Milk thistle for alcoholic and/or hepatitis B or C virus liver diseases

Cardioprotective effect of 2,3-dehydrosilybin preconditioning in isolated rat heart

2,3-dehydrosilybin (DHS) is a minor component of silymarin, Silybum marianum seed extract, used in some dietary supplements. One of the most promising activities of this compound is its anticancer and cardioprotective activity that results, at least partially, from its cytoprotective, antioxidant, and chemopreventive properties. The present study investigated the cardioprotective effects of DHS in myocardial ischemia and reperfusion injury in rats. Isolated hearts were perfused by the Langendorff technique with low dose DHS (100 nM) prior to 30 min of ischemia induced by coronary artery occlusion. After 60 min of coronary reperfusion infarct size was determined by triphenyltetrazolium staining, while lactatedehydrogenase activity was evaluated in perfusate samples collected at several timepoints during the entire perfusion procedure. Signalosomes were isolated from a heart tissue after reperfusion and involved signalling proteins were detected. DHS reduced the extent of infarction compared with untreated control hearts at low concentration; infarct size as proportion of ischemic risk zone was 7.47 ± 3.1% for DHS versus 75.3 ± 4.8% for ischemia. This protective effect was comparable to infarct limitation induced by ischemic preconditioning (22.3 ± 4.5%). Selective inhibition of Src-family kinases with PP2 (4-Amino-3-(4-chlorophenyl)-1-(t-butyl)-1H-pyrazolo[3,4-d]pyrimidine) abrogated the protection afforded by DHS. This study provides experimental evidence that DHS can mediate Src-kinase-dependent cardioprotection against myocardial damage produced by ischemia/reperfusion injury.

Alcoholic liver disease: Treatment

The excess consumption of alcohol is associated with alcoholic liver diseases (ALD). ALD is a major healthcare problem, personal and social burden, and significant reason for economic loss worldwide. The ALD spectrum includes alcoholic fatty liver, alcoholic hepatitis, cirrhosis, and the development of hepatocellular carcinoma. The diagnosis of ALD is based on a combination of clinical features, including a history of significant alcohol intake, evidence of liver disease, and laboratory findings. Abstinence is the most important treatment for ALD and the treatment plan varies according to the stage of the disease. Various treatments including abstinence, nutritional therapy, pharmacological therapy, psychotherapy, and surgery are currently available. For severe alcoholic hepatitis, corticosteroid or pentoxifylline are recommended based on the guidelines. In addition, new therapeutic targets are being under investigation.

Hepatoprotective effect of silymarin

The use of medicinal plants in treating illnesses has been reported since ancestral times. In the case of hepatic diseases, several species such as Silybum marianum, Phyllanthus niruri, and Panus giganteus (Berk.) have been shown to ameliorate hepatic lesions. Silymarin is a natural compound derived from the species Silybum marianum, which is commonly known as Milk thistle. This plant contains at least seven flavoligands and the flavonoid taxifolin. The hepatoprotective and antioxidant activity of silymarin is caused by its ability to inhibit the free radicals that are produced from the metabolism of toxic substances such as ethanol, acetaminophen, and carbon tetrachloride. The generation of free radicals is known to damage cellular membranes and cause lipoperoxidation. Silymarin enhances hepatic glutathione and may contribute to the antioxidant defense of the liver. It has also been shown that silymarin increases protein synthesis in hepatocytes by stimulating RNA polymerase I activity. A previous study on humans reported that silymarin treatment caused a slight increase in the survival of patients with cirrhotic alcoholism compared with untreated controls.

Silybin and the liver: From basic research to clinical practice

Herbal products are increasingly used, mainly in chronic liver disease. Extracts of milk thistle, Silymarin and silybin, are the most prescribed natural compounds, with different indications, but with no definitive results in terms of clinical efficacy. This review analyzes the available studies on the effects of the purified product silybin, both as a free and a conjugated molecule, on liver cells or on experimentally induced liver damage, and in patients with liver disease. We searched PUBMED for articles pertaining to the in vitro and in vivo effects of silybin, its antifibrotic, anti-inflammatory, and antioxidant properties, as well as its metabolic effects, combined with the authors’ own knowledge of the literature. Results indicate that the bioavailability of silybin phytosome is higher than that of silymarin and is less influenced by liver damage; silybin does not show significant interactions with other drugs and at doses < 10 g/d has no significant side effects. Experimental studies have clearly demonstrated the antifibrotic, antioxidant and metabolic effects of silybin; previous human studies were insufficient for confirming the clinical efficacy in chronic liver disease, while ongoing clinical trials are promising. On the basis of literature data, silybin seems a promising drug for chronic liver disease.

