Effects of silymarin in alcoholic patients with cirrhosis of the liver: results of a controlled, double-blind, randomized and multicenter trial

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.

Alcoholic liver disease: pathogenesis, management, and novel targets for therapy

Alcohol use is a leading cause of preventable morbidity and mortality worldwide, with much of its negative impact as the result of alcoholic liver disease (ALD). ALD is a broad term that encompasses a spectrum of phenotypes ranging from simple steatosis to steatohepatitis, progressive fibrosis, cirrhosis, and hepatocellular carcinoma. The mechanisms underlying the development of these different disease stages are incompletely understood. Standard treatment of ALD, which includes abstinence, nutritional support, and corticosteroids, has not changed in the last 40 years despite continued poor outcomes. Novel therapies are therefore urgently needed. The development of such therapies has been hindered by inadequate resources for research and unsuitable animal models. However, recent developments in translational research have allowed for identification of new potential targets for therapy. These targets include: (i) CXC chemokines, (ii) IL-22/STAT3, (iii) TNF receptor superfamily, (iv) osteopontin, (v) gut microbiota and lipopolysaccharide (LPS), (vi) endocannabinoids, and (vii) inflammasomes. We review the natural history, risk factors, pathogenesis, and current treatments for ALD. We further discuss the findings of recent translational studies and potential therapeutic targets.

Translating an understanding of the pathogenesis of hepatic fibrosis to novel therapies

The response to injury is one of wound healing and fibrogenesis, which ultimately leads to fibrosis. The fibrogenic response to injury is a generalized one across virtually all organ systems. In the liver, the injury response, typically occurring over a prolonged period of time, leads to cirrhosis (although it should be pointed out that not all patients with liver injury develop cirrhosis). The fact that many different diseases result in cirrhosis suggests a common pathogenesis. The study of hepatic fibrogenesis over the past 2 decades has been remarkably active, leading to a considerable understanding of this process. It clearly has been shown that the hepatic stellate cell is a central component in the fibrogenic process. It also has been recognized that other effector cells are important in the fibrogenic process, including resident fibroblasts, bone marrow-derived cells, fibrocytes, and even perhaps cells derived from epithelial cells (ie, through epithelial to mesenchymal transition). A key aspect of the biology of fibrogenesis is that the fibrogenic process is dynamic; thus, even advanced fibrosis (or cirrhosis) is reversible. Together, an understanding of the cellular basis for liver fibrogenesis, along with multiple aspects of the basic pathogenesis of fibrosis, have highlighted many exciting potential therapeutic opportunities. Thus, although the most effective antifibrotic therapy is simply treatment of the underlying disease, in situations in which this is not possible, specific antifibrotic therapy is likely not only to become feasible, but will soon become a reality. This review highlights the mechanisms underlying fibrogenesis that may be translated into future antifibrotic therapies and to review the current state of clinical development.

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.

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

Silymarin is an herbal product showing potential as protection against hepatic disorders. In an attempt to develop the agent for the treatment of hepatic fibrosis, we screened the effects of silymarin on a rat model of hepatic fibrosis induced by carbon tetrachloride (CCl₄). Intraperitoneal administration of CCl₄ to rats for 8 weeks not only increased the plasma levels of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) but also induced a marked increase in the formation of hepatic fibrosis. Moreover, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were also reduced in the liver of rats treated with CCl₄. Oral administration of silymarin (200 mg/kg, three times daily), in parallel, decreased the plasma levels of GOT and GPT. Furthermore, in addition to the improvement of hepatic fibrosis, the hepatic levels of hydroxyproline and connective tissue growth factor (CTGF) were both markedly decreased by silymarin. Silymarin also elevated the activities of SOD and GPx in liver isolated from CCl₄-treated rats. The results suggest that oral administration of silymarin protects against CCl₄-induced hepatic fibrosis in rats, likely due to the decrease in fibrotic parameters such as CTGF.

Silibinin, dexamethasone, and doxycycline as potential therapeutic agents for treating vesicant-inflicted ocular injuries

