Microglia are responsible for the brain inflammation and activated by stimulants such as injury and lipopolysaccharide. Amygdalin is abundant in Armeniacae semen. Armeniacae semen is the seed of Prunus armeniaca L. var. ansu Maxim which is classified into Rosaceae. Armeniacae semen. Armeniacae semen has been used for the treatment of pain and inflammatory diseases. We prepared the aqueous extract of the amygdalin from Armeniacae semen. In this study, we compared the effects of the manufactured amygdalin and amygdalin extracted from Armeniacae semen on the lipopolysaccharide (LPS)-stimulated expressions of cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) in the mouse BV2 microglial cells. For this study, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, reverse transcription-polymerase chain reaction (RT-PCR), prostaglandin E₂ (PGE₂) immunoassay, and nitric oxide (NO) detection were performed. The present results showed that the amygdalin extract from Armeniacae semen suppressed PGE₂ synthesis and NO production by inhibiting the LPS-stimulated enhancement of COX-2 and iNOS mRNA expressions, while the manufactured amygdalin did not significantly reduce PGE₂ synthesis and NO production. Here in this study, we showed that the aqueous extract of amygdalin from Armeniacae semen exerts anti-inflammatory and analgesic effects, however, the manufactured amygdalin dose not have such effects.

Keywords: Armeniacae semen, lipopolysaccharide, cyclooxygenase-2, prostaglandin E₂, inducible nitric oxide synthase (iNOS)