Elsevier

Antiviral Research

Volume 118, June 2015, Pages 68-74
Antiviral Research

Short Communication
Antiviral activities of 15 dengue NS2B-NS3 protease inhibitors using a human cell-based viral quantification assay

https://doi.org/10.1016/j.antiviral.2015.03.010Get rights and content

Highlights

  • There are an estimated 50–100 million dengue infections annually worldwide.

  • The viral NS2B-NS3 protease is deemed a plausible drug target.

  • 15 inhibitors published between 2003 and 2013 were screened using our viral titer assay.

  • The most potent compound, an anthraquinone, reduced viral titer 10-fold at 1 μM.

  • This could serve as a plausible scaffold for further medicinal chemistry efforts.

Abstract

The dengue virus is a mosquito-borne pathogen responsible for an estimated 50–100 million human dengue infections annually. There are currently no approved drugs against this disease, resulting in a major unmet clinical need. The dengue viral NS2B-NS3 protease has been identified as a plausible drug target due to its involvement in viral replication in mammalian host cells. In the past decade, at least 20 dengue NS2B-NS3 protease inhibitors have been reported in the literature with a range of inhibitory activities in protease assays. However, such assays do not shed light on an inhibitor’s ability to penetrate human cell membranes where the viral protease resides. In this study, we investigated the antiviral activities of 15 small-molecule and peptide-based NS2B-NS3 inhibitors on dengue serotype 2-infected HuH-7 human hepatocarcinoma cells. Experimental results revealed anthraquinone ARDP0006 (compound 5) to be the most potent inhibitor which reduced dengue viral titer by more than 1 log PFU/mL at 1 μM in our cell-based assays involving HuH-7 and K562 cell lines, suggesting that its scaffold could serve as a lead for further medicinal chemistry studies. Compound 5 was also found to be non-cytotoxic at 1 μM over 3 days incubation on HuH-7 cells using the Alamar Blue cellular toxicity assay.

Section snippets

Acknowledgements

We thank ASTAR Biomedical Research Council for financial support, Dr. Priscilla Yang (Harvard Medical School) for the HuH-7 cells, the Singapore Environmental Health Institute, National Environment Agency, for the CHIKV and Dr. Xing Jie (Shimadzu, Singapore) for mass spectrometry support. This study was supported by Dr Justin Chu’s MINDEF DIRP Grant R182-000-210-232.

References (32)

Cited by (40)

  • Novel reverse genetics of genotype I and III Japanese encephalitis viruses assembled through transformation associated recombination in yeast: The reporter viruses expressing a green fluorescent protein for the antiviral screening assay

    2022, Antiviral Research
    Citation Excerpt :

    Dihydroartemisinin and Digitonin, inhibited the binding of ZIKV or their entry into host cells (Zhang et al., 2021). ARDP0006 exerted its suppression effect on DENV by interfering with the protease activity of DENV NS2B-NS3 (Chu et al., 2015; Constant et al., 2018). BHK-21 cells respectively infected with GI and GIII reporter viruses at an MOI of 0.1 were treated with these four compounds at different concentrations.

  • Exploiting the unique features of Zika and Dengue proteases for inhibitor design

    2019, Biochimie
    Citation Excerpt :

    Surprisingly, the NS3 internal intrahelicase site and NS3-NS4A junction also are exclusively processed in cis [136]. ARDP0006 (1,8-dihydroxy-4,5-dinitroanthraquinone) has been reported as an active-site Dengue protease inhibitor that blocks production of Dengue 2 virus in tissue culture at low micromolar concentrations [136,137]. However, in an assay with a fluorogenic substrate and the purified protease gDenPro (harbouring the hydrophilic part of NS2B, an uncleavable linker and NS3 protease), ARDP0006 appeared to be a 100-fold weaker inhibitor than tissue culture experiments had suggested [138].

View all citing articles on Scopus
View full text