Combination of ascorbic acid and calcitriol attenuates chronic asthma disease by reductions in oxidative stress and inflammation

Schematic design of the protective effects of ascorbic acid and calcitriol and their combination on asthma. Ascorbic acid and calcitriol independently are capable of reducing inflammation and oxidative stress. Combined administration of lower doses of ascor bic acid and calcitriol is also effective against inflammation and oxidative stress due to additive effects. [Display omitted] •Co-administration of low doses of ascorbic acid and calcitriol reduces inflammation.•Co-administration of low doses of ascorbic acid and calcitriol reduces oxidative stress.•Low doses of ascorbic acid and calcitriol has additive effects in the improvement of asthma. Airway inflammation and oxidative stress are the two major characteristics of asthma pathogenesis. Therefore, this study evaluated the protective effects of ascorbic acid in combination with calcitriol on the oxidative damages and inflammation in asthma model. All animals, except in the control group, were sensitized and challenged with ovalbumin. One day after the last challenge, samples of bronchoalveolar lavage fluid was collected for the assessment of total white blood cell counts and differential count of white blood cell and plasma was used for the measurement of pro-oxidant/antioxidant balance level. Lung tissue samples were also stored for examining peribronchial inflammatory cell infiltration, phosphorylated nuclear factor-kappa B expression and measurement of malondialdehyde level. Induction of asthma caused significant increases in total white blood cell counts, percentage of neutrophils and eosinophils and a decrease in the percentage of lymphocytes. Moreover, asthma resulted in significant increases of peribronchial inflammatory cell infiltration, phosphorylated nuclear factor-kappa B expression and malondialdehyde level. However, no significant changes were observed in pro-oxidant/antioxidant balance level with the induction of asthma. Co-administration of low doses of ascorbic acid and calcitriol returned all to the levels measured before sensitization and challenge. Combination of low doses of ascorbic acid with calcitriol improves mouse asthma model by a possible additive effects through the decrease of oxidative stress and inflammation.