Human polymorphonuclear leukocyte activating factor isolated from Aleurites Fordii Hemsl. (Euphorbiaceae) seed

A human polymorphonuclear leukocyte (PMN) activating factor (AFH-S) was isolated from a tropical plant seed, Aleurites Fordii Hemsl. (AFH) in PBS. It is found that the AFH-S stimulate human PMNs and induced superoxide generation and chemotaxis. Superoxide generation was affected by the extracellular calcium ion or pretreatment with H-7 (PK-C inhibitor), but not by mepacrine (PLA2 inhibitor) or pertussis toxin (islet-activating protein: IAP). Furthermore, a lag time exists dose-dependently. In addition the cytosolic calcium was not increased by the stimulation with AFH-S. Thus, the receptor for AFH-S was suggested to be independent from Ni-like protein, PI-response, or PLA2-activation, and stimulate PMNs through activation of PK-C.