Effects of silymarin MZ-80 on oxidative stress in patients with alcoholic cirrhosis. Results of a randomized, double-blind, placebo-controlled clinical study

Are alterations needed in Silybum marianum (Silymarin) administration practices? A novel outlook and meta-analysis on randomized trials targeting liver injury

It is widely believed that Silybum marianum (Silymarin) alleviates liver injury arising from various etiologies with different degrees of damage through its anti-inflammatory and antioxidant activities. This meta-analysis investigated the effects of silymarin administration on serum levels of liver enzymes including AST, ALT and ALP. From inception to November, 2023, a comprehensive literature search was conducted. Inclusion criteria for this study were randomized trials that provided sufficient data for each group at the beginning and end of the follow-up period. Ultimately, 55 studies with a total of 3545 patients were included. Comprehensive Meta-Analysis (CMA) V4 software was used for meta-analysis. Begg's funnel plot symmetry status, Begg's rank correlation, and Egger's weighted regression tests were used to examine potential publication bias. According to the findings of this meta-analysis silymarin administration showed a significant reduction in AST (SMD [95% CI]: - 0.670 [- 0.931, - 0.408], p-value = 0.000), and ALT (SMD [95% CI]: - 0.912 [- 1.177, - 0.646], p-value = 0.000) levels. While it had no statistically significant effect on ALP level (SMD [95% CI]: - 0.236 [- 1.929, 1.458], p-value = 0.159). Meta-regression analysis showed that there is no significant association between dose, age, BMI, treatment duration and hepatoprotective effects of silymarin. In subgroup analysis, a greater reduction in liver enzymes levels was observed in patients under 50 years old. The subgroup analysis was also showed significant decrease in AST and ALT levels for patients with BMI less than 30, while silymarin treatment had no significant effects on AST and ALT levels in patients with BMI ≥ 30. Silymarin at a dose of less than 400 mg and treatment duration ≤ 2 months showed greater decreasing effects on AST and ALT levels compared to its high doses and longer treatment duration. AST and ALT levels significantly decreased in patients with NAFLD and viral hepatitis, while it had no significant hepatoprotective effects in patients with drugs induced liver injury and alcohol-related liver disease. Modifying the dose and treatment duration with silymarin is recommended in patients with various causes of liver damage.

Consumption of Sylimarin, Pyrroloquinoline Quinone Sodium Salt and Myricetin: Effects on Alcohol Levels and Markers of Oxidative Stress-A Pilot Study

BACKGROUND

Alcohol abuse is one of the most common causes of mortality worldwide. This study aimed to investigate the efficacy of a treatment in reducing circulating ethanol and oxidative stress biomarkers.

METHODS

Twenty wine-drinking subjects were investigated in a randomized controlled, single-blind trial (ClinicalTrials.gov. Identifier: NCT06548503; Ethical Committee of the University of Padova (HEC-DSB/12-2023) to evaluate the effect of the intake of a product containing silymarin, pyrroloquinoline quinone sodium salt, and myricetin (referred to as Si.Pi.Mi. for this project) on blood alcohol, ethyl glucuronide (EtG: marker for alcohol consumption) and markers of oxidative stress levels (Reactive Oxygen Species-ROS, Total Antioxidant Capacity-TAC, CoQ10, thiols redox status, 8-isoprostane, NO metabolites, neopterin, and uric acid). The effects of the treatment versus placebo were evaluated acutely and after 1 week of supplementation in blood and/or saliva and urine samples.

RESULTS

Si.Pi.Mi intake reduced circulating ethanol after 120 min (-33%). Changes in oxidative stress biomarkers, particularly a TAC (range +9-12%) increase and an 8-isoprostane (marker of lipidic peroxidation) decrease (range -22-27%), were observed too.

CONCLUSION

After the administration of Si.Pi.Mi, the data seemed to suggest a better alcohol metabolism and oxidative balance in response to wine intake. Further verification is requested.

Effects of silymarin supplementation on liver and kidney functions: A systematic review and dose-response meta-analysis

It is suggested that supplementation with silymarin (SIL) has beneficial impacts on kidney and liver functions. This systematic review and dose-response meta-analysis assessed the impact of SIL administration on certain hepatic, renal, and oxidative stress markers. A systematic search was conducted in various databases to identify relevant trials published until January 2023. Randomized controlled trials (RCTs) that evaluated the effects of SIL on kidney and liver markers were included. A random-effects model was used for the analysis and 41 RCTs were included. The pooled results indicated that SIL supplementation led to a significant reduction in serum levels of alkaline phosphatase, alanine transaminase, creatinine, and aspartate aminotransferase, along with a substantial elevation in serum glutathione in the SIL-treated group compared to their untreated counterparts. In addition, there was a nonsignificant decrease in serum levels of gamma-glutamyl transferase, malondialdehyde (MDA), total bilirubin, albumin (Alb), total antioxidant capacity, and blood urea nitrogen. Sub-group analyses revealed a considerable decline in MDA and Alb serum values among SIL-treated participants with liver disease in trials with a longer duration (≥12 weeks). These findings suggest that SIL may ameliorate certain liver markers with potential hepatoprotective effects, specifically with long-term and high-dose supplementation. However, its nephroprotective effects and impact on oxidative stress markers were not observed. Additional high-quality RCTs with longer durations are required to determine the clinical efficacy of SIL supplementation on renal and oxidative stress markers.

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.

Detecting and Profiling of Milk Thistle Metabolites in Food Supplements: A Safety-Oriented Approach by Advanced Analytics

Milk thistle (Silybum marianum (L.) Gaertn.) is among the top-selling botanicals used as a supportive treatment for liver diseases. Silymarin, a mixture of unique flavonolignan metabolites, is the main bioactive component of milk thistle. The biological activities of silymarin have been well described in the literature, and its use is considered safe and well-tolerated in appropriate doses. However, commercial preparations do not always contain the recommended concentrations of silymarin, failing to provide the expected therapeutic effect. While the poor quality of raw material may explain the low concentrations of silymarin, its deliberate removal is suspected to be an adulteration. Toxic contaminants and foreign matters were also detected in milk thistle preparations, raising serious health concerns. Standard methods for determination of silymarin components include thin-layer chromatography (TLC), high-performance thin-layer chromatography (HPTLC), and high-performance liquid chromatography (HPLC) with various detectors, but nuclear magnetic resonance (NMR) and ultra-high-performance liquid chromatography (UHPLC) have also been applied. This review surveys the extraction techniques of main milk thistle metabolites and the quality, efficacy, and safety of the derived food supplements. Advanced analytical authentication approaches are discussed with a focus on DNA barcoding and metabarcoding to complement orthogonal chemical characterization and fingerprinting of herbal products.

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.

