Silymarin decreases connective tissue growth factor to improve liver fibrosis in rats treated with carbon tetrachloride

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.

Silymarin ameliorates peritoneal fibrosis by inhibiting the TGF-β/Smad signaling pathway

Peritoneal dialysis (PD) is the mainstay of treatment for renal failure replacement therapy. Although PD has greatly improved the quality of life of end-stage renal disease (ESRD) patients, long-term PD can lead to ultrafiltration failure, which in turn causes peritoneal fibrosis (PF). Silymarin (SM) is a polyphenolic flavonoid isolated from the milk thistle (Silybum marianum) species that has a variety of pharmacological actions, including antioxidant, anti-inflammatory, antiviral, and anti-fibrotic pharmacological activities. However, the effect of SM on PF and its potential mechanisms have not been clarified. The aim of this study was to investigate the preventive effect of SM on PF in vitro and in vivo as well as elucidate the underlying mechanisms. We established PF mouse models and human pleural mesothelial cell fibrosis in vitro by intraperitoneal injection of high-glucose peritoneal dialysis solution (PDS) or transforming growth factor-β1 (TGF-β1), and evaluated the effect of SM on peritoneal fibrosis in vivo and in vitro. We found that SM alleviated peritoneal dysfunction. Meanwhile, SM inhibited the expression of fibrotic markers (TGF-β1, collagen I, fibronectin) and restored the expression of E-cadherin, BMP-7 in PF mice and TGF-β1-treated Met-5A cells. Furthermore, SM markedly down-regulated the expression of TGF-β1, p-Smad2, and p-Smad3 and up-regulated the expression of smad7. In conclusion, these findings suggested that SM may be an efficient and novel therapy for the prevention of PF through inhibition of TGF-β/Smad signaling.

Promising hepatoprotective agents from the natural sources: a study of scientific evidence

Background

Natural bioactive components derived from plant secondary metabolites have been pronounced as valuable alternatives for anticipating and subsiding hepatotoxic effects and its chronic complications based on experimental verification. The focus of this review is to elucidate the commonly used modern medicine for the treatment of liver disease and how major phytoconstituents have been tested for hepatoprotective activity, mechanism of action of some promising agents from natural sources, and clinical trial data for treating in patients with different liver diseases by the aid of natural phytoconstituents.

Main text

The review shows fifteen major isolated phytoconstituents, their biological sources, chemical structures, utilized plant parts, type of extracts used, hepatoprotective assay method, and their possible mechanism of action on the hepatoprotection. Nine promising hepatoprotective leads from natural sources with their chemistry and hepatoprotective mechanism are mentioned briefly. The review further includes the recent clinical trial studies of some hepatoprotective leads and their clinical outcome with different liver disease patients. Scientific studies revealed that antioxidant properties are the central mechanism for the phytoconstituents to subside different disease pathways by upsurging antioxidant defense system of cells, scavenging free radicals, down surging lipid peroxidation, improving anti-inflammatory potential, and further protecting the hepatic cell injury. In this review, we summarize recent development of natural product-based hepatoprotective leads and their curative potential for various sort of liver diseases. Furthermore, the usefulness of hit and lead molecules from natural sources for significant clinical benefit to discover new drug molecule and downsizing the problems of medication and chemical-induced hepatotoxic effects is extrapolated.

Conclusion

Further research are encouraged to elucidate the pharmacological principle of these natural-based chemical agents which will stimulate future pharmaceutical development of therapeutically beneficial hepatoprotective regimens.

Plants-based medicine implication in the evolution of chronic liver diseases

Hepatic disorders are considered major health problems, due to their high incidence, increased risk of chronicling or death and the costs involved in therapies. A large number of patients with chronic liver diseases use herbal medicines and dietary supplements in parallel with allopathic treatment. The current review provides a thorough analysis of the studies conducted on the most important species of medicinal plants used in this disease, bioactive compounds and on the activity of herbal medicines in the evolution of chronic liver diseases. However, a negative aspect is that there is frequently a lack of comprehensive data on the progression of the illness and the living standards of patients who are affected when evaluating the effects of these phytocomponents on the evolution of chronic liver disease, the patients' health, and their quality of life. It is essential to take this impairment into account when evaluating the long-term effects of herbal treatments on the health of individuals who suffer from liver illness. Bioactive phytocomponents may be a suitable source for the development of novel medications due to the correlation between traditional uses and medical advances. Additional high-quality preclinical examinations utilizing cutting-edge approaches are needed to assess safety and effectiveness and to detect, categorize, and standardize the active substances and their formulations for the most suitable therapeutic management of liver illnesses.

