title: In vitro determination of the anti-aging potential of four southern African medicinal plants.
abstract: BACKGROUND
  Aging is an inevitable process for all living organisms. During this process reactive oxygen species generation is increased which leads to the activation of hyaluronidase, collagenase and elastase, which can further contribute to skin aging. Four southern African medicinal plants; Clerodendrum glabrum, Schotia brachypetala, Psychotria capensis and Peltophorum africanum, were investigated to assess their anti-aging properties.
  
  
  METHODS
  Anti-elastase, anti-collagenase and anti-hyaluronidase activities of twenty-eight samples, consisting of methanol and ethyl acetate extracts of the four plants, were determined using spectrophotometric methods. Radical scavenging activity was determined by the ability of the plant extracts to scavenge the ABTS•+ radical.
  
  
  RESULTS
  The majority of the samples in the anti-elastase assay and nine in the anti-collagenase assay showed more than 80% inhibition. The ethyl acetate extract of S. brachypetala bark and leaves of P. capensis inhibited elastase activity by more than 90%. The methanol extract of S. brachypetala bark contained the highest anti-hyaluronidase activity (75.13 ± 7.49%) whilst the ethyl acetate extract of P. africanum bark exhibited the highest antioxidant activity (IC50: 1.99 ± 0.23 μg/ml).
  
  
  CONCLUSIONS
  The free radical scavenging activity and enzyme inhibitory activity of the plant extracts investigated suggests that they can help restore skin elasticity and thereby slow the wrinkling process. P. africanum was the plant with the most promising activity and will be subjected to further testing and isolation of the active compound/s.
authors.affiliation: Natural Product Chemistry Group, Biosciences Unit, Council for Scientific and Industrial Research, P,O, Box 395, Pretoria (0001), South Africa. gndlovu1@csir.co.za.
authors.forename: Gugulethu
authors.initials: G
authors.lastname: Ndlovu
authors.forename: Gerda
authors.initials: G
authors.lastname: Fouche
authors.forename: Malefa
authors.initials: M
authors.lastname: Tselanyane
authors.forename: Werner
authors.initials: W
authors.lastname: Cordier
authors.forename: Vanessa
authors.initials: V
authors.lastname: Steenkamp
mesh_terms: D000375:Aging / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000032:analysis* / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D006821:Hyaluronoglucosaminidase / Q000037:antagonists & inhibitors; D010084:Oxidation-Reduction; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors; D010936:Plant Extracts / Q000032:analysis* / Q000302:isolation & purification / Q000494:pharmacology; D010946:Plants, Medicinal / Q000737:chemistry*; D013019:South Africa
chemical_list: D004791:Enzyme Inhibitors; D010936:Plant Extracts; D006821:Hyaluronoglucosaminidase; D010196:Pancreatic Elastase