Role of silymarin as antioxidant in clinical management of chronic liver diseases: a narrative review

Chronic liver disease (CLD), manifested as hepatic injury, is a major cause of global morbidity and mortality. CLD progresses to fibrosis, cirrhosis, and-ultimately-hepatocellular carcinoma (HCC) if left untreated. The different phenotypes of CLD based on their respective clinical features and causative agents include alcoholic liver disease (ALD), non-alcoholic fatty liver disease (NAFLD), metabolic-associated fatty liver disease (MAFLD), and drug-induced liver injury (DILI). The preferred treatment modality for CLD includes lifestyle modification and diet, along with limited pharmacological agents for symptomatic treatment. Moreover, oxidative stress (OS) is an important pathological mechanism underlying all CLD phenotypes; hence, the use of antioxidants to manage the disease is justified. Based on available clinical evidence, silymarin can be utilized as a hepatoprotective agent, given its potent antioxidant, antifibrotic, and anti-inflammatory properties. The role of silymarin in suppressing OS has been well established, and therefore silymarin is recommended for use in ALD and NAFLD in the guidelines approved by the Russian Medical Scientific Society of Therapists and the Gastroenterology Scientific Society of Russia. However, to discuss the positioning of the original silymarin in clinical guidelines and treatment protocols as a hepatoprotective agent for managing CLD concomitantly with other therapies, an expert panel of international and Russian medical professionals was convened on 11 November 2020. The panel reviewed approaches for the prevention and treatment of OS, existing guidelines for patient management for CLD, and available evidence on the effectiveness of silymarin in reducing OS, fibrosis, and hepatic inflammation and presented in the form of a narrative review. Key messagesAn expert panel of international and Russian medical professionals reviewed existing guidelines for ALD, NAFLD, MAFLD, and DILI to establish consensus recommendations that oxidative stress is the common pathophysiological mechanism underlying these conditions.The panel also discussed the positioning of original silymarin in clinical guidelines and treatment protocols as a hepatoprotective agent for managing CLD concomitantly with other therapies.The panel reviewed the effectiveness of 140 mg original silymarin three times a day in reducing oxidative stress in chronic liver diseases such as ALD, NAFLD, MAFLD, and DILI.

Hepatic Myofibroblasts: A Heterogeneous and Redox-Modulated Cell Population in Liver Fibrogenesis

During chronic liver disease (CLD) progression, hepatic myofibroblasts (MFs) represent a unique cellular phenotype that plays a critical role in driving liver fibrogenesis and then fibrosis. Although they could originate from different cell types, MFs exhibit a rather common pattern of pro-fibrogenic phenotypic responses, which are mostly elicited or sustained both by oxidative stress and reactive oxygen species (ROS) and several mediators (including growth factors, cytokines, chemokines, and others) that often operate through the up-regulation of the intracellular generation of ROS. In the present review, we will offer an overview of the role of MFs in the fibrogenic progression of CLD from different etiologies by focusing our attention on the direct or indirect role of ROS and, more generally, oxidative stress in regulating MF-related phenotypic responses. Moreover, this review has the purpose of illustrating the real complexity of the ROS modulation during CLD progression. The reader will have to keep in mind that a number of issues are able to affect the behavior of the cells involved: a) the different concentrations of reactive species, b) the intrinsic state of the target cells, as well as c) the presence of different growth factors, cytokines, and other mediators in the extracellular microenvironment or of other cellular sources of ROS.

Silymarin for Treating Toxic Liver Disease: International Consensus Recommendations

Chronic liver disease (CLD) is a leading health problem impacting the quality of life globally. China shares a major global burden of CLD-including alcoholic liver disease, nonalcoholic fatty liver disease/metabolic dysfunction-associated fatty liver disease, and drug-induced liver injury, except for chronic viral hepatitis. Several exogenous toxins or endogenous metabolic insults trigger hepatic pathology toward steatosis, inflammation, and fibrosis, which, if left untreated, may culminate in liver cirrhosis. Oxidative stress is a common pathomechanism underlying all phenotypes of toxic liver injury; thus, these may be brought under a unified entity, viz. toxic liver disease (TLD). Therefore, a common strategy to treat TLD is to use antioxidants as hepatoprotective agents. The cornerstone for treating fatty liver disease is lifestyle modification, diet, exercise, and behavioral therapy, along with the limited use of pharmacological agents. Available preclinical and clinical evidence indicates that silymarin is a hepatoprotective agent with established antioxidant, anti-inflammatory, antifibrotic effects. An international expert panel of clinicians was convened to discuss combining alcoholic liver disease, nonalcoholic fatty liver disease/metabolic dysfunction-associated fatty liver disease, drug-induced liver injury, and liver cirrhosis under the single definition of TLD, based on the shared pathologic mechanism of oxidative stress. The panel highlighted the significance of silymarin as an antioxidant treatment for TLD.

Milk thistle (Silybum marianum (L.)Gaertn.): An overview about its pharmacology and medicinal uses with an emphasis on oral diseases

BACKGROUND

Milk thistle, a medicinal plant, has different uses and benefits. Pathologies of the oral cavity manifest as different diseases with various therapeutic options. The main phytochemical extract of the milk thistle plant is silymarin. It has optimistic, protective, and therapeutic properties. However, evidence about the role of milk thistle extracts in oral diseases is lacking.

HIGHLIGHT

The pharmacology of milk thistle was overviewed. The role of the plant in some systemic diseases was reviewed. Furthermore, its role in various oral diseases was discussed. The presented articles described such effects in the context of periodontal disease, dental caries, oral candidiasis, oral lichen planus, oral cancer, and oral mucositis. Results on the promising effects of milk thistle extracts with a preference for silymarin were presented from different research designs. A summary of the previously used doses and the currently available pharmaceutical products was proposed for future research.

CONCLUSION

Milk thistle has antioxidant, anti-inflammatory, anticancer, antifungal, immunomodulatory, and other properties. The evidence from human research about the role of milk thistle in oral diseases is limited. Further studies, particularly clinical trials, to test milk thistle either as a potential treatment modality or a supplementary therapy for oral diseases on higher levels would be useful in the future.

In-depth hepatoprotective mechanistic study of Echinacea purpurea flowers: In vitro and in vivo studies

Introduction: Echinacea purpurea is a flowering plant commonly used as an herbal medicine despite insufficient scientific bases to validate its usage. The present study aimed to examine in vitro and in vivo hepatoprotective effects of aqueous and alcoholic extracts of E. purpurea flowers. Methods: In vitro protection against hepato-cytotoxicity was carried out on human HepG-2 cells using colorimetric tetrazolium (MTT) assay, while the in vivo hepatoprotective activity was studied against carbon-tetrachloride (CCl4) induced acute hepatotoxicity in rats. Results: The results revealed that the extracts of E. purpurea induced discernable in vitro protection on HepG-2 cells and in vivo against CCl4 induced hepatotoxicity. Both extracts were significantly able to restore the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total bilirubin, total protein, and albumin to normal levels compared to the CCl4 intoxicated group. In addition, the extracts markedly mitigated the oxidative stress by decreasing Malondialdehyde (MDA) and increasing superoxide dismutase (SOD) and glutathione (GSH) markers compared to the CCl4 intoxicated group. It was also associated with the down-regulation of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels in liver tissues. Histopathological examination revealed a decrease in hepatocytes’ degenerative changes and noticeable improvement of the liver damage by extracts of E. purpurea. Conclusion: These findings have proven that aqueous and alcoholic extracts of E. purpurea flowers have a significant hepatoprotective effect, probably owing to antioxidant, anti-inflammatory activities, and regulating apoptotic-related genes. This confirms the ethnomedicinal uses of E. purpurea in patients suffering from liver diseases.

