Anti-inflammatory and analgesic effects of the aqueous extract of corni fructus in murine RAW 264.7 macrophage cells

Corni fructus is the fruit of Cornus officinalis Sieb. et Zucc, which is classified into the dogwood family of Cornaceae. Corni fructus has antineoplastic, antioxidative, and antidiabetic effects, but its anti-inflammatory and analgesic effects are unknown. Here, we investigated the anti-inflammatory and analgesic effects of an aqueous extract of corni fructus using murine RAW 264.7 macrophage cells. For this study, we used the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, western blot analysis, prostaglandin (PG) E₂ immunoassay, and nitric oxide (NO) detection. In addition, the analgesic effect of corni fructus was assessed by the acetic acid-induced writhing response in mice. The aqueous extract of corni fructus suppressed PGE₂ synthesis and NO production by inhibiting the lipopolysaccharide-induced expression of cyclooxygenase (COX)-2 and inducible NO synthase (iNOS) in murine RAW 264.7 macrophage cells. The extract also suppressed increases in nuclear factor-κB (NF-κB) levels in the nucleus. In vivo study showed that the extract suppressed the acetic acid-induced writhing response in mice. The aqueous extract of corni fructus exerts anti-inflammatory and analgesic effects by suppressing COX-2 and iNOS expression through the down-regulation of NF-κB binding activity.