Mistletoe alkaloid fractions alleviates carbon tetrachloride-induced liver fibrosis through inhibition of hepatic stellate cell activation via TGF-β/Smad interference

Harnessing nature's arsenal: Targeting the TGF-β/Smad Cascade with novel natural anti-fibrotic agents

BACKGROUND

Hepatic fibrosis is a wound healing response that leads to excessive deposition of extracellular matrix (ECM) due to sustained liver injury. Hepatic stellate cells (HSCs) are key players in ECM synthesis, with the TGF-β/Smad signaling pathway being central to their activation. Despite advances in understanding the pathogenesis of hepatic fibrosis, effective anti-fibrotic therapies are still lacking.

METHODS

This treatise conducts a comprehensive review of the literature on the hepatoprotective effects of natural products, including natural medicine compounds, herbal extracts, and polysaccharides. The focus is on their ability to modulate the TGF-β pathway, which is critical in the activation of HSCs and ECM synthesis in hepatic fibrosis.

RESULTS

The review identifies a variety of natural products that have shown promise in inhibiting the TGF-β/Smad signaling cascade, thereby reducing the activation of HSCs and ECM accumulation. These findings highlight the potential of these natural products as therapeutic agents in the treatment of hepatic fibrosis.

CONCLUSIONS

The exploration of natural products as modulators of the TGF-β pathway presents a novel avenue for both clinical and preclinical research into hepatic fibrosis. Further investigation is warranted to fully understand the mechanisms of action and to develop these compounds into effective anti-fibrotic pharmaceuticals.

The advancement of targeted regulation of hepatic stellate cells using traditional Chinese medicine for the treatment of liver fibrosis

ETHNOPHARMACOLOGICAL RELEVANCE

Liver fibrosis, which is a precursor to cirrhosis in chronic liver diseases, is driven by various factors. The activation and proliferation of hepatic stellate cells (HSCs) are recognized as a crucial phase in the progression of liver fibrosis. Compared with western drug therapy, Traditional Chinese medicine (TCM) and herbal medicine not only have the advantages of multi-target and multi-pathways in the treatment of liver fibrosis, but also have high safety without toxic side effects.

AIM OF THE REVIEW

This paper aims to compile and analyze the active ingredients in TCM and their corresponding signaling pathways that target and modulate the phenotype of hepatic stellate cells, offering a potential treatment for hepatic fibrosis.

METHODS

The Literature information was obtained from the scientific databases PubMed, Web of Science and CNKI from January 2010 to June 2020 with the aim of elucidating the intrinsic mechanisms and roles of TCM and natural medicine in the treatment of LF. The search terms included "liver fibrosis" or "hepatic fibrosis", "traditional Chinese medicine" or "Chinese herbal medicine", "medicinal plant", "natural plant", and "herb".

RESULTS

We described the antifibrosis activity of TCM and natural medicine in LF based on different signaling pathways. Plant medicine and herbal formulas regulated the related gene and protein expression via pathways such as TGF-β/Smad, PI3K/AKT/mTOR, MAPK and Wnt/β-catenin, which inhibit the proliferation, apoptosis, autophagy and activation of HSCs.

CONCLUSION

By reviewing both domestic and international literature on TCM interventions in liver fibrosis, this study presents a thorough evaluation of recent research progress and the challenges faced in the clinical application of TCM for this condition. The goal is to lay a solid foundation for further in-depth studies and to strengthen the theoretical framework in this field. The inhibitory effect of TCM and natural medicine on fibrosis was reflected in multiple levels and multiple pathways, providing reasonable evidence for new drug development. To make TCM and natural medicine widely and flexibly used in clinical practice, the efficacy, safety and mechanism of action need more in-depth experimental research. It also seeks to provide a theoretical foundation for future research on targeted therapies for liver fibrosis and related diseases.

Mangiferin for the Management of Liver Diseases: A Review

The liver is a digestive and metabolic organ, and several factors can induce liver damage, which is a severe threat to human health. As a natural polyphenolic compound, mangiferin belongs to xanthone glucoside and mainly exists in many plants, such as mango. It is notorious that mangiferin has remarkable pharmacological activities such as anti-inflammatory, anti-tumor, antioxidative stress, antiviral and so on. Emerging evidence indicates the therapeutic benefits of mangiferin against liver disease, including liver injury, nonalcoholic fatty liver disease, alcoholic liver disease, liver fibrosis, and hepatocellular carcinoma. This review aims to summarize the possible underlying signaling mediated by mangiferin in liver disease treatment and the available findings of mangiferin, which can be used to treat different liver diseases and may contribute to mangiferin as a therapeutic agent for liver disease in humans.