Emerging Therapies for Alcoholic Hepatitis

The incidence of alcoholic hepatitis is increasing while the mortality rate remains high. The single current available therapy for severe alcoholic hepatitis is administration of corticosteroids for patients with severe alcoholic hepatitis, which has demonstrated limited benefits, providing a short-term mortality benefit with a marginal response rate. There is a need for developing safe and effective therapies. This article reviews novel therapies targeting various mechanisms in the pathogenesis of alcoholic hepatitis, such as the gut-liver axis, inflammatory cascade, oxidative stress, and hepatic regeneration. Current ongoing clinical trials for alcoholic hepatitis also are described.

Protective Mechanism of Edible Food Plants against Alcoholic Liver Disease with Special Mention to Polyphenolic Compounds

Alcoholic liver disease (ALD) is one type of liver disease, causing a global healthcare problem and mortality. The liver undergoes tissue damage by chronic alcohol consumption because it is the main site for metabolism of ethanol. Chronic alcohol exposure progresses from alcoholic fatty liver (AFL) to alcoholic steatohepatitis (ASH), which further lead to fibrosis, cirrhosis, and even hepatocellular cancer. Therapeutic interventions to combat ALD are very limited such as use of corticosteroids. However, these therapeutic drugs are not effective for long-term usage. Therefore, additional effective and safe therapies to cope with ALD are urgently needed. Previous studies confirmed that edible food plants and their bioactive compounds exert a protective effect against ALD. In this review article, we summarized the hepatoprotective potential of edible food plants and their bioactive compounds. The underlying mechanism for the prevention of ALD by edible food plants was as follows: anti-oxidation, anti-inflammation, lipid regulation, inhibition of apoptosis, gut microbiota composition modulation, and anti-fibrosis.

Changes in Glutathione Content in Liver Diseases: An Update

Glutathione (GSH), a tripeptide particularly concentrated in the liver, is the most important thiol reducing agent involved in the modulation of redox processes. It has also been demonstrated that GSH cannot be considered only as a mere free radical scavenger but that it takes part in the network governing the choice between survival, necrosis and apoptosis as well as in altering the function of signal transduction and transcription factor molecules. The purpose of the present review is to provide an overview on the molecular biology of the GSH system; therefore, GSH synthesis, metabolism and regulation will be reviewed. The multiple GSH functions will be described, as well as the importance of GSH compartmentalization into distinct subcellular pools and inter-organ transfer. Furthermore, we will highlight the close relationship existing between GSH content and the pathogenesis of liver disease, such as non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), chronic cholestatic injury, ischemia/reperfusion damage, hepatitis C virus (HCV), hepatitis B virus (HBV) and hepatocellular carcinoma. Finally, the potential therapeutic benefits of GSH and GSH-related medications, will be described for each liver disorder taken into account.

Molecular Mechanisms That Link Oxidative Stress, Inflammation, and Fibrosis in the Liver

Activated hepatic stellate cells (HSCs) and myofibroblasts are the main producers of extracellular matrix (ECM) proteins that form the fibrotic tissue that leads to hepatic fibrosis. Reactive oxygen species (ROS) can directly activate HSCs or induce inflammation or programmed cell death, especially pyroptosis, in hepatocytes, which in turn activates HSCs and fibroblasts to produce ECM proteins. Therefore, antioxidants and the nuclear factor E2-related factor-2 signaling pathway play critical roles in modulating the profibrogenic response. The master proinflammatory factors nuclear factor-κB (NF-κB) and the nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 (NLRP3) inflammasome may coordinate to produce and activate profibrogenic molecules such as interleukins 1β and 18, which effectively activate HSCs, to produce large amounts of fibrotic proteins. Furthermore, the NLRP3 inflammasome activates pro-caspase 1, which is upregulated by NF-κB, to produce caspase 1, which induces pyroptosis via gasdermin and the activation of HSCs. ROS play central roles in the activation of the NF-κB and NLRP3 signaling pathways via IκB (an inhibitor of NF-κB) and thioredoxin-interacting protein, respectively, thereby linking the molecular mechanisms of oxidative stress, inflammation and fibrosis. Elucidating these molecular pathways may pave the way for the development of therapeutic tools to interfere with specific targets.

In Vitro Protective Effect of Paste and Sauce Extract Made with Protaetia brevitarsis Larvae on HepG2 Cells Damaged by Ethanol

We made paste and sauce using protein-rich Protaetia brevitarsis larvae (PBL) and evaluated their fermentation levels. After pretreatment with the paste and sauce extracts, HepG2 cells were damaged with ethanol (EtOH), and then the effects of the paste and sauce were evaluated. As a result, we confirmed that the PBL paste and sauce extracts reduced the aspartate aminotransferase (AST) and alanine aminotransaminase (ALT) content in the medium as compared to soybean (Glycine max) sauce and paste extracts. In addition, the PBL paste and sauce extracts significantly lowered the level of tumor necrosis factor (TNF)-α and interleukin (IL)-6, which are biomarkers of inflammation, and significantly increased the inhibition rate of superoxide dismutase (SOD) and reduced glutathione (GSH), which are antioxidative indicators, in proportion to the amount of PBL added to the paste and sauce. These results suggest that an intake of PBL paste and sauce, a novel type of fermented food made from insects, may be effective for liver protection through anti-inflammatory and antioxidative effects against hepatocyte injury caused by EtOH.

Milk thistle (Silybum Marianum) as an antidote or a protective agent against natural or chemical toxicities: a review

Biological and chemical agents cause dangerous effects on human health via different exposing ways. Recently, herbal medicine is considered as a biological and safe treatment for toxicities. Silybum marianum (milk thistle), belongs to the Asteraceae family, possesses different effects such as hepatoprotective, cardioprotective, neuroprotective, anti-inflammatory and anti-carcinogenic activities. Several studies have demonstrated that this plant has protective properties against toxic agents. Herein, the protective effects of S. marianum and its main component, silymarin, which is the mixture of flavonolignans including silibinin, silydianin and silychristin acts against different biological (mycotoxins, snake venoms, and bacterial toxins) and chemical (metals, fluoride, pesticides, cardiotoxic, neurotoxic, hepatotoxic, and nephrotoxic agents) poisons have been summarized. This review reveals that main protective effects of milk thistle and its components are attributed to radical scavenging, anti-oxidative, chelating, anti-apoptotic properties, and regulating the inflammatory responses.