There are no effective and approved therapies against devastating ocular injuries caused by vesicating chemical agents sulfur mustard (SM) and nitrogen mustard (NM). Herein, studies were carried out in rabbit corneal cultures to establish relevant ocular injury biomarkers with NM for screening potential efficacious agents in laboratory settings. NM (100nmol) exposure of the corneas for 2h (cultured for 24h), showed increases in epithelial thickness, ulceration, apoptotic cell death, epithelial detachment microbullae formation, and the levels of VEGF, cyclooxygenase-2 (COX-2) and matrix metalloproteinase-9 (MMP-9). Employing these biomarkers, efficacy studies were performed with agent treatments 2h and every 4h thereafter, for 24h following NM exposure. Three agents were evaluated, including prescription drugs dexamethasone (0.1%; anti-inflammatory steroid) and doxycycline (100nmol; antibiotic and MMP inhibitor) that have been studied earlier for treating vesicant-induced eye injuries. We also examined silibinin (100μg), a non-toxic natural flavanone found to be effective in treating SM analog-induced skin injuries in our earlier studies. Treatments of doxycycline+dexamethasone, and silibinin were more effective than doxycycline or dexamethasone alone in reversing NM-induced epithelial thickening, microbullae formation, apoptotic cell death, and MMP-9 elevation. However, dexamethasone and silibinin alone were more effective in reversing NM-induced VEGF levels. Doxycycline, dexamethasone and silibinin were all effective in reversing NM-induced COX-2 levels. Apart from therapeutic efficacy of doxycycline and dexamethasone, these results show strong multifunctional efficacy of silibinin in reversing NM-induced ocular injuries, which could help develop effective and safe therapeutics against ocular injuries by vesicants.

Alcoholic liver disease

Alcohol use disorders affect millions of individuals worldwide. Alcohol consumption is directly associated with liver disease mortality and accounts for elevated social and economic costs. Alcoholic liver disease (ALD) may take the form of acute involvement (alcoholic hepatitis) or chronic liver disease (steatosis, steatohepatitis, fibrosis and cirrhosis). The severity and prognosis of alcohol-induced liver disease depends on the amount, pattern and duration of alcohol consumption, as well as on the presence of liver inflammation, diet, nutritional status and genetic predisposition of an individual. While steatosis is an almost completely benign disease, liver cirrhosis is associated with marked morbidity, mortality and life expectancy shortening. The median survival of patients with advanced cirrhosis is 1-2 years. Severe acute alcoholic hepatitis (AH) is associated with mortality as high as 50%. It has been managed with corticoids, pentoxifylline and enteral nutrition, although evidence based data are still conflicting. Some author suggest that pentoxifylline could be a better first-line treatment in patients with severe AH. Absolute abstinence is a basic condition for any treatment of acute or chronic ALD, the other therapeutical procedure being of a supportive nature and questionable significance. Acamprosate appears to be an effective treatment strategy for supporting continuous abstinence in alcohol dependent patients. Patients with advanced liver cirrhosis who demonstrably abstain can be considered for liver transplantation, which leads to a markedly prolonged life expectancy. The crucial step in ALD prevention is in the prevention of alcohol abuse, whereas the prevention of liver injury in active alcohol abusers is not clinically applicable.

Oxidative stress and benefits of antioxidant agents in acute and chronic hepatitis

CONTEXT

Oxidative damage due to oxidative stress is the failure of the cell's defense against the deleterious effects of harmful agents by means of its numerous autoprotective mechanisms. oxidative stress is a key impairment induced by various conditions, including atherosclerosis, hypertension, ischemia-reperfusion, hepatitis, pancreatitis, cancer, and neurodegenerative diseases.

EVIDENCE ACQUISITION

Oxidative stress is a common pathogenetic mechanism contributing to the initiation and progression of hepatic damage in cases of inflammatory liver disorders, including acute and chronic hepatitis. Antioxidant administration is a good therapeutic strategy for the treatment of hepatitis.

RESULTS

Our comprehensive review of the literature revealed that contradictory results have been obtained with many antioxidants and antioxidant agents.

CONCLUSION

Since clinical studies to date have generally involved testing of the effects of antioxidant mixtures containing more than 2 antioxidants and also have been limited because of toxic effects of high doses of some antioxidants, antioxidant therapy for acute and chronic hepatitis needs further study.

Do dietary supplements have beneficial health effects in industrialized nations: what is the evidence?

BACKGROUND

Dietary supplements are regularly used by at least half of the American population, yet the health benefits of these agents are unclear.

OBJECTIVE

A systematic review to determine the benefits and risks of dietary supplements in Westernized societies.

DATA SOURCES

MEDLINE, Embase, Cochrane Register of Controlled Trials and citation review of relevant articles.

STUDY SELECTION

Randomized, placebo-controlled clinical trials in non-pregnant Westernized adults that evaluated clinical outcomes of nutritional supplements.

DATA EXTRACTION

Data were abstracted on study design, study size, study setting, patient population, dietary intervention and clinical outcomes. The outcome of each study was classified as non-beneficial, beneficial or harmful according to whether the end-point(s) of interest reached statistical significance.

