title: Production, purification and characterisation of polysaccharides from Pleurotus ostreatus with antitumour activity.
abstract: BACKGROUND
  Mushroom polysaccharides play an important role in functional foods because they exhibit biological modulator properties such as antitumour, antiviral and antibacterial activities. The present study involved the production, purification and characterisation of intracellular and extracellular free and protein-bound polysaccharides from Pleurotus ostreatus and the investigation of their growth-inhibitory effect on human carcinoma cell lines.
  
  
  RESULTS
  Several fermentation parameters were obtained: batch polysaccharide productivities of 0.013 ± 8.12 × 10⁻⁵ and 0.037 ± 0.0005 g L⁻¹ day⁻¹ for intracellular and extracellular polysaccharides respectively, a maximum biomass concentration of 9.35 ± 0.18 g L⁻¹ , P(max) = 0.935 ± 0.018 g L⁻¹ day⁻¹, µ(max) = 0.218 ± 0.02 day⁻¹, Y(EP/X) = 0.040 ± 0.0015 g g⁻¹ and Y(IP/X) = 0.014 ± 0.0003 g g⁻¹ . Some polysaccharides exhibited superoxide dismutase (SOD)-like activity of 50-200 units. Fourier transform infrared analysis of the polysaccharides revealed absorption bands characteristic of such biological macromolecules. Cytotoxicity assays showed that both intracellular and extracellular polysaccharides exhibited antitumour activity towards several tested human carcinoma cell lines in a dose-dependent manner.
  
  
  CONCLUSIONS
  The polysaccharides of P. ostreatus exhibited high SOD-like activity, which strongly supports their biological effect on tumour cell lines. The extracellular polysaccharides presented the highest antitumour activity towards the RL95 carcinoma cell line and should be further investigated as an antitumour agent.
authors.affiliation: Chemical Engineering and Biotechnology Research Center and Department of Chemical Engineering, Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emídio Navarro 1, P-1959-007 Lisboa, Portugal.
authors.forename: Sara
authors.initials: S
authors.lastname: Silva
authors.forename: Sónia
authors.initials: S
authors.lastname: Martins
authors.forename: Amin
authors.initials: A
authors.lastname: Karmali
authors.forename: Eduardo
authors.initials: E
authors.lastname: Rosa
mesh_terms: D000970:Antineoplastic Agents / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D001688:Biological Products / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D018533:Biomass; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D005285:Fermentation; D006801:Humans; D009369:Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D008517:Phytotherapy; D020076:Pleurotus / Q000737:chemistry*; D011134:Polysaccharides / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D013482:Superoxide Dismutase / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D001688:Biological Products; D011134:Polysaccharides; D013482:Superoxide Dismutase