Herbal product use by persons enrolled in the hepatitis C Antiviral Long-Term Treatment Against Cirrhosis (HALT-C) Trial

Graveoline attenuates D-GalN/LPS-induced acute liver injury via inhibition of JAK1/STAT3 signaling pathway

Graveoline exhibits various biological activities. However, only limited studies have focused on its hepatoprotective properties. This study evaluated the anti-inflammatory and hepatoprotective activities of graveoline, a minor 2-phenylquinolin-4-one alkaloid isolated from Ruta graveolens L., in a liver injury model in vitro and in vivo. A network pharmacology approach was used to investigate the potential signaling pathway associated with the hepatoprotective activity of graveoline. Subsequently, biological experiments were conducted to validate the findings. Topological analysis of the KEGG pathway enrichment revealed that graveoline mediates its hepatoprotective activity through genes associated with the hepatitis B viral infection pathway. Biological experiments demonstrated that graveoline effectively reduced the levels of alanine transaminase and aspartate transaminase in lipopolysaccharide (LPS)-induced HepG2 cells. Graveoline exerted antihepatitic activity by inhibiting the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) and elevated the anti-inflammatory cytokines interleukin-4 (IL-4) and interleukin-10 (IL-10) in vitro and in vivo. Additionally, graveoline exerted its hepatoprotective activity by inhibiting JAK1 and STAT3 phosphorylation both in vitro and in vivo. In summary, graveoline can attenuate acute liver injury by inhibiting the TNF-α inflammasome, activating IL-4 and IL-10, and suppressing the JAK1/STAT3 signaling pathway. This study sheds light on the potential of graveoline as a promising therapeutic agent for treating liver injury.

Natural products and dietary interventions on liver enzymes: an umbrella review and evidence map

Background

The association between natural products and dietary interventions on liver enzymes is unclear; therefore, this study aimed to examine their effects on liver enzymes in adults.

Methods

PubMed, Embase, and Cochrane Library of Systematic Reviews databases were searched from inception until March 2023. The Assessment of Multiple Systematic Reviews-2 (AMSTAR-2) and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) systems were used to assess the methodological and evidence quality, and the therapeutic effects were summarized in a narrative form.

Results

A total of 40 meta-analyses on natural products (n = 25), dietary supplements (n = 10), and dietary patterns (n = 5) were evaluated, and results were presented in a narrative form. The overall methodological quality of the included studies was relatively poor. The results indicated that positive effects were observed for nigella sativa, garlic, artichoke, curcumin, silymarin, vitamin E, vitamin D, L-carnitine, propolis, and polyunsaturated fatty acids on certain liver enzymes. The dietary patterns, including high-protein, Mediterranean, and calorie-restriction diets and evening snacks, may reduce liver enzymes; however, other supplements and herbs did not reduce liver enzyme levels or have minimal effects. The evidence quality was generally weak given the risk of bias, heterogeneity, and imprecision.

Conclusion

This umbrella review suggests that natural products and dietary interventions have beneficial therapeutic effects on liver enzymes levels. Further clinical trials are necessary to establish the effectiveness of supplements that reduce liver enzymes.

Medicinal plant molecules against hepatitis C virus: Current status and future prospect

Hepatitis C virus (HCV), a global malady, causes acute and chronic hepatitis leading to permanent liver damage, hepatocellular carcinoma, and death. Modern anti-HCV therapies are efficient, but mostly inaccessible for residents of underdeveloped regions. To innovate more effective treatments at affordable cost, medicinal plant-based products need to be explored. The aim of this article is to review plant constituents in the light of putative anti-HCV mechanisms of action, and discuss existing problems, challenges, and future directions for their potential application in therapeutic settings. One hundred sixty literatures were collected by using appropriate search strings via scientific search engines: Google Scholar, PubMed, ScienceDirect, and Scopus. Bibliography was prepared using Mendeley desktop software. We found a substantial number of plants that were reported to inhibit different stages of HCV life cycle. Traditional medicinal plants such as Phyllanthus amarus Schumach. and Thonn., Eclipta alba (L.) Hassk., and Acacia nilotica (L.) Delile exhibited strong anti-HCV activities. Again, several phytochemicals such as epigallocatechin-3-gallate, honokilol, punicalagin, and quercetin have shown broad-spectrum anti-HCV effect. We have presented promising phytochemicals like silymarin, curcumin, glycyrrhizin, and camptothecin for nanoparticle-based hepatocyte-targeted drug delivery. Nevertheless, only a few animal studies have been performed to validate the anti-HCV effect of these plant products. Again, insufficient clinical evaluation of the safety and effectiveness of herbal medications remain a problem. Selected plants products could be developed as novel therapeutics for HCV patients only after scrupulous evaluation of their safety and efficacy in a clinical set-up.

A Review of African Medicinal Plants and Functional Foods for the Management of Alzheimer's Disease-related Phenotypes, Treatment of HSV-1 Infection and/or Improvement of Gut Microbiota

Alzheimer's disease (AD), which is a progressive neurodegenerative disorder is the most common form of dementia globally. Several studies have suggested alteration in the gut microbiota and HSV-1 infection as contributing factors to the development of the disease. As at now, there are no AD attenuating agents and AD pharmacotherapy is focused on managing symptoms while plants used in ethnomedicine remain potential sources of drugs for the treatment of the condition. Here, we reviewed published databases for African ethnomedicinal plants and functional foods of African origin that are used in the management of AD-related phenotypes, treatment of herpes simplex virus −1 (HSV-1) and/or improvement of gut microbiota. A total of 101 unique plant species and 24 different types of traditionally prepared African functional foodstuff were identified. Of the 101 identified plant species, 50 species serve as functional foodstuffs. Twenty-three (23) of the ethnomedicinal plant families were successfully identified for the treatment and management of AD-related phenotypes and age-related dementia. Eighteen (18) African plant species from 15 families were also identified as potent remedies for HSV-1; while many African wild fruits (3 species), roots and tubers (7 species), leafy vegetables (14 species), and seaweeds (26 species) were functional foods for modifying AD-related phenotypes. It was concluded that African medicinal plants are potential sources of both AD attenuating agents and phytocompounds that may be used against HSV-1 infection and alteration of gut microbiota. Additionally, a number of African functional foods are important sources of prebiotics and probiotics.