DATA SYNTHESIS

Sixty-three studies met the criteria for our systematic review. No benefit was recorded in 45 studies, with 10 of these showing a trend towards harm and with two showing a trend towards benefit. Four studies reported harm with increased cancer deaths (n=2) and increased fractures (n=2). Two studies reported both a harmful as well as a beneficial outcome. A beneficial outcome was reported in 12 studies; 6 which studied vitamin D and three which investigated omega-3 fatty acids. While a benefit was reported in one study each which investigated Vitamin E, folic acid and Ginkgo biloba this benefit was not confirmed by larger and more adequately powered studies.

CONCLUSIONS

With the possible exceptions of Vitamin D and omega-3 fatty acids there is no data to support the widespread use of dietary supplements in Westernized populations; indeed, many of these supplements may be harmful.

Predicting in vivo anti-hepatofibrotic drug efficacy based on in vitro high-content analysis

Background/Aims

Many anti-fibrotic drugs with high in vitro efficacies fail to produce significant effects in vivo. The aim of this work is to use a statistical approach to design a numerical predictor that correlates better with in vivo outcomes.

Methods

High-content analysis (HCA) was performed with 49 drugs on hepatic stellate cells (HSCs) LX-2 stained with 10 fibrotic markers. ∼0.3 billion feature values from all cells in >150,000 images were quantified to reflect the drug effects. A systematic literature search on the in vivo effects of all 49 drugs on hepatofibrotic rats yields 28 papers with histological scores. The in vivo and in vitro datasets were used to compute a single efficacy predictor (E_predict).

Results

We used in vivo data from one context (CCl₄ rats with drug treatments) to optimize the computation of E_predict. This optimized relationship was independently validated using in vivo data from two different contexts (treatment of DMN rats and prevention of CCl₄ induction). A linear in vitro-in vivo correlation was consistently observed in all the three contexts. We used E_predict values to cluster drugs according to efficacy; and found that high-efficacy drugs tended to target proliferation, apoptosis and contractility of HSCs.

Conclusions

The E_predict statistic, based on a prioritized combination of in vitro features, provides a better correlation between in vitro and in vivo drug response than any of the traditional in vitro markers considered.

Alcoholic liver disease: pathogenesis and new therapeutic targets

Alcoholic liver disease (ALD) is a major cause of chronic liver disease worldwide and can lead to fibrosis and cirrhosis. The latest surveillance report published by the National Institute on Alcohol Abuse and Alcoholism showed that liver cirrhosis was the 12th leading cause of death in the United States, with a total of 29,925 deaths in 2007, 48% of which were alcohol related. The spectrum of ALD includes simple steatosis, alcoholic hepatitis, fibrosis, cirrhosis, and superimposed hepatocellular carcinoma. Early work on the pathogenesis of the disease focused on ethanol metabolism-associated oxidative stress and glutathione depletion, abnormal methionine metabolism, malnutrition, and production of endotoxins that activate Kupffer cells. We review findings from recent studies that have characterized specific intracellular signaling pathways, transcriptional factors, aspects of innate immunity, chemokines, epigenetic features, microRNAs, and stem cells that are associated with ALD, improving our understanding of its pathogenesis. Despite this progress, no targeted therapies are available. The cornerstone of treatment for alcoholic hepatitis remains as it was 40 years ago: abstinence, nutritional support, and corticosteroids. There is an urgent need to develop new pathophysiology-oriented therapies. Recent translational studies of human samples and animal models have identified promising therapeutic targets.

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.

Alcoholic liver disease: pathogenesis and new targets for therapy

Alcoholic liver disease (ALD) is a major cause of morbidity and mortality worldwide. The spectrum of disease ranges from fatty liver to hepatic inflammation, necrosis, progressive fibrosis and hepatocellular carcinoma. In developed countries, ALD is a major cause of end-stage liver disease that requires transplantation. The most effective therapy for ALD is alcohol abstinence. However, for patients with severe forms of ALD (that is, alcoholic hepatitis) and for those who do not achieve abstinence from alcohol, targeted therapies are urgently needed. The development of new drugs for ALD is hampered by the scarcity of studies and the drawbacks of existing animal models, which do not reflect all the features of the human disease. However, translational research using liver samples from patients with ALD has identified new potential therapeutic targets, such as CXC chemokines, osteopontin and tumor necrosis factor receptor superfamily member 12A. The pathogenetic roles of these targets, however, remain to be confirmed in animal models. This Review summarizes the epidemiology, natural history, risk factors and current knowledge of the pathogenetic mechanisms of ALD. In addition, this article provides a detailed description of the findings of these translational studies and of the animal models used to study ALD.