Silymarin Administration Attenuates Cirrhotic-induced Cardiac Abnormality in the Rats: A Possible Role of β1-adrenergic Receptors and L-type Voltage-Dependent Calcium Channels

Background

Cirrhotic cardiomyopathy is a well-recognized cardiac dysfunction in cirrhotic patients. Studies have confirmed the protective effects of silymarin in different types of cardiac injury. This study aimed to examine the effectiveness and molecular mechanism of silymarin against myocardial dysfunction and hypertrophy in a rat model of cirrhosis.

Methods

The experiment was performed at Alborz University of Medical Sciences (Karaj, Iran) during 2020-2021. Thirty-two male Wistar rats were randomly divided into four groups of Sham-operated (control group for surgical procedures), Bile Duct Ligated (BDL), and two Silymarin extract (SE)-treated groups of 300 and 600 mg/Kg/day. After 28 days, serum levels of AST, ALT, GGT, and ALP, liver histopathological status, as well as cardiac mechanical function, were assessed. Cardiac β₁-adrenergic receptors (β₁-AR), L-type voltage-dependent calcium channels (L-VDCC), and GATA4 mRNA expression were also determined using real-time RT-PCR. Data analysis was performed using the one-way ANOVA followed by Duncan's multiple range test. Histological data has been analyzed with Kruskal-Wallis nonparametric test. The analysis was performed at P≤0.05.

Results

BDL was associated with a significant elevation in serum AST, ALT, GGT, and ALP, development of necrosis and fibrosis of the liver texture, increased Heart Weight and Heart Weight to Body Weight ratio, enhanced cardiac mechanical function as well as a significant up-regulation of ventricular β₁-AR and L-VDCC. Administration of SE600, but not SE300, significantly reduced the serum levels of the enzymes and alleviated signs of liver necrosis and fibrosis. Cirrhotic-induced cardiac dysfunction was also restored by SE600, but not by the lower dose. In addition, cardiac expression of the β₁-AR and L-VDCC was down-regulated toward normal values by either higher or lower doses of the SE.

Conclusion

Silymarin treatment in higher dose attenuated cirrhosis-associated cardiac remodeling and reduced cardiac mechanical dysfunctions.

Culture and maintenance of neural progressive cells on cellulose acetate/graphene‑gold nanocomposites

In this study, the first CA nanofibers were fabricated by electrospinning under optimal conditions: flow rate of 0.5 ml/h, a voltage of 20 kV, electrospinning distance of 15 cm, and an internal temperature of 25 °C, and humidity of 38%. The used Graphene/gold nanoparticles for CA performance improvement were examined by TGA, XRD, and SEM analysis. Then the CA/graphene‑gold nanocomposite was synthesized under optimum electrospinning conditions: flow rate 3 ml/h, voltage 20 kV, electrospinning distance 15 cm, internal temperature 26 °C, and humidity 36%. The SEM images revealed that the nanofibers' thicknesses of Graphene‑gold NPs (CA₁) and Chitosan (CA₂) were 350 and 120 nm, respectively. The XRD diagrams of CA₀, CA₁ and CA₂ revealed the peaks at 2θ, 8°, and 21° with Miller indices of (001) and (110) are related to CA (CA₀), which proves its presence in other scaffolds. The FTIR analysis of samples indicated the presence of graphene‑gold NPs in scaffolding CA₁ and CA₂. The CA₂ nanofibers exhibited a high-water absorption capacity of about 2500% with the water contact-angle and Swelling method. The antibacterial properties of this nanocomposite were also confirmed by an antibacterial test on Staphylococcus aureus bacteria. The growth of Schwann cells on three scaffolds showed the highest growth of cells on CA₁ scaffolds.

Anti-fibrotic activity of natural products, herbal extracts and nutritional components for prevention of liver fibrosis: review

Liver fibrosis is a grave problem worldwide, and the development of this condition is the first step towards cirrhosis. In fact, when lesions of different aetiologies chronically affect the liver, it triggers fibrogenesis, the resulting damage and the progression of fibrosis cause serious clinical influences including severe complications, expensive treatments, and death in end-stage liver disease. Although impressive progress has been reported in understanding the pathogenesis of liver fibrosis, no effective agent has been developed to prevent or reverse the fibrotic process directly. This article reviews natural products, herbal medicines and nutritional components that exhibited an anti-fibrotic activity through different mechanisms of action, including suppressing of cytokine production, inhibition of hepatic stellate cells "HSCs" propagation, modulation of the molecular mechanisms leading to hepatic fibrosis, free radical scavenging and anti-inflammatory properties.

