Intestinal Anti-Inflammatory Activity of Perillaldehyde.

Monoterpenoid perillaldehyde (PA) is the major component in Perilla frutescens leaf essential oil, but its function regarding anti-inflammatory effect is unclear. We explored the anti-inflammatory activity of PA in a dextran sulfate sodium (DSS)-induced colitis mouse model using relief of bodyweight loss (avg. 49.2% mitigation; P = 0.094) and colon damage (avg. 35.3% mitigation; P < 0.05) by administration of PA at a 100 mg/kg dosage. The PA administration resulted in suppression of DSS-induced expression of pro-inflammatory cytokine genes and matrix metalloproteinase-9 in the colon (e.g., avg. 60.6% mitigation for TNF-α mRNA levels; P < 0.05). These effects were confirmed in macrophage RAW264.7 cells stimulated with lipopolysaccharide (LPS). Application of PA induced cell suppression of LPS-induced expressions of genes and proteins of pro-inflammatory cytokines and induced activation of c-Jun N-terminal kinases (JNKs, p54 and p46; P < 0.05) but not nuclear factor-κB p65. The half maximal inhibitory concentration for decreased expression levels of TNF-α mRNA was 171.7 μM. We discuss the in vivo function of PA in amelioration of intestinal inflammation via JNK-mediated cytokine regulation.