Dual effect of taraxacum officinale leaves: Anticholinergic and inhibitory effect on inflammatory cells in ovalbumin-sensitized guinea-pigs

Bronchospasm is an important characteristic of allergen-induced airway inflammation.Taraxacum officinale herb is believed to have several therapeutic effects including anti-inflammatory properties. The anticholinergic effect of the T. officinale leaves extract (TOLE) was determined in ovalbumin (OA)-sensitized guinea-pig trachea. The test drugs (TOLE or prednisolone) were administered orally 1 h prior to aerosolized 2% ovalbumin challenge. Isolated ovalbumin-sensitized guinea-pig tracheal was challenged with acetylcholine and OA in the absence and presence of TOLE. The blood samples were collected and neutrophils, lymphocytes and monocytes (eosinophils, basophils and macrophages) counts assayed. Prednisolone (2.5 mg/kg body weight (BW) orally) was used as reference standard. TOLE application showed significant antagonistic effect on contraction of trachea to both acetylcholine (35.10 ± 0.04) and OA (18.6 ± 1.5). Also, the extract reduced monocytes (0.62 ± 0.23), lymphocytes (3.4 ± 0.59) and neutrophils (3.65 ± 0.20) counts in OA-sensitized guinea-pigs. Thus, TOLE possesses anticholinergic and reduces neutrophil, eosinophil and basophil counts in ovalbumin-sensitized guinea-pigs.   Key words: Taraxacum officinale, inflammation, blood cell counts, anticholinergic.