The Role of Cancer-Associated Fibroblasts in Hepatocellular Carcinoma and the Value of Traditional Chinese Medicine Treatment

Invasion and metastasis are the main reasons for the high mortality of liver cancer, which involve the interaction of tumor stromal cells and malignant cells. Cancer-associated fibroblasts (CAFs) are one of the major constituents of tumor stromal cells affecting tumor growth, invasion, and metastasis. The heterogeneous properties and sources of CAFs make both tumor-supporting and tumor-suppression effects possible. The mechanisms for CAFs in supporting hepatocellular carcinoma (HCC) progression can be categorized into upregulated aggressiveness and stemness, transformed metabolism toward glycolysis and glutamine reductive carboxylation, polarized tumor immunity toward immune escape of HCC cells, and increased angiogenesis. The tumor-suppressive effect of fibroblasts highlights the functional heterogenicity of CAF populations and provides new insights into tumor–stromal interplay mechanisms. In this review, we introduced several key inflammatory signaling pathways in the transformation of CAFs from normal stromal cells and the heterogeneous biofunctions of activated CAFs. In view of the pleiotropic regulation properties of traditional Chinese medicine (TCM) and heterogeneous effects of CAFs, we also introduced the application and values of TCM in the treatment of HCC through targeting CAFs.

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.

Mitochondria-targeted antioxidant mitoquinone attenuates liver inflammation and fibrosis in cirrhotic rats

In liver cirrhosis, oxidative stress plays a major role in promoting liver inflammation and fibrosis. Mitochondria dysregulation is responsible for excessive reactive oxygen species production. Therefore, in an experimental model of cirrhosis, we investigated the effect of mitochondria-targeted antioxidant mitoquinone. Liver cirrhosis was induced in Spraque-Dawley rats by common bile duct ligation (CBDL). Mitoquinone (10 mg·kg^-1·day^-1, oral gavage) or vehicle was administered from 3rd to 28th day after CBDL, when animals were euthanized; liver oxidative stress, inflammation, fibrosis, mitophagy were evaluated; and in vivo and ex vivo hemodynamic studies were performed. In cirrhotic rats, mitoquinone prevented liver inflammation, hepatocyte necrosis, and fibrosis at histological examination; decreased circulating TNF-α, gene expression of transforming growth factor-β1, collagen type 1a1, TNF-α, IL-6, IL-1β, tissue inhibitor of metalloproteinase-1, matrix metalloproteinase (MMP)-2, and MMP-13; and reduced hepatic oxidative stress, as shown by reduced oxidative carbonylation of the proteins, by modulating antioxidants catalase, Mn superoxide dismutase, and Cu/Zn superoxide dismutase. Furthermore, mitoquinone attenuated apoptosis by reducing hepatic protein expression of cleaved caspase-3. A selective removal of dysfunctional mitochondria was improved by mitoquinone, as shown by the increase in Parkin translocation to mitochondria. Treatment with mitoquinone normalized the weight of the spleen; however, it increased portal blood flow and reduced splenic artery intrahepatic resistance, suggesting an effect on resistance index. Mitochondria-targeted antioxidant mitoquinone improves liver inflammation and fibrosis in cirrhotic rats by reducing hepatic oxidative stress, preventing apoptosis, and promoting removal of dysfunctional mitochondria. Therefore, it may represent a promising strategy for the prevention and treatment of liver cirrhosis.