Echinacea in hepatopathy: A review of its phytochemistry, pharmacology, and safety

BACKGROUND

Echinacea, one of the most popular herbs with double function of immunity and anti-inflammatory activity, has now attracted much interest for a possible alternative for the treatment of hepatopathy. This review is aimed at providing a comprehensive overview of Echinacea regarding its chemical composition, pharmacological action against various hepatopathy, and safety.

METHODS

A comprehensive search of published articles was conducted to focus on original publications related to Echinacea and hepatopathy till the end of 2020 using various literature databases, including China National Knowledge Infrastructure, PubMed, and Web of Science database.

RESULTS

Echinacea exhibited excellent activities in resisting a variety of hepatopathy induced by different causes in preclinical experiments and clinical trials by regulating cell proliferation and apoptosis, antioxidant defense mechanism, voltage-gated sodium channels, lipid metabolism, circadian rhythm, p38 MAPK signaling pathway, JNK signaling pathway, Nrf2/HO-1 signaling pathway, PI3K/AKT signaling pathway, and Akt/GSK3 beta signaling pathways. The high efficacy of Echinacea is related to its immunomodulatory and anti-inflammatory activities. The main ingredients of Echinacea include caffeic acid derivatives, alkylamides, and polysaccharides, which have been well established in preclinical studies of liver diseases. Studies on acute and subacute toxicity show that Echinacea preparations are well-tolerated herbal medicines.

CONCLUSION

Echinacea may offer a novel potential strategy for clinical prevention and treatment of liver diseases and related diseases. Extensive studies are necessary to identify the underlying mechanisms and establish future therapeutic potentials of this herb. Well-designed clinical trials are still warranted to confirm the safety and effectiveness of Echinacea for hepatopathy.

Kadsura heteroclita stem ethanol extract protects against carbon tetrachloride-induced liver injury in mice via suppression of oxidative stress, inflammation, and apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Kadsura heteroclita stem (KHS) is a well-known hepatoprotective Tujia ethnomedicine (folk named Xuetong), has long been used for the prevention and treatment of hepatitis and liver diseases.

AIM OF THE STUDY

To explore the protective effects of KHS against carbon tetrachloride (CCl4)-induced liver injury and the underlying mechanism, particularly antioxidative, anti-inflammatory, and anti-apoptotic potentials.

MATERIALS AND METHODS

The acute toxicity of KHS was measured by the method of maximum tolerated dose (MTD). Liver injury in mice was induced by intraperitoneal injection of 25% carbon tetrachloride (olive oil solubilization) 2 times every week. After modeling, mice in KHS groups were treated with KHS at 100, 200, 400 mg/kg/d, mice in positive control group were treated with bifendate (30 mg/kg/d), and mice in normal and model groups were given ultrapure water. After 4 weeks of treatment, blood of mice was taken from the orbital venous plexus before mice euthanized, the liver, spleen, and thymus of mice were weighed by dissecting the abdominal cavity after mice euthanized. Moreover, the liver of mice was selected for histological examination. The alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in mice serum were measured using the automatic biochemical analyzer. The levels of superoxide dismutase (SOD), myeloperoxidase (MPO), malondialdehyde (MDA), glutathione peroxidase (GPX-2), tumor necrosis factor (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), Bcl-2-associated X (Bax), B-cell lymphoma-2 (Bcl-2), Caspase-3, and Caspase-8 in mice liver were measured by Elisa kits. Furthermore, the protein expression of Bcl-2 and Bax in mice liver tissue was detected by Western blot.

RESULTS

The MTD of KHS was determined to be 26 g/kg in both sexes of mice. Treatment with KHS dose-dependently protected the liver and other main organs against CCl4-induced liver injury in mice. The ALT and AST levels in mice liver were significantly reduced after treatment with KHS at the dose of 100, 200, and 400 mg/kg. In addition, the liver histopathological analyses revealed that KHS markedly alleviated inflammatory cell infiltration, hepatic fibrosis, hepatocyte ballooning, necrosis and severe apoptosis of hepatocytes induced by CCl4. Further assay indicated that KHS significantly suppressed the production of MDA and MPO, while markedly increased the level of SOD and GPx-2. The TNF-α and IL-6 level in mice liver tissue were decreased by KHS, whereas the IL-10 level was increased. KHS also inhibited hepatocyte apoptosis by significantly reducing the expression of Bax, Caspase-3, Caspase-8, as well as increasing the expression of Bcl-2. Besides, the Western blot results strongly demonstrated that KHS inhibited hepatocyte apoptosis, as evidenced by reducing the expression of Bax protein and increasing the expression of Bcl-2 protein in liver injury tissues.

CONCLUSIONS

This research firstly clarified that KHS has a significant protective effect against CCl4-induced liver injury, which might be closely related to alleviating oxidative stress, reducing inflammatory response, and inhibiting hepatocyte apoptosis.

Effectiveness and safety of traditional Chinese medicines for non-alcoholic fatty liver disease: Protocol for systematic review and meta-analysis

BACKGROUND

Previous reviews indicate that the effect of Traditional Chinese medicines (TCM) on non-alcoholic fatty liver disease (NAFLD) remains uncertainty. The study results published in the past 8 years may change this situation, but there is no updated systematic review. Therefore, we designed this study to systematically evaluate the effectiveness and safety of TCM in the treatment of NAFLD.

METHODS AND ANALYSIS

We will search nine online databases from inception to October 01 2019, and the language will not be restricted on included trials. Randomized controlled trials that included patients with NAFLD receiving TCM therapy versus a control group will be included. Two researcher will perform independently the selection of studies, risk of bias assessment and data extraction. We will use the RevMan V.5.2 software with fixed effects model or random effects model according to the heterogeneity test to conduct the data synthesis. We will present the dichotomous data and the continuous data with risk ratios with 95% CIs and weighted mean differences or standardized mean differences with 95% CIs. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system will be used to evaluate the evidence quality with low risk, unclear risk, and high risk.

RESULTS

This study will demonstrate an evidence-based review of TCM for NAFLD.

CONCLUSION

The study will provide clear evidence to assess the effectiveness and side effects of TCM for NAFLD.

Natural products for the management of the hepatitis C virus: a biochemical review

Chronic hepatitis C virus (HCV) infection is a significant public health problem, with a worldwide prevalence of approximately 170 million. Current therapy for HCV infection includes the prolonged administration of a combination of ribavirin and PEGylated interferon-α, for over a decade. This regimen is expensive and often associated with a poor antiviral response and unwanted side effects. A highly effective combination treatment is likely required for the future management of HCV infections and entry inhibitors could play an important role. Currently, no entry inhibitor has been licensed for the prophylactic treatment of hepatitis C. Therefore, additional agents that combat HCV infection are urgently needed and must be developed. Many phytochemical constituents have been identified that display considerable inhibition of HCV at some stage of the life cycle. This review will summarise the current state of knowledge on natural products and their possible activities in the context of HCV infection.

