Allergic asthma is a complicated disease characterized by coughing, wheezing, airway inflammation, mucus hyper-secretion and increased airway hyperresponsiveness (AHR). Basil seed, or Ocimum basilicum (OB), has an anti-inflammatory effect that is utilized in traditional medicine. The aim of this study was to investigate the effects of OB on IL-4, IL-5, IL-13 and MUC5a gene expression in an asthma model. Eighteen female BALB/c mice were divided into three groups as follows: an untreated asthmatic group, a healthy group and an asthmatic group receiving OB. Broncho-alveolar lavage fluid (BALE) was collected and Real-Time PCR was done for IL-4, 5, 13 and mucus (MUC5a) genes, and lung histopathological sections were prepared. Asthmatic mice treated with OB had suppression of cytokines and mucus gene expression (IL-4: 2.90 +/- 1.08, IL-5: 1.11 +/- 0.37, IL-13 0.72 +/- 0.19 and mucus: 1.83 +/- 1.08) in comparison to the untreated asthmatic group (IL-4: 8.00 +/- 2.54, IL-5: 2.91 +/- 0.46, IL-13 2.00 +/- 0.22 and mucus: 12.24 +/- 1.88). In the histopathological section, mucus hyper-secretion and goblet cell hyperplasia were reduced in the OB-treated group in comparison to untreated asthmatic group. Th2 cytokines and mucus gene expression were reduced in the OB-treated group in comparison to untreated asthmatic group. Mucus hyper-secretion and goblet cell hyperplasia were regulated by OB treatment in asthmatic mice. OB showed immunomodulatory and anti-inflammatory effects in allergic asthma and could reverse airway obstruction. (C) 2018 Elsevier Masson SAS. All rights reserved.