Jasminum humile (Linn) ameliorates CCl4-induced oxidative stress by regulating ER stress, inflammatory, and fibrosis markers in rats

Jasminum humile (Linn) is highly valued for its medicinal properties. The pulp and decoction made from its leaves are effective for skin diseases. Juice prepared from roots is used against ringworm illness. Our current study aims to illustrate the non-toxicity and protective potential of methanol extract of Jasminum humile (JHM) against CCl₄-induced oxidative stress in the liver of rats. Qualitative phytochemical screening, total flavonoids (TFC), and total phenolic content (TPC) assays were performed with JHM. The toxicity of the plant was estimated by treating female rats at different JHM doses while to assess anti-inflammatory potential of plant nine groups of male rats (six rats/group) received different treatments such as: CCl₄ only (1 ml/kg mixed with olive oil in a ratio of 3:7), silymarin (200 mg/kg) + CCl₄, different doses of JHM alone at a ratio of 1:2:4, and JHM (at a ratio of 1:2:4) + CCl₄, and were examined for different antioxidant enzymes, serum markers, and histological changes, while mRNA expression of stress, inflammatory and fibrosis markers were assessed by real-time polymerase chain reaction analysis. Different phytochemicals were found in JHM. A high amount of total phenolic and flavonoid content was found (89.71 ± 2.79 mg RE/g and 124.77 ± 2.41 mg GAE/g) in the methanolic extract of the plant. Non-toxicity of JHM was revealed even at higher doses of JHM. Normal levels of serum markers in blood serum and antioxidant enzymes in tissue homogenates were found after co-administration of JHM along with CCl₄. However, CCl₄ treatment caused oxidative stress in the liver by enhancing the levels of stress and inflammatory markers and reducing antioxidant enzyme levels, while JHM treatment showed significant (P < 0.05) downregulation was in mRNA expression of those markers. Investigation of mechanism of specific signaling pathways related to apoptosis and clinical trials to assess safety and efficacy of optimal dosage of Jasminum humile will be helpful to develop FDA-approved drug.

The Preventive and Therapeutic Potential of the Flavonoids in Liver Cirrhosis: Current and Future Perspectives

Non-alcoholic fatty liver disease (NAFLD) may vary from moderately mild non-alcohol fatty liver (NAFL) towards the malignant variant known as non-alcoholic steatohepatitis (NASH), which is marked by fatty liver inflammation and may progress to liver cirrhosis (LC), liver cancer, fibrosis, or liver failure. Flavonoids can protect the liver from toxins through their anti-inflammatory, antioxidant, anti-cancer, and antifibrogenic pharmacological activities. Furthermore, flavonoids protect against LC by regulation of hepatic stellate cells (HSCs) trans-differentiation, inhibiting growth factors like TGF-β and platelets-derived growth factor (PDGF), vascular epithelial growth factor (VEGF), viral infections like hepatitis-B, C and D viruses (HBV, HCV & HDV), autoimmune-induced, alcohol-induced, metabolic disorder-induced, causing by apoptosis, and regulating MAPK pathways. These flavonoids may be explored in the future as a therapeutic solution for hepatic diseases.

Combination therapy based on targeted nano drug co-delivery systems for liver fibrosis treatment: A review

Liver fibrosis is the hallmark of liver disease and occurs prior to the stages of cirrhosis and hepatocellular carcinoma. Any type of liver damage or inflammation can result in fibrosis. Fibrosis does not develop overnight, but rather as a result of the long-term action of injury factors. At present, however, there are no good treatment methods or specific drugs other than removing the pathogenic factors. Drug application is still limited, which means that drugs with good performance in vitro cannot achieve good therapeutic effects in vivo, owing to various factors such as poor drug targeting, large side effects, and strong hydrophobicity. Hepatic stellate cells (HSC) are the primary effector cells in liver fibrosis. The nano-drug delivery system is a new and safe drug delivery system that has many advantages which are widely used in the field of liver fibrosis. Drug resistance and side effects can be reduced when two or more drugs are used in combination drug delivery. Combination therapy of drugs with different targets has emerged as a novel approach to treating liver fibrosis, and the nano co-delivery system enhances the benefits of combination therapy. While nano co-delivery systems can maximize benefits while avoiding drug side effects, this is precisely the advantage of the nano co-delivery system. This review briefly described the pathogenesis and current treatment strategies, the different co-delivery systems of combination drugs in the nano delivery system, and targeting strategies for nano delivery systems on liver fibrosis therapy. Because of their superior performance, nano delivery systems and targeting drug delivery systems have received a lot of attention in the new drug delivery system. The new delivery systems offer a new pathway in the treatment of liver fibrosis, and it is believed that it can be a new treatment for fibrosis in the future. Nano co-delivery system of combination drugs and targeting strategies has proven the effectiveness of anti-fibrosis at the experimental level.

Exploring the resources of the genus Viscum for potential therapeutic applications

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Viscum comprises approximately 100 species that are mainly distributed across Africa, Asia and Europe. The extracts and preparations of Viscum species are widely used as common complementary and alternative medicines in the treatment of rheumatism and cancer.

AIM OF THE REVIEW

This review aims to explore the medicinal properties of twelve species belonging to the genus Viscum for potential therapeutic applications.