Herbal drug discovery for the treatment of nonalcoholic fatty liver disease

Few medications are available for meeting the increasing disease burden of nonalcoholic fatty liver disease (NAFLD) and its progressive stage, nonalcoholic steatohepatitis (NASH). Traditional herbal medicines (THM) have been used for centuries to treat indigenous people with various symptoms but without clarified modern-defined disease types and mechanisms. In modern times, NAFLD was defined as a common chronic disease leading to more studies to understand NAFLD/NASH pathology and progression. THM have garnered increased attention for providing therapeutic candidates for treating NAFLD. In this review, a new model called “multiple organs-multiple hits” is proposed to explain mechanisms of NASH progression. Against this proposed model, the effects and mechanisms of the frequently-studied THM-yielded single anti-NAFLD drug candidates and multiple herb medicines are reviewed, among which silymarin and berberine are already under U.S. FDA-sanctioned phase 4 clinical studies. Furthermore, experimental designs for anti-NAFLD drug discovery from THM in treating NAFLD are discussed. The opportunities and challenges of reverse pharmacology and reverse pharmacokinetic concepts-guided strategies for THM modernization and its global recognition to treat NAFLD are highlighted. Increasing mechanistic evidence is being generated to support the beneficial role of THM in treating NAFLD and anti-NAFLD drug discovery.

Complex Evaluation of Antioxidant Capacity of Milk Thistle Dietary Supplements

Numerous in vitro assays are used to characterize the antioxidant properties of natural-based matrices. However, many of them generate contradictory and non-compliant results. In our study, we focused on the characterization of traditionally used biochemical (2,2′-azino-bis-(3-ethylbenzothiazoline-6 sulfonic acid) (ABTS), Oxygen Radical Absorption Capacity (ORAC), and 2,2-diphenyl-1-picrylhydrazyl (DPPH)) and cellular (CAA) antioxidant tests on a broad set of milk thistle dietary supplements containing silymarin. In addition to 26 commercially available preparations, also the natural silymarin extract available from Sigma Aldrich, St. Louis, MI, USA, and a model mixture of pure flavonoid/flavonolignans mimicking the silymarin composition were investigated as control samples. Significant differences in the antioxidant capacity of the supplements were observed. Unlike the DPPH, the results of the ABTS and ORAC methods correlated with the silymarin components determined by U-HPLC-HRMS/MS. The responses in CAA were considerably lower than in other assays. Silymarin exhibited a significantly higher antioxidant capacity than the artificially prepared flavonoid/flavonolignans mixture in all tests, indicating possible presence of other antioxidants of natural origin. The follow-up U-HPLC-HRMS/MS screening revealed the presence of tens of non-silymarin compounds with reported antioxidant activity (not only in the silymarin extract, but also in the milk thistle preparations). The sum of the total phenolics and the sum of the simple phenolics correlated with CAA results more than silymarin.

A closer look at the spectrum of drug-induced liver injury in sub-Saharan Africa

Introduction: Drug-induced liver injury (DILI) has become the most frequent cause of acute liver failure in high-income countries. However, little is known about the determinants of DILI in sub-Saharan Africa (SSA), where the prescription of antimicrobials and the use of potentially hepatotoxic traditional medicine are common. Areas covered: Based on an extensive literature search, we summarize current data available on the epidemiology and risk factors of DILI in SSA. We discuss the most likely causes of DILI in the region, including antimicrobial therapies and traditional medicine. We also highlight research gaps as well as barriers to diagnosis and management of the condition, and explore ways to address these important challenges. Expert opinion: DILI is underestimated in SSA and several factors challenge its early diagnosis, including lack of information on the causes of DILI in the region, sub-optimal knowledge about the condition among clinicians, and structural difficulties faced by health care systems. In order to better prevent the occurrence of DILI and its complications, it is crucial to enhance awareness among health care providers and patients, adapt drug prescription habits and regulations, and improve current knowledge on the main risk factors for DILI, including host genetic and environmental determinants.

Drug-Drug Interactions Potential of Direct-Acting Antivirals for the treatment of Chronic Hepatitis C Virus infection

The advent of direct-acting antiviral agents (DAAs) has transformed the hepatitis C virus (HCV) therapeutic landscape in terms of efficacy and safety, with a cure rate of more than 90%. However, an important potential for drug-drug interactions (DDIs) is expected with these combinations, particularly in patients with other comorbidities (e.g. HIV co-infection, cardiovascular diseases). Each DAA can be a substrate, an inhibitor and/or an inducer of metabolic enzymes and drug efflux transporters. DAAs can act as both victims and perpetrators of DDIs and can sometimes increase the risk and/or intensity of side effects or limit the efficacy of treatment. Therefore, knowledge and management of DDIs with DAAs should be considered a key issue of HCV therapy. This review describes the pharmacokinetic profile of currently used and recommended DAA regimens and summarizes available data regarding DDIs to optimize HCV treatment in clinical practice.

Antiviral potential of medicinal plants against HIV, HSV, influenza, hepatitis, and coxsackievirus: A systematic review

