Anti-inflammatory effect of Prunus yedoensis through inhibition of nuclear factor-κB in macrophages

BACKGROUND Prunus yedoensis (PY) is a traditional anti-allergy and anti-inflammatory herb medicine used in South Korea. However, until date, little is known regarding its mechanism of action. METHODS In order to elucidate the mechanism of anti-inflammatory effect of PY, the constituents of PY were analysed by high performance liquid chromatography (HPLC), and nitric oxide (NO) and prostaglandin E2 (PGE2) production were measured enzyme-linked immuno sorbent assay (ELISA). The expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear factor-κB (NF-κB) were also measured by western blotting in lipopolysaccharide (LPS)-induced RAW 264.7 macrophage cells treated with PY. RESULTS The results indicate that (50, 100 μg/mL) methanol and ethyl acetate fractionation extracts of PY not only inhibited LPS-mediated NO production and iNOS expression, but also decreased LPS-induced PGE2 production and COX-2 expression. The anti-inflammatory effects of PY were also due to the attenuation of nuclear translocation of NF-κB, as evaluated by the use of anti-p50 on nuclear fractions. LPS-induced nuclear translocation of NF-κB decreased significantly by the methanol extract and ethyl acetate fraction of PY. High performance liquid chromatography (HPLC) analyses revealed that methanol extract and ethyl acetate fraction have similar patterns of retention time and peaks. CONCLUSION Our results demonstrate that methanol extracts and the ethyl acetate fraction of PY have anti-inflammatory properties, thus emphasizing the potential of PY as a natural health product.