Connective tissue growth factor in hepatocytes is elevated by carbon tetrachloride via STAT3 activation

Carbon tetrachloride (CCl4) is widely used to induce hepatic fibrosis. Therapeutic agents alleviate hepatic fibrosis by inhibiting signal transducer and activator of transcription 3 (STAT3) activation. To understand the direct effects of CCl4 on STAT3 expression in the liver, the present study incubated cultured hepatocytes expressing connective tissue growth factor (CTGF) with CCl4. Rats exposed to CCl4 for 8 weeks exhibited hepatic fibrosis, which was confirmed through the assessment of plasma biomarkers. Isolated liver samples were used to determine the protein levels of CTGF and STAT3 using western blotting. In addition, STAT3 expression was silenced in α mouse liver 12 (AML‑12) cells using small interfering RNA transfection. In addition, a pharmacological inhibitor, stattic, was used to inhibit STAT3 expression. The incubation of AML‑12 cells with CCl4 induced a dose‑dependent increase in CTGF expression and STAT3 activation. Notably, silymarin, an extract from milk thistle, inhibited these changes in AML‑12 cells and the antioxidant tiron produced similar effects. Silencing of STAT3 reduced the CTGF expression promoted by CCl4 in the hepatocytes. Additionally, similar to tiron, stattic inhibited CTGF expression induced by CCl4. In conclusion, CCl4 may activate STAT3 through oxidative stress to promote CTGF expression, which is one of the main factors contributing to the risk of hepatic fibrosis.

Identification of the Multifaceted Chemopreventive Activity of Curcumin Against the Carcinogenic Potential of the Food Additive, KBrO3

Background:

Potassium bromate (KBrO3), a food additive, has been used in many bakery products as an oxidizing agent. It has been shown to induce renal cancer in many in-vitro and in-vivo experimental models

Objectives:

This study evaluated the carcinogenic potential of potassium bromate (KBrO3) and the chemopreventive mechanisms of the anti-oxidant and anti-inflammatory phytochemical, curcumin against KBrO3-induced carcinogenicity.

Method:

Lactate dehydrogenase (LDH) cytotoxicity assay and morphological characteristics were used to assess curcumin's cytoprotective potential against KBrO3 toxicity. To assess the chemopreventive potential of curcumin against KBrO3-induced oxidative insult, intracellular H2O2 and the nuclear concen-tration of the DNA adduct 8-OHdG were measured. PCR array, qRT-PCR, and western blot analysis were used to identify dysregulated genes by KBrO3 exposure. Furthermore, immunofluorescence was used to evaluate the ciliary loss and the disturbance of cellular tight junction induced by KBrO3.

Results:

Oxidative stress assays showed that KBrO3 increased the levels of intracellular H2O2 and the DNA adduct 8-OHdG. Combination of curcumin with KBrO3 efficiently reduced the level of H2O2 and 8-OHdG while up-regulating the expression of catalase. PCR array, qRT-PCR, and western blot analysis revealed that KBrO3 dysregulated multiple genes involved in inflammation, proliferation, and apoptosis, namely CTGF, IL-1, and TRAF3. Moreover, qRT-PCR and immunofluorescence studies showed that KBrO3 negatively affected the tight junctional protein (ZO-1) and induced a degeneration of primary ciliary proteins. The negative impact of KBrO3 on cilia was markedly repressed by curcumin.

Conclusion:

Curcumin could potentially be used as a protective agent against carcinogenicity of KBrO3.

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.

Effects of silymarin on p65 NF-κB, p38 MAPK and CYP450 in LPS-induced hoof dermal inflammatory cells of dairy cows

Background

Laminitis is considered as one of the most important causes of hoof lameness in dairy cows, which can lead to enormous economic losses. However, the etiology and pathogenesis of laminitis have not been clarified yet. Besides, it is of great significant to find alternative herbs for the prevention and treatment of dairy hooves to avoid the antibiotic abuse. In this study, the primary hoof dermal cells of dairy cows were isolated, the inflammatory model was induced by LPS, and treated with silymarin to find whether silymarin has protective effect on the inflammatory dermal cells. The viability of dermal cells, the levels of IL-1β and TNF-α, the degree of p65 NF-κB and p38 MAPK phosphorylation, the expressions of CYP3A4 and CYP1A1 were measured.

Results

Hoof dermal cells of dairy cows were successfully isolated and cultured by tissue adherent culture method. Certain concentrations of LPS can increase the levels of IL-1β and TNF-α, promote the phosphorylation of p65 NF-κB and p38 MAPK, and inhibit the mRNA expressions of CYP3A4 and CYP1A1. The optimal concentration for LPS to establish a hoof dermal cells inflammatory model was 10 μg/mL. Certain concentrations of silymarin can markedly decrease the secretions of IL-1β and TNF-α, inhibit the phosphorylation of p65 NF-κB and p38 MAPK, and promote the mRNA expressions of CYP3A4 and CYP1A1 in LPS-induced dermal inflammatory model.

