title: Anti-inflammatory, antioxidant, anti-tyrosinase and phenolic contents of four Podocarpus species used in traditional medicine in South Africa.
abstract: BACKGROUND
  Species of Podocarpus are used traditionally in their native areas for the treatment of fevers, asthma, coughs, cholera, chest complaints, arthritis, rheumatism, venereal diseases and distemper in dogs.
  
  
  OBJECTIVE
  To investigate the antioxidant, anti-inflammatory and anti-tyrosinase activities of four Podocarpus species, Podocarpus elongatus, Podocarpus falcatus, Podocarpus henkelii and Podocarpus latifolius, used in traditional medicine in South Africa. Phytochemical analysis to determine the phenolic contents was also carried out.
  
  
  METHODS
  DPPH, FRAP and β-carotene-linoleic acid assays were used to determine the antioxidant/radical scavenging activities of these species. Anti-inflammatory activity of these species was assayed against two cyclooxygenase enzymes (COX-1 and COX-2). Tyrosinase inhibition activity was analysed using the modified dopachrome method with l-DOPA as the substrate. Phenolics were quantitatively determined using spectrophotometric methods.
  
  
  RESULTS
  Stems of Podocarpus latifolius exhibited the lowest EC(50) (0.84 μg/ml) inhibition against DPPH. The percentage antioxidant activity based on the bleaching rate of β-carotene ranged from 96% to 99%. High ferric reducing power was observed in all the extracts. For COX-1, the lowest EC(50) value was exhibited by stem extracts of Podocarpus elongatus (5.02 μg/ml) and leaf extract of Podocarpus latifolius showed the lowest EC(50) against COX-2 (5.13 μg/ml). All extracts inhibited tyrosinase activity in a dose-dependent manner with stem extract of Podocarpus elongatus being the most potent with an EC(50) value of 0.14 mg/ml. The total phenolic content ranged from 2.38 to 6.94 mg of GAE/g dry sample.
  
  
  CONCLUSIONS
  The significant pharmacological activities observed support the use of these species in traditional medicine and may also be candidates in the search for modern pharmaceuticals in medicine, food and cosmetic industries.
authors.affiliation: Research Centre for Plant Growth and Development, School of Biological and Conservation Sciences, University of KwaZulu-Natal Pietermaritzburg, Scottsville, South Africa.
authors.forename: H S
authors.initials: HS
authors.lastname: Abdillahi
authors.forename: J F
authors.initials: JF
authors.lastname: Finnie
authors.forename: J
authors.initials: J
authors.lastname: Van Staden
mesh_terms: D000893:Anti-Inflammatory Agents / Q000032:analysis / Q000494:pharmacology*; D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000378:metabolism; D032462:Cycadopsida / Q000737:chemistry*; D051545:Cyclooxygenase 1 / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism; D016861:Cyclooxygenase Inhibitors / Q000032:analysis / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000032:analysis / Q000494:pharmacology*; D016488:Medicine, African Traditional; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors*; D010084:Oxidation-Reduction; D010636:Phenols / Q000032:analysis / Q000494:pharmacology; D010851:Picrates / Q000378:metabolism; D010936:Plant Extracts / Q000032:analysis / Q000494:pharmacology*; D018547:Plant Stems; D013019:South Africa; D019207:beta Carotene / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D001713:Biphenyl Compounds; D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D019207:beta Carotene; C004931:1,1-diphenyl-2-picrylhydrazyl; D014442:Monophenol Monooxygenase; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2