Cumin seeds (Cuminum cyminumL.) have been commonly used in food flavoring and perfumery. In this study, cumin essential oil (CuEO) extracted from seeds was employed to investigate the anti-inflammatory effects in lipopolysaccharide- (LPS-) stimulated RAW 264.7 cells and the underlying mechanisms. A total of 26 volatile constituents were identified in CuEO by GC-MS, and the most abundant constituent was cuminaldehyde (48.773%). Mitochondrial-respiration-dependent 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) reduction assay demonstrated that CuEO did not exhibit any cytotoxic effect at the employed concentrations (0.0005–0.01%). Real-time PCR tests showed that CuEO significantly inhibited the mRNA expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX-2), interleukin- (IL-) 1, and IL-6. Moreover, western blotting analysis revealed that CuEO blocked LPS-induced transcriptional activation of nuclear factor-kappa B (NF-κB) and inhibited the phosphorylation of extracellular signal regulated kinase (ERK) and c-Jun N-terminal kinase (JNK). These results suggested that CuEO exerted anti-inflammatory effects in LPS-stimulated RAW 264.7 cells via inhibition of NF-κB and mitogen-activated protein kinases ERK and JNK signaling; the chemical could be used as a source of anti-inflammatory agents as well as dietary complement for health promotion.
5-Hydroxytryptophan Acts on the Mitogen-Activated Protein Kinase Extracellular-Signal Regulated Protein Kinase Pathway to Modulate Cyclooxygenase-2 and Inducible Nitric Oxide Synthase Expression in RAW 264.7 Cells