Viral infections are being managed therapeutically through available antiviral regimens with unsatisfactory clinical outcomes. The refractory viral infections resistant to available antiviral drugs are alarming threats and a serious health concern. For viral hepatitis, the interferon and vaccine therapies solely are not ultimate solutions due to recurrence of hepatitis C virus. Owing to the growing incidences of viral infections and especially of resistant viral strains, the available therapeutic modalities need to be improved, complemented with the discovery of novel antiviral agents to combat refractory viral infections. It is widely accepted that medicinal plant heritage is nature gifted, precious, and fueled with the valuable resources for treatment of metabolic and infectious disorders. The aims of this review are to assemble the facts and to conclude the therapeutic potential of medicinal plants in the eradication and management of various viral diseases such as influenza, human immunodeficiency virus (HIV), herpes simplex virus (HSV), hepatitis, and coxsackievirus infections, which have been proven in diverse clinical studies. The articles, published in the English language since 1982 to 2017, were included from Web of Science, Cochrane Library, AMED, CISCOM, EMBASE, MEDLINE, Scopus, and PubMed by using relevant keywords including plants possessing antiviral activity, the antiviral effects of plants, and plants used in viral disorders. The scientific literature mainly focusing on plant extracts and herbal products with therapeutic efficacies against experimental models of influenza, HIV, HSV, hepatitis, and coxsackievirus were included in the study. Pure compounds possessing antiviral activity were excluded, and plants possessing activity against viruses other than viruses in inclusion criteria were excluded. Hundreds of plant extracts with antiviral effect were recognized. However, the data from only 36 families investigated through in vitro and in vivo studies met the inclusion criteria of this review. The inferences from scientific literature review, focusing on potential therapeutic consequences of medicinal plants on experimental models of HIV, HSV, influenza, hepatitis, and coxsackievirus have ascertained the curative antiviral potential of plants. Fifty-four medicinal plants belonging to 36 different families having antiviral potential were documented. Out of 54 plants, 27 individually belong to particular plant families. On the basis of the work of several independent research groups, the therapeutic potential of medicinal plants against listed common viral diseases in the region has been proclaimed. In this context, the herbal formulations as alternative medicine may contribute to the eradication of complicated viral infection significantly. The current review consolidates the data of the various medicinal plants, those are Sambucus nigra, Caesalpinia pulcherrima, and Hypericum connatum, holding promising specific antiviral activities scientifically proven through studies on experimental animal models. Consequently, the original research addressing the development of novel nutraceuticals based on listed medicinal plants is highly recommended for the management of viral disorders.

A natural small molecule inhibitor corilagin blocks HCV replication and modulates oxidative stress to reduce liver damage

Hepatitis C virus (HCV) infection causes chronic liver disease, which often leads to hepatocellular carcinoma. Earlier, we have demonstrated anti-HCV property of the methanolic extract of Phyllanthus amarus, an age-old folk-medicine against viral hepatitis. Here, we report identification of a principal bioactive component 'corilagin', which showed significant inhibition of the HCV key enzymes, NS3 protease and NS5B RNA-dependent-RNA-polymerase. This pure compound could effectively inhibit viral replication in the infectious cell culture system, displayed strong antioxidant activity by blocking HCV induced generation of reactive oxygen species and suppressed up-regulation of NOX4 and TGF-β mRNA levels. Oral administration of corilagin in BALB/c mice demonstrated its better tolerability and systemic bioavailability. More importantly, corilagin could restrict serum HCV RNA levels, decrease collagen deposition and hepatic cell denaturation in HCV infected chimeric mice harbouring human hepatocytes. Taken together, results provide a basis towards developing a pure natural drug as an alternate therapeutic strategy for restricting viral replication and prevent liver damage towards better management of HCV induced pathogenesis.

Role of MAIT cells in the immunopathogenesis of inflammatory diseases: New players in old game

Current advances in immunology have led to the identification of a population of novel innate immune T cells, called mucosa-associated invariant T (MAIT) cells. The cells in humans express an invariant TCRα chain (Vα7.2-Jα33) paired with a limited subset of TCRβ chains (Vβ2, 13 and 22), are restricted by the MHC class I (MH1)-related (MR)-1, and recognize molecules that are produced in the bacterial riboflavin (vitamin B2) biosynthetic pathway. They are present in the circulation, liver and at various mucosal sites (i.e. intestine, lungs and female reproductive tract, etc.). They kill host cells infected with bacteria and yeast, and secrete soluble mediators such as TNF-α, IFN-γ, IL-17, etc. The cells regulate immune responses and inflammation associated with a wide spectrum of acute and chronic diseases in humans. Since their discovery in 1993, significant advances have been made in understanding biology of MAIT cells and the potential role of these cells in the pathogenesis of autoimmune, inflammatory and infectious diseases as well as cancer in humans. The purpose of this review is to provide a current state of our knowledge about MAIT cell biology and delineate their role in autoimmune and inflammatory diseases (sterile or caused by infectious agents) and cancer in humans. A better understanding of the role of MAIT cells in human diseases may lead to novel ways of immunotherapies.

Phytotherapeutics: The Emerging Role of Intestinal and Hepatocellular Transporters in Drug Interactions with Botanical Supplements

In herbalism, botanical supplements are commonly believed to be safe remedies, however, botanical supplements and dietary ingredients interact with transport and metabolic processes, affecting drug disposition. Although a large number of studies have described that botanical supplements interfere with drug metabolism, the mode of their interaction with drug transport processes is not well described. Such interactions may result in serious undesired effects and changed drug efficacy, therefore, some studies on interaction between botanical supplement ingredients and drug transporters such as P-gp and OATPs are described here, suggesting that the interaction between botanical supplements and the drug transporters is clinically significant.

Complementary and Alternative Medicine Use in United States Adults With Liver Disease

GOALS

To describe the complementary and alternative medicine (CAM) use in US adults with liver disease.

BACKGROUND

The prevalence and patterns of CAM use among US adults with liver disease have not been well characterized. The 2012 National Health Interview Survey is considered the most current and comprehensive source of information on CAM use in US adults.

STUDY

Using the results of the 2012 National Health Interview Survey, the prevalence of CAM use, most common modalities used, reasons for CAM use, perceived benefits, perceived helpfulness and importance, and disclosure of CAM to health care providers were compared between adults with and without liver disease.

RESULTS

Of the 647 adults with liver disease, 41% reported using CAM in the prior year, compared with 33% of adults without liver disease. The most common modality was herbs and supplements (23%), and 3% of respondents reported consumption of a potentially hepatotoxic substance in the previous 30 days. Only a small proportion of CAM therapies were used specifically for liver disease, with milk thistle being the most common. Among respondents with liver disease, CAM was used more commonly for anxiety or depression, fatigue, and substance use. The majority believed that these therapies improved health. Nearly one-third of therapies were not reported to health care providers, mostly due to failure of the provider to ask.

CONCLUSIONS

CAM use, particularly herbs and supplements, is prevalent among US adults with liver disease. Many do not disclose their CAM use to their providers, despite some using potentially hepatotoxic substances.

Silymarin suppresses basal and stimulus-induced activation, exhaustion, differentiation, and inflammatory markers in primary human immune cells

Silymarin (SM), and its flavonolignan components, alter cellular metabolism and inhibit inflammatory status in human liver and T cell lines. In this study, we hypothesized that SM suppresses both acute and chronic immune activation (CIA), including in the context of HIV infection. SM treatment suppressed the expression of T cell activation and exhaustion markers on CD4+ and CD8+ T cells from chronically-infected, HIV-positive subjects. SM also showed a trend towards modifying CD4+ T cell memory subsets from HIV+ subjects. In the HIV-negative setting, SM treatment showed trends towards suppressing pro-inflammatory cytokines from non-activated and pathogen-associated molecular pattern (PAMP)-activated primary human monocytes, and non-activated and cytokine- and T cell receptor (TCR)-activated mucosal-associated invariant T (MAIT) cells. The data suggest that SM elicits broad anti-inflammatory and immunoregulatory activity in primary human immune cells. By using novel compounds to alter cellular inflammatory status, it may be possible to regulate inflammation in both non-disease and disease states.

