title: Antibiotic-modifying activity of riachin, a non-cyanogenic cyanoglycoside extracted from Bauhinia pentandra.
abstract: BACKGROUND
  The search for new active compounds from the Brazilian flora has intensified in recent years, especially for new drugs with antibiotic potential. Accordingly, the aim of this study was to determine whether riachin has antibiotic activity in itself or is able to modulate the activity of conventional antibiotics.
  
  
  METHODS
  A non-cyanogenic cyanoglycoside known as riachin was isolated from Bauhinia pentandra, and was tested alone and in combination with three antibiotics (clindamycin, amikacin, and gentamicin) against multiresistant bacterial strains (Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus).
  
  
  RESULTS
  Riachin did not show significant antibiotic activity when tested alone against any strain (P>0.05). However, when combined with conventional antibiotics, it showed drug-modifying activity against strains of S. aureus exposed to clindamycin (P<0.001) as well as against P. aeruginosa exposed to amikacin (P<0.001). Although riachin did not show direct antibiotic activity, it had synergistic activity when combined with amikacin or clindamycin. The mechanism of action of this synergism is under investigation.
  
  
  CONCLUSIONS
  The results of this work demonstrate that some substances of natural origin can enhance the effectiveness of certain antibiotics, which means a substantial reduction in the drug dose required and possibly in consequent adverse events for patients.
authors.affiliation: Development and Technological Innovation in Medicines, Universidade Federal do Ceará - UFC, Juazeiro do Norte-CE, PE, Brazil ; College of Pharmacy, Faculdade de Medicina Estácio de Juazeiro do Norte-Estácio, Juazeiro do Norte-CE, PE, Brazil.
authors.forename: Pablo Antonio Maia
authors.initials: PA
authors.lastname: de Farias
authors.affiliation: College of Biomedicine, Faculdade Leão Sampaio-FLS, Juazeiro do Norte-CE, PE, Brazil ; College of Pharmacy, Faculdade de Medicina Estácio de Juazeiro do Norte-Estácio, Juazeiro do Norte-CE, PE, Brazil.
authors.forename: Fernando Gomes
authors.initials: FG
authors.lastname: Figueredo
authors.affiliation: College of Pharmacy, Faculdade de Medicina Estácio de Juazeiro do Norte-Estácio, Juazeiro do Norte-CE, PE, Brazil.
authors.forename: Aline Maria Brito
authors.initials: AM
authors.lastname: Lucas
authors.affiliation: College of Pharmacy, Faculdade de Medicina Estácio de Juazeiro do Norte-Estácio, Juazeiro do Norte-CE, PE, Brazil.
authors.forename: Rafael Barbosa
authors.initials: RB
authors.lastname: de Moura
authors.affiliation: College of Biomedicine, Faculdade Leão Sampaio-FLS, Juazeiro do Norte-CE, PE, Brazil ; College of Biomedicine, Faculdade Leão Sampaio-FLS, Juazeiro do Norte-CE, PE, Brazil.
authors.forename: Henrique Douglas Melo
authors.initials: HD
authors.lastname: Coutinho
authors.affiliation: Department of Molecular Sciences, Universidade Federal Rural de Pernambuco, Recife, PE, Brazil.
authors.forename: Tania Maria Sarmento
authors.initials: TM
authors.lastname: da Silva
authors.affiliation: College of Biomedicine, Faculdade Leão Sampaio-FLS, Juazeiro do Norte-CE, PE, Brazil ; College of Pharmacy, Faculdade de Medicina Estácio de Juazeiro do Norte-Estácio, Juazeiro do Norte-CE, PE, Brazil.
authors.forename: Ana Luiza de Aguiar Rocha
authors.initials: AL
authors.lastname: Martin
authors.affiliation: Development and Technological Innovation in Medicines, Universidade Federal do Ceará - UFC, Juazeiro do Norte-CE, PE, Brazil.
authors.forename: Marta Maria de França
authors.initials: MM
authors.lastname: Fonteles
mesh_terms: D000181:Acrylonitrile / Q000031:analogs & derivatives* / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D036481:Bauhinia / Q000737:chemistry*; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects; D004357:Drug Synergism; D004926:Escherichia coli / Q000187:drug effects; D005960:Glucosides / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D005960:Glucosides; D010936:Plant Extracts; C000604474:riachin; D000181:Acrylonitrile
keywords: Escherichia coli; Pseudomonas aeruginosa; Staphylococcus aureus; riachin