MATERIALS AND METHODS

We collected online information (including PubMed, CNKI, Google Scholar, and Web of Science) from January 1915 to April 2021 and knowledge from classical books on Chinese herbal medicines available for 12 species of the genus Viscum, including Viscum coloratum (Kom.) Nakai, Viscum album L., Viscum articulatum Burm. f., Viscum liquidambaricola Hayata, Viscum ovalifolium DC., Viscum capitellatum Sm., Viscum cruciatum Sieber ex Boiss., Viscum nudum Danser, Viscum angulatum B.Heyne ex DC., Viscum tuberculatum A.Rich., Viscum multinerve Hayata, and Viscum diospyrosicola Hayata.

RESULTS

At least 250 different compounds have been reported across twelve Viscum species, including amino acid and peptides, alkaloids, phenolic acids, flavonoids, terpenoids, carbohydrates, fatty acids, lipids, and other types of compounds. In particular, for Viscum coloratum (Kom.) Nakai and Viscum album L., the plants, preparations, and bioactive components have been thoroughly reviewed. This has allowed to elucidate the role of active components, including lectins, viscotoxins, flavonoids, terpenoids, phenolic acids, and polysaccharides, in multiple bioactivities, such as anti-cancer, anti-rheumatism arthralgia, anti-inflammation, anti-cardiovascular diseases, enhancing immunity, and anti-chemotherapy side effects. We also evaluated quality control methods based on active compounds, in vivo exposure compounds, and discriminated chemical markers.

CONCLUSIONS

This is the first report to systematically review the pharmaceutical development history, chemical composition, clinical evidence, pharmacological activity, discriminated chemical markers, in vivo exposure, and quality control on twelve distinct species of Viscum plants with medicinal properties. The significant safety and efficacy, along with the minor side effects are constantly confirmed in clinics. The genus Viscum is thus an important medicinal resource that is worth exploring and developing in future pharmacological and chemical studies.

Pilea umbrosa ameliorate CCl4 induced hepatic injuries by regulating endoplasmic reticulum stress, pro-inflammatory and fibrosis genes in rat

BACKGROUND

Pilea umbrosa (Urticaceae) is used by local communities (district Abbotabad) for liver disorders, as anticancer, in rheumatism and in skin disorders.

METHODS

Methanol extract of P. umbrosa (PUM) was investigated for the presence of polyphenolic constituents by HPLC-DAD analysis. PUM (150 mg/kg and 300 mg/kg) was administered on alternate days for eight weeks in rats exposed with carbon tetrachloride (CCl4). Serum analysis was performed for liver function tests while in liver tissues level of antioxidant enzymes and biochemical markers were also studied. In addition, semi quantitative estimation of antioxidant genes, endoplasmic reticulum (ER) induced stress markers, pro-inflammatory cytokines and fibrosis related genes were carried out on liver tissues by RT-PCR analysis. Liver tissues were also studied for histopathological injuries.

RESULTS

Level of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD), peroxidase (POD) and glutathione (GSH) decreased (p < 0.05) whereas level of thiobarbituric acid reactive substance (TBARS), H2O2 and nitrite increased in liver tissues of CCl4 treated rat. Likewise increase in the level of serum markers; alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP) and total bilirubin was observed. Moreover, CCl4 caused many fold increase in expression of ER stress markers; glucose regulated protein (GRP-78), x-box binding protein1-total (XBP-1 t), x-box binding protein1-unspliced (XBP-1 u) and x-box binding protein1-spliced (XBP-1 s). The level of inflammatory mediators such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) was aggregated whereas suppressed the level of antioxidant enzymes; γ-glutamylcysteine ligase (GCLC), protein disulfide isomerase (PDI) and nuclear erythroid 2 p45-related factor 2 (Nrf-2). Additionally, level of fibrosis markers; transforming growth factor-β (TGF-β), Smad-3 and collagen type 1 (Col1-α) increased with CCl4 induced liver toxicity. Histopathological scrutiny depicted damaged liver cells, neutrophils infiltration and dilated sinusoids in CCl4 intoxicated rats. PUM was enriched with rutin, catechin, caffeic acid and apigenin as evidenced by HPLC analysis. Simultaneous administration of PUM and CCl4 in rats retrieved the normal expression of these markers and prevented hepatic injuries.

CONCLUSION

Collectively these results suggest that PUM constituted of strong antioxidant chemicals and could be a potential therapeutic agent for stress related liver disorders.

