Antifungal activity of two oxadiazole compounds for the paracoccidioidomycosis treatment

PLoS Negl Trop Dis. 2019 Jun 4;13(6):e0007441. doi: 10.1371/journal.pntd.0007441. eCollection 2019 Jun.

Abstract

Paracoccidioidomycosis (PCM) is a neglected disease present in Latin America with difficulty in treatment and occurrence of serious sequelae. Thus, the development of alternative therapies is imperative. In the current work, two oxadiazole compounds (LMM5 and LMM11) presented fungicidal activity against Paracoccidioides spp. The minimum inhibitory and fungicidal concentration values ranged from 1 to 32 μg/mL, and a synergic effect was observed for both compounds when combined with Amphotericin B. LMM5 and LMM11 were able to reduce CFU counts (≥2 log10) on the 5th and 7th days of time-kill curve, respectively. The fungicide effect was confirmed by fluorescence microscopy (FUN-1/FUN-2). The hippocratic screening and biochemical analysis were performed in Balb/c male mice that received a high dose of each compound, and the compounds showed no in vivo toxicity. The treatment of experimental PCM with the new oxadiazoles led to significant reduction in CFU (≥1 log10). Histopathological analysis of the groups treated exhibited control of inflammation, as well as preserved lung areas. These findings suggest that LMM5 and LMM11 are promising hits structures, opening the door for implementing new PCM therapies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amphotericin B / pharmacology
  • Animals
  • Antifungal Agents / administration & dosage
  • Antifungal Agents / pharmacology*
  • Colony Count, Microbial
  • Disease Models, Animal
  • Drug Synergism
  • Histocytochemistry
  • Lung / microbiology
  • Lung / pathology
  • Male
  • Mice, Inbred BALB C
  • Microbial Sensitivity Tests
  • Microbial Viability / drug effects
  • Oxadiazoles / administration & dosage
  • Oxadiazoles / pharmacology*
  • Paracoccidioides / drug effects*
  • Paracoccidioidomycosis / drug therapy
  • Paracoccidioidomycosis / microbiology
  • Paracoccidioidomycosis / pathology
  • Treatment Outcome

Substances

  • Antifungal Agents
  • Oxadiazoles
  • Amphotericin B

Grants and funding

This study was funded by National Council for Scientific and Technological Development (CNPq) (http://www.cnpq.br/) - Grant number 481446/2013-3 to ESK, CAPES and Fundação Araucária to FAVRV. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.