Integration of complementary and alternative medicine into family practices in Germany: results of a national survey

More than two-thirds of patients in Germany use complementary and alternative medicine (CAM) provided either by physicians or non-medical practitioners ("Heilpraktiker"). There is little information about the number of family physicians (FPs) providing CAM. Given the widespread public interest in the use of CAM, this study aimed to ascertain the use of and attitude toward CAM among FPs in Germany. A postal questionnaire developed based on qualitatively derived data was sent to 3000 randomly selected FPs in Germany. A reminder letter including a postcard (containing a single question about CAM use in practice and reasons for non-particpation in the survey) was sent to all FPs who had not returned the questionnaire. Of the 3000 FPs, 1027 (34%) returned the questionnaire and 444 (15%) returned the postcard. Altogether, 886 of the 1471 responding FPs (60%) reported using CAM in their practice. A positive attitude toward CAM was indicated by 503 FPs (55%), a rather negative attitude by 127 FPs (14%). Chirotherapy, relaxation and neural therapy were rated as most beneficial CAM therapies by FPs, whereas neural therapy, phytotherapy and acupuncture were the most commonly used therapies in German family practices. This survey clearly demonstrates that CAM is highly valued by many FPs and is already making a substantial contribution to first-contact primary care in Germany. Therefore, education and research about CAM should be increased. Furthermore, with the provision of CAM by FPs, the role of non-medical CAM practitioners within the German healthcare system is to be questioned.

Advances in the use of milk thistle (Silybum marianum)

Milk thistle (Silybum marianum) is an herbal supplement used to treat liver and biliary disorders. Silymarin, a mixture of flavanoid complexes, is the active component that protects liver and kidney cells from toxic effects of drugs, including chemotherapy. Although milk thistle has not significantly altered the course of chronic liver disease, it has reduced liver enzyme levels and demonstrated anti-inflammatory and T cell-modulating effects. There is strong preclinical evidence for silymarin's hepatoprotective and anticarcinogenic effects, including inhibition of cancer cell growth in human prostate, skin, breast, and cervical cells. Milk thistle is considered safe and well-tolerated, with gastrointestinal upset, a mild laxative effect, and rare allergic reaction being the only adverse events reported when taken within the recommended dose range. More clinical trials of rigorous methodology, using standardized and well-defined products and dosages, are needed to evaluate the potential of silymarin against liver toxicity, chronic liver disease, and human cancers.

Review of clinical trials evaluating safety and efficacy of milk thistle (Silybum marianum [L.] Gaertn.)

Milk thistle extracts have been used as traditional herbal remedies for almost 2000 years. The extracts are still widely used to protect the liver against toxins and to control chronic liver diseases. Recent experimental and clinical studies suggest that milk thistle extracts also have anticancer, antidiabetic, and cardioprotective effects. This article reviews clinical trials of milk thistle conducted in the past 5 years including pharmacokinetic and toxicity studies, herb-drug interactions, and other safety issues. Several trials have studied the effects of milk thistle for patients with liver diseases, cancer, hepatitis C, HIV, diabetes, and hypercholesterolemia. Promising results have been reported in the protective effect of milk thistle in certain types of cancer, and ongoing trials will provide more evidence about this effect. In addition, new established doses and improvement on the quality and standardization of this herb will provide the much-awaited evidence about the efficacy of milk thistle in the treatment of liver diseases. Milk thistle extracts are known to be safe and well tolerated, and toxic or adverse effects observed in the reviewed clinical trials seem to be minimal. The future of milk thistle research is promising, and high-quality randomized clinical trials on milk thistle versus placebo may be needed to further demonstrate the safety and efficacy of this herb.

Therapeutic challenges in hepatitis C-infected injection drug using patients

Hepatitis C Viral (HCV) infection in the injection drug user (IDU) population is a major medical concern. Concurrent substance abuse, co-morbid mental health conditions, poor socioeconomic status and a complex treatment protocol that is often incompatible with the life styles of IDUs combine to account for poor uptake and completion of HCV treatment. This article discusses HCV antiviral treatment issues relevant to IDUs chronically infected with this virus. The effect of non-injected substances of abuse on treatment outcome is considered. Priority issues requiring research are discussed.

Anabolic-androgenic steroids for alcoholic liver disease

BACKGROUND

Alcohol is one of the most common causes of liver disease in the Western World. Randomised clinical trials have examined the effects of anabolic-androgenic steroids for alcoholic liver disease.

