title: Anti-Mayaro virus activity of Cassia australis extracts (Fabaceae, Leguminosae).
abstract: BACKGROUND
  The arthropod-borne Mayaro virus (MAYV) causes 'Mayaro fever', a disease of medical significance, primarily affecting individuals in permanent contact with forested areas in tropical South America. Studies showed that the virus could also be transmitted by the mosquito Aedes aegypti. Recently, MAYV has attracted attention due to its likely urbanization. To date, there are no drugs that can treat this illness.
  
  
  METHODS
  Fractions and compounds were obtained by chromatography from leaf extracts of C. australis and chemically identified as flavonoids and condensed tannins using spectroscopic and spectrometric techniques (UV, NMR, and ESI-FT-ICR MS). Cytotoxicity of EtOAc, n-BuOH and EtOAc-Pp fractions were measured by the dye-uptake assay while their antiviral activity was evaluated by a virus yield inhibition assay. Larvicidal activity was measured by the procedures recommended by the WHO expert committee for determining acute toxicity.
  
  
  RESULTS
  The following group of substances was identified from EtOAc, n-BuOH and EtOAc-Pp fractions: flavones, flavonols, and their glycosides and condensed tannins. EtOAc and n-BuOH fractions inhibited MAYV production, respectively, by more than 70% and 85% at 25 μg/mL. EtOAc-Pp fraction inhibited MAYV production by more than 90% at 10 μg/mL, displaying a stronger antiviral effect than the licensed antiviral ribavirin. This fraction had an excellent antiviral effect (IC90 = 4.7 ± 0.3 μg/mL), while EtOAc and n-BuOH fractions were less active (IC90 = 89.1 ± 4.4 μg/mL and IC90 = 40.9 ± 5.7 μg/mL, respectively).
  
  
  CONCLUSIONS
  C. australis can be used as a source of compounds with anti-Mayaro virus activity. This is the first report on the biological activity of C. australis.
authors.affiliation: Natural Product Research Institute, Center of Health Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. kawaldhelm@gmail.com.
authors.forename: Kassia C W
authors.initials: KC
authors.lastname: Spindola
authors.affiliation: Natural Product and Food Department. Center of Health Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. naomisimas@yahoo.com.
authors.forename: Naomi K
authors.initials: NK
authors.lastname: Simas
authors.affiliation: Chemistry Institute, Biochemistry Department, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. tiagosouzasalles@gmail.com.
authors.forename: Tiago S
authors.initials: TS
authors.lastname: Salles
authors.affiliation: Microbiology Institute, Virology Department, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. marcelomeneses@micro.ufrj.br.
authors.forename: Marcelo D F
authors.initials: MD
authors.lastname: de Meneses
authors.affiliation: Botanical Department. Center of Biological and Health Sciences, Federal University of the State of Rio de Janeiro, Rio de Janeiro, Brazil. alissat@uol.com.br.
authors.forename: Alice
authors.initials: A
authors.lastname: Sato
authors.affiliation: Microbiology Institute, Virology Department, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. davisf@micro.ufrj.br.
authors.forename: Davis
authors.initials: D
authors.lastname: Ferreira
authors.affiliation: Petroleomic and Forensic Laboratory, Department of Chemistry, Federal University of Espírito Santo, 29075-910, Vitória, ES, Brazil. wandersonromao@gmail.com.
authors.forename: Wanderson
authors.initials: W
authors.lastname: Romão
authors.affiliation: Natural Product Research Institute, Center of Health Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. kusterrm@gmail.com.
authors.forename: Ricardo M
authors.initials: RM
authors.lastname: Kuster
mesh_terms: D000524:Alphavirus; D000818:Animals; D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology*; D002366:Cassia / Q000737:chemistry*; D002522:Chlorocebus aethiops; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D014709:Vero Cells
chemical_list: D000998:Antiviral Agents; D010936:Plant Extracts