Activation of Nrf2/AREs-mediated antioxidant signalling, and suppression of profibrotic TGF-β1/Smad3 pathway: a promising therapeutic strategy for hepatic fibrosis - A review

Hepatic fibrosis (HF) is a wound-healing response that occurs during chronic liver injury and features by an excessive accumulation of extracellular matrix (ECM) components. Activation of hepatic stellate cell (HSC), the leading effector in HF, is responsible for overproduction of ECM. It has been documented that transforming growth factor-β1 (TGF-β1) stimulates superfluous accumulation of ECM and triggers HSCs activation mainly via canonical Smad-dependent pathway. Also, the pro-fibrogenic TGF-β1 is correlated with generation of reactive oxygen species (ROS) and inhibition of antioxidant mechanisms. Moreover, involvement of oxidative stress (OS) can be clearly elucidated as a fundamental event in liver fibrogenesis. Nuclear factor erythroid 2-related factor 2-antioxidant response elements (Nrf2-AREs) pathway, a group of OS-mediated transcription factors with diverse downstream targets, is associated with the induction of diverse detoxifying enzymes and the most pivotal endogenous antioxidative system. More specifically, Nrf2-AREs pathway has recently assigned as a new therapeutic target for cure of HF. The overall goal of this review will focus on recent findings about activation of Nrf2-AREs-mediated antioxidant and suppression of profibrotic TGF-β1/Smad3 pathway in the liver, providing an overview of recent advances in transcriptional repressors that dislocated during HF formation, and highlighting possible novel therapeutic targets for liver fibrosis.

Biological activity of mistletoe: in vitro and in vivo studies and mechanisms of action

Mistletoe has been used as treatment of many diseases in traditional and folk medicine. To date, anticancer, immunomodulatory, cardiac, antidiabetic, hepatoprotective, neuropharmacological, antibacterial and antifungal properties of mistletoe extracts have been studied the most. In this review, we summarized in vitro and in vivo studies on the pharmacological activity of Viscum species. Furthermore, we proposed the possible mechanisms of action of this herb, which might include many signalling pathways. Mistletoe could regulate either similar or different targets in various pathways that act on membrane receptors, enzymes, ion channels, transporter proteins and transcriptional targets. Still, pharmacological activities of mistletoe have been investigated mainly for crude extracts. It is a new field for scientists to determined which chemical compounds are responsible for the individual biological activities of mistletoe and how these activities are achieved. As a result, mistletoe might become a source of new complementary therapies supporting the treatment of many diseases.

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

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

miR-219-3p regulates the occurrence of hepatic fibrosis by targeting Smad2

Abnormal expression of microRNA (miR)-219-3p has been widely identified in different tumors. However, whether miR-219-3p is involved in the progression of hepatic fibrosis (HF) has never been explored. The present study showed that compared with healthy controls, the levels of miR-291-3p in peripheral blood were decreased in patients with HF. Furthermore, much lower levels of miR-291-3p were identified in fibrotic liver tissues compared with that of normal liver tissues. Receiver operating characteristic curve analysis showed that the levels of miR-291-3p in peripheral blood may screen patients with HF from healthy controls. Reverse transcription quantitative polymerase chain reaction analysis showed that overexpression of miR-291-3p significantly suppressed the mRNA levels of Snai1, vascular endothelial-specific cadherin (VE-cadherin), Vimentin, transforming growth factor (TGF)-β1, and glial fibrillary acidic protein (GFAP). The protein levels of Snai1, VE-cadherin, Vimentin, TGF-β1, and GFAP were also decreased in hepatic stellate cells transfected with miR-291-3p mimics. Further study indicated that mothers against decapentaplegic homolog 2 (Smad2) was a target gene of miR-291-3p. More importantly, silencing of Smad2 could abolish miR-291-3p inhibition-induced TGF-β1 signaling activation. In summary, reduced peripheral blood miR-291-3p may be involved in the progression of HF via targeting Smad2.

Regulation of CCl4-induced liver cirrhosis by hepatically differentiated human dental pulp stem cells

Liver transplantation is the most effective treatment for treating liver cirrhosis. However, a limited number of donors, graft rejection, and other complications can undermine transplant success. It is considered that cell transplantation is an alternative approach of liver transplantation. We previously developed a protocol for hepatic differentiation of cluster of differentiation 117+ stem cells isolated from human exfoliated deciduous tooth pulp (SHEDs) under hydrogen sulfide exposure. These cells showed excellent hepatic function. Here, we investigated whether hepatocyte-like cell transplantation is effective for treating carbon tetrachloride (CCl₄)-induced liver cirrhosis. SHEDs were hepatically differentiated, which was confirmed via immunological analyses and albumin concentration determination in the medium. Rats were intraperitoneally injected with CCl₄ for and the differentiated cells were injected into rat spleen. Histopathological and immunohistochemical analyses were performed. Liver functions were serologically and pathologically determined. Quantitative real-time-polymerase chain reaction was implemented to clarify the treatment procedure of liver cirrhosis. In vitro-differentiated hepatocyte-like cells were positive for all examined hepatic markers. SHED-derived hepatocyte transplantation eliminated liver fibrosis and restored liver structure in rats. Liver immunohistochemical analyses showed the presence of human-specific hepatic markers, i.e., a large amount of human hepatic cells were very active in the liver and spleen. Serological tests revealed significant liver function recovery in the transplantation group. Expression of genes promoting fibrosis increased after cirrhosis induction but was suppressed after transplantation. Our results suggest that xenotransplantation of hepatocyte-like cells of human origin can treat cirrhosis. Moreover, cell-based therapy of chronic liver conditions may be an effective option.

