title: Protective effect of silymarin in antigen challenge- and histamine-induced bronchoconstriction in in vivo guinea-pigs.
abstract: The effects of silymarin on bronchoconstriction induced by antigen challenge and on post-antigen challenge hyperresponsiveness to substance P were evaluated in sensitized guinea-pigs. Silymarin significantly decreased the bronchoconstriction due to antigen administration in the early phase of the response. In contrast, the dose-response curve for substance P recorded 1 h after antigen challenge was not modified by pretreatment with silymarin. The influence of the flavonoid on hyperresponsiveness to histamine in propranolol- and PAF (platelet-activating factor)-treated animals was also assessed. Silymarin did not affect hyperresponsiveness to histamine induced by either propranolol or PAF although it had inhibitory activity on the bronchial contractile response to the autacoid. These results suggest that silymarin has a protective effect in the early phase of allergic asthma, an effect, which may be related to a negative influence of the flavonoid on bronchial responsiveness to histamine.
authors.affiliation: Department of Psychiatry, Neurobiology, Pharmacology and Biotechnology, University of Pisa, Via Bonanno 6, 56126, Pisa, Italy. breschi@farm.unipi.it
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Breschi
authors.forename: Enrica
authors.initials: E
authors.lastname: Martinotti
authors.forename: Filippo
authors.initials: F
authors.lastname: Apostoliti
authors.forename: Paola
authors.initials: P
authors.lastname: Nieri
mesh_terms: D000818:Animals; D016535:Bronchial Hyperreactivity / Q000139:chemically induced / Q000503:physiopathology / Q000517:prevention & control; D016084:Bronchoconstriction / Q000187:drug effects* / Q000276:immunology; D006168:Guinea Pigs; D006632:Histamine / Q000008:administration & dosage*; D008297:Male; D010047:Ovalbumin / Q000276:immunology; D010972:Platelet Activating Factor / Q000008:administration & dosage; D011433:Propranolol / Q000008:administration & dosage; D020011:Protective Agents / Q000494:pharmacology*; D012838:Silymarin / Q000494:pharmacology*; D013373:Substance P / Q000494:pharmacology; D013997:Time Factors
chemical_list: D010972:Platelet Activating Factor; D020011:Protective Agents; D012838:Silymarin; D013373:Substance P; D006632:Histamine; D010047:Ovalbumin; D011433:Propranolol