Importantly, we found that CA ameliorated the increase in HMGB1 and Toll-like receptor 4 (TLR4) caused by BDL, and inhibited NF-κB p65 nuclear translocation in fibrotic livers. In vitro, CA inhibited LX2 cell activation by inhibiting HMGB1/TLR4 signaling pathway. Furthermore, miR-29b-3p decreased HMGB1 expression, and a dual-luciferase assay validated these results. Moreover, CA down-regulated HMGB1 and inhibited LX2 cell activation, and these effects were significantly counteracted by antago-miR-29b-3p, indicating that the CA-mediated inhibition of HMGB1 expression might be miR-29b-3p dependent. Collectively, the results demonstrate that a miR-29b-3p/HMGB1/TLR4/NF-κB signaling pathway, which can be modulated by CA, is important in liver fibrosis, and indicate that CA might be a prospective therapeutic drug for liver fibrosis.