The anti-inflammatory activity of Taraxacum officinale leaves in ovalbumin-sensitized guinea-pigs

Objective: Inflammatory mediators, such as histamine and eicosanoids have been implicated in the pathophysiology of allergen-induced asthma including bronchospasm, vasodilation, increased vascular permeability, perivascular and peribronchial oedema, acute functional changes in the lungs and diarrhoea due to increase intestinal motility. This study aims to ascertain the anti-inflammatory effect of the Taraxacum officinale ethanolic leaf extract (TOLE) on pulmonary vascular permeability and H₁-receptors in the ileum of ovalbumin-sensitized guinea-pigs. Method: OA-sensitized guinea-pigs were challenged with 2% OA aerosols prior to 1 hr per os of drugs (TOLE or prednisolone). A piece of excised ileum was suspended in a tissue bath and challenged with histamine in the presence and absence of TOLE. Lungs were fixed in buffered formalin for histological studies using H & E stains. The results were reported as mean ± SEM. Statistical analysis was performed using one-way ANOVA and Benferroni post hoc test. Results: The results showed a significant dose-dependent reduction in anti-histaminic activity (p < 0.05) on isolated guinea-pig ileum. Histopathological lesions such as perivascular oedema, hypertrophy of smooth muscles, infiltration of eosinophils and basophils were reduced in the lungs of TOLE treated group compared to OA-sensitized controls. Conclusion: The study has shown that, TOLE has the potential to reduce pulmonary vascular permeability and intestinal motility in OA-sensitized guinea-pigs.