Bronchodilatory effect of Portulaca oleracea in airways of asthmatic patients

Therapeutic effects of Portulaca oleracea for respiratory diseases are indicated in ancient Iranian medical books. The relaxant effect of this plant have also been observed on smooth muscle tissue in previous studies. Therefore, in the present study, the bronchodilatory effect of the boiled extract of Portulaca oleracea in the airway of asthmatic patients was examined. The relaxant effect of the orally administered 0.25 ml/kg of 5% boiled extract in comparison with 3 mg/kg oral theophylline and 200 lug inhaled salbutamol was studied by measuring forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), maximal mid-expiratory flow (MEF25-75), and specific airway conductance (sGaw). The FEV1, PEF, MEF25-75, and sGaw were measured before, administration and repeated 15, 30, 60, 90, and 120 min after administration of the oral extract and theopylline. For inhaled salbutamol measurements were performed 5, 15, 30, and 60 min post-inhalation. Results showed that the boiled extract of Portulaca oleracea caused significant increases in all measured pulmonary function tests (PFTs), (P < 0.05 to P < 0.01). There was no significant difference between the maximum increase in measured PFTs due to the boiled extract and theophylline. However, maximum increase in PEF and MEF25-75 due to the boiled extract were significantly lower than those of salbutamol (P < 0.05 for both cases). The onset of brochodilatory effect of extract was similar to that of theophylline beginning 60 min, but the effect of extract decline after 120 min after administration. In conclusion, the results of the present study showed that Portulaca oleracea has a relatively potent but transient bronchodilatory effect on asthmatic airways. (C) 2004 Published by Elsevier Ireland Ltd.