Liver Fibrosis: Mechanistic Concepts and Therapeutic Perspectives

Liver fibrosis due to viral or metabolic chronic liver diseases is a major challenge of global health. Correlating with liver disease progression, fibrosis is a key factor for liver disease outcome and risk of hepatocellular carcinoma (HCC). Despite different mechanism of primary liver injury and disease-specific cell responses, the progression of fibrotic liver disease follows shared patterns across the main liver disease etiologies. Scientific discoveries within the last decade have transformed the understanding of the mechanisms of liver fibrosis. Removal or elimination of the causative agent such as control or cure of viral infection has shown that liver fibrosis is reversible. However, reversal often occurs too slowly or too infrequent to avoid life-threatening complications particularly in advanced fibrosis. Thus, there is a huge unmet medical need for anti-fibrotic therapies to prevent liver disease progression and HCC development. However, while many anti-fibrotic candidate agents have shown robust effects in experimental animal models, their anti-fibrotic effects in clinical trials have been limited or absent. Thus, no approved therapy exists for liver fibrosis. In this review we summarize cellular drivers and molecular mechanisms of fibrogenesis in chronic liver diseases and discuss their impact for the development of urgently needed anti-fibrotic therapies.

Silymarin as Supportive Treatment in Liver Diseases: A Narrative Review

Silymarin, an extract from milk thistle seeds, has been used for centuries to treat hepatic conditions. Preclinical data indicate that silymarin can reduce oxidative stress and consequent cytotoxicity, thereby protecting intact liver cells or cells not yet irreversibly damaged. Eurosil 85® is a proprietary formulation developed to maximize the oral bioavailability of silymarin. Most of the clinical research on silymarin has used this formulation. Silymarin acts as a free radical scavenger and modulates enzymes associated with the development of cellular damage, fibrosis and cirrhosis. These hepatoprotective effects were observed in clinical studies in patients with alcoholic or non-alcoholic fatty liver disease, including patients with cirrhosis. In a pooled analysis of trials in patients with cirrhosis, silymarin treatment was associated with a significant reduction in liver-related deaths. Moreover, in patients with diabetes and alcoholic cirrhosis, silymarin was also able to improve glycemic parameters. Patients with drug-induced liver injuries were also successfully treated with silymarin. Silymarin is generally very well tolerated, with a low incidence of adverse events and no treatment-related serious adverse events or deaths reported in clinical trials. For maximum benefit, treatment with silymarin should be initiated as early as possible in patients with fatty liver disease and other distinct liver disease manifestations such as acute liver failure, when the regenerative potential of the liver is still high and when removal of oxidative stress, the cause of cytotoxicity, can achieve the best results.

Milk thistle (Silybum marianum): A concise overview on its chemistry, pharmacological, and nutraceutical uses in liver diseases

Milk thistle (MT; Silybum marianum), a member of the Asteraceae family, is a therapeutic herb with a 2,000-year history of use. MT fruits contain a mixture of flavonolignans collectively known as silymarin, being silybin (also named silibinin) the main component. This article reviews the chemistry of MT, the pharmacokinetics and bioavailability, the pharmacologically relevant actions for liver diseases (e.g., anti-inflammatory, immunomodulating, antifibrotic, antioxidant, and liver-regenerating properties) as well as the clinical potential in patients with alcoholic liver disease, nonalcoholic fatty liver disease, viral hepatitis, drug-induced liver injury, and mushroom poisoning. Overall, literature data suggest that, despite encouraging preclinical data, further well-designed randomized clinical trials are needed to fully substantiate the real value of MT preparations in liver diseases.

Pharmacological interventions for alcoholic liver disease (alcohol-related liver disease): an attempted network meta-analysis

BACKGROUND

Alcohol-related liver disease is due to excessive alcohol consumption. It includes a spectrum of liver diseases such as alcohol-related fatty liver, alcoholic hepatitis, and alcoholic cirrhosis. Mortality associated with alcoholic hepatitis is high. The optimal pharmacological treatment of alcoholic hepatitis and other alcohol-related liver disease remains controversial.

OBJECTIVES

To assess the comparative benefits and harms of different pharmacological interventions in the management of alcohol-related liver disease through a network meta-analysis and to generate rankings of the available pharmacological interventions according to their safety and efficacy in order to identify potential treatments. However, even in the subgroup of participants when the potential effect modifiers appeared reasonably similar across comparisons, there was evidence of inconsistency by one or more methods of assessment of inconsistency. Therefore, we did not report the results of the network meta-analysis and reported the comparative benefits and harms of different interventions using standard Cochrane methodology.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Science Citation Index Expanded, World Health Organization International Clinical Trials Registry Platform and randomised controlled trials registers until February 2017 to identify randomised clinical trials on pharmacological treatments for alcohol-related liver diseases.

SELECTION CRITERIA

Randomised clinical trials (irrespective of language, blinding, or publication status) including participants with alcohol-related liver disease. We excluded trials that included participants who had previously undergone liver transplantation and those with co-existing chronic viral diseases. We considered any of the various pharmacological interventions compared with each other or with placebo or no intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified trials and independently extracted data. We calculated the odds ratio (OR) and rate ratio with 95% confidence intervals (CIs) using both fixed-effect and random-effects models based on available-participant analysis with Review Manager. We assessed risk of bias according to Cochrane, controlled risk of random errors with Trial Sequential Analysis, and assessed the quality of the evidence using GRADE.

MAIN RESULTS

We identified a total of 81 randomised clinical trials. All the trials were at high risk of bias, and the overall quality of the evidence was low or very low for all outcomes. Alcoholic hepatitisFifty randomised clinical trials included 4484 participants with alcoholic hepatitis. The period of follow-up ranged from one to 12 months. Because of concerns about transitivity assumption, we did not perform the network meta-analysis. None of the active interventions showed any improvement in any of the clinical outcomes reported in the trials, which includes mortality (at various time points), cirrhosis, decompensated cirrhosis, liver transplantation. None of the trials reported health-related quality of life or incidence of hepatocellular carcinoma. Severe alcoholic hepatitisOf the trials on alcoholic hepatitis, 19 trials (2545 participants) included exclusively participants with severe alcoholic hepatitis (Maddrey Discriminat Function > 32). The period of follow-up ranged from one to 12 months. There was no alteration in the conclusions when only people with severe alcoholic hepatitis were included in the analysis.

SOURCE OF FUNDING

Eleven trials were funded by parties with vested interest in the results. Sixteen trials were funded by parties without vested interest in the results. The source of funding was not reported in 23 trials. Other alcohol-related liver diseasesThirty-one randomised clinical trials included 3695 participants with other alcohol-related liver diseases (with a wide spectrum of alcohol-related liver diseases). The period of follow-up ranged from one to 48 months. The mortality at maximal follow-up was lower in the propylthiouracil group versus the no intervention group (OR 0.45, 95% CI 0.26 to 0.78; 423 participants; 2 trials; low-quality evidence). However, this result is based on two small trials at high risk of bias and further confirmation in larger trials of low risk of bias is necessary to recommend propylthiouracil routinely in people with other alcohol-related liver diseases. The mortality at maximal follow-up was higher in the ursodeoxycholic acid group versus the no intervention group (OR 2.09, 95% CI 1.12 to 3.90; 226 participants; 1 trial; low-quality evidence).