Conclusions

LPS can be used for inducing the hoof dermal cells inflammatory model of dairy cows. Silymarin has protective effects on the LPS-induced inflammatory model.

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.

Food components with antifibrotic activity and implications in prevention of liver disease

Increasing prevalence of nonalcoholic fatty liver disease (NAFLD) in parallel with the obesity epidemic has been a major public health concern. NAFLD is the most common chronic liver disease in the United States, ranging from fatty liver to steatohepatitis, fibrosis and cirrhosis in the liver. In response to chronic liver injury, fibrogenesis in the liver occurs as a protective response; however, prolonged and dysregulated fibrogenesis can lead to liver fibrosis, which can further progress to cirrhosis and eventually hepatocellular carcinoma. Interplay of hepatocytes, macrophages and hepatic stellate cells (HSCs) in the hepatic inflammatory and oxidative milieu is critical for the development of NAFLD. In particular, HSCs play a major role in the production of extracellular matrix proteins. Studies have demonstrated that bioactive food components and natural products, including astaxanthin, curcumin, blueberry, silymarin, coffee, vitamin C, vitamin E, vitamin D, resveratrol, quercetin and epigallocatechin-3-gallate, have antifibrotic effects in the liver. This review summarizes current knowledge of the mechanistic insight into the antifibrotic actions of the aforementioned bioactive food components.

Silybin attenuates LPS-induced lung injury in mice by inhibiting NF-κB signaling and NLRP3 activation

Silybin is one of the main flavonoids produced by milk thistle, which has been used in the treatment of liver diseases. In this study, we examined the protective effects and possible mechanisms of action of silybin in lipopolysaccharide (LPS)-induced lung injury and inflammation. Pre-treatment of mice with silybin significantly inhibited LPS-induced airway inflammatory cell recruitment, including macrophages, T cells and neutrophils. The production of cytokines, such as interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in bronchoalveolar fluid and serum was also decreased following treatment with silybin. Elevated cytokine mRNA levels induced by LPS in lung tissue were all suppressed by silybin and lung histological alterations were also improved. In addition, experiments using cells indicated that silybin significantly decreased the mRNA levels and secretion of IL-1β and TNF-α in THP-1 cells. Moreover, the mechanisms responsible for these effects were attributed to the inhibitory effect of silybin on nuclear factor-κB (NF-κB) signaling and NLR family pyrin domain containing 3 (NLRP3) inflammasome activation. The data form our study thus support the utility of silybin as a potential medicine for the treatment of acute lung injury-associated inflammation and pathological changes. Silybin exerts protective effects against lung injury by regulating NF-κB signaling and the NLRP3 inflammasome activation.

Expression levels of TGF-β1 and CTGF are associated with the severity of Duchenne muscular dystrophy

The present study aimed to analyze the association of transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF) expression levels in skeletal muscle with the clinical manifestation of Duchenne muscular dystrophy (DMD). A total of 18 cases of DMD, which were confirmed by routine pathological diagnosis were recruited into the present study, along with 8 subjects who suffered from acute trauma but did not present any neuromuscular diseases and were enrolled as the healthy controls. Immunohistochemical staining was used to detect the expression levels of CTGF and TGF-β1 in muscle biopsy specimens. Furthermore, Spearman rank correlation analysis was conducted among the expression levels of CTGF and TGF-β1, age, clinical severity and pathological severity in DMD patients. The immunohistochemical staining results revealed that the expression levels of CTGF and TGF-β1 were significantly increased in the DMD group compared with those in the control group (P<0.05). These levels were not found to be significantly correlated with the onset age (P>0.05), but there was a significant correlation with the degree of pathology and clinical severity (P<0.05). In conclusion, an upregulated expression of CTGF and TGF-β1 was revealed in the skeletal muscle of DMD patients, which were in positive correlation with the degree of pathology and clinical severity. These two factors may be involved in the pathophysiology of fibrosis in DMD.