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

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

Semen Brassicae ameliorates hepatic fibrosis by regulating transforming growth factor-β1/Smad, nuclear factor-κB, and AKT signaling pathways in rats

Purpose

There is no effective treatment for liver fibrosis, which is a common phase during the progression of many chronic liver diseases to cirrhosis. Previous studies found that Semen Brassicae therapy can effectively improve the clinical symptoms of patients with asthma, allergic rhinitis, and chronic lung diseases; however, its effects on liver fibrosis in rats and its possible mechanisms of action remain unclear.

Methods

Rats were injected intraperitoneally with 4% thioacetamide aqueous solution (5 mL·kg⁻¹) at a dose of 200 mg·kg⁻¹ twice a week for 8 consecutive weeks to establish the liver fibrosis model and were then treated with different concentrations of Semen Brassicae extract. After Semen Brassicae treatment, the morphology of the liver tissue was analyzed using hematoxylin and eosin and Masson’s trichrome staining, and liver index and liver fibrosis grade were calculated. Thereafter, the levels of collagen-I, collagen-III, α-SMA, transforming growth factor (TGF)-β1, p-Smad 2/3, Smad 2/3, Smad4, NF-κB-p65, p-NF-κB-p65, IL-1β, IL-6, AKT, and p-AKT were determined using Western blotting.

Results

Compared with the untreated model group, the Semen Brassicae-treated group showed significantly decreased liver function indices; expression levels of collagen-I, collagen-III, and α-SMA; and hepatic fibrosis. Further studies also showed that the expression of TGF-β1, Smad4, p-Smad 2/3/Smad 2/3, p-NF-κB-p65/NF-κB-p65, IL-1β, IL-6, and p-AKT/AKT significantly decreased after the treatment.

Conclusion

These results indicate that Semen Brassicae exhibits an anti-hepatic fibrosis effect, and the underlying mechanism of action may be related to the regulation of TGF-β1/Smad, NF-κB, and AKT signaling pathways and the reduction of extracellular matrix deposition.

MicroRNA-21-5p mediates TGF-β-regulated fibrogenic activation of spinal fibroblasts and the formation of fibrotic scars after spinal cord injury

Little regeneration of transected axons occurs after the damage caused by traumatic spinal cord injury (SCI), and unidirectional and irreversible fibrotic scars are thought to be the main chemical and physical obstacle for axonal regrowth in SCI pathology. We previously demonstrated that microRNA (miR)-21-5p and transforming growth factor (TGF)-β1, a central pathological mediator of fibrotic diseases, were significantly up-regulated in the lesion epicenter after SCI. Here, we found that TGF-β1 enhanced miR-21-5p expression in primary spinal fibroblasts, and regulated the expression of fibrosis-related genes. The overexpression of miR-21-5p promoted the pro-fibrogenic activity of TGF-β1 in spinal fibroblasts, while miR-21-5p knockdown attenuated this activity. We identified Smad7 as a target gene of miR-21-5p, suggesting a potential mechanism for the role of miR-21-5p in spinal fibrosis through regulating Smad7 expression. Furthermore, miR-21-5p knockdown in a mouse model significantly improved motor functional recovery after spinal cord injury. These data demonstrate that miR-21-5p functions in an amplifying circuit to enhance TGF-β signaling events in the activation of spinal fibroblasts and suggest that miR-21-5p is a potential therapeutic target in the treatment of fibrotic scar formation after SCI.

Mistletoe (Viscum album) extract targets Axl to suppress cell proliferation and overcome cisplatin- and erlotinib-resistance in non-small cell lung cancer cells

BACKGROUND

Mistletoe extract of Visucm album extract (VAE) contains many biologically active components and has been reported to be not only a complementary and alternative medicine, but also a potent therapeutic agent for many types of cancer.

PURPOSE

In this study, we examined the effect of VAE on expression and activation of Axl and scrutinized the involvement of Axl in the anti-cancer activity of VAE in parental and chemo-resistant non-small cell lung cancer (NSCLC) cells.

METHODS

The levels of Axl protein and mRNA were determined by Western blot analysis and RT-PCR, respectively. Phosphorylation of Axl upon Gas6 stimulation was observed by Western blot analysis. For ectopic expression or gene silencing of Axl, the recombinant plasmid, pcDNA3-Axl, or specific siRNA targeting Axl were transfected into A549 and H460 cells using Lipofectamine 2000, respectively. The anti-cancer activity of mistletoe extract was examined against the parental cells and each of their cisplatin- or erlotinib-resistant cells using trypan blue exclusion assays and colony formation assay.

RESULTS

The levels of Axl mRNA were also reduced by VAE treatment, implying the transcriptional downregulation of Axl expression by VAE. In addition, the phosphorylation of Axl protein upon its ligand, Gas6, stimulation was found to be abrogated by VAE. We next found cytotoxic effect of VAE on both the parental NSCLC cells and their variants which are resistant to cisplatin (A549/CisR and H460/CisR) or erlotinib (H460/ER and H1975/ER). Treatment of these cells with VAE caused a dose-dependent decrease of cell viability and clonogenicity. This anti-proliferative effect of VAE was attenuated in Axl-overexpressing cells, while it was augmented in cells transfected Axl specific siRNA. Next, we also found that in cisplatin-resistant cells and erlotinib-resistant cells, VAE treatment decreased Axl protein level, colonogenicity. The levels of several cell cycle regulator, p21 and apoptosis related protein, X-linked inhibitor of apoptosis, was found to be induced and reduced by VAE treatment, respectively.

