Stimulation of Phagocytosis in Alveolar Macrophages and Resistance against Infection in Mice by the Aqueous Extract of Rhizomes of Aframomum danielli, Schum (zingiberaceae)

Background: Alveolar Macrophages (AMs) play important role in preservation of lungs from infectious diseases development through a series of activities including phagocytosis. The present study examined the effects of aqueous extract of Aframomum danielli rhizomes on the AMs functions. Methods: Extract was investigated for microbe’s ingestion, bacteria killing and reactive oxygen and nitrogen species production in alveolar macrophages. Extract was investigated for repository, suppressive and curative treatments of S. aureus infection in mice.  Results: The extract of Aframomum danielli augmented (approximately threefold) the ingestion of Candida albicans by phagocytes. Furthermore, extract concentration dependently increased the killing ability of S. aureus of mice AMs. Moreover, the extract significantly stimulated the production of O2, H2O2 and nitric oxide (NO) by mice AMs. In addition, extract make mice to become more resistant to S. aureus infection. Finally, aqueous extract of A. danielli dose dependently increased reduced the bacteremia density in Dex-mice in suppressive, curative and repository treatments. Conclusion: Together the results showed that aqueous extract of A. dalnielli promotes the phagocytosis of microbes by alveolar macrophages and thereby may contribute to respiratory tract prevention from bacterial colonization.