SOURCE OF FUNDING

Twelve trials were funded by parties with vested interest in the results. Three trials were funded by parties without vested interest in the results. The source of funding was not reported in 16 trials.

AUTHORS' CONCLUSIONS

Because of very low-quality evidence, there is uncertainty in the effectiveness of any pharmacological intervention versus no intervention in people with alcoholic hepatitis or severe alcoholic hepatitis. Based on low-quality evidence, propylthiouracil may decrease mortality in people with other alcohol-related liver diseases. However, these results must be confirmed by adequately powered trials with low risk of bias before propylthiouracil can be considered effective.Future randomised clinical trials should be conducted with approximately 200 participants in each group and follow-up of one to two years in order to compare the benefits and harms of different treatments in people with alcoholic hepatitis. Randomised clinical trials should include health-related quality of life and report serious adverse events separately from adverse events. Future randomised clinical trials should have a low risk of bias and low risk of random errors.

Silibinin induces hepatic stellate cell cycle arrest via enhancing p53/p27 and inhibiting Akt downstream signaling protein expression

BACKGROUND

Proliferation of hepatic stellate cells (HSCs) plays a pivotal role in the progression of liver fibrosis consequent to chronic liver injury. Silibinin, a flavonoid compound, has been shown to possess anti-fibrogenic effects in animal models of liver fibrosis. This was attributed to an inhibition of cell proliferation of activated HSCs. The present study was to gain insight into the molecular pathways involved in silibinin anti-fibrogenic effect.

METHODS

The study was conducted on LX-2 human stellate cells treated with three concentrations of silibinin (10, 50 and 100 μmol/L) for 24 and 96 hours. At the end of the treatment cell viability and proliferation were evaluated. Protein expression of p27, p21, p53, Akt and phosphorylated-Akt was evaluated by Western blotting analysis and Ki-67 protein expression was by immunocytochemistry. Sirtuin activity was evaluated by chemiluminescence based assay.

RESULTS

Silibinin inhibits LX-2 cell proliferation in dose- and time-dependent manner; we showed that silibinin upregulated the protein expressions of p27 and p53. Such regulation was correlated to an inhibition of both downstream Akt and phosphorylated-Akt protein signaling and Ki-67 protein expression. Sirtuin activity also was correlated to silibinin-inhibited proliferation of LX-2 cells.

CONCLUSION

The anti-proliferative effect of silibinin on LX-2 human stellate cells is via the inhibition of the expressions of various cell cycle targets including p27, Akt and sirtuin signaling.

In vitro assessment of hepatoprotective agents against damage induced by acetaminophen and CCl4

BACKGROUND

In vitro bioassays are important in the evaluation of plants with possible hepatoprotective effects. The aims of this study were to evaluate the pretreatment of HepG2 cells with hepatoprotective agents against the damage induced by carbon tetrachloride (CCl₄) and paracetamol (APAP).

METHODS

Antioxidative activity was measured using an assay to measure 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. The in vitro hepatotoxicity of CCl₄ and APAP, and the cytotoxic and hepatoprotective properties of silymarin (SLM), silybinin (SLB), and silyphos (SLP) were evaluated by measuring cell viability; activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH); total antioxidant capacity (TAOxC); and reduced glutathione (GSH), superoxide dismutase (SOD), and lipid peroxidation (malondialdehyde (MDA) levels).

RESULTS

Only SLB and SLM showed strong antioxidative activity in the DPPH assay (39.71 ± 0.85 μg/mL and 14.14 ± 0.65 μg/mL, respectively). CCl₄ induced time- and concentration-dependent changes. CCl₄ had significant effects on cell viability, enzyme activities, lipid peroxidation, TAOxC, and SOD and GSH levels. These differences remained significant up to an exposure time of 3 h. APAP induced a variety of dose- and time-dependent responses up to 72 h of exposure. SLM, SLB, and SLP were not cytotoxic. Only SLB at a concentration of 100 μg/mL or 150 μg/mL significantly decreased the enzyme activities and MDA level, and prevented depletion of total antioxidants compared with CCl₄.

CONCLUSIONS

CCl₄ was more consistent than APAP in inducing cell injury. Only SLB provided hepatoprotection. AST, LDH, and MDA levels were good markers of liver damage.

Targeting Hepatic Fibrosis in Autoimmune Hepatitis

Hepatic fibrosis develops or progresses in 25 % of patients with autoimmune hepatitis despite corticosteroid therapy. Current management regimens lack reliable noninvasive methods to assess changes in hepatic fibrosis and interventions that disrupt fibrotic pathways. The goals of this review are to indicate promising noninvasive methods to monitor hepatic fibrosis in autoimmune hepatitis and identify anti-fibrotic interventions that warrant evaluation. Laboratory methods can differentiate cirrhosis from non-cirrhosis, but their accuracy in distinguishing changes in histological stage is uncertain. Radiological methods include transient elastography, acoustic radiation force impulse imaging, and magnetic resonance elastography. Methods based on ultrasonography are comparable in detecting advanced fibrosis and cirrhosis, but their performances may be compromised by hepatic inflammation and obesity. Magnetic resonance elastography has excellent performance parameters for all histological stages in diverse liver diseases, is uninfluenced by inflammatory activity or body habitus, has been superior to other radiological methods in nonalcoholic fatty liver disease, and may emerge as the preferred instrument to evaluate fibrosis in autoimmune hepatitis. Promising anti-fibrotic interventions are site- and organelle-specific agents, especially inhibitors of nicotinamide adenine dinucleotide phosphate oxidases, transforming growth factor beta, inducible nitric oxide synthase, lysyl oxidases, and C-C chemokine receptors types 2 and 5. Autoimmune hepatitis has a pro-fibrotic propensity, and noninvasive radiological methods, especially magnetic resonance elastography, and site- and organelle-specific interventions, especially selective antioxidants and inhibitors of collagen cross-linkage, may emerge to strengthen current management strategies.

Nature and Implications of Oxidative and Nitrosative Stresses in Autoimmune Hepatitis

Oxidative and nitrosative stresses can damage cellular membranes, disrupt mitochondrial function, alter gene expression, promote the apoptosis and necrosis of hepatocytes, and increase fibrosis in diverse acute and chronic liver diseases, including autoimmune hepatitis. The objectives of this review are to describe the mechanisms of oxidative and nitrosative stresses in inflammatory liver disease, indicate the pathogenic implications of these stresses in autoimmune hepatitis, and suggest investigational opportunities to develop interventions that counter them. The principal antioxidant defenses, including glutathione production, the activities of antioxidant enzymes, and the release of the nuclear factor erythroid 2-related factor 2, may be inadequate or suppressed by transforming growth factor beta. The generation of reactive oxygen species can intensify nitrosative stress, and this stress may not be adequately modulated by the thioredoxin-thioredoxin reductase system and induce post-translational modifications of proteins that further disrupt hepatocyte function. The unfolded protein response and autophagy may be unable to restore redox stability, meet metabolic demands, and maintain hepatocyte survival. Emerging interventions with highly selective site- and organelle-specific actions may improve outcomes, and they include inhibitors of nicotinamide adenine dinucleotide phosphate oxidase, nitric oxide synthase, and transforming growth factor beta. Pharmacological manipulation of nuclear transcription factors may favor expression of antioxidant genes, and stimulation of chaperone proteins within the endoplasmic reticulum and modulation of autophagy may prevent hepatic fibrosis and enhance cell survival. These interventions constitute investigational opportunities to improve the management of autoimmune hepatitis.