CONCLUSION

Taken together, our data provide that VAE targets Axl to suppress cell proliferation and to circumvent cisplatin- and erlotinib-resistance in NSCLC cells.

肝纤维化逆转机制的研究进展及治疗概况

肝纤维化是肝脏对慢性损伤的一种修复反应, 多是持续性肝脏损伤或纤维化刺激因子刺激产生的共有病理改变, 是一项严重的全球性健康难题. 近年来临床研究发现, 由病毒性肝炎造成肝纤维化或肝硬化的患者, 在成功接受病毒性肝炎治疗后, 其肝纤维化甚至肝硬化发生了逆转现象. 因此研究和了解肝纤维化逆转的机制有利于发现新的针对肝纤维化的治疗靶向. 本文就近年来有关肝纤维化逆转机制的研究以及治疗概况作一综述, 以期为肝纤维化的研究提供帮助.

The inhibition of microRNA-15a suppresses hepatitis B virus-associated liver cancer cell growth through the Smad/TGF-β pathway

In the present study, the role of microRNA‑15a (miR‑15a) was investigated in hepatitis B virus (HBV)‑associated liver cancer. The results revealed that the expression levels of miR-15a were increased in HBV-associated liver cancer tissues compared with the levels in normal tumor‑adjacent tissues. Moreover, Smad-7 protein expression in patients with HBV-associated liver cancer was higher than that in normal tumor-adjacent tissues. In addition, miR-15a expression and Smad-7 protein expression were increased in HepG2 hepatocellular carcinoma cells compared with that noted in L-02 normal hepatocytes. In HepG2 cells, miR-15a inhibition suppressed cell proliferation and increased Smad-7 protein expression. The inhibition of miR-15a was also demonstrated to decrease transforming growth factor (TGF)-β1 protein expression and Smad-2, p-Smad-2 and Smad-4 expression levels in HepG2 cells. Furthermore, FSP1 protein expression and caspase-3/-7 activities were enhanced by miR-15a inhibition in HepG2 cells compared with the control group. Treatment with recombinant TGF-β1 was demonstrated to activate Smad‑2/-4 and FSP1 protein expression and increase caspase-3/-7 activity in HepG2 cells. Collectively, these findings demonstrate that the miR-15a/Smad-7/TGF-β pathway is important in HBV-associated liver cancer.

Caffeic acid phenethyl ester attenuates liver fibrosis via inhibition of TGF-β1/Smad3 pathway and induction of autophagy pathway

Caffeic acid phenethyl ester (CAPE) has been reported to possess the hepatoprotective effect. This study was to investigate the mechanism underlying CAPE against liver fibrosis in a liver fibrosis model induced by toxic carbon tetrachloride (CCl4) in male Sprague-Dawley rats and in vitro in CAPE (5 μM, 10 μM, 15 μM) treated hepatic stellate cells (HSC-T6). We found that CAPE treatment remarkably attenuated CCl4-induced liver fibrosis by blocking the activation of HSCs as determined by the expression alternation of transforming growth factor (TGF)-β1, phosphorylated Smad3 (p-Smad3), collage I, α-smooth muscle actin (α-SMA), matrix metalloproteinases (MMPs) 2, tissue inhibitor of matrix metalloproteinases (TIMPs) 1. The hepatoprotective effects of CAPE were also associated with upregulation of autophasomes in HSCs as determined by transmission electron microscopy (TEM) detection. The in vitro study further confrimed that CAPE attenuated liver fibrogenesis via inducing authophagic markers including LC3, ATG5, Beclin 1 expressions, while inhibiting AKT/mTOR signaling in HSC-T6 cells. Thus, the protective effects of CAPE against liver fibrosis might due to the inhibition of TGF-β1/Smad3 signaling and induction of authophagy in HSCs.

Metabolomic mechanisms of gypenoside against liver fibrosis in rats: An integrative analysis of proteomics and metabolomics data

Aims

To investigate mechanisms and altered pathways of gypenoside against carbon tetrachloride (CCl₄)-induced liver fibrosis based on integrative analysis of proteomics and metabolomics data.

Methods

CCl₄-induced liver fibrosis rats were administrated gypenoside. The anti-fibrosis effects were evaluated by histomorphology and liver hydroxyproline (Hyp) content. Protein profiling and metabolite profiling of rats liver tissues were examined by isobaric tags for relative and absolute quantitation (iTRAQ) approach and gas chromatography-mass spectrometer (GC-MS) technology. Altered pathways and pivotal proteins and metabolites were searched by integrative analysis of proteomics and metabolomics data. The levels of some key proteins in altered pathways were determined by western blot.

