title: Correlation between polyphenol content and anti-inflammatory activity of Verbascum phlomoides (mullein).
abstract: BACKGROUND
  Verbascum phlomoides L. (Scrophulariaceae) (mullein) used in the European folk medicine due to its anti-inflammatory and soothing action on the respiratory tract is thoroughly documented in handbooks and scientific literature. Nevertheless, information regarding the influence of the polyphenol content on pharmacological activity is scarce.
  
  
  OBJECTIVE
  This study explored the antioxidant and anti-inflammatory potential of V. phlomoides polyphenol-rich extract.
  
  
  METHODS
  Dried mullein flowers (200 g) were subjected to water extraction (60 °C, 2 h, herb/solvent ratio = 1/10 m/v) and further to n-butanol partition. Total phenolics were spectrophotometrically determined and specific compounds were evaluated by HPLC. The antioxidant activity was assessed by the 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) assay. The anti-inflammatory potential of the extract (50-200 μg/mL) was evaluated in vitro by ELISA measurement of ICAM-1 expression in TNF-α-stimulated endothelial cells and in vivo by the rat paw edema assay.
  
  
  RESULTS
  The mullein extract contained 4.18% total polyphenols expressed as gallic acid. The main components identified by HPLC were: rosmarinic acid (14.93 mg/g), caffeic acid (39.96 mg/g), ferulic acid (29.61 mg/g) and quercetin (17.29 mg/g). Acteoside was not detected; aucubin was detected in traces (0.028 mg/g). Depending on concentration, the extract exerted scavenging activity on DPPH radical (EC50 7.09 mg/mL), significantly inhibited TNF-α-induced ICAM-1 expression by 55-58.8% on human umbilical vein endothelial cells at 100 and 200 μg/mL, but failed to reduce egg-white-induced rat paw edema.
  
  
  CONCLUSIONS
  Mullein polyphenols play an important role in exerting the antioxidant effect but have a weak influence on anti-inflammatory activity that is correlated, probably, to a higher content of iridoids and phenylethanoids.
authors.affiliation: Department of Pharmaceutical Biotechnologies, National Institute for Chemical-Pharmaceutical Research and Development, Bucharest, Romania. alicearmatu@yahoo.com
authors.forename: Alice
authors.initials: A
authors.lastname: Grigore
authors.forename: Svetlana
authors.initials: S
authors.lastname: Colceru-Mihul
authors.forename: Simona
authors.initials: S
authors.lastname: Litescu
authors.forename: Minerva
authors.initials: M
authors.lastname: Panteli
authors.forename: Iuksel
authors.initials: I
authors.lastname: Rasit
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D000975:Antioxidants / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004487:Edema / Q000188:drug therapy / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D035264:Flowers; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008519:Medicine, Traditional; D010936:Plant Extracts / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D059808:Polyphenols / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D032265:Verbascum / Q000737:chemistry*
chemical_list: D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D010936:Plant Extracts; D059808:Polyphenols; D018799:Intercellular Adhesion Molecule-1