Protective effects of combined β-caryophyllene and silymarin against ketoprofen-induced hepatotoxicity in rats

Ketoprofen (Ket), widely utilized in treatment of many inflammatory disorders, is found to induce liver toxicity especially with overdose. This study aimed to evaluate the possible protective effects of concomitant β-caryophyllene (Cary) and silymarin (Sily) against Ket-induced hepatotoxicity in rats. Forty adult male albino rats were divided into 5 groups (each n = 8): the control group received distilled water for 6 weeks; the Ket-treated group received distilled water for 5 weeks and Ket in a dose of 8 mg·kg(-1)·day(-1) p.o. for the 6th week; the Cary + Ket treated group received Cary in a dose of 200 mg·kg(-1)·day(-1) orally for 6 weeks and Ket for the 6th week; the Sily + Ket treated group received Sily in the dose of 150 mg·kg(-1)·day(-1) for 6 weeks and Ket for the 6th week; and the Cary + Sily + Ket treated group received Sily and Cary for 6 weeks and Ket for the 6th week. At end of the experiment, serum ALT, AST, and albumin and liver total antioxidant capacity (t.TAC) and malondialdehyde (t.MDA) were measured in all rats. Ket increased serum ALT and AST and t.MDA and decreased t.TAC. Cary and Sily improved these changes. Combined Cary and Sily restored these liver changes to nearly normal. Combined Cary and Sily is hepatoprotective, with the ability to scavenge oxidants against Ket-induced hepatotoxicity in rats.

Molecular basis of alcoholic fatty liver disease: From incidence to treatment

Alcoholic liver diseases have complex and multiple pathogenic mechanisms but still no effective treatment. Steatosis or alcoholic fatty liver disease (AFLD) has a widespread incidence and is the first step in the progression to more severe stages of alcoholic liver disease, with concomitant increases in morbidity and mortality rates. The ways in which this progression occurs and why some individuals are susceptible are still unanswered scientific questions. Research with animal models and clinical evidence have shown that it is a multifactorial disease that involves interactions between lipid metabolism, inflammation, the immune response and oxidative stress. Each of these pathways provides a better understanding of the pathogenesis of AFLD and contributes to the development of therapeutic strategies. This review emphasizes the importance of research on alcoholic steatosis based on incidence data, key pathogenic mechanisms and therapeutic interventions, and discusses perspectives on the progression of this disease.

Modulation of Metabolic Detoxification Pathways Using Foods and Food-Derived Components: A Scientific Review with Clinical Application

Research into human biotransformation and elimination systems continues to evolve. Various clinical and in vivo studies have been undertaken to evaluate the effects of foods and food-derived components on the activity of detoxification pathways, including phase I cytochrome P450 enzymes, phase II conjugation enzymes, Nrf2 signaling, and metallothionein. This review summarizes the research in this area to date, highlighting the potential for foods and nutrients to support and/or modulate detoxification functions. Clinical applications to alter detoxification pathway activity and improve patient outcomes are considered, drawing on the growing understanding of the relationship between detoxification functions and different disease states, genetic polymorphisms, and drug-nutrient interactions. Some caution is recommended, however, due to the limitations of current research as well as indications that many nutrients exert biphasic, dose-dependent effects and that genetic polymorphisms may alter outcomes. A whole-foods approach may, therefore, be prudent.

In vivo efficacy study of milk thistle extract (ETHIS-094™) in STAM™ model of nonalcoholic steatohepatitis

INTRODUCTION

A subcategory of nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH) is characterized by accumulation of fat accompanied by inflammatory infiltration and hepatocellular damage. The active complex of milk thistle is a lipophilic extract from its seeds, comprising three isomers, collectively known as silymarin. Silymarin has demonstrated antioxidant, anti-inflammatory, and antifibrotic properties, and has been extensively studied in the treatment of liver diseases. The majority of published clinical research on silymarin has used Legalon(®) (Rottapharm/Madaus), containing the patented extract of milk thistle ETHIS-094™ (Euromed). The current study was undertaken to examine the effects of ETHIS-094™ in the Stelic Animal Model (STAM™), a validated and widely used animal model for NASH.

METHODS

After 4 h fasting from 4 to 8 weeks of age, 15 male mice in whom NASH had been induced were orally administered, once daily, either (1) vehicle (saline) at a volume of 10 mL/kg, (2) vehicle supplemented with milk thistle at a dose of 500 mg/kg, or (3) vehicle supplemented with milk thistle at a dose of 1,000 mg/kg.

RESULTS

Mean liver weight and the liver-to-body weight ratio were significantly (P < 0.01) decreased in the milk thistle high-dose group compared with the vehicle group. NAFLD activity score (NAS) tended to decrease in the milk thistle treatment groups compared with vehicle group, as did steatosis scores.

CONCLUSION

Milk thistle extract administration induced a decreasing trend in NAS compared with the vehicle group. Milk thistle induced a numerical decrease of the steatosis score compared with vehicle, and this was accompanied by a statistically significant decrease in liver weight and the liver-to-body weight ratio, implying a potential anti-steatosis effect of milk thistle.

Ascorbic acid suppresses endotoxemia and NF-κB signaling cascade in alcoholic liver fibrosis in guinea pigs: a mechanistic approach

Alcohol consumption increases the small intestinal bacterial overgrowth (SIBO) and intestinal permeability of endotoxin. The endotoxin mediated inflammatory signaling plays a major role in alcoholic liver fibrosis. We evaluated the effect of ascorbic acid (AA), silymarin and alcohol abstention on the alcohol induced endotoxemia and NF-κB activation cascade pathway in guinea pigs (Cavia porcellus). Guinea pigs were administered ethanol at a daily dose of 4g/kg b.wt for 90days. After 90days, ethanol administration was stopped. The ethanol treated animals were divided into abstention, silymarin (250mg/kg b.wt) and AA (250mg/kg b.wt) supplemented groups and maintained for 30days. The SIBO, intestinal permeability and endotoxin were significantly increased in the ethanol group. The mRNA expressions of intestinal proteins claudin, occludin and zona occludens-1 were significantly decreased in ethanol group. The mRNA levels of inflammatory receptors, activity of IKKβ and the protein expressions of phospho-IκBα, NF-κB, TNF-α, TGF-β1 and IL-6 were also altered in ethanol group. The expressions of fibrosis markers α-SMA, α1 (I) collagen and sirius red staining in the liver revealed the induction of fibrosis. But the supplementation of AA could induce greater reduction of ethanol induced SIBO, intestinal barrier defects, NF-κB activation and liver fibrosis than silymarin. The possible mechanism may be the inhibitory effect of AA on SIBO, intestinal barrier defect and IKKβ, which decreased the activation of NF-κB and synthesis of cytokines. This might have led to suppression of HSCs activation and liver fibrosis.

