title: Antioxidant activities and tyrosinase inhibition effects of Phaleria macrocarpa extracts.
abstract: BACKGROUND
  The ethyl acetate and chloroform extracts of stems, leaves and fruits of Phaleria macrocarpa were screened for their antioxidant capacity and tyrosinase inhibition properties.
  
  
  METHODS
  The total phenolic content (TPC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and ferric-ion reducing power (FRAP) were used to evaluate their antioxidant capacity. Tyrosinase inhibition effect was measured using mushroom tyrosinase inhibition assay.
  
  
  RESULTS
  Ethyl acetate extract of P. macrocarpa's stem exhibited highest total phenolic content, DPPH free radical scavenging and ferric reducing power. Meanwhile, chloroform extracts of leaves and fruits demonstrated potent anti-tyrosinase activities as compared to a well-known tyrosinase inhibitor, kojic acid.
  
  
  CONCLUSIONS
  Since chloroform extracts of leaves and fruits have low antioxidant capacities, the tyrosinase inhibition effect observed are antioxidant independent. This study suggests direct tyrosinase inhibition by chloroform extracts of Phaleria macrocarpa.
authors.affiliation: Department of Bioscience and Health Sciences, Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor, Malaysia.
authors.forename: Muhammad Helmi
authors.initials: MH
authors.lastname: Nadri
authors.affiliation: Department of Bioscience and Health Sciences, Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor, Malaysia.
authors.forename: Yushatika
authors.initials: Y
authors.lastname: Salim
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor, Malaysia.
authors.forename: Norazah
authors.initials: N
authors.lastname: Basar
authors.affiliation: Department of Bioscience and Health Sciences, Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor, Malaysia.
authors.forename: Azli
authors.initials: A
authors.lastname: Yahya
authors.affiliation: Department of Bioscience and Health Sciences, Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor, Malaysia.
authors.forename: Razauden Mohamed
authors.initials: RM
authors.lastname: Zulkifli
mesh_terms: D000363:Agaricales / Q000201:enzymology; D000975:Antioxidants / Q000032:analysis*; D004791:Enzyme Inhibitors / Q000032:analysis*; D005638:Fruit / Q000737:chemistry; D005656:Fungal Proteins / Q000032:analysis / Q000037:antagonists & inhibitors*; D014442:Monophenol Monooxygenase / Q000032:analysis / Q000037:antagonists & inhibitors*; D010636:Phenols / Q000032:analysis; D010936:Plant Extracts / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry; D029645:Thymelaeaceae / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D010636:Phenols; D010936:Plant Extracts; D014442:Monophenol Monooxygenase
keywords: Antioxidant; Phaleria macrocarpa; Total phenolic content; Tyrosinase inhibition