title: A study of hydrogen peroxide generation by, and antioxidant activity of, Granuflex (DuoDERM) Hydrocolloid Granules and some other hydrogel/hydrocolloid wound management materials.
abstract: The effect of Granuflex Hydrocolloid Granules (0.01-0.50% w/v) on the rate of proliferation of murine (L929) fibroblasts was examined. The dose-response curve showed a significant (P < 0.02) pro-proliferant effect at 0.05%, and a significant (P < 0.02) antiproliferant effect at 0.50%, mirroring the dose-response curve produced by hydrogen peroxide in the concentration range 10(-9) - 10(-4) mol/l. The antiproliferant effect at 0.20% w/v was abolished by catalase, suggesting that the biological activity of Granuflex was mediated by the in situ generation of hydrogen peroxide. Formation of hydrogen peroxide by Granuflex was confirmed by performing the scopoletin-horseradish peroxidase assay in the presence and absence of catalase. The total concentration of hydrogen peroxide detected was about 8 x 10(-6) mol/l (using 0.5% w/v Granuflex) after 48 h at 37 degrees C. In contrast, when hydrogen peroxide itself was added to L929 cultures, a similar antiproliferant activity was observed at concentrations between 10(-4) and 10(-5) mol/l. These results suggested that Granuflex was undergoing autoxidation in the culture medium, and hence that it might possess antioxidant activity. In assays for antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH), Granuflex, and two other hydrocolloid dressings (Comfeel Powder and Bard Absorption Dressing) showed significant ability to reduce DPPH to DPPH2. These three dressings also displayed superoxide scavenging activity in a nitroblue tetrazolium reduction assay. We conclude that, in addition to providing a moist wound-healing environment, Granuflex and certain other hydrocolloids might contribute to the establishment and maintenance of the reducing environment necessary for energy production and hence cell division.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Welsh School of Pharmacy, UWCC, Cardiff, U.K.
authors.forename: L Y
authors.initials: LY
authors.lastname: Chung
authors.forename: R J
authors.initials: RJ
authors.lastname: Schmidt
authors.forename: A M
authors.initials: AM
authors.lastname: Andrews
authors.forename: T D
authors.initials: TD
authors.lastname: Turner
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000737:chemistry* / Q000494:pharmacology; D047070:Bandages, Hydrocolloid; D015764:Bepridil / Q000031:analogs & derivatives; D001713:Biphenyl Compounds; D002374:Catalase / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003102:Colloids / Q000008:administration & dosage / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000187:drug effects; D005609:Free Radicals; D005782:Gels / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000494:pharmacology; D007202:Indicators and Reagents; D051379:Mice; D009779:Occlusive Dressings; D010851:Picrates; D013481:Superoxides / Q000737:chemistry; D014945:Wound Healing
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D003102:Colloids; D005609:Free Radicals; D005782:Gels; D007202:Indicators and Reagents; D010851:Picrates; D013481:Superoxides; D015764:Bepridil; D006861:Hydrogen Peroxide; C004931:1,1-diphenyl-2-picrylhydrazyl; D002374:Catalase