Emergence of hepatitis B virus S gene mutants in patients experiencing hepatitis B surface antigen seroconversion after peginterferon therapy

With anti-hepatitis B virus (anti-HBV) therapy using peginterferon, the seroconversion of hepatitis B surface antigen (HBsAg), which is considered a cure of the disease, can be achieved in a small percentage of patients. Eight of 245 consecutive patients (3.27%) with chronic hepatitis B who received peginterferon therapy at our center achieved HBsAg seroclearance. Surprisingly, two of the eight patients remained viremic according to standard HBV DNA assays. The coding regions of the HBV pre-S/S gene, which were derived from serial serum samples, were analyzed. Site-directed mutagenesis experimentation was performed to verify the phenotypic alterations in Huh-7 cells. In patient 1, an sT125A mutant developed during the HBsAg-negative stage and constituted 11.2% of the viral population. The HBV DNA level was 2.73 × 10(4) IU/mL at the time of detection. This mutant was not detectable in the HBsAg-positive stages. A phenotypic study of Huh-7 cells showed a significant reduction of antigenicity. In patient 2, an sW74* truncation mutation was found during the HBsAg-negative stage and constituted 83.1% of the viral population. The HBV DNA level was 4.12 × 10(4) IU/mL at the time of detection. A phenotypic study of Huh-7 cells showed a complete loss of antigenicity. Patient 2 subsequently experienced an episode of hepatitis relapse 7 months after the end of treatment and was negative for HBsAg throughout the hepatitis flare.

CONCLUSION

During antiviral therapy with peginterferon, the achievement of HBsAg seroconversion does not necessarily indicate viral eradication. The emergence of S gene mutants is another possibility, and a relapse with HBsAg-negative hepatitis can occur.

Molecular mechanism of silymarin-induced apoptosis in a highly metastatic lung cancer cell line anip973

BACKGROUND

Silymarin, the main flavonoid constituent element extracted from Silybum marianum possessing antioxidant activity, is already known to be able to block the NF-κB activation process and result in cell apoptosis, implicating silymarin's potential to control cancer cell growth.

MATERIALS AND METHODS

In this study, based upon the above assumption, silymarin was administered to a highly metastatic lung cancer cell line Anip973 to test silymarin's role in cancer cell proliferation.

RESULTS

Silymarin had significant inhibitory effects on the proliferation of Anip973 cells in a dose-dependent and time-response manner within 48 hours. Silymarin can induce Anip973 apoptosis.

CONCLUSIONS

Silymarin may in vitro inhibit the proliferation of the human lung adenocarcinoma cell line Anip973 and induce apoptosis via the mitochondria-dependent caspase cascade pathway.

Hepatic stellate cells and innate immunity in alcoholic liver disease

Constant alcohol consumption is a major cause of chronic liver disease, and there has been a growing concern regarding the increased mortality rates worldwide. Alcoholic liver diseases (ALDs) range from mild to more severe conditions, such as steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. The liver is enriched with innate immune cells (e.g. natural killer cells and Kupffer cells) and hepatic stellate cells (HSCs), and interestingly, emerging evidence suggests that innate immunity contributes to the development of ALDs (e.g. steatohepatitis and liver fibrosis). Indeed, HSCs play a crucial role in alcoholic steatosis via production of endocannabinoid and retinol metabolites. This review describes the roles of the innate immunity and HSCs in the pathogenesis of ALDs, and suggests therapeutic targets and strategies to assist in the reduction of ALD.

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.

Silymarin use and liver disease progression in the Hepatitis C Antiviral Long-Term Treatment against Cirrhosis trial

BACKGROUND

Silymarin is the most commonly used herbal product for chronic liver disease; yet, whether silymarin protects against liver disease progression remains unclear.

AIM

To assess the effects of silymarin use on subsequent liver disease progression in 1049 patients of the Hepatitis C Antiviral Long-Term Treatment against Cirrhosis (HALT-C) trial who had advanced fibrosis or cirrhosis and had failed prior peginterferon plus ribavirin treatment.

METHODS

Patients recorded their use of silymarin at baseline and were followed up for liver disease progression (two point increase in Ishak fibrosis score across baseline, year 1.5, and year 3.5 biopsies) and over 8.65 years for clinical outcomes.

RESULTS

At baseline, 34% of patients had used silymarin, half of whom were current users. Use of silymarin was associated (P < 0.05) with male gender; oesophageal varices; higher ALT and albumin; and lower AST/ALT ratio, among other features. Baseline users had less hepatic collagen content on study biopsies and had less histological progression (HR: 0.57, 95% CI: 0.33-1.00; P-trend for longer duration of use=0.026). No effect was seen for clinical outcomes.

CONCLUSIONS

Silymarin use among patients with advanced hepatitis C-related liver disease is associated with reduced progression from fibrosis to cirrhosis, but has no impact on clinical outcomes (Clinicaltrials.gov #NCT00006164).