Ascorbic acid is superior to silymarin in the recovery of ethanol-induced inflammatory reactions in hepatocytes of guinea pigs

Both oxidative stress and inflammatory reactions play a major role in alcoholic liver fibrosis. We evaluated the efficacy of ascorbic acid (AA) and silymarin in the regression of alcohol-induced inflammation in hepatocytes of guinea pigs (Cavia porcellus). Animals were administered with ethanol at a daily dose of 4 g/kg body weight (b.wt) for 90 days. On the ninety-first day, ethanol administration was stopped and animals were divided into alcohol abstention group and silymarin- (25 mg/100 g b.wt) and AA- (25 mg/100 g b.wt) supplemented groups and maintained for 30 days. There was a significant increase in the activities of alanine aminotransferase, aspartate aminotransferase, and γ-glutamyl transpeptidase in the serum of the ethanol group. The intracellular reactive oxygen species (ROS) and expressions of cytochrome P4502E1 and nuclear factor κB1, tumor necrosis factor-α, and transforming growth factor-β(1) in hepatocytes were significantly increased in ethanol group. The fibrotic markers α-smooth muscle actin and α(1)(I) collagen and activity of cytotoxicity marker caspase-3 were significantly increased and AA content was significantly reduced in hepatocytes of alcohol-treated guinea pigs. But the AA and silymarin supplementation significantly reduced these changes in comparison with alcohol abstention group. AA could induce greater reduction of inflammatory and fibrotic markers in hepatocytes than silymarin. This indicates that AA is superior to silymarin in inhibiting intracellular ROS generation and thereby reducing the ethanol-induced inflammation in hepatocytes.

A new approach to facilitate diagnosis of nonalcoholic fatty liver disease through a galactose single point method in rats with fatty liver

BACKGROUND

Liver biopsy reliably diagnoses nonalcoholic fatty liver disease, but its invasiveness and inter- and intra-observer errors limit its usefulness in monitoring.

AIMS

Use a galactose single point method or combined biochemical parameters to improve assessments of nonalcoholic fatty liver disease in a rat model.

METHODS

Three nonalcoholic fatty liver disease severities were generated in 50 rats: a control group (n=18) on a standard diet, and 2 study groups on a choline-deficient diet (n=18), with and without treatment with silymarin (n=14). At weeks 4, 8, and 18, a galactose solution (0.5 g/kg/body weight) was rapidly injected intravenously. Sixty minutes later, internal artery blood was taken for biochemical analyses, including galactose. The livers were then removed for haematoxylin-eosin staining and to measure the hepatic lipid content.

RESULTS

Alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, albumin, and total protein were each significantly correlated with nonalcoholic fatty liver disease severity. Regarding logistic regression, galactose single point method and total protein were significantly predictive. The optimal alanine aminotransferase cutoff point for nonalcoholic fatty liver disease prediction from the receiver-operating characteristic curve had 72.4% sensitivity and 52.4% specificity; galactose single point method alone had 82.8% and 72.4%, whereas galactose single point method+total protein showed 82.8% and 81.0%.

CONCLUSIONS

Both galactose single point method and galactose single point method+total protein had greater diagnostic sensitivity and specificity for nonalcoholic fatty liver disease than traditional biochemical tests.

Milk thistle and its derivative compounds: a review of opportunities for treatment of liver disease

Milk thistle extracts have been used as a "liver tonic" for centuries. In recent years, silibinin, the active ingredient in milk thistle extracts, has been studied both in vitro and in vivo to evaluate the beneficial effects in hepatic disease. Silibinin increases antioxidant concentrations and improves outcomes in hepatic diseases resulting from oxidant injury. Silibinin treatment has been associated with protection against hepatic toxins, and also has resulted in decreased hepatic inflammation and fibrosis. Limited information currently is available regarding silibinin use in veterinary medicine. Future study is justified to evaluate dose, kinetics, and treatment effects in domestic animals.

Absorption and metabolism of milk thistle flavanolignans in humans

This study evaluated the absorption and metabolism of milk thistle flavonolignans silychristin, silydianin, silybin and isosilybin isomers (all together known as silymarin) in humans. Fourteen volunteers consumed an extract of milk thistle and urine was collected up to 48 h after consumption. Thirty-one metabolites were identified in urine by means of HPLC-MS/MS, monoglucuronides being the most common excreted form, followed by sulphate-glucuronides and diglucuronides, respectively. The excretion of monoglucuronides peaked 2 h after consumption, whereas sulphate-glucuronide and diglucuronide excretion peaked at 8 h. The bioavailability of milk thistle flavanolignans was 0.45±0.28% (mean±SD). In conclusion, milk thistle flavonolignans are extensively modified after ingestion and recovered in urine as sulpho- and glucuronyl-conjugates, indicating a strong affinity for hepatic phase II enzymes. All future studies (in vitro and in vivo) dealing with the effects of milk thistle should start by considering the modification of its flavonolignans after ingestion by humans.

Antioxidants as therapeutic agents for liver disease

Oxidative stress is commonly associated with a number of liver diseases and is thought to play a role in the pathogenesis of chronic hepatitis C, alcoholic liver disease, non-alcoholic steatohepatitis (NASH), haemochromatosis and Wilson's disease. Antioxidant therapy has thus been considered to have the possibility of beneficial effects in the management of these liver diseases. Despite this promise, antioxidants have produced mixed results in a number of clinical trials of efficacy. This review summarizes the results of clinical trials of antioxidants as sole or adjuvant therapy of chronic hepatitis C, alcoholic liver disease and non-alcoholic steatohepatitis (NASH). Overall, the most promising results to date are for vitamin E therapy of NASH but some encouraging results have been obtained with antioxidant therapy of acute alcoholic hepatitis as well. Despite evidence for small reductions of serum alanine aminotransferase, there is as yet no convincing evidence that antioxidant therapy itself is beneficial to patients with chronic hepatitis C. Problems such as small sample size, short follow up duration, inadequate endpoints, failure to demonstrate tissue delivery and antioxidant efficacy, and heterogeneous nature of the 'antioxidant' compounds used have complicated interpretation of results of the clinical studies. These limitations and their implications for future trial design are discussed.

Effect of silymarin in the treatment of allergic rhinitis

OBJECTIVE

Although the role of oxidative stresses has been confirmed in the pathophysiology of allergic rhinitis and the protective effect of silymarin against oxidative stresses has been proven in different organs, no study has yet been conducted on the impact of silymarin on allergic rhinitis treatment.

STUDY DESIGN

A randomized clinical trial study.

SETTING

Two tertiary referral centers with otorhinolaryngology-head and neck surgery and allergy and immunology departments.

