title: Inhibition of ozone-induced SP-A oxidation by plant polyphenols.
abstract: Surfactant protein-A (SP-A) is the best studied and most abundant of the protein components of lung surfactant and plays an important role in host defense of the lung. It has been shown that ozone-induced oxidation of SP-A protein changes its functional and biochemical properties. In the present study, eight plant polyphenols (three flavonoids, three hydroxycinnamic acids, and two hydroxybenzoic acids) known as strong antioxidants, were tested for their ability to inhibit ozone-induced SP-A oxidation as a mechanism for chemoprevention against lung damage. SP-A isolated from alveolar proteinosis patients was exposed to ozone (1 ppm) for 4 h. The flavonoids protected SP-A from oxidation in a dose dependent manner. ( - )-Epicatechin was the most potent flavonoid and exhibited inhibition of ozone-induced formation of carbonyls by 35% at a concentration as low as 5 microM. Hydroxybenzoic acids inhibited SP-A oxidation in a dose-dependent manner although they were less potent than flavonoids. On the other hand, hydroxycinnamic acids exhibited a different inhibitory pattern. Inhibition was observed only at medium concentrations. The results indicate that inhibition of SP-A oxidation by plant polyphenols may be a mechanism accounting for the protective activity of natural antioxidants against the effects of ozone exposure on lungs.
authors: Department of Biochemistry, University of Thessaly, Larissa, Greece.
authors: Dimitrios
authors: D
authors: Stagos
authors: Todd M
authors: TM
authors: Umstead
authors: David S
authors: DS
authors: Phelps
authors: Leandros
authors: L
authors: Skaltsounis
authors: Serko
authors: S
authors: Haroutounian
authors: Joanna
authors: J
authors: Floros
authors: Demetrios
authors: D
authors: Kouretas
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D010084:Oxidation-Reduction / Q000187:drug effects; D010126:Ozone / Q000037:antagonists & inhibitors*; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology*; D010944:Plants / Q000737:chemistry; D059808:Polyphenols; D037662:Pulmonary Surfactant-Associated Protein A / Q000737:chemistry* / Q000187:drug effects*
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D037662:Pulmonary Surfactant-Associated Protein A; D010126:Ozone