Role of UDP-Glucuronosyltransferase 1A1 in the Metabolism and Pharmacokinetics of Silymarin Flavonolignans in Patients with HCV and NAFLD

Silymarin is the most commonly used herbal medicine by patients with chronic liver disease. Silymarin flavonolignans undergo rapid first-pass metabolism primarily by glucuronidation. The aims of this investigation were: (1) to determine the association of UGT1A1*28 polymorphism with the area under the plasma concentration-time curves (AUCs) for silybin A (SA) and silybin B (SB); (2) to evaluate the effect of UGT1A1*28 polymorphism on the profile of flavonolignan glucuronide conjugates found in the plasma; and (3) to investigate the role of UGT1A1 enzyme kinetics on the pharmacokinetics of SA and SB. AUCs and metabolic ratios for thirty-three patients with chronic liver disease administered oral doses of silymarin were compared between different UGT1A1*28 genotypes. The AUCs, metabolic ratios, and the profiles of major SA and SB glucuronides did not differ significantly among the three UGT1A1 genotypes. In contrast, an increase in the proportion of sulfated flavonolignan conjugates in plasma was observed in subjects with UGT1A1*28/*28 genotype compared to subjects carrying wild type alleles. Differences in SA and SB in vitro intrinsic clearance estimates for UGTIA1 correlated inversely with SA and SB exposures observed in vivo indicating a major role for UGT1A1 in silymarin metabolism. In addition, a significant difference in the metabolic ratio observed between patients with NAFLD and HCV suggests that any effect of UGT1A1 polymorphism may be obscured by a greater effect of liver disease on the pharmacokinetics of silymarin. Taken together, these results suggest the presence of the UGT1A1*28 allele does not contribute significantly to a large inter-subject variability in the pharmacokinetics of silybin A and silybin B which may obscure the ability to detect beneficial effects of silymarin in patients with liver disease.

Silybin supplementation during HCV therapy with pegylated interferon-α plus ribavirin reduces depression and anxiety and increases work ability

BACKGROUND

Hepatitis C virus infection and interferon treatment are often associated with anxiety, depressive symptoms and poor health-related quality of life. To evaluate the Silybin-vitamin E-phospholipids complex effect on work ability and whether health related factors (anxiety and depression) were associated with work ability in subjects with chronic hepatitis C treated with Pegylated-Interferon-α2b (Peg-IFN) and Ribavirin (RBV).

METHODS

Thirty-one patients (Group A) with chronic hepatitis and other 31 subjects in Group B were recruited in a randomized, prospective, placebo controlled, double blind clinical trial. Group A received 1.5 mg/kg per week of Peg-IFN plus RBV and placebo, while Group B received the same dosage of Peg-IFN plus RBV plus association of Silybin 94 mg + vitamin E 30 mg + phospholipids 194 mg in pills for 12 months. All subjects underwent to laboratory exams and questionnaires to evaluate depression (Beck Depression Inventory - BDI), anxiety (State-trait anxiety inventory - STAI) and work ability (Work ability Index - WAI).

RESULTS

The comparison between group A and group B showed significant differences after 6 months in ALT (P < 0.001), and viremia (P < 0.05), after 12 months in ALT (P < 0.001), and AST (P < 0.001), at follow up in AST (P < 0.05), and ALT (P < 0.001). Significant difference were observed after 1 month in WAI (p < 0.001) and BDI (P < 0.05), after 6 months in WAI (P < 0.05) and STAI (P < 0.05), after 12 months and at follow up in WAI, STAI and BDI (p < 0.01).

CONCLUSIONS

The supplementation with Silybin-vitamin E -phospholipids complex increased work ability and reduced depression and anxiety in patients treated with Peg-IFN and RBV.

TRIAL REGISTRATION

NCT01957319 , First received: September 25, 2013. Last updated: September 30, 2013 (retrospectively registered).

Intestinal and Hepatocellular Transporters: Therapeutic Effects and Drug Interactions of Herbal Supplements

Herbal supplements are generally considered safe; however, drug disposition is influenced by the interactions of herbal supplements and food constituents with transport and metabolic processes. Although the interference of herbal supplements with drug metabolism has been studied extensively, knowledge of how they interact with the drug transport processes is less advanced. Therefore, we describe here specific examples of experimental and human interaction studies of herbal supplement components with drug transporters addressing, for example, organic anion transporting polypeptides or P-glycoprotein, as such interactions may lead to severe side effects and altered drug efficacy. Hence, it is clearly necessary to increase the awareness of the clinical relevance of the interference of herbal supplements with the drug transport processes.

Severe Cholestasis and Bile Acid Nephropathy From Anabolic Steroids Successfully Treated With Plasmapheresis

Severe cholestasis with anabolic androgenic steroids is well-known to cause acute liver injury. Treatment is usually supportive after withdrawal of the offending agent. Acute kidney injury (AKI) frequently occurs in acute liver injury and may complicate management and prognosis. We highlight the use of plasmapheresis resulting in rapid improvement in cholestatic jaundice with resolution of AKI. Plasmapheresis should be considered in special cases in which there is progressive clinical decline despite supportive care.

Safety and efficacy of Qurse-e-istisqua in chronic hepatitis C infection: an exploratory study

Background:

Qurse-e-istisqua (Q-e-I), an Unani medicine commonly prescribed to treat liver disorders.

Objectives:

To study efficacy and safety of Q-e-I in hepatitis C virus (HCV) infection.

Methods:

In this randomized double-blind exploratory study, 60 naive patients of HCV infection were assigned to receive either interferonα2a (IFNα2a) (3 mIU, subcutaneous, thrice weekly), ribavirin (RBV) (1000 mg, orally, twice daily in divided doses) and placebo (n = 30) or IFNα2a, RBV and Q-e-I (5 g, orally, thrice daily in divided doses) (n = 30). HCV RNA levels, serum hyaluronic acid (SHA), ultrasound image scoring for fibrosis, liver and renal function test, prothrombin time, were done at the baseline and thereafter periodically.