PATIENTS AND METHODS

In a randomized clinical trial, 94 patients with the signs and symptoms of allergic rhinitis and a positive skin prick test were selected and randomly divided into 2 groups. Their signs and symptoms, eosinophil percentage on nasal smear, serum IgE, and interleukin (IL-4, IL-5, interferon-γ) levels were recorded. The study group was treated with silymarin, whereas the control group received placebo, both for 1 month, along with routine antihistamine treatment. At the end of the treatment course, clinical and laboratory findings were statistically analyzed.

RESULTS

Sixty patients completed the trial. Based on the Sino-Nasal Outcome Test 20 (SNOT-20), a significant improvement in clinical symptom severity was observed in both groups (9.23 ± 5.14 vs 2.20 ± 2.69; P < .001), which was statistically significantly higher in the study group (P < .001). Posttreatment percentage of nasal eosinophils and cytokine levels showed no significant difference (P > .05). Rise in serum IgE level was seen after treatment with silymarin (P = .003).

CONCLUSION

Considering the statistically effective role of silymarin in alleviating the severity of allergic rhinitis symptoms, applying this herbal antioxidant along with other medications may result in better management.

Antioxidant and hepatoprotective effects of silibinin in a rat model of nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is a progressive liver disease related to the metabolic syndrome, obesity and diabetes. The rising prevalence of NASH and the lack of efficient treatments have led to the exploration of different therapeutic approaches. Milk thistle (Silibum marianum) is a medicinal plant used for its hepatoprotective properties in chronic liver disease since the 4th century BC. We explored the therapeutic effect of silibinin, the plant's most biologically active extract, in an experimental rat NASH model. A control group was fed a standard liquid diet for 12 weeks. The other groups were fed a high-fat liquid diet for 12 weeks without (NASH) or with simultaneous daily supplement with silibinin-phosphatidylcholine complex (Silibinin 200 mg kg(-1)) for the last 5 weeks. NASH rats developed all key hallmarks of the pathology. Treatment with silibinin improved liver steatosis and inflammation and decreased NASH-induced lipid peroxidation, plasma insulin and TNF-α. Silibinin also decreased O(2) (∙-) release and returned the relative liver weight as well as GSH back to normal. Our results suggest that milk thistle's extract, silibinin, possesses antioxidant, hypoinsulinemic and hepatoprotective properties that act against NASH-induced liver damage. This medicinal herb thus shows promising therapeutic potential for the treatment of NASH.

Treatment of alcoholic liver disease

Alcoholic liver disease (ALD) remains a major cause of liver-related mortality in the US and worldwide. The correct diagnosis of ALD can usually be made on a clinical basis in conjunction with blood tests, and a liver biopsy is not usually required. Abstinence is the hallmark of therapy for ALD, and nutritional therapy is the first line of therapeutic intervention. The role of steroids in patients with moderate to severe alcoholic hepatitis is gaining increasing acceptance, with the caveat that patients be evaluated for the effectiveness of therapy at 1 week. Pentoxifylline appears to be especially effective in ALD patients with renal dysfunction/hepatorenal syndrome. Biologics such as specific anti-TNFs have been disappointing and should probably not be used outside of the clinical trial setting. Transplantation is effective in patients with end-stage ALD who have stopped drinking (usually for ≥6 months), and both long-term graft and patient survival are excellent.

Hepatoprotective effects of the nitric oxide donor isosorbide-5-mononitrate alone and in combination with the natural hepatoprotectant, silymarin, on carbon tetrachloride-induced hepatic injury in rats

The aim of this study was to investigate the effect of the nitric oxide donor isosorbide-5-mononitrate (5-ISMN) alone or in combination with the natural hepatoprotectant with anti-oxidant activity silymarin on the carbon tetrachloride (CCl(4))-induced hepatic injury in rats. 5-ISMN (1.8, 3.6 or 7.2 mg/kg), silymarin (25 mg/kg) or 5-ISMN (1.8, 3.6 or 7.2 mg/kg) combined with silymarin was given once daily orally simultaneously with CCl(4) and for 15 days thereafter. Liver damage was assessed by determining serum enzyme activities and hepatic histopathology. 5-ISMN given at the above doses conferred significant protection against the hepatotoxic actions of CCl(4) in rats, reducing serum alanine aminotransferase (ALT) levels by 31.2, 39.3 and 61.6%, respectively, when compared with controls. Serum aspartate aminotransferase (AST) levels decreased by 19.8, 22.7 and 59.4%, respectively, while alkaline phosphatase (ALP) decreased by 26.1 and 32.6% by the drug at 3.6 and 7.2 mg/kg, respectively. When silymarin was added to 5-ISMN (1.8, 3.6 or 7.2 mg/kg), ALT decreased by 32.8, 59.6, 70.2% and AST by 28.7, 50.3, 60%, when compared with CCl(4) control group levels. Silymarin in combination with 3.6 or 7.2 mg/kg 5-ISMN resulted in 37.5 and 39.2% reductions in ALP when compared with CCl(4) control group. Meanwhile, silymarin alone reduced ALT, AST and ALP levels by 65.9, 52 and 62.3%, respectively. Blood levels of reduced glutathione were markedly decreased in CCl(4)-treated rats. Reduced glutathione levels were increased by the administration of 5-ISMN and restored to near normal values by silymarin treatment. Histopathological alterations by CCl(4) were markedly reduced after treatment with 5-ISMN alone or in combination with silymarin. Histopathologic examination of the livers of CCl(4)-treated rats administered 5-ISMN at 7.2 mg/kg showed marked restoration of the normal architecture of the liver tissue and minimal fibrosis. Silymarin co-administered with 5-ISMN resulted in further improvement of the histologic picture. These results indicates that treatment with 5-ISMN protects against hepatocellular necrosis induced by CCl(4). The study suggests a potential therapeutic use for 5-ISMN in combination with silymarin in liver injury.

Silymarin ascending multiple oral dosing phase I study in noncirrhotic patients with chronic hepatitis C

Silymarin, derived from the milk thistle plant Silybum marianum, is widely used for self-treatment of liver diseases, including hepatitis C virus (HCV), and its antiviral activity has been demonstrated in vitro and in HCV patients administered an intravenous formulation of the major silymarin flavonolignans, silybin A and silybin B. The safety and dose-exposure relationships of higher than customary oral doses of silymarin and its acute effects on serum HCV RNA were evaluated in noncirrhotic HCV patients. Four cohorts of 8 patients with well-compensated, chronic noncirrhotic HCV who failed interferon-based therapy were randomized 3:1 to silymarin or placebo. Oral doses of 140, 280, 560, or 700 mg silymarin were administered every 8 hours for 7 days. Steady-state exposures for silybin A and silybin B increased 11-fold and 38-fold, respectively, with a 5-fold increase in dose, suggesting nonlinear pharmacokinetics. No drug-related adverse events were reported, and no clinically meaningful reductions from baseline serum transaminases or HCV RNA titer were observed. Oral doses of silymarin up to 2.1 g per day were safe and well tolerated. The nonlinear pharmacokinetics of silybin A and silybin B suggests low bioavailability associated with customary doses of silymarin may be overcome with doses above 700 mg.