Milk thistle in liver diseases: past, present, future

Silybum marianum or milk thistle (MT) is the most well-researched plant in the treatment of liver disease. The active complex of MT is a lipophilic extract from the seeds of the plant and is composed of three isomer flavonolignans (silybin, silydianin, and silychristin) collectively known as silymarin. Silybin is a component with the greatest degree of biological activity and makes up 50% to 70% of silymarin. Silymarin is found in the entire plant but it is concentrated in the fruit and seeds. Silymarin acts as an antioxidant by reducing free radical production and lipid peroxidation, has antifibrotic activity and may act as a toxin blockade agent by inhibiting binding of toxins to the hepatocyte cell membrane receptors. In animals, silymarin reduces liver injury caused by acetaminophen, carbon tetrachloride, radiation, iron overload, phenylhydrazine, alcohol, cold ischaemia and Amanita phalloides. Silymarin has been used to treat alcoholic liver disease, acute and chronic viral hepatitis and toxin-induced liver diseases.

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.

Antioxidant effect of 2-hydroxy-4-methoxy benzoic acid on ethanol-induced hepatotoxicity in rats

Alcoholic liver disease (ALD) is one of the most common diseases in society. A large number of studies are in progress to identify natural substances that are effective in reducing the severity of ALD. 2-Hydroxy-4-methoxy benzoic acid (HMBA), the active principle of Hemidesmus indicus, an indigenous Ayurvedic medicinal plant in India, is expected to significantly inhibit the development of liver injury in ethanol administration. It is expected to reduce the severity of liver damage in terms of body weight, hepatic marker enzymes, oxidative stress, antioxidant status and histological changes in ethanol-induced hepatotoxic rats. Hepatotoxicity was induced by administering 20% ethanol (5 g kg−1 daily) for 60 days to male Wistar rats, which resulted in significantly decreased body weight and an increase in liver-body weight ratio. The liver marker enzymes aspartate transaminase, alanine transaminase, alkaline phosphatase, γ-glutamyl transpeptidase and lactate dehydrogenase were elevated. In addition, the levels of plasma, erythrocyte and hepatic thiobarbituric acid reactive substances, hydroperoxides and conjugated dienes were also elevated in ethanol-fed rats as compared with those of the experimental control rats. Decreased activity of superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, vitamin C and α-tocopherol was also observed on alcohol administration as compared with experimental control rats. HMBA was co-administered at a dose of 200 μgkg−1 daily for the last 30 days of the experiment to rats with alcohol-induced liver injury, which significantly increased body weight, significantly decreased the liver-body weight ratio, transaminases, alkaline phosphatase, γ-glutamyl transpeptidase and lactate dehydrogenase, significantly decreased the levels of lipid peroxidative markers, significantly elevated the activity of enzymic and non-enzymic antioxidants in plasma, erythrocytes and liver and also increased levels of plasma and liver vitamin C and α-tocopherol at the end of the experimental period as compared with untreated ethanol-administered rats. The histological changes were also in correlation with the biochemical findings. The results suggest that HMBA administration may afford protection against ethanol-induced liver injury in rats.

Combination of ginsenoside Rg3 with docetaxel enhances the susceptibility of prostate cancer cells via inhibition of NF-kappaB

Ginsenoside Rg3 has been a subject of interest for use as a cancer preventive or therapeutic agent. Nuclear factor-kappa (NF-kappaB) is constitutively activated in prostate cancer, and gives cancer cells resistance to chemotherapeutic agents. To investigate whether Rg3 can suppress the activation of NF-kappaB, and thus increase susceptibility of prostate (LNCaP and PC-3, DU145) cells against chemotherapeutics, prostate cancer cell growth as well as activation of NF-kappaB was examined. We found that a combination treatment of Rg3 (50 microM) with a conventional agent docetaxel (5 nM) was more effective in the inhibition of prostate cancer cell growth and induction of apoptosis as well as G(0)/G(1) arrest accompanied with the significant inhibition of NF-kappaB activity than those by treatment of Rg3 or docetaxel alone. It was also found that NF-kappaB target gene expression of Bax, caspase-3, and caspase-9 was much more significantly enhanced, but the expression of Bcl-2, inhibitor of apoptosis protein (IAP-1) and X chromosome IAP (XIAP), and the expression of cell cycle regulatory proteins cyclin B, D1 and E, and cyclin dependent kinases 2 and 4 was also much more significantly inhibited by the combination treatment. The combination of Rg3 (50 microM) with cisplatin (10 microM) and doxorubicin (2 microM) was also more effective in the inhibition of prostate cancer cell growth and NF-kappaB activity than those by the treatment of Rg3 or chemotherapeutics alone. These results indicate that ginsenoside Rg3 inhibits NF-kappaB, and enhances the susceptibility of prostate cancer cells to docetaxel and other chemotherapeutics. Thus, ginsenoside Rg3 could be useful as an anti-cancer agent.