Results:

Early virologic response (EVR), end of treatment response (ETR) and sustained virologic response (SVR) were 90%, 96.6% and 90% in the control group and 86.6%, 90.0% and 83.3% in the treatment group. SHA level was lower in the treatment group at the end of the treatment as compared to the control group. Mean end of follow-up ultrasound image scoring for fibrosis in the control and the treatment group was 1.37 ± 0.07 and 1.22 ± 0.06 respectively. Aspartate aminotransferase (AST) levels were significantly lower in the treatment group than the control group at 1-month. Commonly observed adverse drug reactions included fever, hair fall, fatigue, anemia, and diarrhea.

Conclusion:

Q-e-I was well tolerated and showed anti-fibrotic activity. EVR, ETR and SVR suggested that Q-e-I do not have any anti-HCV activity. Early recovery in AST and inhibition of progress of fibrosis in Q-e-I group was probably due to the anti-inflammatory and antioxidant activity of its ingredients.

Cell culture-derived HCV cannot infect synovial fibroblasts

Worldwide 170 million individuals are infected with hepatitis C virus (HCV), up to 45 million of whom are affected by arthropathy. It is unclear whether this is due to viral infection of synovial cells or immune-mediated mechanisms. We tested the capacity of primary synovial fibroblasts to support HCV propagation. Out of the four critical HCV receptors, only CD81 was expressed to any significant extent in OASF and RASF. Consistent with this, pseudotyped HCV particles were unable to infect these cells. Permissiveness for HCV replication was investigated by transfecting cells with a subgenomic replicon of HCV encoding a luciferase reporter. OASF and RASF did not support replication of HCV, possibly due to low expression levels of miR-122. In conclusion, primary human synovial fibroblasts are unable to support propagation of HCV in vitro. HCV-related arthropathy is unlikely due to direct infection of these cells.

Current Status of Herbal Medicines in Chronic Liver Disease Therapy: The Biological Effects, Molecular Targets and Future Prospects

Chronic liver dysfunction or injury is a serious health problem worldwide. Chronic liver disease involves a wide range of liver pathologies that include fatty liver, hepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. The efficiency of current synthetic agents in treating chronic liver disease is not satisfactory and they have undesirable side effects. Thereby, numerous medicinal herbs and phytochemicals have been investigated as complementary and alternative treatments for chronic liver diseases. Since some herbal products have already been used for the management of liver diseases in some countries or regions, a systematic review on these herbal medicines for chronic liver disease is urgently needed. Herein, we conducted a review describing the potential role, pharmacological studies and molecular mechanisms of several commonly used medicinal herbs and phytochemicals for chronic liver diseases treatment. Their potential toxicity and side effects were also discussed. Several herbal formulae and their biological effects in chronic liver disease treatment as well as the underlying molecular mechanisms are also summarized in this paper. This review article is a comprehensive and systematic analysis of our current knowledge of the conventional medicinal herbs and phytochemicals in treating chronic liver diseases and on the potential pitfalls which need to be addressed in future study.

Natural History of Hepatitis C

Hepatitis C infection is a common cause of cirrhosis and indication for liver transplantation in the United States. The incidence of chronic hepatitis C has been declining, but rates of cirrhosis and hepatocellular carcinoma are projected to increase. The outcome of chronic hepatitis C is variable. It is estimated that 20% to 25% will develop cirrhosis over a 25-year to 30-year period. The rate of disease progression is influenced by many host, viral, and environmental factors. Few can be modified.

Natural Products as Tools for Defining How Cellular Metabolism Influences Cellular Immune and Inflammatory Function during Chronic Infection

Chronic viral infections like those caused by hepatitis C virus (HCV) and human immunodeficiency virus (HIV) cause disease that establishes an ongoing state of chronic inflammation. While there have been tremendous improvements towards curing HCV with directly acting antiviral agents (DAA) and keeping HIV viral loads below detection with antiretroviral therapy (ART), there is still a need to control inflammation in these diseases. Recent studies indicate that many natural products like curcumin, resveratrol and silymarin alter cellular metabolism and signal transduction pathways via enzymes such as adenosine monophosphate kinase (AMPK) and mechanistic target of rapamycin (mTOR), and these pathways directly influence cellular inflammatory status (such as NF-κB) and immune function. Natural products represent a vast toolkit to dissect and define how cellular metabolism controls cellular immune and inflammatory function.

Critical review of resveratrol in xenobiotic-induced hepatotoxicity

Use of natural products is increasingly popular. In fact, many patients with liver diseases self-medicate with herbal supplements. Resveratrol (RSV), in particular, is a common natural product that can reduce injury in experimental models of liver disease. Xenobiotic hepatotoxicity is a particularly important area-of-need for therapeutics. Drug-induced liver injury, for example, is the most common cause of acute liver failure (ALF) and ALF-induced deaths in many countries. Importantly, RSV protects against hepatotoxicity in animal models in vivo caused by several drugs and chemicals and may be an effective intervention. Although many mechanisms have been proposed to explain the protection, not all are consistent with other data. Furthermore, RSV suffers from other issues, including limited bioavailability due to extensive hepatic metabolism. The purpose of this article is to summarize recent findings on the protective effects of RSV in xenobiotic-induced liver injury and other forms of liver injury and to provide a critical review of the underlying mechanisms. New mechanisms that are more consistent with data emerging from the toxicology field are suggested. Efforts to move RSV into clinical use are also considered. Overall, RSV is a promising candidate for therapeutic use, but additional studies are needed to better understand its effects.

Drug-Induced Liver Injury

CONTEXT

Drug-induced liver injury (DILI) represents a diverse set of responses following exposure to any manufactured or naturally occurring chemical compound. Drug-induced liver injury is of major concern owing to the ever increasing number of compounds introduced into the market for treatment of various diseases as well as the increasing popularity of herbals, which lend themselves to self-medication but are not rigorously regulated.

OBJECTIVE

To provide an overview of the prevalence, classification, and diagnosis of DILI with emphasis on pathogenesis and the role of a liver biopsy. To focus on the most common, emerging, and herbal agents that cause DILI with emphasis on the histologic pattern of injury observed.

DATA SOURCES

A review of the literature was drawn from the PubMed (US National Library of Medicine) repository, textbooks, and online databases. All figures were taken from cases seen at our tertiary referral center, which is 1 of 12 participating sites in the National Institutes of Health-funded Drug-Induced Liver Injury Network.

