Effect of aqueous extract of Antiaris africana stem bark on phagocytic activities of human neutrophils ex-vivo.

The immune system is one of the most complex biological systems in the body. During infection, the immune system is under attack by a large number of viruses, bacteria, fungi and parasites. Immune response firstly involves, recognition of the pathogen or foreign object and secondly, a reaction to eliminate it. Aqueous extract of Antiaris africana is used to study their immune modulator activity. This plant has its various parts used in folk medicines. The mechanism of action has not been fully elucidated. Therefore, this research work studies the effect of aqueous extract of Antiaris Africana stem bark on phagocytic activities of neutrophil isolated from apparently healthy individual using a non-subjective commercial colourimetric assay kit obtained from Cell-Biolab Inc., USA. The purity and viability of isolated neutrophils were >90% and >95% respectively. The extract enhances neutrophil phagocytosis at 1.0, 5.0, 10.0, 15.0, 20.0 and 25 g/ml by 2.5%, 11.6%, 18.4%, 24.4%, 31.2% and 38.2% respectively, compared to the control (100%). Hence, it was observed that neutrophil phagocytosis increases with increased extract concentrations. It can be concluded from the study that enhancement of phagocytosis may be the possible mechanism of action of the plant as an immune modulator.