Anti-Asthmatic Effects of Portulaca Oleracea and its Constituents, a Review

OBJECTIVES: The medicinal plants are believed to enhance the natural resistance of the body to infections. Some of the main constituents of the plant and derived materials such as, proteins, lectins and polysaccharides have anti-inflammatory effects. Portulaca oleracea (P. oleracea) were used traditionally for dietary, food additive, spice and various medicinal purposes. This review article is focus on the anti-asthmatic effects of P. oleracea and its constituents. METHODS: Various databases, such as the PubMed, Scopus, and Google Scholar, were searched the keywords including “Portulaca oleracea”, “Quercetin”, “Anti-inflammatory”, “Antioxidant”, “Cytokines”, “Smooth muscle “, and “ Relaxant effects “ until the end of Jul 2018. RESULTS: P. oleracea extracts and its constituents increased IFN-γ, IL-2, IFNγ/IL-4 and IL- 10/IL-4 ratio, but decreased secretion of TNF-α, IL-4 and chemokines in both in vitro and in vivo studies. P. oleracea extracts and quercetin also significantly decreased production of NO, stimulated β-adrenoceptor and/or blocking muscarinic receptors in tracheal smooth muscles. Conclusion: P. oleracea extracts and quercetin showed relatively potent anti-asthmatic effects due to decreased production of NO, inflammatory cytokines and chemokines, reduced oxidant while enhanced antioxidant markers, and also showed potent relaxant effects on tracheal smooth muscles via stimulatory on β-adrenoceptor or/and blocking muscarinic receptors.