Two flavonoids extracts from Glycyrrhizae radix inhibit in vitro hepatitis C virus replication.

AIM: Traditional herbal medicines have been used for several thousand years in China and other Asian countries. In this study we screened herbal drugs and their purified compounds, using the Feo replicon system, to determine their effects on in vitro HCV replication. METHODS: We screened herbal drugs and their purified extracts for the activities to suppress hepatitis C virus (HCV) replication using an HCV replicon system that expressed chimeric firefly luciferase reporter and neomycin phosphotransferase (Feo) genes. We tested extracts and 13 purified compounds from the following herbs: Glycyrrhizae radix; Rehmanniae radix; Paeoniae radix; Artemisiae capillari spica; and Rhei rhizoma. RESULTS: The HCV replication was significantly and dose-dependently suppressed by two purified compounds, isoliquiritigenin and glycycoumarin, which were from Glycyrrhizae radix. Dose-effect analyses showed that 50% effective concentrations were 6.2 +/- 1.0 microg/mL and 15.5 +/- 0.8 microg/mL for isoliquiritigenin and glycycoumarin, respectively. The MTS assay did not show any effect on cell growth and viability at these effective concentrations, indicating that the effects of the two compounds were specific to HCV replication. These two compounds did not affect the HCV IRES-dependent translation nor did they show synergistic action with interferon-alpha. CONCLUSION: Two purified herbal extracts, isoliquiritigenin and glycycoumarin, specifically suppressed in vitro HCV replication. Further elucidation of their mechanisms of action and evaluation of in vivo effects and safety might constitute a new anti-HCV therapeutics.

Serum KL-6 as a novel tumor marker for hepatocellular carcinoma in hepatitis C virus infected patients.

The up-regulation of MUC1 protein is associated with malignant phenotype of cancer. We investigated the significance of KL-6, one of the MUC1 antigens, as a tumor marker in hepatitis C virus positive hepatocellular carcinoma (HCC). Serum KL-6 was determined in 203 patients with chronic hepatitis (CH), 47 patients with liver cirrhosis (LC) and 78 patients with HCC. KL-6 was higher in HCC compared to non-HCC (p=0.0005) and was higher in patients with multiple HCC nodules compared to a single nodule (p=0.02). There was no correlation between KL-6 and existent tumor markers for HCC such as alpha-fetoprotein, lens culinaris agglutinin-reactive alpha-fetoprotein or des-gamma-carboxyprothrombin. In the prospective analysis, the cumulative incidence of HCC was significantly greater in CH and LC patients with high initial KL-6 (above 400U/ml) compared to the others (p=0.02). Moreover, in the prospective observation of 25 patients whose HCC was completely cured by radiofrequency ablation therapy, the cumulative incidence of distant recurrences was significantly greater in patients with high initial KL-6 compared to the others (p=0.005). These results suggest that serum KL-6 could be a novel tumor marker in the diagnosis and the prediction of prognosis of HCC that may have additive value to the existent markers.

Mutagenic effects of ribavirin and response to interferon/ribavirin combination therapy in chronic hepatitis C.

BACKGROUND/AIMS: To elucidate whether ribavirin acts as a mutagen in the clinical setting and to clarify the relationship between ribavirin-induced mutations and virological response to combined therapy. METHODS: Thirty-four patients with hepatitis C virus (HCV) genotype 1b received ribavirin monotherapy for 4 weeks, followed by a 24-week course of IFN/ribavirin therapy. HCV mutations during a non-treatment observation period and during subsequent ribavirin monotherapy were determined, and the relationship between mutations and response to subsequent IFN/ribavirin therapy was evaluated. RESULTS: Serum HCV significantly decreased from 6.90 to 6.56 log10copy/ml in response to ribavirin monotherapy (P < 0.0001). Nucleotide mutations in the NS5A and NS5B regions occurred during ribavirin monotherapy at a rate of 2.9 x 10(-2)/site/year and 1.3 x 10(-2)/site/year, respectively, a significantly higher rate than the mutation rates during the prior non-treatment observation period (0.60 x 10(-2)/site/year and 0.24 x 10(-2)/site/year, P = 0.02, respectively). Mutation rates in the NS5A region were significantly higher in sustained viral responders (SVRs, n = 10) than in non-responders (8.8 x 10(-2)/site/year vs. 0.38 x 10(-2)/site/year, P = 0.0005, respectively). In the NS5A region, non-synonymous mutations only occurred in SVRs. CONCLUSIONS: Ribavirin may act as a mutagen, and mutations occurring during ribavirin therapy correlate with the virological response to subsequent IFN/ribavirin combination therapy.

Polymerase domain B mutation is associated with hepatitis relapse during long-term lamivudine therapy for chronic hepatitis B.

Breakthrough hepatitis remains the major issue in long-term lamivudine therapy for chronic hepatitis B. However, the emergence of drug-resistant hepatitis B virus (HBV) is not always accompanied by a relapse of hepatitis. To elucidate factors predictive of breakthrough hepatitis, 53 patients with genotype C of HBV on long-term lamivudine therapy were analyzed. HBV reappeared during therapy in 19 patients with a cumulative incidence of 15% at 1 year, 34% at 2 years, and 60% at 3 years. Within this group, breakthrough hepatitis developed in 12 patients (63%). A polymerase gene domain B mutation (rt180M) emerged in 13 patients, and domain C mutations (rt204I, rt204V) were found in 19 patients. The rt180M mutation was associated with breakthrough hepatitis (p < 0.05) with a positive predictive value of 85% and a negative predictive value of 83%. Patients with the rt180M mutation had higher HBV-DNA levels during viral breakthrough compared to patients with rt180wt (p < 0.05). The mutational pattern of rt204 was not associated with breakthrough hepatitis. In conclusion, genotypic assays for the rt180M mutation after viral breakthrough may be useful in predicting the risk of breakthrough hepatitis and in deciding when to initiate alternative or additive nucleoside analogue therapy.

Development of hepatocellular carcinoma after interferon therapy in chronic hepatitis C. Is it possible to reduce the incidence by ribanirin and IFN combination therapy?

OBJECTIVES: Although the incidence of hepatocellular carcinoma (HCC) has been shown to be reduced after interferon (IFN) monotherapy in chronic hepatitis C, the risk factors for the development of HCC have not been fully understood. The aim of this study is to investigate the risk factors for the development of HCC after IFN in chronic hepatitis C as well as whether the incidence of HCC will be reduced by ribavirin and IFN combination therapy or not. METHODS: 495 patients with chronic hepatitis C and which received IFN monotherapy were followed and the incidence and risk factors for the development of HCC were examined. On the other hand, in the patients which received ribavirin and IFN combination therapy, the sustained response rate was assessed and the reduction rate of HCC development was predicted. RESULTS: Multivariate analysis by the Cox proportional hazard model revealed that the risk factors for HCC development were age, male gender, severe fibrosis and outcome of IFN therapy. On ribavirin and IFN combination therapy, the sustained response rate reached 17.3% in genotype 1b and 74% in genotypes 2a and 2b infection, thus reducing 20% of the estimated incidence of HCC. CONCLUSION: To reduce the incidence of HCC in chronic hepatitis C, improvement of the sustained response rate is an essential issue, and ribavirin and IFN combination therapy shows to be promising.