title: Influence of Plantaginaceae species on E. coli K12 growth in vitro: Possible relation to phytochemical properties.
abstract: BACKGROUND
  The data concerning the influence of Plantaginaceae water extracts on bacterial growth are contradictory.
  
  
  OBJECTIVE
  This study investigates the influence of Plantago maxima Juss. ex Jacq., Plantago lanceolata L., Plantago major L., Veronica teucrium L., Veronica spicata L., and Veronica incana L. aqueous extracts on growth of Escherichia coli K12 culture and the relation to antioxidant, reducing, and iron-binding activities.
  
  
  METHODS
  Aqueous extracts were prepared from the dried leaves with the final concentration of 1/10, 1/15, 1/20, 1/25, 1/30, 1/35, and 1/40 (w/w). Comparative analysis of total flavonoids, iridoids, and tannins in Plantaginaceae species was performed. Iron-binding, antioxidant, and reducing activities of plant extracts were analyzed spectrophotometrically. The influence of plant extracts on E. coli K12 growth was studied in vitro by estimating the bacterial growth in the extract-containing medium.
  
  
  RESULTS
  Total tannin content in plant leaves positively correlated with iron-binding activity (r = 0.641), whereas total flavonoids correlated with antioxidant activity (r = 0.687). In an in vitro model, it is estimated that water extracts of studied Plantaginaceae species stimulated bacterial growth. Prebiotic activity significantly of 1/20 and 1/40 plant extracts positively correlated with antioxidant (r = 0.589; r = 0.576, respectively) and reducing activity (r = 0.721; r = 0.620, respectively) of plant aqueous extracts at 6-24 h. Negative correlation was observed between iron-binding activity and bacterial growth (r = -0.503 and r = -0.534 for 1/20 and 1/40 extracts, respectively).
  
  
  CONCLUSIONS
  Aqueous Plantaginaceae extracts possess prebiotic activity depending on the phytochemical content of plant leaves.
authors.affiliation: Department of Biochemistry, Orenburg State Medical Academy , Orenburg , Russia and.
authors.forename: Olga N
authors.initials: ON
authors.lastname: Nemereshina
authors.forename: Alexey A
authors.initials: AA
authors.lastname: Tinkov
authors.forename: Viktor A
authors.initials: VA
authors.lastname: Gritsenko
authors.forename: Alexandr A
authors.initials: AA
authors.lastname: Nikonorov
mesh_terms: D004305:Dose-Response Relationship, Drug; D048168:Escherichia coli K12 / Q000187:drug effects* / Q000254:growth & development*; D064209:Phytochemicals / Q000302:isolation & purification / Q000494:pharmacology; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D018515:Plant Leaves; D000068377:Plantaginaceae
chemical_list: D064209:Phytochemicals; D010936:Plant Extracts
keywords: Flavonoids; Plantago; Veronica; iron-binding; prebiotic activity