Inhibition of liver fibrosis by solubilized coenzyme Q10: Role of Nrf2 activation in inhibiting transforming growth factor-beta1 expression

Coenzyme Q10 (CoQ10), an endogenous antioxidant, is important in oxidative phosphorylation in mitochondria. It has anti-diabetic and anti-cardiovascular disease effects, but its ability to protect against liver fibrosis has not been studied. Here, we assessed the ability of solubilized CoQ10 to improve dimethylnitrosamine (DMN)-induced liver fibrogenesis in mice. DMN treatments for 3 weeks produced a marked liver fibrosis as assessed by histopathological examination and tissue 4-hydroxyproline content. Solubilized CoQ10 (10 and 30 mg/kg) significantly inhibited both the increases in fibrosis score and 4-hydroxyproline content induced by DMN. Reverse transcription-polymerase chain reaction and Western blot analyses revealed that solubilized CoQ10 inhibited increases in the transforming growth factor-beta1 (TGF-beta1) mRNA and alpha-smooth muscle actin (alpha-SMA) protein by DMN. Interestingly, hepatic glutamate-cysteine ligase (GCL) and glutathione S-transferase A2 (GSTA2) were up-regulated in mice treated with CoQ10. Solubilized CoQ10 also up-regulated antioxidant enzymes such as catalytic subunits of GCL and GSTA2 via activating NF-E2 related factor2 (Nrf2)/antioxidant response element (ARE) in H4IIE hepatoma cells. Moreover, CoQ10's inhibition of alpha-SMA and TGF-beta1 expressions disappeared in Nrf2-null MEF cells. In contrast, Nrf2 overexpression significantly decreased the basal expression levels of alpha-SMA and TGF-beta1 in Nrf2-null MEF cells. These results demonstrated that solubilized CoQ10 inhibited DMN-induced liver fibrosis through suppression of TGF-beta1 expression via Nrf2/ARE activation.

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.

Cosmeceuticals and silibinin

Cosmeceuticals are used for nourishing and improving the appearance of the skin and are also documented as effective agents for treating various dermatologic conditions. Cosmeceutical preparations from herbal origin are most popular among consumers because these agents are mostly nontoxic and possess strong antioxidant activity. Because oxidative stress is one of the major mechanisms for skin aging and dermatologic conditions, phytochemicals with proven antioxidant activity, such as silibinin, could be useful for treating many dermatologic conditions as well as skin aging. Silibinin is a flavonolignan compound from Silybum marianum (milk thistle plant) that possesses strong antioxidant activity and also modulates many molecular changes caused by xenobiotics and ultraviolet radiation to protect the skin. This contribution reviews the evidence generated from laboratory studies to support the scientific rationale for the effective use of silibinin in cosmeceutical preparations.

[Liver fibrosis: from pathophysiology to therapeutic openings]

Understanding of liver fibrosis pathogenesis has undergone tremendous advances over the past twenty years. In this respect, demonstration of the reversibility of fibrosis was a major turnpoint. The panel of therapeutic targets is continuously expanding. Clinical development has however remained limited, heretofore, but should rapidly progress owing to the availability of accurate non-invasive methods for assessment of fibrosis, to improvement in the selection patients included in therapeutic trials, and to the development of cell specific targeting devices for agents at risk of adverse effects.

Management of alcoholic liver disease

Understanding alcohol addiction and abstinence is key to treating alcoholic liver disease, since abstinence leads to improvement in all forms of alcoholic liver damage. Although pharmacotherapy for alcoholism, using agents such as naltrexone, acamprosate, topiramate, and baclofen, is an exciting field, few studies have included patients with liver disease or cirrhosis. To treat alcoholic liver injury, corticosteroids have become the standard of care in patients with severe alcoholic hepatitis. In contrast, the role of pharmacotherapy to treat alcoholic fibrosis is unclear, with failure to observe a benefit in randomized, placebo-controlled clinical trials of colchicine, S-adenosylmethionine (SAMe), or phosphatidylcholine. Liver transplantation remains an option in selected patients with life-threatening alcoholic liver disease.

