title: Commercial Carlinae radix herbal drug: botanical identity, chemical composition and antimicrobial properties.
abstract: BACKGROUND
  Carlinae radix is an herbal drug, commonly used by the locals in southeastern Serbia for the treatment of respiratory and urogenital diseases and, externally, for various skin conditions. There still seems to be no detailed studies correlating the chemical composition of this drug and its ethnopharmacological uses.
  
  
  OBJECTIVE
  Chemical composition, antimicrobial activity and mode of action of C. radix essential oil, isolated from commercial samples (confirmation of whose true biological identity was also the aim of this work) were analyzed. Antimicrobial potential of decoctions (extracts prepared by boiling plant material in a given solvent), used in ethnomedicine preferentially to the pure essential oil, was also investigated.
  
  
  METHODS
  The essential oil obtained by hydrodistillation was screened for antimicrobial activity by disc diffusion and broth microdilution methods. Effects of the oil on the growth of Staphylococcus aureus cells were investigated using turbidimetric measurements and visualized using scanning electron microscopy. Analyses of the chemical composition of the oils were done using gas chromatography and gas chromatography/mass spectrometry.
  
  
  CONCLUSIONS
  Both the essential oil and the decocts exhibited a very high antimicrobial activity against all tested strains, with S. aureus as the most sensitive one [e.g., for the oil sample the values for minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were 0.02, 0.04 µL/mL, respectively]. Growth curves of S. aureus demonstrated a significant decrease in turbidity (for the MIC concentration this amounted to ca. 70%) showing a concentration-dependent lysis of the cells, confirmed by scanning electron microscopy. Chemical composition, anatomical and morphological features of the sample pointed to Carlina acanthifolia L. (Asteraceae) instead of Carlina acaulis L. (Asteraceae).
  
  
  CONCLUSIONS
  The results showed significant antimicrobial effect of the essential oil and the decoctions and support the use of this plant in ethnomedicine for the treatment of various human infections, especially those caused by S. aureus. Adulteration of the drug would not cause significant differences in its biological activity, since chemical composition of the sample showed high similarity with those containing C. acaulis roots.
authors.affiliation: Department of Biology and Ecology, Faculty of Science and Mathematics, University of Niš, Niš, Serbia. lab3zmm@yahoo.com
authors.forename: Zorica
authors.initials: Z
authors.lastname: Stojanović-Radić
authors.forename: Ljiljana
authors.initials: L
authors.lastname: Čomić
authors.forename: Niko
authors.initials: N
authors.lastname: Radulović
authors.forename: Polina
authors.initials: P
authors.lastname: Blagojević
authors.forename: Tatjana
authors.initials: T
authors.lastname: Mihajilov-Krstev
authors.forename: Jelena
authors.initials: J
authors.lastname: Rajković
mesh_terms: D000480:Alkynes / Q000032:analysis / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D019659:Asteraceae / Q000737:chemistry*; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development; D002473:Cell Wall / Q000187:drug effects / Q000648:ultrastructure; D020834:Ethnopharmacology; D005410:Flame Ionization; D005663:Furans / Q000032:analysis / Q000494:pharmacology; D008401:Gas Chromatography-Mass Spectrometry; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D009822:Oils, Volatile / Q000737:chemistry* / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry*; D055771:Serbia; D012997:Solvents / Q000737:chemistry; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure
chemical_list: D000480:Alkynes; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D005663:Furans; D009822:Oils, Volatile; D010936:Plant Extracts; D012997:Solvents; C054087:carlina oxide