A beneficial influence of provinol on the reduction of allergen induced hyperreactivity in guinea pigs.

BACKGROUND: The anti-inflammatory, anti-allergic, antioxidant properties of flavonoids are known in the respiratory tract. We are interested in the role of Provinol during an allergic inflammation of the airway.
OBJECTIVES: The aim of this study was to examine the influence of an acute administration of Provinol on tracheal smooth muscle reactivity in guinea pigs and to assess the involvement of nitric oxide in the mechanism of Provinol action.
METHODS: This experiment was performed 14 days after the sensitization of animals by ovalbumin. In vivo, the specific airway conductance, as a tracheal smooth muscle reactivity parameter in response to bronchoconstrictor histamine, was evaluated after peroral administration of Provinol alone or together with L-NAME (N(omega)-nitro-L-arginine methyl ester). In vitro, Provinol alone or in combination with L-NAME were added into an organ baths before the supplement of direct bronchoconstrictor histamine, acetylcholine and the allergen ovalbumin in rising concentrations. The amplitude of the tracheal smooth muscle contraction, as a tracheal smooth muscle reactivity parameter in response to histamine, acetylcholine and ovalbumin was evaluated.
RESULTS: Our results showed that a Provinol has significant bronchodilatory activities both in vivo and in vitro.
CONCLUSION: Provinol alleviated the contraction of tracheal smooth muscle in guinea pigs sumin. Nitric oxide plays an important role in the mechanism of Provinol action (Fig. 2, Ref. 28n.(Fig. 2, Ref. 28).