title: Antioxidant potential of Sutherlandia frutescens and its protective effects against oxidative stress in various cell cultures.
abstract: BACKGROUND
  Sutherlandia frutescens (L.) R.Br. (SF) is a South African plant that is widely used to treat stress, infections, cancer, and chronic diseases, many of which involve oxidative stress. The aim of the study was to quantitatively assess the antioxidant potential of SF extracts in cell-free system as well as in cell lines.
  
  
  METHODS
  Dried SF vegetative parts were extracted using six different solvents, and the extracts were assessed for total phenolic and flavonoid contents, total reducing power, iron chelating capacity, and free radical scavenging power, including, scavenging of hydroxyl radicals, superoxide anions, nitric oxide, and hydrogen peroxide. We further investigated the freeze-dried hot water extract of SF (SFE) to assess its effect against oxidative stress induced by tert-butyl hydroperoxide (t-BHP), an organic peroxide. Three different cell lines: Chinese hamster ovary (CHO), human hepatoma (HepaRG), and human pulmonary alveolar carcinoma (A549) cells, were employed to determine cell viability, intracellular reactive oxygen species (ROS) levels, and reduced to oxidized glutathione levels (GSH/GSSG).
  
  
  RESULTS
  The results indicated that: (1) SF extracts have significant antioxidant potential that is dependent upon the nature of the extraction solvent and (2) SFE protects against tBHP-induced oxidative stress in cells by scavenging ROS and preserving intracellular GSH/GSSG.
  
  
  CONCLUSIONS
  Oxidative stress is implicated in a number of disorders, and due to the public's concerns about synthetic antioxidants, various natural antioxidants are being explored for their therapeutic potential. Our findings support claims for S. frutescens being a promising adjunctive therapeutic for oxidative stress-related health problems.
authors: Shakila
authors: S
authors: Tobwala
authors: Weili
authors: W
authors: Fan
authors: Connor J
authors: CJ
authors: Hines
authors: William R
authors: WR
authors: Folk
authors: Department of Chemistry, Missouri University of Science and Technology, 400 West 11th Street, 142 Schrenk Hall, Rolla, MO 65409, USA. nercal@mst.edu.
authors: Nuran
authors: N
authors: Ercal
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D016466:CHO Cells; D002460:Cell Line; D002470:Cell Survival; D002477:Cells / Q000187:drug effects* / Q000378:metabolism; D003412:Cricetulus; D007887:Fabaceae / Q000737:chemistry*; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D020011:Protective Agents / Q000737:chemistry / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D020011:Protective Agents; D017382:Reactive Oxygen Species; D005978:Glutathione