Inhibitory effects of phyto-extract mixture (PEM381) on type I allergic reaction

The purpose of this study is to investigate the anti-type I allergic effects and mechanisms of the phyto-extract mixture (PEM381) which contains Camellia sinensis (leaf), Psidium guajava (leaf), and Rosa hybrida (flower). PEM381 was tested for its inhibitory effects on arachidonic acid cascade-related enzymes (5-lipoxygenase and cyclooxygenase), the mast cell-mediated allergic reaction and passive cutaneous anaphylaxis. IC₅₀ value of PEM381 against 5-lipoxygenase was 14.11±0.51 ppm while that of positive control (nordihydroguaiaretic acid) was 0.54±0.08 ppm. PEM381 also exhibited considerable selective inhibition of cyclooxygenase-2. PEM381 could inhibit both degranulation and histamine release in a dose-dependent manner from rat peritoneal mast cells activated by compound 48/80. In addition, oral administration of PEM381 showed an inhibitory effect on passive cutaneous anaphylaxis reaction activated by anti-dinitrophenyl IgE antibody in mice. These results suggest that PEM381 may be useful for the prevention and treatment of type I allergy-related diseases.