Effect of nutritional antioxidant supplementation on systemic and pulmonary antioxidant status, airway inflammation and lung function in heaves-affected horses.

This study examines how nutritional antioxidant supplementation could improve lung function and decrease airway inflammation in horses affected by a chronic respiratory disease known as heaves. The results suggested that the antioxidant supplement tested affected the balance between oxidants and antioxidants, and decreased airway inflammation in these horses.

Details of the Research

• The teams studied if dietary antioxidant supplements over a span of 4 weeks could improve lung function and reduce airway inflammation in horses affected by heaves- a chronic respiratory disease. It is well-known that an imbalance of oxidant/antioxidant is a decisive factor in the pathogenesis of chronic inflammatory airway diseases. Antioxidant supplementation could potentially decrease oxidative damage by enhancing the antioxidant defense system and modulating inflammatory processes..
• The study used an approach that was placebo-controlled and blind, meaning neither the researchers administering the treatment nor the subjects knew what treatment they were receiving to avoid any placebo effect. The experimental group received antioxidant supplements, which contained a combination of natural antioxidants like vitamins E and C and selenium from various sources. The control group, on the other hand, was administered with oatfeed pellets devoid of additives.
• Eight horses were chosen for the experiment, all of whom were clinically in remission from heaves. The horses were examined at rest and post standardized exercise sessions before and after the treatment.

The Measurements and Results

• Various markers were observed to monitor the effects of the treatment. The investigators considered pulmonary function, exercise tolerance, systemic and pulmonary lining fluid uric acid, glutathione, and 8-epi-PGF(2alpha). In addition, they also conducted bronchoalveolar lavage (BAL), which is a diagnostic test of the lower respiratory tract, and inflammatory scoring of the airways.
• The results of the antioxidant treatment were significantly positive. It improved the exercise tolerance in horses and also reduced the endoscopic inflammatory score, which indicates a reduced level of airway inflammation.
• The study also observed a significant reduction in the concentration of plasma uric acid which indicates a downregulation of the xanthine-dehydrogenase and xanthine-oxydase pathway – both responsible for oxidation of uric acid.
• Other markers such as haemolysate glutathione showed a trend towards an increase, although it was not statistically significant. Plasma 8-epi-PGF(2alpha) remained ultimately unchanged. The bronchoalveolar lavage cytology and pulmonary markers did not exhibit any significant deviations due to the antioxidant supplementation.
• In conclusion, the antioxidant supplement successfully affected the oxidant/antioxidant balance and mitigated the airway inflammation in horses affected by heaves.