Results

Histopathological changes and Hyp content in gypenoside group had significant improvements (P<0.05). Compared to liver fibrosis model group, we found 301 up-regulated and 296 down-regulated proteins, and 9 up-regulated and 8 down-regulated metabolites in gypenoside group. According to integrative analysis, some important pathways were found, including glycolysis or gluconeogenesis, fructose and mannose metabolism, glycine, serine and threonine metabolism, lysine degradation, arginine and proline metabolism, glutathione metabolism, and sulfur metabolism. Furthermore, the levels of ALDH1B1, ALDH2 and ALDH7A1 were found increased and restored to normal levels after gypenoside treated (P<0.05).

Conclusions

Gypenoside inhibited CCl₄-induced liver fibrosis, which may be involved in the alteration of glycolysis metabolism and the protection against the damage of aldehydes and lipid peroxidation by up-regulating ALDH.

MicroRNAs regulate hepatic fibrosis via TGF-β/Smad pathway

Studies have shown that transforming growth factor-β (TGF-β) is one of the most important factors to promote hepatic fibrosis (HF), and the TGF-β/Smad pathway is a major signaling pathway involved in HF. Abnormal expression of microRNAs (miRNAs) has a key role in the development of HF. In recent years, studies suggest that regulating miRNAs may affect the TGF-β/Smad pathway. This paper discusses the TGF-β/Smad pathway and the related miRNAs that are associated with HF.

MircoRNA-145 promotes activation of hepatic stellate cells via targeting krüppel-like factor 4

Krüppel-like Factor 4 (KLF4), a target gene of miR-145, can negatively regulate lung fibrosis. However, the potential role of KLF4 and miR-145 in hepatic stellate cells (HSCs) activation or in hepatic fibrosis keeps unclear. This study aims to characterize miR-145 and KLF4 in activated HSCs and liver cirrhotic, and the underlying molecular basis. miR-145 was significantly up-regulated, while KLF4 was dramatically down-regulated during the activation of rat primary HSCs and TGF-βtreated HSCs. Furthermore, miR-145 mimics induced and inhibition of miR-145 reduced α-SMA and COL-I expression in primary HSCs. Additionally, the mRNA and protein levels of KLF4 in the liver of cirrhotic patients and rats were significantly down-regulated. α-SMA and COL-I were increased after inhibition of KLF4 by specific shRNA in primary HSCs. Forced KLF4 expression led to a reduction of α-SMA and COL-I expression in HSCs. miR-145 promotes HSC activation and liver fibrosis by targeting KLF4.

Huangqi decoction alleviates dimethylnitrosamine-induced liver fibrosis: An analysis of bile acids metabolic mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Huangqi Decoction (HQD), a classical traditional Chinese medicine (TCM) formula, is used to treating liver injury in China. The aim of the study is to investigate mechanisms of HQD against dimethylnitrosamine (DMN)-induced liver fibrosis underlying metabolic profiles of bile acids.

MATERIALS AND METHODS

DMN-induced liver fibrosis rats were administrated HQD and its compounds, astragalosides (AS), glycyrrhizic acid (GA) and their combination. The anti-fibrosis effects were evaluated and targeted metabolomics by UPLC-MS was used to examine whether HQD had an influence on bile acid metabolism. The levels of mRNAs associated with bile acid metabolism were expressed by RT-PCR. Chenodeoxycholic acid (CDCA)-induced hepatic stellate cells (HSCs) proliferation and activation were examined using MTS assay and Western blot.

RESULTS

Histopathological changes and serum liver function in HQD group had significant improvements (P<0.01). Concentrations of free bile acids and taurine conjugates were significantly increased in DMN group (P<0.05). HQD and its compounds restored the increased bile acids to normal levels, and HQD was more effected on parts of bile acids. Furthermore, the levels of mRNAs related bile acid synthesis and reabsorption such as CYP7A1, CYP8B1, CYP27A1, OATP2, OATP3, OATP4 and NTCP were significantly down-regulated in DMN group (P<0.05), mRNAs related excretion such as MRP3 and BESP were up-regulated (P<0.01), and CYP7A1, CYP8B1, OATP3, OATP4, NTCP and MRP3 restored to normal levels by HQD treatment. Moreover, CDCA-induced HSCs proliferation and activation were weaken by HQD (P<0.05) with down-regulated α-SMA, TGF-β1, p-Smad2 and p-Smad3 expressions.

CONCLUSIONS

HQD alleviated DMN-induced liver fibrosis with a better effect than its compounds, which may be involved in the regulation of bile acid metabolism enzyme. Moreover, HQD may inhibit CDCA-induced HSCs proliferation and activation.

