title: In vitro study of antiviral activity of mycophenolic acid on Brazilian orthobunyaviruses.
abstract: OBJECTIVE
  Oropouche, Caraparu, Guama, Guaroa and Tacaiuma are ssRNA viruses that belong to the genus Orthobunyavirus and have been associated with human febrile illnesses and/or encephalitis. In this study, we evaluated the antiviral action of mycophenolic acid (MPA) on theseorthobunyaviruses to achieve a therapeutic agent to treat the diseases caused by these viruses.
  
  
  METHODS
  The in vitro antiviral evaluation to MPA was done by using plaque assay at different periods of treatment.
  
  
  RESULTS
  Results showed that MPA at a concentration of 10 microg/ml has significant antiviral activity on Tacaiuma virus when treatment was initiated either 24 h before or 2 h after viral infection. Moreover, MPA has an inhibitory effect on Guama virus replication, but only when treatment was initiated before cell infection. Addition of guanosine in the culture reverted the inhibitory effect of MPA on Tacaiuma and Guama viruses, suggesting that the antiviral activity of this substance was via depletion of the intracellular guanosine pool.
  
  
  CONCLUSIONS
  Our results suggest that MPA would not be a good therapeutic agent to treat the diseases caused by Oropouche, Caraparu, Guama, Guaroa, and Tacaiuma viruses.
authors.affiliation: Centre of Research in Virology, School of Medicine of Ribeirão Preto, University of São Paulo-USP, Ribeirão Preto, SP, Brazil.
authors.forename: Márcia Cristina
authors.initials: MC
authors.lastname: Livonesi
authors.forename: Ricardo Luiz
authors.initials: RL
authors.lastname: Moro de Sousa
authors.forename: Luiz Tadeu
authors.initials: LT
authors.lastname: Moraes Figueiredo
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002522:Chlorocebus aethiops; D006151:Guanosine / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D009173:Mycophenolic Acid / Q000494:pharmacology*; D016851:Orthobunyavirus / Q000187:drug effects*; D013997:Time Factors; D014709:Vero Cells; D010948:Viral Plaque Assay; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D006151:Guanosine; D009173:Mycophenolic Acid