MBZM-N-IBT, a Novel Small Molecule, Restricts Chikungunya Virus Infection by Targeting nsP2 Protease Activity In Vitro, In Vivo, and Ex Vivo

Antimicrob Agents Chemother. 2022 Jul 19;66(7):e0046322. doi: 10.1128/aac.00463-22. Epub 2022 Jun 29.

Abstract

The increase in disease incidences and persistent Chikungunya virus (CHIKV)-induced arthritis have been a huge burden on public health globally. In the absence of specific antivirals or vaccines, it is essential to continue efforts to develop effective anti-CHIKV strategies. Our previous study showing the in vitro anti-CHIKV potential of a novel molecule 1-[(2-methylbenzimidazol-1-yl) methyl]-2-oxo-indolin-3-ylidene] amino] thiourea (MBZM-N-IBT) encouraged us to further validate its efficacy. Here, the effect of MBZM-N-IBT was evaluated in vitro in RAW 264.7 cells, in vivo in C57BL/6 mice, and ex vivo in human peripheral blood mononuclear cells (hPBMCs). The study demonstrated that CHIKV infection was efficiently abrogated in RAW 264.7 cells (IC50 = 22.34 μM) with significant inhibition in viral proteins. The inhibition was effective in the postentry step, and MBZM-N-IBT predominately interfered in the early stages of CHIKV life cycle. It was further supported when the protease activity of CHIKV-nsP2 was hindered by the compound. Moreover, it diminished the CHIKV-induced inflammatory responses in vitro through significant downregulation of all the major mitogen-activated protein kinases (MAPKs), NF-κB, cyclooxygenase (COX)-2, and cytokines. Furthermore, MBZM-N-IBT restricted CHIKV infection and inflammation in vivo, leading to reduced clinical scores and complete survival of C57BL/6 mice. Additionally, it has been noticed that the CHIKV infection was reduced remarkably in hPBMC-derived monocyte-macrophage populations ex vivo by the compound. In conclusion, it can be suggested that this novel compound MBZM-N-IBT has been demonstrated to be a potential anti-CHIKV molecule in vitro, in vivo, and ex vivo and fulfilled all the criteria to investigate further for successful treatment of CHIKV infection.

Keywords: Chikungunya; anti-viral; infection; inflammation; replication.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzimidazoles
  • Chikungunya Fever* / drug therapy
  • Chikungunya virus*
  • Humans
  • Isatin / analogs & derivatives
  • Leukocytes, Mononuclear / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Peptide Hydrolases / metabolism
  • Virus Replication

Substances

  • 1-((2-methylbenzimidazol-1-yl)methyl)-2-oxoindolin-3-ylidene)amino)thiourea
  • Benzimidazoles
  • Isatin
  • Peptide Hydrolases