Silymarin suppressed lung cancer growth in mice via inhibiting myeloid-derived suppressor cells

In this study, we investigated the antitumor activity of Silymarin in a mouse model of colon cancer xenograft of Lewis lung cancer (LLC) cells. Silymarin significantly suppressed tumor growth and induced apoptosis of cells in tumor tissues at a dose of 25 and 50mg/kg. Silymarin treatment enhanced the infiltration and function of CD8(+) T cells. In the meantime, Silymarin decreased the level of IL-10 while elevated the level of IL-2 and IFN-γ in the serum of tumor-bearing mice. Finally, Silymarin reduced the proportion of myeloid-derived suppressor cells (MDSC) in the tumor tissue and also the mRNA expressions of inducible nitric oxide synthases-2 (iNOS2), arginase-1 (Arg-1) and MMP9, which indicated that the function of MDSC in tumor tissues were suppressed. Altogether, our data here showed that Silymarin inhibited the MDSC and promoted the infiltration and function of CD8(+) T cells thus suppressed the growth of LLC xenografts, which provides evidence for the possible use of Silymarin against lung cancer.

Hepatoprotective and Anti-fibrotic Agents: It's Time to Take the Next Step

Hepatic fibrosis and cirrhosis cause strong human suffering and necessitate a monetary burden worldwide. Therefore, there is an urgent need for the development of therapies. Pre-clinical animal models are indispensable in the drug discovery and development of new anti-fibrotic compounds and are immensely valuable for understanding and proofing the mode of their proposed action. In fibrosis research, inbreed mice and rats are by far the most used species for testing drug efficacy. During the last decades, several hundred or even a thousand different drugs that reproducibly evolve beneficial effects on liver health in respective disease models were identified. However, there are only a few compounds (e.g., GR-MD-02, GM-CT-01) that were translated from bench to bedside. In contrast, the large number of drugs successfully tested in animal studies is repeatedly tested over and over engender findings with similar or identical outcome. This circumstance undermines the 3R (Replacement, Refinement, Reduction) principle of Russell and Burch that was introduced to minimize the suffering of laboratory animals. This ethical framework, however, represents the basis of the new animal welfare regulations in the member states of the European Union. Consequently, the legal authorities in the different countries are halted to foreclose testing of drugs in animals that were successfully tested before. This review provides a synopsis on anti-fibrotic compounds that were tested in classical rodent models. Their mode of action, potential sources and the observed beneficial effects on liver health are discussed. This review attempts to provide a reference compilation for all those involved in the testing of drugs or in the design of new clinical trials targeting hepatic fibrosis.

Identification of cromolyn sodium as an anti-fibrotic agent targeting both hepatocytes and hepatic stellate cells

Liver fibrosis and cirrhosis, the late stage of fibrosis, are threatening diseases that lead to liver failure and patient death. Although aberrantly activated hepatic stellate cells (HSCs) are the main cause of disease initiation, the symptoms are primarily related to damaged hepatocytes. Thus, damaged hepatocytes, as well as HSCs, need to be simultaneously considered as therapeutic targets to develop more efficient treatments. Here, we suggest cromolyn sodium as an anti-fibrotic agent to commonly modulate hepatocytes and hepatic stellate cells. The differentially expressed genes from 6 normal and 40 cirrhotic liver tissues which were collected from GEO data were assessed by pharmacokinetic analysis using a connectivity map to identify agents that commonly revert abnormal hepatocytes and HSCs to normal conditions. Based on a series of analyses, a few candidates were selected. Candidates were tested in vitro to determine their anti-fibrotic efficacy on HSCs and hepatocytes. Cromolyn, which was originally developed as a mast cell stabilizer, showed the potential to ameliorate activated HSCs in vitro. The activation and collagen accumulation for HSC cell lines LX2 and HSC-T6 were reduced by 50% after cromolyn treatment at a low concentration without apoptosis. Furthermore, cromolyn treatment compromised the TGF-β-induced epithelial mesenchyme transition and replicative senescence rate of hepatocytes, which are generally associated with fibrogenesis. Taken together, cromolyn may be the basis for an effective cure for fibrosis and cirrhosis because it targets both HSCs and hepatocytes.

Antioxidants in liver health

Liver diseases are a worldwide medical problem because the liver is the principal detoxifying organ and maintains metabolic homeostasis. The liver metabolizes various compounds that produce free radicals (FR). However, antioxidants scavenge FR and maintain the oxidative/antioxidative balance in the liver. When the liver oxidative/antioxidative balance is disrupted, the state is termed oxidative stress. Oxidative stress leads to deleterious processes in the liver and produces liver diseases. Therefore, restoring antioxidants is essential to maintain homeostasis. One method of restoring antioxidants is to consume natural compounds with antioxidant capacity. The objective of this review is to provide information pertaining to various antioxidants found in food that have demonstrated utility in improving liver diseases.

