Effect of Poncirus fructus on stem cell factor-induced mast cell migration

Mast cell hyperplasia can be causally related with chronic inflammation. Stem cell factor (SCF), the ligand of the c-kit protooncogene product, is a major regulator and chemoattractant of mast cells. Poncirus fructus (PF) has been used against allergic diseases for generations in South Korea. PF (1 mg ml(-1)) significantly inhibited the SCF-induced migration of rat peritoneal mast cells (RPMCs). RPMCs exposed to SCF (50 ng ml(-1)) resulted in a drastic shape change with a polarized morphology while the cells exposed to PF (1 mg ml(-1)) remained resting, with little or no shape alteration. The drastic morphological alteration and distribution of polymerized actin were blocked by pretreatment with PF. In addition, PF inhibited both TNF-alpha and IL-6 secretion from RPMCs stimulated with SCF. Our findings provide evidence that PF inhibits chemotactic response and inflammatory cytokines secretion to SCF in mast cells.