title: Evaluation of phenolic contents and antioxidant activities of brown seaweeds belonging to Turbinaria spp. (Phaeophyta, Sargassaceae) collected from Gulf of Mannar.
abstract: OBJECTIVE
  To evaluate the antioxidant activities and total phenolic contents of brown seaweeds belonging to Turbinaria spp. [Turbinaria conoides (T. conoides) and Turbinaria ornata (T. ornata) collected from Gulf of Mannar of southeastern coast of India in various in vitro systems.
  
  
  METHODS
  The antioxidant activity was evaluated using different in vitro systems, viz., 1, 1-diphenyl-2-picrylhydrazyl (DPPH), 2, 2'-azino-bis-3 ethylbenzothiozoline-6-sulfonic acid diammonium salt (ABTS), H2O2/HO radical scavenging, Fe(2+) ion chelating ability, and reducing potential. Folin-Ciocalteu method was used to determine the total phenolic content of the extracts, and the results were expressed as mg of gallic acid equivalents (GE)/g of the seaweed extracts. Thiobarbituric acid-reactive substances assay was employed to assess the ability of the seaweed extracts to inhibit lipid oxidation.
  
  
  RESULTS
  Ethyl acetate (EtOAc) fraction of T. conoides registered significantly higher phenolic content (105.97 mg GE/g) than that of T. ornata (69.63 mg GE/g). Significantly higher antioxidant potential as determined by DPPH (64.14%) radical scavenging activity was registered in EtOAc fraction of T. ornata. A higher ABTS(•+) radical scavenging (IC50 3.16 µg/mL), Fe(2+) chelating (IC50 0.46 mg/mL), H2O2 scavenging (IC50 4.25 mg/mL), lipid peroxidation inhibitory (TBARS, IC50 0.21 mg/mL), and reducing abilities (IC50 52.67 mg/mL) (P<0.05) were realized in EtOAc fraction of T. ornata than other fractions.
  
  
  CONCLUSIONS
  This study indicated the potential use of T. conoides and T. ornata as candidate species to be used as food supplements/functional foods to increase shelf-life of food items for human consumption, and nutraceuticals to deter deleterious free radical-induced life-threatening diseases.
authors.affiliation: Marine Biotechnology Division, Central Marine Fisheries Research Institute, Ernakulam North, Cochin-682018, Kerala, India.
authors.forename: Kajal
authors.initials: K
authors.lastname: Chakraborty
authors.forename: Nammunayathuputhenkotta Krishnankartha
authors.initials: NK
authors.lastname: Praveen
authors.forename: Kodayan Kizekadath
authors.initials: KK
authors.lastname: Vijayan
authors.forename: Gonugontla Syda
authors.initials: GS
authors.lastname: Rao
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry; D007194:India; D000459:Phaeophyceae / Q000737:chemistry*; D010636:Phenols / Q000032:analysis*; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry; D013045:Species Specificity
chemical_list: D000975:Antioxidants; D010636:Phenols; D010936:Plant Extracts
keywords: Antioxidant activity; Brown seaweeds; Total phenolic contents; Turbinaria conoides; Turbinaria ornata