The effects of different fractions of garlic extracts on allergen-induced asthma

Abstract

Background: Garlic has been extensively used for the therapy of antibacterial, anticancer and anticoagulant activities in folk medicine. Although garlic shows anti-inflammatory activities, its effect on airway inflammation of allergic asthma has not been studied. In this study, we explored the protective effect of n-hexane, dichloromethane, ethylacetate, n-butanol and water garlic extracts against airway inflammation in asthmatic mice. Methods: Allergic asthma in mice was sensitized and challenged by Dermatophagoides pteronyssinus (Der p). Mice were administered in oral with different fractions of garlic extracts daily at doses of 80 mg/kg on 4 weeks. Inflammatory cell counts and classification in bronchoalveolar lavage fluid (BALF) were analyzed. Histopathological evaluation of lung tissue was performed by hematoxylin and eosin (H&E) staining. The IgE, IgG1 and IgG2a levels in serum were measured by using enzyme-linked immunoassay (ELISA). ELISA was also used to detect the levels of Th1 and Th2 cytokine and expression in BALF. Result: histological results revealed that water fraction of garlic extract (WH) could ameliorate Der p-induced histological changes by attenuating inflammatory cell infiltration, mucus hypersecretion and goblet cell hyperplasia in the lung. Treatment with WH significantly decreased the elevated inflammatory cell numbers in BALF and IgE, IgG1 and IgG2a productions in serum. WH treatment reduced the production of Th2 cytokine IL-4, IL-5, IL-13, and promoted Th1 cytokine IFN-r, IL-12 production in BALF. Conclusions: These findings suggest that water fraction of garlic extracts has markedly anti-inflammatory effect on Der p-induced allergic asthma in mice, and could be a promising protective agent recommended for allergic asthma patients.