OBJECTIVES

To assess the beneficial and harmful effects of anabolic-androgenic steroids for patients with alcoholic liver disease based on the results of randomised clinical trials.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Controlled Trials Register in The Cochrane Library, MEDLINE, EMBASE, LILACS, and Science Citation Index Expanded until June 2006. Electronic searches were combined with full text searches. Manufacturers and researchers in the field were also contacted.

SELECTION CRITERIA

Randomised clinical trials studying patients with alcoholic steatosis, alcoholic fibrosis, alcoholic hepatitis, and/or alcoholic cirrhosis were included. Interventions encompassed anabolic-androgenic steroids at any dose or duration versus placebo or no intervention. The trials could be double blind, single blind, or unblinded. The trials could be unpublished or published, and no language limitations were applied.

DATA COLLECTION AND ANALYSIS

Outcomes are assessed at maximal follow-up. All analyses were performed according to the intention-to-treat method. The statistical package RevMan Analyses was used. The methodological quality of the randomised clinical trials was assessed.

MAIN RESULTS

Combining the results of five randomised clinical trials randomising 499 patients with alcoholic hepatitis and/or cirrhosis demonstrated no significant effects of anabolic-androgenic steroids on mortality (relative risk (RR) 1.01, 95% confidence interval (CI) 0.79 to 1.29), liver-related mortality (RR 0.83, 95% CI 0.60 to 1.15), complications of liver disease (RR 1.25, 95% CI 0.74 to 2.10), and liver histology. Anabolic-androgenic steroids did not significantly affect a number of other outcome measures, including sexual function and liver biochemistry. Anabolic-androgenic steroids were not associated with a significantly increased risk of non-serious adverse events (RR 1.14, 95% CI 0.50 to 2.59) or with serious adverse events (RR 4.54, 95% CI 0.57 to 36.30).

AUTHORS' CONCLUSIONS

This systematic review could not demonstrate any significant beneficial effects of anabolic-androgenic steroids on any clinically important outcomes (mortality, liver-related mortality, liver complications, and histology) of patients with alcoholic liver disease.

Effect of milk thistle (Silybum marianum) on the pharmacokinetics of irinotecan

PURPOSE

Milk thistle (Silybum marianum) is one of the most commonly used herbal therapies, and its principal constituent silybin significantly inhibits cytochrome P450 isoform 3A4 (CYP3A4) and UDP glucuronosyltransferase isoform 1A1 (UGT1A1) in vitro. Here, we investigated whether milk thistle affects the pharmacokinetics of irinotecan, a substrate for CYP3A4 and UGT1A1, in humans.

EXPERIMENTAL DESIGN

Six cancer patients were treated with irinotecan (dose, 125 mg/m(2)) given as a 90-minute infusion once every week. Four days before the second dose, patients received 200 mg milk thistle, thrice a day, for 14 consecutive days. Pharmacokinetic studies of irinotecan and its metabolites 7-ethyl-10-hydroxycamptothecin (SN-38), 7-ethyl-10-[3,4,5-trihydroxy-pyran-2-carboxylic acid]-camptothecin (SN-38-glucuronide), and 7-ethyl-10-[4-N-(5-aminopentanoic acid)-1-piperidino]-carbonyloxycamptothecin were done during the first three irinotecan administrations.

RESULTS

Short-term (4 days) or more prolonged intake of milk thistle (12 days) had no significant effect on irinotecan clearance (mean, 31.2 versus 25.4 versus 25.6 L/h; P = 0.16). The area under the curve ratio of SN-38 and irinotecan was slightly decreased by milk thistle (2.58% versus 2.23% versus 2.17%; P = 0.047), whereas the relative extent of glucuronidation of SN-38 was similar (10.8 versus 13.5 versus 13.1; P = 0.64). Likewise, the area under the curve ratio of 7-ethyl-10-[4-N-(5-aminopentanoic acid)-1-piperidino]-carbonyloxycamptothecin and irinotecan was unaffected by milk thistle (0.332 versus 0.285 versus 0.337; P = 0.53). The maximum plasma concentrations of silybin ranged between 0.0249 and 0.257 micromol/L.

CONCLUSIONS

Silybin concentrations after intake of milk thistle are too low to significantly affect the function of CYP3A4 and UGT1A1 in vivo, indicating that milk thistle is unlikely to alter the disposition of anticancer drugs metabolized by these enzymes.