title: Non-toxic melanin production inhibitors from Garcinia livingstonei (Clusiaceae).
abstract: BACKGROUND
  The stem bark of Garcinia livingstonei is used traditionally as a skin lightening agent.
  
  
  OBJECTIVE
  To isolate and identify compounds responsible for the observed skin lightening activity of Garcinia livingstonei and to evaluate their cytotoxicity.
  
  
  METHODS
  Constituents of the stem bark and fruits of Garcinia livingstonei were isolated using chromatographic techniques and structures were determined using 1D and 2D NMR and MS analysis. MeWo cells were used to evaluate the cytotoxicity and impact on melanin levels of extracts and compounds isolated, in vitro.
  
  
  RESULTS
  Twelve known compounds, morelloflavone (1), morelloflavone-7″-sulphate (2), guttiferone A (3), sargaol (4), isojacareubin (5), 6-deoxyisojacareubin (6) and in addition to the common triterpenoids, betulin, betulin aldehyde, lupeol, lupenone, euphol and stigmasterol were isolated in this investigation. Morelloflavone, morelloflavone-7″-sulphate and sargaol, were found to be considerably less cytotoxic and more effective as skin lightening agents than hydroquinone.
  
  
  CONCLUSIONS
  A range of compounds was isolated from the stem bark and fruit of Garcinia livingstonei. Although the bark extract contained the cytotoxic guttiferone A, it was found to be less toxic than hydroquinone, and morelloflavone, the 7″-sulphate derivative and sargaol show potential for development as depigmentation/skin lightening agents.
authors.affiliation: Department of Chemistry, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey, United Kingdom. d.mulholland@surrey.ac.uk
authors.forename: Dulcie A
authors.initials: DA
authors.lastname: Mulholland
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Mwangi
authors.forename: Ncoza C
authors.initials: NC
authors.lastname: Dlova
authors.forename: Nick
authors.initials: N
authors.lastname: Plant
authors.forename: Neil R
authors.initials: NR
authors.lastname: Crouch
authors.forename: Phillip H
authors.initials: PH
authors.lastname: Coombes
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D005638:Fruit; D029760:Garcinia; D006801:Humans; D008543:Melanins / Q000378:metabolism*; D024301:Plant Bark; D010936:Plant Extracts / Q000494:pharmacology*
chemical_list: D008543:Melanins; D010936:Plant Extracts
keywords: Clusiaceae; Garcinia livingstonei; MeWo cells; Melanin production inhibitor; Skin lightening agents