title: Phytopharmacologic preparations as predictors of plant bioactivity: A particular approach to Echinacea purpurea (L.) Moench antioxidant properties.
abstract: OBJECTIVE
  A large body of evidence has confirmed a multitude of health benefits of plant products and their derived formulations. Echinacea purpurea (L.) Moench is a good example, widely used due to its therapeutic properties. In the present study, the chemical composition of the different samples and antioxidant properties of E. purpurea hydroethanolic and aqueous extracts obtained from dry or fresh raw material were evaluated and compared with dietary supplements based on the same plant (tablets and syrup), to determine the most active phytopharmacologic preparation or formulation.
  
  
  METHODS
  Chemical composition of the different samples was assessed through the determination of free sugars, organic acids and tocopherols. The in vitro antioxidant properties were determined using four assays: 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging activity, reducing power, inhibition of b-carotene bleaching and inhibition of lipid peroxidation by thiobarbituric acid reactive substances (TBARS) assay. Total phenolics and flavonoids were also determined.
  
  
  RESULTS
  Overall, the hydroethanolic extract of fresh plant revealed the highest activity, directly related with its higher contents in phenolic (229.22 ± 4.38 mg gallic acid equivalent [GAE]/mL), flavonoids (124.83 ± 7.47 mg GAE/mL), organic acids (8.89 ± 0.10 g/100 g), and tocopherols (4.55 ± 0.02 mg/100 g). Tablets followed by syrup revealed the worst effect, positively correlated with the lowest abundance in bioactive molecules. The weak in vitro antioxidant potential of commercial phytopharmacologic formulations could be related to their chemical composition, including the addition of excipients.
  
  
  CONCLUSIONS
  Further studies are necessary to deepen knowledge on this area, namely focusing on in vivo experiments, to establish upcoming guidelines to improve the quality and bioavailability of phytopharmacologic formulations.
authors.affiliation: Mountain Research Centre (CIMO), ESA, Polytechnic Institute of Bragança, Campus de Santa Apolónia, Bragança, Portugal.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Pires
authors.affiliation: Mountain Research Centre (CIMO), ESA, Polytechnic Institute of Bragança, Campus de Santa Apolónia, Bragança, Portugal.
authors.forename: Natália
authors.initials: N
authors.lastname: Martins
authors.affiliation: Mountain Research Centre (CIMO), ESA, Polytechnic Institute of Bragança, Campus de Santa Apolónia, Bragança, Portugal.
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Carvalho
authors.affiliation: Mountain Research Centre (CIMO), ESA, Polytechnic Institute of Bragança, Campus de Santa Apolónia, Bragança, Portugal.
authors.forename: Lillian
authors.initials: L
authors.lastname: Barros
authors.affiliation: Mountain Research Centre (CIMO), ESA, Polytechnic Institute of Bragança, Campus de Santa Apolónia, Bragança, Portugal. Electronic address: iferreira@ipb.pt.
authors.forename: Isabel C F R
authors.initials: IC
authors.lastname: Ferreira
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology*; D001713:Biphenyl Compounds; D019587:Dietary Supplements; D020900:Echinacea / Q000737:chemistry*; D015227:Lipid Peroxidation / Q000187:drug effects; D010084:Oxidation-Reduction / Q000187:drug effects; D010851:Picrates; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology*; D024505:Tocopherols
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D010851:Picrates; D010936:Plant Extracts; C004931:1,1-diphenyl-2-picrylhydrazyl; D024505:Tocopherols
keywords: Antioxidant activity; Aqueous/hydroethanolic extracts; Medicinal plants; Purple cone flower