title: Hepatoprotection by chemical constituents of the marine brown alga Spatoglossum variabile: a relation to free radical scavenging potential.
abstract: BACKGROUND
  In the course of searching hepatoprotective agents from natural sources, the protective effect of chemical constituents of the marine brown alga Spatoglossum variabile Figaro et DE Notar (Dictyoaceae) against CCl₄-induced liver damage in Wistar rats was investigated. The compounds were first investigated for in vitro radical scavenging potential and were also tested for β-glucuronidase inhibition to further explore the relationship between hepatoprotection and antiradical potential.
  
  
  METHODS
  The compounds cinnamic acid esters 1 and 2 and aurone derivatives 3 and 4 were first investigated for in vitro radical scavenging potential against 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH), and superoxide anion radicals. In vivo hepatoprotective studies were performed in seven groups (n = 6) of Wistar rats. The test groups were pretreated with compounds (10 mg/kg body weight, po) orally for 30 min before the intraperitoneal administration of a dose of 20% CCl₄ diluted with dietary cooking oil. Moreover, compounds were also tested for β-glucuronidase inhibition to explore the relationship between hepatoprotection and radical scavenging potential.
  
  
  RESULTS
  The test compounds 1-4 were found to exhibit antiradical activity against 1,1-diphenyl-2-picrylhydrazyl radicals with IC₅₀ values ranging between 54 and 138 µM, whereas aurone derivatives 3 and 4 additionally exhibited superoxide anion scavenging effects with IC₅₀ values of 95 and 87 µM, respectively. In addition, these compounds were found to be weak inhibitors of xanthine oxidase (IC₅₀ ≥1000 µM). In animal model, pretreatment with compounds 2-4 significantly blocked the CCl₄-induced increase in the levels of the serum biochemical markers.
  
  
  CONCLUSIONS
  It appears that the hepatoprotection afforded by these compounds was mainly due to their radical scavenging activity that protected the cells from the free radicals generated by CCl₄-induced hepatotoxicity.
authors: Dr Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan. makhmoor@iccs.edu
authors: Talat
authors: T
authors: Makhmoor
authors: Suad
authors: S
authors: Naheed
authors: Shahida
authors: S
authors: Shujaat
authors: Saima
authors: S
authors: Jalil
authors: Safdar
authors: S
authors: Hayat
authors: M Iqbal
authors: MI
authors: Choudhary
authors: Khalid M
authors: KM
authors: Khan
authors: Junaid M
authors: JM
authors: Alam
authors: Samina
authors: S
authors: Nazir
mesh_terms: D000818:Animals; D001572:Benzofurans / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D002252:Carbon Tetrachloride Poisoning / Q000097:blood / Q000503:physiopathology / Q000517:prevention & control*; D002470:Cell Survival / Q000187:drug effects; D002934:Cinnamates / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D055808:Drug Discovery; D004791:Enzyme Inhibitors / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D029968:Escherichia coli Proteins / Q000037:antagonists & inhibitors; D016166:Free Radical Scavengers / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D005966:Glucuronidase / Q000037:antagonists & inhibitors; D006801:Humans; D008099:Liver / Q000187:drug effects* / Q000503:physiopathology; D008297:Male; D008894:Milk Proteins / Q000037:antagonists & inhibitors; D009504:Neutrophils / Q000187:drug effects; D000459:Phaeophyceae / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors
chemical_list: C422348:4'-chloro-2-hydroxyaurone; C422347:4'-chloroaurone; D001572:Benzofurans; D015415:Biomarkers; D002934:Cinnamates; D004791:Enzyme Inhibitors; D029968:Escherichia coli Proteins; D016166:Free Radical Scavengers; D008894:Milk Proteins; C471394:butyl-3,5-dimethoxy-4-hydroxycinnamate; C471393:isopropyl 3,5-dimethoxy-4-hydroxycinnamate; D014969:Xanthine Oxidase; D005966:Glucuronidase