Effects of Pithecellobium clypearia Benth extract and its main components on inflammation and allergy.

The ethanol extract of Pithecellobium clypearia Benth (PCE) was characterized to be rich in polyphenols by HPLC analysis, and investigated for its anti-inflammatory and anti-allergic activities. In our assay, PCE showed anti-inflammatory activity in both acute and auto-immune inflammation animal models. Administration of PCE can effectively inhibit the croton oil-induced ear edema and capillary permeability, the carrageenin-induced paw edema, and the liver injury caused by propionibacterium acnes plus lipopolysaccharide. PCE was also found to possess anti-allergic activity in inhibiting the DNFB-induced delayed hypersensitivity reaction. Meanwhile, seven main components (1-7) from PCE were studied for their effect on histamine release stimulated by compound 48/80 from rat peritoneal mast cells in vitro. Compound 2 ((-)-epigallocatechin-7-gallate), 3 ((-)-5, 7, 3', 4', 5'-pentahydroxyflavan), and 5 ((-)-tetra hydroxyflavan-7-gallate) showed significant inhibition effect on histamine release.