Potent natural products and herbal medicines for treating liver fibrosis

Liver fibrosis is a wound-healing response to chronic liver injury characterized by progressive inflammation and deposition of extracellular matrix components. The pathological condition of liver fibrosis involves secretion of extracellular matrix proteins and formation of scar tissue. The major regulators involved in hepatic fibrogenesis are the transforming growth factor (TGF)-β1/SMAD and toll-like receptor 4 (TLR4)-initiated myeloid differentiation primary response 88 gene (MyD88)/NF-ĸB cell signaling pathways. This article reviews natural products and herbal medicines that have demonstrated activity against liver fibrosis through different mechanisms of action, including anti-hepatitis B and C virus activity, anti-inflammation, inhibition of cytokine production and nuclear receptor activation, and free radical scavenging.

Melatonin limits the expression of profibrogenic genes and ameliorates the progression of hepatic fibrosis in mice

We investigated whether melatonin ameliorates fibrosis and limits the expression of fibrogenic genes in mice treated with carbon tetrachloride (CCl4). Mice in treatment groups received CCl4 5 μL/g body weight intraperitoneally twice a week for 4 or 6 weeks. Melatonin was given at 5 or 10 mg/kg/d intraperitoneally, beginning 2 weeks after the start of CCl4 administration. Treatment with CCl4 resulted in fibrosis evidenced by the staining of Van Gieson and α-smooth muscle actin (α-SMA) positive cells in the liver. At both 4 and 6 weeks, CCl4 induced an increase in the messenger RNA levels of collagens I and III, transforming growth factor (TGF)-β, platelet-derived growth factor (PDGF), connective tissue growth factor (CTGF), amphiregulin, matrix metalloproteinase (MMP)-9, and tissue inhibitor of metalloproteinase (TIMP)-1. Protein concentrations of CTGF, amphiregulin, MMP-9, TIMP-1, and phospho-Smad3 were also significantly augmented in fibrotic mice. Melatonin successfully attenuated liver injury, as shown by histopathology and decreased levels of serum transaminases. Immunohistochemical staining of α-SMA indicated an abrogation of hepatic stellate cell activation by the indol. Furthermore, melatonin treatment resulted in significant inhibition of the expression of collagens I and III, TGF-β, PDGF, CTGF, amphiregulin, and phospho-Smad3. The MMP-9 activity decreased and the expression of nuclear factor erythroid-2-related factor 2 (Nrf2) increased in mice receiving melatonin. Data obtained suggest that attenuation of multiple profibrogenic gene pathways contributes to the beneficial effects of melatonin in mice with CCl4-induced liver fibrosis.

Protective mechanisms of medicinal plants targeting hepatic stellate cell activation and extracellular matrix deposition in liver fibrosis

During chronic liver injury, hepatic stellate cells (HSC) are activated and proliferate, which causes excessive extracellular matrix (ECM) deposition, leading to scar formation and fibrosis. Medicinal plants are gaining popularity as antifibrotic agents, and are often safe, cost-effective, and versatile. This review aims to describe the protective role and mechanisms of medicinal plants in the inhibition of HSC activation and ECM deposition during the pathogenesis of liver fibrosis. A systematic literature review on the anti-fibrotic mechanisms of hepatoprotective plants was performed in PubMed, which yielded articles about twelve relevant plants. Many of these plants act via disruption of the transforming growth factor beta 1 signaling pathway, possibly through reduction in oxidative stress. This reduction could explain the inhibition of HSC activation and reduction in ECM deposition. Medicinal plants could be a source of anti-liver fibrosis compounds.

Silymarin induces insulin resistance through an increase of phosphatase and tensin homolog in Wistar rats

BACKGROUND AND AIMS

Phosphatase and tensin homolog (PTEN) is a phosphoinositide phosphatase that regulates crucial cellular functions, including insulin signaling, lipid and glucose metabolism, as well as survival and apoptosis. Silymarin is the active ingredient in milk thistle and exerts numerous effects through the activation of PTEN. However, the effect of silymarin on the development of insulin resistance remains unknown.

METHODS

Wistar rats fed fructose-rich chow or normal chow were administered oral silymarin to identify the development of insulin resistance using the homeostasis model assessment of insulin resistance and hyperinsulinemic- euglycemic clamping. Changes in PTEN expression in skeletal muscle and liver were compared using western blotting analysis. Further investigation was performed in L6 cells to check the expression of PTEN and insulin-related signals. PTEN deletion in L6 cells was achieved by small interfering ribonucleic acid transfection.

