Preliminary Investigation of the Anti-asthmatic Potential of Kalanchoe integra Leaf Extract Using a Model of Allergic Airway Inflammation

Objective: Kalanchoe integra is known to possess antihistaminic and mast cell stabilizing effect. 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 diarrhea due to increased intestinal motility. This study is to ascertain the anti-inflammatory effect of Kalanchoe integra aqueous leaf extract (KILE) on bronchial hyper-responsiveness in ovalbumin-sensitized guinea-pigs.

Method: Bronchial asthma was induced in guinea pigs using Ovalbumin. In vivo skin tests were carried out on all guinea pigs using ovalbumin and histamine as allergens. The diameters of wheals were recorded and the means determined. OA-sensitized guinea-pigs were challenged with 2% OA aerosols after 1 hour per os of drugs (KILE or prednisolonefor the treated groups) for two weeks. A piece of excised trachea was suspended in a tissue bath and challenged with histamine in the presence and absence of KILE, as well as Prednisolone (2.5 mg/kg). The results were reported as mean ±S.E.M. Statistical analysis was performed using one-way ANOVA and Bonferroni’s post hoc test.

Results: Biological assaying of KILE showed significant dose-dependent reduction in histamine induced vasodilation of cutaneal blood vessels (P<0.05 in all groups at all times of wheal measurements) and contractile responses of isolated trachea to histamine. KILE generally reduced the effect of histamine in all groups.

Conclusion: This study has shown that KILE has the potential of alleviating signs of bronchial hyper-responsiveness and skin allergies in ovalbumin-sensitized guinea pigs with the female models been more sensitive than the male counterparts.