Interleukin (IL)-10 is an important immunoregulatory and anti-inflammatory
cytokine, whereas
nuclear factor-kappaB (
NF-kappaB) plays an important role in the pathogenesis of
asthma. In the present study, the effects of
montelukast on the level of
IL-10 and on the activation of
NF-kappaB in the inflammatory airway of asthmatic guinea pigs were investigated. Guinea pigs were sensitized by
ovalbumin.
Pulmonary inflammation was observed by
hematoxylin and
eosin staining. The eosinophils in broncho-alveolar lavage fluid and blood were separated by density gradient centrifugation and counted under microscope. The level of
IL-10 in broncho-alveolar lavage fluid was measured by
enzyme-linked
immunoadsorbent assay. Activation of
NF-kappaB in lung tissues was inspected by immunohistochemistry.
Montelukast at medium and high doses prevented the decrease of
IL-10 in broncho-alveolar lavage fluid (n = 8, p < 0.01 vs.
asthma model group), inhibited the activation of
NF-kappaB in lung tissues (n = 8; medium dose, p < 0.05; high dose, p < 0.01; vs.
asthma model group). There was a significantly negative correlation between the level of
IL-10 and the activation of
NF-kappaB in lung tissues (r = -0.488, p < 0.01).
Montelukast reduced the severity of airway
inflammation and the number of eosinophils in asthmatic guinea pigs. From all these findings we conclude that
montelukast can prevent the decrease of
IL-10 and inhibit the activation of
NF-kappaB in inflammatory airway of asthmatic guinea pigs, which may be the new important mechanisms of
montelukast's anti-airway-
inflammation effects in asthmatic guinea pigs.