Comparison of Anti-HCV Activity of Multiple Punica granatum Extracts and Fractions in Virus-infected Human Hepatocytes

Background: Plants extracts and their bioactive constituents can provide an alternative approach for new treatment. Pakistani flora reveals a huge, largely untapped source of potential antiviral constituents. Objective: High-cost concerns of direct-acting anti-HCV drugs limit their employment specifically in developing countries like Pakistan. Therefore, discovery of inexpensive and nontoxic agents is needed for HCV treatment. Methodology: In this study, we used plasmid constructs of pCR3.1/FLAGtag/HCV NS3/4A (genotype 1a & 3a) and Punica granatum extracts (PK AV 003) and semi-purified fractions (P1-P11) were evaluated for their anti-HCV activity. Acetone extract along with two fractions (P4 & P11) revealed a useful therapeutic index. Results: The fractions P4 (IC50=28.5±0.02 μg/ml; IC25=16±0.02 μg/ml) and P11 (IC50=72±0.02 μg/ml; IC25=41±0.03 μg/ml) dramatically suppressed HCV replication as measured by quantitative PCR (qPCR) and HCV NS3 protein expression level in transient transfection model. Consistent with suppression in genome replication, inhibition of HCV infectious particles by PK AV 003 extract was also judged in an infectious model system. This data is the first description of Pakistani indigenous cultivated fruit-producing plant, Punica granatum, possessing anti-HCV activity. Further analyses are being performed for investigating the mechanistic studies and structural characterization of purified fractions of PK AV 003. Conclusion: Our findings suggest that PK AV 003 fruit extract might be useful as an add-on therapeutic candidate for treating HCV infection.