A standardized methanol extract of Eclipta prostrata (L.) L. (Asteraceae) reduces bronchial hyperresponsiveness and production of Th2 cytokines in a murine model of asthma

Eclipta prostrata (L.) L. (Asteraceae) has been used in Brazilian traditional medicine to treat asthma and other respiratory illnesses. To investigate the effects of different doses of a standardized extract of E. prostrata using a murine model of allergen induced asthma. Balb/c mice were sensitized twice with ovalbumin (OVA) administered intraperitoneally and challenged over four alternate days with nasal instillations of OVA solution. The standardized methanol extract of E. prostrata was administered in doses of 100, 250 and 500mgkg−1 concomitantly with nasal instillation over seven consecutive days. Control animals were treated with dexamethasone or saline solution. Bronchial hyperresponsiveness, production of Th1 and Th2 cytokines, allergen sensitization, airway and lung inflammation, mucous secretion and airway remodeling were assessed. The concentrations of chemical markers in the standardized methanol extract were 0.02% oroboside, 1.69% demethylwedelolactone and 1.71% wedelolactone. Treatment with 250mgkg−1 of extract, which provided 0.745, 4.22 and 4.30mgkg−1day−1 of oroboside, demethylwedelolactone and wedelolactone, respectively, significantly reduced (P