title: Antioxidant and tyrosinase inhibition activity of the fertile fronds and rhizomes of three different Drynaria species.
abstract: BACKGROUND
  For generations, the rhizomes of Drynaria ferns have been used as traditional medicine in Asia. Despite this, the bioactivities of Drynaria rhizomes and leaves have rarely been studied scientifically.
  
  
  METHODS
  This study evaluates the antioxidant properties of the methanolic extracts of the fertile fronds and rhizomes from three species in this genus: Drynaria quercifolia, Drynaria rigidula and Drynaria sparsisora. The phenolic and flavonoid contents of the samples were respectively quantified with the total phenolic content (TPC) and total flavonoid content (TFC) assays, while the antioxidant activities were determined via measuring the DPPH radical scavenging activity (FRS), ferric reducing power (FRP), ferrous ion chelating (FIC) activity and lipid peroxidation inhibition (LPI). The tyrosinase inhibition activity of all three species was also reported.
  
  
  RESULTS
  The fertile fronds of D. quercifolia were found to exhibit the highest overall TPC (2939 ± 469 mg GAE/100 g) and antioxidant activity amongst all the samples, and the fertile fronds of D. quercifolia and D. rigidula exhibited superior TPC and FRP compared to their rhizomes, despite only the latter being widely used in traditional medicine. The fronds of D. quercifolia had high tyrosinase inhibition activity (56.6 ± 5.0 %), but most of the Drynaria extracts showed unexpected tyrosinase enhancement instead, particularly for D. sparsisora's fronds.
  
  
  CONCLUSIONS
  The high bioactivity of the fertile fronds in the fern species indicate that there is value in further research on the fronds of ferns which are commonly used mostly, or only, for their rhizomes.
authors.affiliation: School of Science, Monash University Malaysia, Bandar Sunway, 46150, Petaling Jaya, Selangor, Malaysia. joasht@hotmail.com.
authors.forename: Joash Ban Lee
authors.initials: JB
authors.lastname: Tan
authors.affiliation: School of Science, Monash University Malaysia, Bandar Sunway, 46150, Petaling Jaya, Selangor, Malaysia. lim.yau.yan@monash.edu.
authors.forename: Yau Yan
authors.initials: YY
authors.lastname: Lim
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D005419:Flavonoids / Q000378:metabolism; D015227:Lipid Peroxidation; D014442:Monophenol Monooxygenase / Q000378:metabolism*; D010636:Phenols / Q000378:metabolism; D010936:Plant Extracts / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D029621:Polypodiaceae / Q000145:classification / Q000378:metabolism*; D027343:Rhizome / Q000378:metabolism*; D013045:Species Specificity
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D010940:Plant Proteins; D014442:Monophenol Monooxygenase