title: Inhibition of inducible nitric oxide synthesis by Cimicifuga racemosa (Actaea racemosa, black cohosh) extracts in LPS-stimulated RAW 264.7 macrophages.
abstract: OBJECTIVE
  Cimicifuga racemosa (Actaea racemosa, black cohosh) is used as an anti-inflammatory, antipyretic and analgesic remedy in traditional medicines. The present study focuses on the effects of C. racemosa root extracts on inducible nitric oxide synthase (iNOS) in lipopolysaccharide-stimulated murine macrophages (RAW 264.7).
  
  
  METHODS
  C. racemosa rhizome and phosphate-buffered saline extracts were analysed for phenolcarboxylic acids and triterpene glycosides using an HPLC photodiode array/evaporative light-scattering detector system. iNOS was characterised by measurement of iNOS protein (immunoblotting), iNOS mRNA (semiquantitative competitive RT-PCR), nitric oxide production (nitrite levels) and nuclear translocation of nuclear factor-kappaB (p65 subunit) protein.
  
  
  RESULTS
  Incubation of lipopolysaccharide-stimulated macrophages with aqueous C. racemosa extracts (0-6 mg/ml) inhibited nitrite accumulation in a concentration-dependent manner. C. racemosa extracts also reduced iNOS protein expression and iNOS mRNA levels in a dose-dependent manner. C. racemosa extracts did not significantly inhibit iNOS activity and did not affect nuclear translocation of nuclear factor-kappaB (p65 subunit) protein. Incubation with the extract was associated with a concentration-dependent reduction of interferon beta and interferon regulatory factor 1 mRNA. Among the triterpene glycosides, 23-epi-26-deoxyactein was identified as an active principle in C. racemosa extracts.
  
  
  CONCLUSIONS
  Extracts from the roots of C. racemosa inhibit nitric oxide production by reducing iNOS expression without affecting activity of the enzyme. This might contribute to the anti-inflammatory activities of C. racemosa.
authors.affiliation: Institute for Physiology, Section of Vegetative Physiology, Center for Physiology and Pharmacology, Medical University of Vienna, Austria.
authors.forename: Diethart
authors.initials: D
authors.lastname: Schmid
authors.forename: Miriam
authors.initials: M
authors.lastname: Gruber
authors.forename: Florian
authors.initials: F
authors.lastname: Woehs
authors.forename: Sonja
authors.initials: S
authors.lastname: Prinz
authors.forename: Barbara
authors.initials: B
authors.lastname: Etzlstorfer
authors.forename: Christina
authors.initials: C
authors.lastname: Prucker
authors.forename: Nicola
authors.initials: N
authors.lastname: Fuzzati
authors.forename: Brigitte
authors.initials: B
authors.lastname: Kopp
authors.forename: Thomas
authors.initials: T
authors.lastname: Moeslinger
mesh_terms: D000818:Animals; D002264:Carboxylic Acids / Q000302:isolation & purification / Q000494:pharmacology; D002478:Cells, Cultured; D031885:Cimicifuga / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006027:Glycosides / Q000302:isolation & purification / Q000494:pharmacology; D008070:Lipopolysaccharides; D008264:Macrophages; D008519:Medicine, Traditional; D051379:Mice; D009569:Nitric Oxide / Q000096:biosynthesis*; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors*; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D018517:Plant Roots; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D011817:Rabbits; D014315:Triterpenes / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D002264:Carboxylic Acids; D006027:Glycosides; D008070:Lipopolysaccharides; D010936:Plant Extracts; D012333:RNA, Messenger; D014315:Triterpenes; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II