title: Bio-screening of a few green seaweeds from India for their cytotoxic and antioxidant potential.
abstract: BACKGROUND
  It has been evidenced in several epidemiological studies that seaweeds when consumed as diet protect against several chronic oxidative stress-related diseases. Seaweeds, raw, cooked, or dried, are used as food in many cultures, although not very popularly in India. Globally, several studies have indicated that seaweeds are a rich source of phenolic compounds and have antioxidant properties. In the present study, we screened methanolic extracts (MEs) of five species of green seaweeds commonly found in India for their cytotoxic activity by brine shrimp lethality assay and antioxidant properties using various in vitro assays, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, reducing power and metal ion chelating assays.
  
  
  RESULTS
  A markedly variable, dose-dependent activity was observed in all the seaweed extracts relative to their total phenolic content. Statistical analysis indicated a significantly strong correlation between the DPPH radical scavenging activity and total phenolic content (R(2) = 0.88, P < 0.05) as well as reducing power and total phenolic content (R(2) = 0.99, P < 0.01) of the dry MEs. Also, a very poor correlation between total phenolic content and metal chelating activity (R(2) = 0.13, P > 0.05) was noted. None of the seaweed extracts were potently cytotoxic.
  
  
  CONCLUSIONS
  The underlying results endorse seaweeds as a rich, novel source of antioxidant compounds needing systemic exploration.
authors.affiliation: Aquaculture Laboratory, Biological Oceanography Division, National Institute of Oceanography, Panaji, Goa, India. rashmi.vinayak@gmail.com
authors.forename: Rashmi C
authors.initials: RC
authors.lastname: Vinayak
authors.forename: Sabu Appukuttan
authors.initials: SA
authors.lastname: Sudha
authors.forename: Anil
authors.initials: A
authors.lastname: Chatterji
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000032:analysis* / Q000494:pharmacology / Q000633:toxicity; D001156:Artemia / Q000187:drug effects; D001681:Biological Assay; D046068:Caulerpa / Q000737:chemistry; D000460:Chlorophyta / Q000737:chemistry*; D055808:Drug Discovery; D016166:Free Radical Scavengers / Q000032:analysis / Q000494:pharmacology / Q000633:toxicity; D007194:India; D007502:Iron Chelating Agents / Q000032:analysis / Q000494:pharmacology / Q000633:toxicity; D000432:Methanol / Q000737:chemistry; D010636:Phenols / Q000032:analysis; D019163:Reducing Agents / Q000032:analysis / Q000494:pharmacology / Q000633:toxicity; D012624:Seaweed / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D007502:Iron Chelating Agents; D010636:Phenols; D019163:Reducing Agents; D012997:Solvents; D000432:Methanol