Effect of beclomethasone dipropionate and dexamethasone isonicotinate on lung function, bronchoalveolar lavage fluid cytology, and transcription factor expression in airways of horses with recurrent airway obstruction.

This research article studies the effects of glucocorticoids (GCs) on horses suffering from recurrent airway obstruction (RAO). The study specifically compared two GCs, beclomethasone and dexamethasone, and found that low-dose inhaled beclomethasone resulted in a notable improvement in pulmonary function, without affecting airway inflammatory cells or the activity of certain transcription factors.

Research Methodology

• The study involved seven horses diagnosed with RAO. The horses were exposed to mouldy hay to induce airway obstruction across three separate instances.
• The researchers created a crossover design in which the horses were treated with a placebo, inhaled beclomethasone, or dexamethasone injections respectively and monitored for ten days.
• Pulmonary function, bronchoalveolar lavage fluid cytology, and the activity of transcription factors NF-kappaB and AP-1 in bronchial cells were measured both before and after the treatments.

Research Findings

• Beclomethasone significantly improved the pulmonary function in RAO-affected horses when compared with the placebo and dexamethasone treatments. This indicates the therapeutic potential of beclomethasone in treating horse RAO.
• None of the treatments, including beclomethasone, influenced the bronchoalveolar lavage fluid cytology, implying that these treatments did not substantially impact the cellular profile in the lungs.
• NF-kappaB and AP-1 activity remained unchanged after the treatments. These transcription factors are critical in inflammatory response regulation. Their unchanged activity suggests that the beneficial effects of beclomethasone on lung function did not originate from the suppression of these transcription factors.

Implications of the Study

• This study provides valuable insights into the potential use of beclomethasone in treating RAO in horses, a disease often likened to asthma in humans.
• Moreover, the finding that beclomethasone does not affect NF-kappaB and AP-1 activity raises questions about the anti-inflammatory mechanism of GCs, indicating a need for further research to elucidate how these drugs affect pulmonary function.
• Since beclomethasone offers significant improvement in RAO without influencing inflammatory cell activity, it could indicate a potential treatment route with fewer side effects.