Understanding and treating patients with alcoholic cirrhosis: an update

Alcoholic cirrhosis represents the terminal stage of alcoholic liver disease (ALD) and one of the main causes of death among alcohol abusers. The aim of this review was to provide an update on alcoholic cirrhosis, with an emphasis on recent findings. Increased alcohol consumption in developing countries is expected to increase cirrhosis mortality. There is a need, therefore, to develop new approaches to the prevention of ALD, including more attention to co-factors that may increase risk of ALD (i.e., obesity and diabetes, chronic HCV infection, and smoking). Furthermore, a better understanding of the pathological mechanisms on the basis of alcohol cirrhosis represents a cornerstone in order to develop new pharmacological treatments. Inflammatory and immune responses along with oxidative stress and alterations in adipokine secretion might contribute in different ways to the evolution of alcohol-induced fibrosis/cirrhosis. As of this date, patients with severe alcoholic hepatitis with a Maddrey Discriminant Factor (MDF) 32 should be offered pentoxifylline and/or corticosteroids unless contraindications exist. For ambulatory patients, S-adenosylmethionine (SAMe) may be considered in a motivated patient with nutritional support. Current studies do not support use of anti-tumor necrosis factor (TNF)-alpha antibody. Finally, achieving total alcohol abstinence should represent the main aim in the management of patients affected by any stage of cirrhosis. In the last decades, several drugs able to increase abstinence and prevent alcohol relapse have been evaluated and some of them have obtained approval for alcohol dependence. Patients with alcoholic cirrhosis; however, are usually excluded from such treatments. A recent study demonstrated the efficacy and safety of baclofen in inducing and maintaining alcohol abstinence in cirrhotic alcohol-dependent patients with cirrhosis. All together the information available suggests the need of a multimodal approach in the clinical management of these patients.

Hepatoprotective effects of misoprostol and silymarin on carbon tetrachloride-induced hepatic damage in rats

The aim of this study was to investigate the effect of misoprostol, silymarin or the co-administration of misoprostol + silymarin on the carbon tetrachloride (CCl(4))-induced hepatic injury in rats. Misoprostol (10, 100, 1000 microg/kg), silymarin (25 mg/kg) or misoprostol (100 microg/kg) + silymarin (25 mg/kg) was given once daily orally simultaneously with CCl(4) and for 15 days thereafter. The results showed that misoprostol (10, 100 or 1000 microg/kg) conferred significant protection against the hepatotoxic actions of CCl(4) in rats, reducing serum alanine aminotransferase (ALT) levels by 24.7%, 42.6% and 49.4%, respectively compared with controls. Misoprostol, given at 100 or 1000 microg/kg, decreased aspartate aminotransferase (AST) by 28 and 43.6% and alkaline phosphatase (ALP) by 19.3% and 53.4% respectively. Meanwhile, silymarin reduced ALT, AST and ALP levels by 62.7%, 66.1% and 65.1% respectively. The co-administration of misoprostol (100 microg/kg) and silymarin (25 mg/kg) resulted in 61.4%, 66.1% and 57.5% reduction in ALT, AST and ALP levels respectively. Histopathological alterations and depletion of hepatocyte glycogen and DNA content by CCl(4) were markedly reduced after treatment with misoprostol, silymarin or misoprostol + silymarin. Image analysis of liver specimens revealed a marked reduction in liver necrosis; area of damage: 32.4%, 24% and 10.2% after misoprostol (10, 100 or 1000 microg/kg), 7.2% after silymarin and 10.9% after treatment with misoprostol 100 microg/kg + silymarin, compared with CCl(4) control group (46.7%). These results indicate that treatment with misoprostol protects against hepatocellular necrosis induced by CCl(4). This study suggests a potential therapeutic use for misoprostol in liver injury.

[Silymarin in the treatment of chronic liver diseases: past and future]

In the treatment of chronic liver diseases adequate therapy can be chosen only in the knowledge of pathogenetic processes. In the liver diseases caused by oxidative stress (alcoholic and non-alcoholic fatty liver and steatohepatitis, drug and compound induced liver toxicity) the antioxidant drugs, like silymarin, in chronic hepatitis caused by hepatitis B and hepatitis C virus, combined peginterferon and nucleosid treatments are the primary therapy modalities to be selected. The main effects of silymarin are the membrane stabilising and antioxidant effects, it is able to help the liver cell regeneration, it can decrease the inflammatory reaction and inhibit the fibrogenesis in the liver. These results have been established by experimental and clinical trials. According to open studies, the long administration of silymarin significantly increased the survival time of patients with alcohol-induced liver cirrhosis. Recently it was demonstrated that high-dosage silibinin infusion treatment could significantly decrease the number of hepatitis C viruses after four-week application. On the basis of the results with the methods of molecular biology, silymarin is able to decrease significantly tumor cell proliferation, angiogenesis as well as insulin resistance. These results support the administration of silymarin preparations in the therapy of chronic liver diseases, especially in alcoholic and non-alcoholic steatohepatitis in current clinical practice, and as it can be awaited, also in the future. In some neoplastic diseases they could also be administered as adjuvant therapy.