CONCLUSIONS

Drug-induced liver injury due to prescription, over-the-counter, and herbal products is a major cause of liver disease in the United States and around the world. Diagnosis of DILI is challenging because there is no single clinical, laboratory, or histologic feature specific to DILI. Accurate diagnosis requires establishing a causal relationship with the suspected agent and excluding competing causes of liver injury. The liver biopsy is an essential component in the management of DILI by offering clues to the underlying pathogenesis, providing prognostic information, and guiding therapy.

Plants Consumption and Liver Health

The liver is a very important organ with a lot of functions for the host to survive. Dietary components are essential for and can be beneficial or detrimental to the healthy or diseased liver. Plants food is an essential part of the human diet and comprises various compounds which are closely related to liver health. Selected food plants can provide nutritional and medicinal support for liver disease. At the present, the knowledge of the effects of plants on the liver is still incomplete. The most urgent task at the present time is to find the best dietary and medicinal plants for liver health in an endless list of candidates. This review article updates the knowledge about the effects of plants consumption on the health of the liver, putting particular emphasis on the potential beneficial and harmful impact of dietary and medicinal plants on liver function.

Herbal products and the liver: a review of adverse effects and mechanisms

Herbal products have been used for centuries among indigenous people to treat symptoms and illnesses. Recently, their use in Western countries has grown significantly, rivaling that of prescription medications. Currently, herbal products are used mainly for weight loss and bodybuilding purposes but also to improve well-being and symptoms of chronic diseases. Many people believe that because they are natural, they must be effective and safe; however, these beliefs are erroneous. Few herbal products have been studied in well-designed controlled trials of patients with liver or other diseases, despite testimony to the contrary. Moreover, current highly effective antiviral drugs make efforts to treat hepatitis C with herbal products redundant. Herbal products are no safer than conventional drugs and have caused liver injury severe enough to require transplantation or cause death. Furthermore, their efficacy, safety, and claims are not assessed by regulatory agencies, and there is uncertainty about their reported and unreported contents. We review the history of commonly used herbal products, as well as their purported efficacies and mechanisms and their adverse effects.

Provision of clinical pharmacist services for individuals with chronic hepatitis C viral infection: Joint Opinion of the GI/Liver/Nutrition and Infectious Diseases Practice and Research Networks of the American College of Clinical Pharmacy

The objective of this opinion paper was to identify and describe potential clinical pharmacists' services for the prevention and management of patients infected with the hepatitis C virus (HCV). The goals of this paper are to guide the establishment and development of pharmacy services for patients infected with HCV and to highlight HCV research and educational opportunities. Recommendations were based on the following: a review of published data on clinical pharmacist involvement in the treatment and management of HCV-infected patients; a consensus of clinical pharmacists who provide direct patient care to HCV-infected patients and practice in different pharmacy models, including community-based and academic settings; and a review of published guidelines and literature focusing on the treatment and management of HCV infections. The recommendations provided in this opinion paper define the areas of clinical pharmacist involvement and clinical pharmacy practice in the treatment and management of patients with HCV. Clinical pharmacists can promote preventive measures and education about reducing HCV transmission, improve medication adherence, assist in monitoring clinical and adverse effects, recommend treatment strategies to minimize adverse effects and drug interactions, and facilitate medication acquisition and logistics that positively improve patient outcomes and reduce the health care system costs.

Dietary supplement use among patients with hepatocellular carcinoma

BACKGROUND

More than 50% of US adults, and an even larger proportion of cancer patients, use dietary supplements. Since many supplements require hepatic metabolism, they may be particularly likely to cause toxicities in patients with hepatocellular carcinoma (HCC). However, little is known about supplement use in patients with HCC.

METHODS

From 2008 to 2012, we gave newly diagnosed HCC patients at our institution a standardized questionnaire about dietary supplement use, demographic factors, and clinical characteristics. We then followed patients for four years or until time to death to examine the relationship with supplement use.

RESULTS

Of 146 patients, 71% had used vitamins and 45% herbal supplements. Most commonly used supplements were antioxidants (51%), multivitamins (46%), vitamin D (25%), and milk thistle (23%). People in mid-higher income brackets were more likely to use herbal supplements (19% of those earning <$30 000, 50% of those earning $30 000-60 000, and 34% of those earning >$60 000 used supplements). Hepatitis C (HCV) patients were more likely to use milk thistle than those without HCV (30% vs 13%, P = .03), and patients with hepatitis B (HBV) were more likely than non-HBV patients to use vitamin C (32% vs 14%, P = .01). Supplement use was not associated with overall survival.

CONCLUSIONS

Like cancer patients in other studies, the majority of our HCC patients used dietary supplements. Supplement use was not associated with overall survival but should be studied in larger patient samples.

Effects and tolerance of silymarin (milk thistle) in chronic hepatitis C virus infection patients: a meta-analysis of randomized controlled trials

OBJECTIVE

This study aimed to evaluate the efficacy and safety of silymarin on chronic hepatitis C virus- (HCV-) infected patients.

METHODS

Randomized controlled trials (RCTs) of silymarin in chronic HCV-infected patients up to April 1, 2014 were systematically identified in PubMed, Ovid, Web of Science, and Cochrane Library databases.

RESULTS

A total of 222 and 167 patients in five RCTs were randomly treated with silymarin (or intravenous silibinin) and placebo, respectively. Serum HCV RNA relatively decreased in patients treated with silymarin compared with those administered with placebo, but no significance was found (P = 0.09). Meta-analysis of patients orally treated with silymarin indicated that the changes of HCV RNA are similar in the two groups (P = 0.19). The effect on alanine aminotransferase (ALT) of oral silymarin is not different from that of placebo (P = 0.45). Improvements in quality-of-life (Short Form-36) in both silymarin and placebo recipients were impressive but relatively identical (P = 0.09).

CONCLUSION

Silymarin is well tolerated in chronic HCV-infected patients. However, no evidence of salutary effects of oral silymarin has yet been reported based on intermediate endpoints (ALT and HCV RNA) in this population. Moreover, intravenous administration of silymarin should be further studied.

Herbs and liver injury: a clinical perspective

Despite a perception that herbal and dietary supplements are safe, devastating liver injury has been reported to result from their use. The difficulty in characterizing liver injury attributable to herbal and dietary supplements stems from the permissive regulatory environment, the complexity of marketed products, and underreporting by the patients who use them. Despite these limitations, researchers, clinicians, and regulators have increasing awareness of the need for study in this area.

