LAUSR

An experimental model of ovalbumin (OVA) induced asthma was used to assess the effects of nebivolol, the third-generation selective β1-adrenergic receptor blocker, on airway reactivity, lung inflammation, and oxidative stress markers. The asthma induction protocol was done by OVA sensitization and challenge. Guinea pigs were classified into control, asthmatic, or asthmatic receiving nebivolol either 7.5 or 15 mg·kg-1·day-1 orally. At the end of the study respiratory, the anti-inflammatory and antioxidative effects of nebivolol were assessed. The asthmatic group exhibited a significant increase in early and late airway resistance, airway hyperreactivity to histamine, total and absolute leucocytic count, tumor necrosis factor-α, and interleukin-6 in bronchoalveolar lavage fluid and lung lipid peroxidation and a significant decrease in superoxide dismutase and glutathione compared to the control group. Additionally, there was a significant decrease in lung endothelial nitric oxide synthase (eNOS) and a significant increase in inducible nitric oxide synthase (iNOS) mRNA expression compared to the control group. The high dose of nebivolol counteracted the increased airway resistance induced by OVA, whereas it had no effect on airway hyperresponsiveness. Moreover, nebivolol exhibited significant anti-inflammatory and antioxidant effects and restored the altered levels of eNOS and iNOS compared to the asthmatic group. Collectively, these results suggest a beneficial effect of nebivolol in asthma.