Phenylethanol Glycosides from Cistanche tubulosa Suppress Hepatic Stellate Cell Activation and Block the Conduction of Signaling Pathways in TGF-β1/smad as Potential Anti-Hepatic Fibrosis Agents

Cistanche tubulosa is a traditional Chinese herbal medicine widely used for regulating immunity and phenylethanol glycosides (CPhGs) are among the primary components responsible for this activity. Previous studies have indicated the preventive and therapeutic effects of CPhGs on bovine serum albumin (BSA)-induced hepatic fibrosis in rats. The aim of the study was to evaluate the anti-hepatic fibrosis effect of CPhGs and the monomers echinacoside and acteoside by inhibiting hepatic stellate cell (HSC) activation, blocking the conduction of signaling pathways in transforming growth factor-β1 (TGF-β1)/smad, and determine their in vitro hepatoprotective activity. HSC proliferation was obviously inhibited after treatment with CPhGs (100, 50 μg/mL)/echinacoside (500, 250, 125 μg/mL)/acteoside (6, 3 μg/mL), with IC50 values of 119.125, 520.345 and 6.999 μg/mL, respectively, in the MTT assay. Different concentrations of CPhGs/echinacoside/acteoside did not affect the cellular toxicity on HSC according to lactate dehydrogenase (LDH) measurements. Different concentrations of CPhGs/echinacoside/acteoside increased the mRNA level and protein expression of smad7, and decreased the mRNA levels of smad2, smad3 and the protein expression of smad2, phospho-smad2 (p-smad2), smad3, phospho-smad3 (p-smad3) in HSC. In summary, these results demonstrate that CPhGs/echinacoside/acteoside can block the conduction of the signaling pathways in TGF-β1/smad, and inhibit the activation of HSC, suggesting that C. tubulosa may thus be a potential herbal medicine for the treatment of liver fibrosis.

Plumbagin Ameliorates CCl 4 -Induced Hepatic Fibrosis in Rats via the Epidermal Growth Factor Receptor Signaling Pathway

Epidermal growth factor (EGF) and its signaling molecules, EGFreceptor (EGFR) and signal transducer and activator of transcription factor 3 (STAT3), have been considered to play a role in liver fibrosis and cirrhosis. Plumbagin (PL) is an extracted component from the plant and has been used to treat different kinds of cancer. However, its role in regulation of EGFR and STAT3 during liver fibrosis has not been investigated. In this study, the effects of PL on the regulation of EGFR and STAT3 were investigated in carbon tetrachloride (CCl4) induced liver fibrosis and hepatic stellate cells (HSC-T6). PL significantly attenuated liver injury and fibrosis in CCl4 treated rats. At concentrations of 2 to 6 μM, PL did not induce significant cytotoxicity of HSC-T6 cells. Moreover, PL reduced phosphorylation of EGFR and STAT3 in both fibrotic liver and heparin-binding EGF-like growth factor (HB-EGF) treated HSC-T6 cells. Furthermore, PL reduced the expression of α-SMA, EGFR, and STAT3 in both fibrotic liver and HB-EGF treated HSC-T6 cells. In conclusion, plumbagin could ameliorate the development of hepatic fibrosis through its downregulation of EGFR and STAT3 in the liver, especially in hepatic stellate cells.

Xia-yu-xue decoction (XYXD) reduces carbon tetrachloride (CCl4)-induced liver fibrosis through inhibition hepatic stellate cell activation by targeting NF-κB and TGF-β1 signaling pathways

Background

Hepatic stellate cell (HSC) activation is activated mainly by endotoxin and transforming growth factor (TGF-β1) in chronic liver injury, consequently, can be important therapeutic targets. Xia-yu-xue decoction (XYXD), a classical recipe used in China to treat liver fibrosis, and has been revealed to inhibit hepatic fibrosis in animal models, the mechanism of action of XYXD remains elusive. In the present study, we evaluated whether XYXD reduced endotoxin and pro-fibrogenic pathways induced by lipopolysaccharide (LPS) and TGF-β1 in HSCs.

Methods

The in vivo effect of XYXD on fibrosis progression was assessed in mice model induced by carbon tetrachloride (CCl₄), The in vitro effect of XYXD on mice GFP-Col-HSC cells was evaluated using LPS and TGF-β1 stimulation.

Results

XYXD treatment reduced CCl₄-induced liver fibrosis and decreased hepatic hydroxyproline (Hyp) content, the mRNA levels of smooth muscle actin (α-SMA) and Col 1(α1) in fibrotic liver. XYXD suppressed nuclear factor-κB (NF-κB) activation induced by LPS and TGF-β1 assessed by using NF-κB-luciferase reporter. The expression of NF-κB target genes, chemokine (C-C motif) ligand 2 (CCL2) and chemokine (C-X-C motif) ligand 2 (CXCL2) induced by LPS was suppressed after XYXD treatment. The expression of TGF-β1 targets genes, Col1(α1) and tissue inhibitor of metalloproteinases (TIMP1) induced by TGF-β1 was inhibit after XYXD treatment.

Conclusion

XYXD treatment attenuates liver fibrosis by inhibiting HSC activation via inhibition of NF-κB and TGF-β1 signaling pathway, thereby blocking the synthesis of Col1 (α1) and TIMP-1. These findings from present study suggest that XYXD may be a therapeutic decoction for liver fibrosis in which NF-κB and TGF-β1 are thought to take part.