title: Potential of medicinal plants from the Brazilian semi-arid region (Caatinga) against Staphylococcus epidermidis planktonic and biofilm lifestyles.
abstract: BACKGROUND
  Medicinal plants from the Caatinga, a Brazilian xeric shrubland, are used in folk medicine to treat infections. These ethnopharmacological data can contribute to obtaining new antimicrobial/antibiofilm extracts and natural product prototypes for the development of new drugs. The aim of this study was to investigate the antibiofilm and antibacterial activities of 45 aqueous extracts from 24 Caatinga plant species.
  
  
  METHODS
  The effect of aqueous extracts on planktonic cells and on biofilm formation by Staphylococcus epidermidis was studied by the OD(600) absorbance and by the crystal violet assay, respectively. Scanning electron microscopy (SEM) was used to generate comparative images of extract-treated and untreated biofilms. Chromatographic analyses were performed to characterize the active extracts.
  
  
  RESULTS
  The in vitro screening, at 0.4 mg/mL and 4.0mg/mL, showed 20 plants effective in preventing biofilm formation and 13 plants able to inhibit planktonic bacterial growth. SEM images demonstrated distinct profiles of bacterial adhesion, matrix production and cell morphology according to different treatments and surfaces. The phytochemical analysis of the selected active extracts indicates the polyphenols, coumarins, steroids and terpenes as possible active compounds.
  
  
  CONCLUSIONS
  This study describes the first antibiofilm and antibacterial screening of Caatinga plants against S. epidermidis. The evaluation presented in this study confirms several ethnopharmacological reports and can be utilized to identify new antibiofilm and antibacterial products against S. epidermidis from traditional Brazilian medicine.
authors.affiliation: Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Danielle da Silva
authors.initials: Dda S
authors.lastname: Trentin
authors.forename: Raquel Brandt
authors.initials: RB
authors.lastname: Giordani
authors.forename: Karine Rigon
authors.initials: KR
authors.lastname: Zimmer
authors.forename: Alexandre Gomes
authors.initials: AG
authors.lastname: da Silva
authors.forename: Márcia Vanusa
authors.initials: MV
authors.lastname: da Silva
authors.forename: Maria Tereza Dos Santos
authors.initials: MT
authors.lastname: Correia
authors.forename: Israel Jacob Rabin
authors.initials: IJ
authors.lastname: Baumvol
authors.forename: Alexandre José
authors.initials: AJ
authors.lastname: Macedo
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D001938:Brazil; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004305:Dose-Response Relationship, Drug; D020834:Ethnopharmacology; D008519:Medicine, Traditional; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D010933:Plankton / Q000187:drug effects* / Q000254:growth & development; D010936:Plant Extracts / Q000494:pharmacology*; D010946:Plants, Medicinal; D013056:Spectrophotometry, Ultraviolet; D013212:Staphylococcus epidermidis / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure
chemical_list: D000900:Anti-Bacterial Agents; D010936:Plant Extracts