Processes to manage analyses and publications in a phase III multicenter randomized clinical trial

Background

The timely publication of findings in peer-reviewed journals is a primary goal of clinical research. In clinical trials, the processes leading to publication can be complex from choice and prioritization of analytic topics through to journal submission and revisions. As little literature exists on the publication process for multicenter trials, we describe the development, implementation, and effectiveness of such a process in a multicenter trial.

Methods

The Hepatitis C Antiviral Long-Term Treatment against Cirrhosis (HALT-C) trial included a data coordinating center (DCC) and clinical centers that recruited and followed more than 1,000 patients. Publication guidelines were approved by the steering committee, and the publications committee monitored the publication process from selection of topics to publication.

Results

A total of 73 manuscripts were published in 23 peer-reviewed journals. When manuscripts were closely tracked, the median time for analyses and drafting of manuscripts was 8 months. The median time for data analyses was 5 months and the median time for manuscript drafting was 3 months. The median time for publications committee review, submission, and journal acceptance was 7 months, and the median time from analytic start to journal acceptance was 18 months.

Conclusions

Effective publication guidelines must be comprehensive, implemented early in a trial, and require active management by study investigators. Successful collaboration, such as in the HALT-C trial, can serve as a model for others involved in multidisciplinary and multicenter research programs.

Trial registration

The HALT-C Trial was registered with clinicaltrials.gov (NCT00006164).

Herb-drug interactions: challenges and opportunities for improved predictions

Supported by a usage history that predates written records and the perception that "natural" ensures safety, herbal products have increasingly been incorporated into Western health care. Consumers often self-administer these products concomitantly with conventional medications without informing their health care provider(s). Such herb-drug combinations can produce untoward effects when the herbal product perturbs the activity of drug metabolizing enzymes and/or transporters. Despite increasing recognition of these types of herb-drug interactions, a standard system for interaction prediction and evaluation is nonexistent. Consequently, the mechanisms underlying herb-drug interactions remain an understudied area of pharmacotherapy. Evaluation of herbal product interaction liability is challenging due to variability in herbal product composition, uncertainty of the causative constituents, and often scant knowledge of causative constituent pharmacokinetics. These limitations are confounded further by the varying perspectives concerning herbal product regulation. Systematic evaluation of herbal product drug interaction liability, as is routine for new drugs under development, necessitates identifying individual constituents from herbal products and characterizing the interaction potential of such constituents. Integration of this information into in silico models that estimate the pharmacokinetics of individual constituents should facilitate prospective identification of herb-drug interactions. These concepts are highlighted with the exemplar herbal products milk thistle and resveratrol. Implementation of this methodology should help provide definitive information to both consumers and clinicians about the risk of adding herbal products to conventional pharmacotherapeutic regimens.

Complementary and alternative medications in hepatitis C infection

Chronic hepatitis C (CHC) infection affects almost 3% of the global population and can lead to cirrhosis, liver failure, and hepatocellular carcinoma in a significant number of those infected. Until recently, the only treatments available were pegylated interferon and ribavirin, which traditionally were not very effective and have considerable side effects. For this reason, interest in complementary and alternative medications (CAM) in the management of hepatitis C has been investigated. Some CAM has demonstrated therapeutic potential in chronic hepatitis C treatment. Unfortunately, some CAM has been shown to have the potential to cause drug-induced liver injury. This article will review and evaluate many of the natural molecules that interact with the hepatitis C virus (HCV) life cycle and discuss their potential use and safety in HCV therapy, as well as highlight some important interactions between medical and complementary treatments.

Null anticarcinogenic effect of silymarin on diethylnitrosamine-induced hepatocarcinogenesis in rats

The aim of this study was to investigate the anticarcinogenic effects of silymarin in diethylnitrosamine (DEN)-induced hepatocarcinogenic rat models. Severe and mild models of hepatocellular carcinoma (HCC) were generated by the intraperitoneal administration of 40 mg/kg DEN once a week for 18 weeks and 100 mg/kg DEN every 2 weeks for 6 weeks in male Wistar rats, respectively. In the severe and mild models of HCC, the rats were treated with 0.1 and 0.5% silymarin for 18 weeks and with 0.1% silymarin for 5 weeks, respectively. Serum transaminase levels were not significantly decreased by the silymarin treatment in either model. Macroscopic and microscopic features indicated that the silymarin-containing formulations did not significantly inhibit the hepatic tumor formation induced by DEN. Furthermore, immunohistochemical and western blot analyses demonstrated that the expression levels of proliferating cell nuclear antigen and glutathione S-transferase P, which are hepatocarcinogenic markers, were not significantly modified by the silymarin treatment. These results indicate that silymarin may not be considered as a candidate agent against hepatocarcinogenesis.

Liver injury induced by herbal complementary and alternative medicine

Herbal and dietary supplement use is common. Most marketed products consist of complex mixtures. Although they are perceived as safe, instances of hepatotoxicity attributable to these products underscore their potential for injury, but the exact component that is responsible for injury is difficult to discern. The lenient regulatory environment in the United States, which opens the possibility of adulteration and contamination, adds to the challenge of disease attribution. Although many different herbal and dietary supplements have been reported to cause liver injury, in the United States, products used for bodybuilding and weight loss are the most commonly implicated.

Drug-drug interactions during antiviral therapy for chronic hepatitis C

The emergence of direct-acting antiviral agents (DAAs) for HCV infection represents a major advance in treatment. The NS3 protease inhibitors, boceprevir and telaprevir, were the first DAAs to receive regulatory approval. When combined with PEG-IFN and ribavirin, these agents increase rates of sustained virologic response in HCV genotype 1 to ∼70%. However, this treatment regimen is associated with several toxicities. In addition, both boceprevir and telaprevir are substrates for and inhibitors of the drug transporter P-glycoprotein and the cytochrome P450 enzyme 3A4 and are, therefore, prone to clinically relevant drug interactions. Several new DAAs for HCV are in late stages of clinical development and are likely to be approved in the near future. These include the protease inhibitors, simeprevir and faldaprevir, the NS5A inhibitor, daclatasvir, and the nucleotide polymerase inhibitor, sofosbuvir. Herein, we review the clinical pharmacology and drug interactions of boceprevir, telaprevir and these investigational DAAs. Although boceprevir and telaprevir are involved in many interactions, these interactions are manageable if health-care providers proactively identify and adjust treatments. Emerging DAAs seem to have a reduced potential for drug interactions, which will facilitate their use in the treatment of HCV.