RESULTS

Oral administration of silymarin at a dose of 200 mg/kg once daily induced insulin resistance in normal rats and enhanced insulin resistance in fructose-rich chow-fed rats. An increase of PTEN expression was observed in the skeletal muscle and liver of rats with insulin resistance. A decrease in the phosphorylation of Akt in L6 myotube cells, which was maintained in a high-glucose condition, was also observed. Treatment with silymarin aggravated high-glucose-induced insulin resistance. Deletion of PTEN in L6 cells reversed silymarin-induced impaired insulin signaling and glucose uptake.

CONCLUSIONS

Silymarin has the ability to disrupt insulin signaling through increased PTEN expression. Therefore, silymarin should be used carefully in type-2 diabetic patients.

New Therapeutic Potentials of Milk Thistle (Silybum marianum)

Silymarin is a bioflavonoid complex extract derived from dry seeds of Milk thistle [( Silybum marianum(L.) Gaernt. (Fam. Asteraceae/Compositaceae)] whose hepatoprotective effect has clinically been proved. Low toxicity, favorable pharmacokinetics, powerful antioxidant, detoxifying, preventive, protective and regenerative effects and side effects similar to placebo make silymarin extremely attractive and safe for therapeutic use. The medicinal properties of silymarin and its main component silibinin have been studied in the treatment of Alzheimer's disease, Parkinson's disease, sepsis, burns, osteoporosis, diabetes, cholestasis and hypercholesterolemia. Owing to its apoptotic effect, without cytotoxic effects, silymarin possesses potential applications in the treatment of various cancers. Silymarin is being examined as a neuro-, nephro- and cardio-protective in the damage of different etiologies due to its strong antioxidant potentials. Furthermore, it has fetoprotective (against the influence of alcohol) and prolactin effects and is safe to be used during pregnancy and lactation. Finally, the cosmetics industry is examining the antioxidant and UV-protective effects of silymarin. Further clinical studies and scientific evidence that silymarin and silibinin are effective in the therapy of various pathologies are indispensable in order to confirm their different flavonolignan pharmacological effects.

Models of drug-induced liver injury for evaluation of phytotherapeutics and other natural products

Extracts from medicinal plants, many of which have been used for centuries, are increasingly tested in models of hepatotoxicity. One of the most popular models to evaluate the hepatoprotective potential of natural products is acetaminophen (APAP)-induced liver injury, although other hepatotoxicity models such as carbon tetrachloride, thioacetamide, ethanol and endotoxin are occasionally used. APAP overdose is a clinically relevant model of drug-induced liver injury. Critical mechanisms and signaling pathways, which trigger necrotic cell death and sterile inflammation, are discussed. Although there is increasing understanding of the pathophysiology of APAP-induced liver injury, the mechanism is complex and prone to misinterpretation, especially when unknown chemicals such as plant extracts are tested. This review discusses the fundamental aspects that need to be considered when using this model, such as selection of the animal species or in vitro system, timing and dose-responses of signaling events, metabolic activation and protein adduct formation, the role of lipid peroxidation and apoptotic versus necrotic cell death, and the impact of the ensuing sterile inflammatory response. The goal is to enable researchers to select the appropriate model and experimental conditions for testing of natural products that will yield clinically relevant results and allow valid interpretations of the pharmacological mechanisms.

Electrospun cellulose acetate nanofibers: the present status and gamut of biotechnological applications

Cellulose acetate (CA) has been a material of choice for spectrum of utilities across different domains ranging from high absorbing diapers to membrane filters. Electrospinning has conferred a whole new perspective to polymeric materials including CA in the context of multifarious applications across myriad of niches. In the present review, we try to bring out the recent trend (focused over last five years' progress) of research on electrospun CA fibers of nanoscale regime in the context of developmental strategies of their blends and nanocomposites for advanced applications. In the realm of biotechnology, electrospun CA fibers have found applications in biomolecule immobilization, tissue engineering, bio-sensing, nutraceutical delivery, bioseparation, crop protection, bioremediation and in the development of anti-counterfeiting and pH sensitive material, photocatalytic self-cleaning textile, temperature-adaptable fabric, and antimicrobial mats, amongst others. The present review discusses these diverse applications of electrospun CA nanofibers.