In vitro activities of Cedrela tubiflora aqueous leaf extracts on murine macrophages, polymorphonuclear leukocytes and complement

Cedrela tubiflora aqueous leaf extracts are capable of inhibiting in vitro the activity of some components of the mouse immune system related to inflammatory responses. A significant reduction in the phagocytic capability and respiratory burst response (61.5% and 57.6%, respectively) of murine peritoneal macrophages was observed when these cells were incubated for 24 h with medium containing 1 mg/mL extract. On the other hand, at a concentration of 4 mg/mL, the extract reduced significantly the phagocytic activity of mouse polymorphonuclear leukocytes (87.5%) without altering the oxidative metabolism of these cells. Finally, a concentration of 2 mg/mL was required to inhibit the haemolytic activity of both pathways of mouse complement.