(-)-Epigallocatechin gallate inhibits hepatitis C virus (HCV) viral protein NS5B.

In this study, we elucidated a small molecule inhibitor on viral protein NS5B identified through a high-throughput screening strategy using optical nanoparticle-based RNA oligonucleotide. We have previously shown that quantum dots (QDs)-RNA oligonucleotide can specifically recognize the HCV viral proteins. We have also demonstrated that conjugated QDs-RNA oligonucleotide can specifically and sensitively interact with designed biochips [1,2]. Among the flavonoids examined, (-)-epigallocatechin gallate (EGCG) demonstrated a remarkable inhibition activity on HCV viral protein, NS5B. (-)-Epigallocatechin gallate, at 0.005 μg mL(-1) or more, concentration-dependently attenuated the binding affinity on a designed biochip as evidenced by QDs-RNA oligonucleotide. At a concentration of 0.1 μg mL(-1), (-)-epigallocatechin gallate showed a 50% inhibition activity on QDs-RNA oligonucleotide biochip assay. We screened a small molecule inhibitor on the viral protein, NS5B, identified through a high-throughput screening strategy using on-chip optical nanoparticle-based RNA oligonucleotide on chip. In this designed strategy, the convenient and efficient screening and development of an on-chip viral protein inhibitor using a QDs-RNA oligonucleotide assay is achievable with high sensitivity and simplicity. In addition, this platform is expected to be applicable toward the inhibitor screening of other types of diseases.