Capsaicin stimulates the migration of human polymorphonuclear cells (PMN) in vitro

Capsaicin, a homovanillic acid derivative in plants, has distinct pharmacological effects in vivo, e.g. it depletes primary afferent neurons of substance P and other tachykinins. The effect of capsaicin on the migration of human neutrophils was tested in concentrations ranging from 10(-8) M to 10(-3) M. In comparison to the control 10(-8) M capsaicin significantly enhanced the migration of PMN cells (CI 1.29; 2P < 0.009) and a peak migration activity was detected with 10(-6) M (CI 1.32; 2P < 0.01). With higher concentrations of capsaicin the CI was not significantly changed. These results show that capsaicin, a plant derived neurotoxin, exhibits a migration modifying activity on human neutrophils through a direct mechanism not mediated by neuropeptides. In addition capsaicin (10(-7) and 10(-5) M) did not affect the luminol-dependent chemiluminescence and therefore does not contribute to a superoxide anion generation in human PMN.