Current and future anti-fibrotic therapies for chronic liver disease

Chronic injury results in a wound healing response that eventually leads to fibrosis. The response is generalized, with features common among multiple organ systems. In the liver, various different types of injury lead to fibrogenesis, implying a common pathogenesis. Although several specific therapies for patients who have different liver diseases have been successfully developed, including antiviral therapies for those who have hepatitis B and hepatitis C virus infection, specific and effective antifibrotic therapy remains elusive. Over the past 2 decades, great advances in the understanding of fibrosis have been made and multiple mechanisms underlying hepatic fibrogenesis uncovered. Elucidation of these mechanisms has been of fundamental importance in highlighting novel potential therapies. Preclinical studies have indicated several putative therapies that might abrogate fibrogenesis. This article emphasizes mechanisms underlying fibrogenesis and reviews available and future therapeutics.

Treatment with silybin-vitamin E-phospholipid complex in patients with hepatitis C infection

The aim of this study was to evaluate the hepatoprotective and anti-inflammatory effects of silybin-phospholipids and vitamin E complex (SPV complex), by determining cytokine patterns and various markers of liver disease. Forty Caucasian patients with chronic HCV infection were recruited and divided into two groups: 30 were treated with SPV complex for 3 months, while the other 10 did not receive any treatment. Ten other subjects without HCV infection but with staeatosic diagnosis were recruited and treated with SPV complex. Biochemical and hepatic principal parameters were investigated at 0 (T0) and 3 months (T3). The group of HCV patients treated showed an improvement trend of hepatic indecises and viral load, and had a significant and persistent reduction of ALT (P = 0.02) and AST serum level (P = 0.01). In this group cytokines showed a statistically significant increase of IL-2 (P = 0.03) and IL-6 were significantly reduced (P = 0.02) at T0 and T3. After the treatment the group of hepatic steatosics showed a significant decrease in ALT (P = 0.02), AST (0.008), gammaGT (0.004) alkaline phosphatase (0.05), total cholesterol (P = 0.03), fasting glucose (P = 0.008), insulinemia (0.0006), HOMA value (0.002) and C-reactive protein (CRP; 0.04). There was a significant reduction of IFN-gamma, TNF-alpha, and IL-6 (P = 0.02, 0.05 and 0.04, respectively). The data suggest that the SPV complex exerts hepatoprotective, anti-inflammatory and antifibrotic effects. This new compound may therefore be useful in clinical practice in patients with chronic hepatitis C who cannot undergo conventional antiviral therapy.

The pharmacokinetics of silymarin is altered in patients with hepatitis C virus and nonalcoholic Fatty liver disease and correlates with plasma caspase-3/7 activity

Silymarin, used by 30 to 40% of liver disease patients, is composed of six major flavonolignans, each of which may contribute to silymarin's hepatoprotective properties. Previous studies have only described the pharmacokinetics for two flavonolignans, silybin A and silybin B, in healthy volunteers. The aim of this study was to determine the pharmacokinetics of the major silymarin flavonolignans in liver disease patients. Healthy volunteers and three patient cohorts were administered a single, 600-mg p.o. dose of milk thistle extract, and 14 blood samples were obtained over 24 h. Silybin A and B accounted for 43% of the exposure to the sum of total silymarin flavonolignans in healthy volunteers and only 31 to 38% in liver disease cohorts as a result of accumulation of silychristin (20-36%). Area under the curve (AUC(0-24h)) for the sum of total silymarin flavonolignans was 2.4-, 3.3-, and 4.7-fold higher for hepatitis C virus (HCV) noncirrhosis, nonalcoholic fatty liver disease (p Collapse

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MESH Headings

• Adolescent
• Adult
• Aged
• Apoptosis
• Area Under Curve
• Caspase 3/blood
• Caspase 7/blood
• Cohort Studies
• Fatty Liver/metabolism
• Female
• Half-Life
• Hepatitis C/metabolism
• Humans
• Male
• Middle Aged
• Oxidative Stress
• Silymarin/blood
• Silymarin/pharmacokinetics

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Grants

• K24 DK066144 NIDDK NIH HHS
• RR00046 NCRR NIH HHS

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Affiliation(s)

Sarah J Schrieber Division of Pharmacotherapy and Experimental Therapeutics,School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7360, USA
Zhiming Wen
Manoli Vourvahis
Philip C Smith
Michael W Fried
Angela D M Kashuba
Roy L Hawke

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Collaborators Collapse