In vivo nonspecific immunomodulatory and antispasmodic effects of common purslane (Portulaca oleracea Linn.) leaf extracts in ICR mice

Ethnopharmacological relevance: Portulaca oleracea (common purslane) is used in traditional medicine to cure various illnesses. However, its immune-protective properties and antispasmodic effects still need more pharmacological data if the plant will be utilized in herbal and drug formulations. Therefore, the present study determined the capacity of this plant species to modulate nonspecific immune responses and to confirm its antispasmodic activity in vivo in ICR mice. Materials and methods: Phagocytic activity of peritoneal macrophage, splenic lymphocyte proliferation and plasma lysozyme levels were measured in mice that were immunosuppressed using cyclophosphamide and treated with the ethyl acetate extract of Portulaca oleracea. In addition, the charcoal meal transit test was used to measure intestinal motility using ethanolic (EtOH), hexane (HEX), and ethyl acetate (EA) solvent extracts. Phytochemical analysis was undertaken and DPPH scavenging properties of the three solvent extracts were also determined. Results: The EA extract of P. oleracea exhibited immunoactivity through significant increase in phagocytosis and higher proliferative response in splenic lymphocytes. Plasma lysozyme level was also higher in EA-treated mice at high dose but this was not statistically significant. Decreased intestinal motility was also exhibited in mice treated with the three leaf solvent extracts compared to the negative control and the acetylcholine-treated group. The antispasmodic activity of the solvent extracts was comparable to that of the atropine-treated group. Phytochemical analysis showed the presence of tannins in EA extract in addition to alkaloids and steroids. The EtOH and HEX extracts contain alkaloids, steroids and terpenoids. DPPH scavenging activity was highest in the EA extract. Conclusions: The present study showed that the EA extract of P. oleracea leaves ameliorated the immunosuppressive action of cyclophosphamide in mice. The results also indicated that the three solvent extracts of the plant decreased smooth muscle spasms in mice ileum. However, further experiments are warranted to further isolate the plant's immunoactive component. Also, the mechanisms involved in the immunoactivity and antispasmodic properties of P. oleracea deserve full elucidation.