Background: Dracocephalum kotschyi is traditionally used for its anti-inflammatory
effects. We aimed to investigate the effects of ethyl acetate extract of D. kotschyi on
the expression of key inflammatory mediators and main signaling molecules involved in the
regulation of inflammation.
Methods: Lipopolysaccharide (LPS)-stimulated J774.1 mouse macrophages were cultured
in the presence of the plant extract and examined by the real time-PCR for gene expressions
of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS)
and cyclooxygenase (COX)-2. Cytokine levels and phosphorylated forms of stressactivated
protein kinases/c-Jun N-terminal kinase (SAPK/JNK), signal transducer and activator
of transcription (STAT)-3, p38, IκB-α and nuclear factor (NF)-κB p65 were determined
Results: The extract significantly reduced the expression of key mediators of inflammation.
iNOS expression level decreased from 138±8.5 fold in LPS-only treated cells to 6.5±2.6
fold after treatment with 25 µg/ml of the extract (p<0.001). Similarly, COX-2 expression
decreased from 632 ±98.8 fold in control to 124 ±24.6 fold (p<0.01). Treatment of cells
with the extract significantly reduced IL-1β and TNF-α cytokines at both gene and protein
expression levels. The extract at 25 µg/ml caused significant decreases in phospho-
SAPK/JNK and phospho-STAT3 levels in macrophages (p<0.01). Proteins of phospho-p38,
NFκB-p65 and phospho-NF-κB p65 had a reduced level in treated cells (p<0.05). No significant
change in phospho-IκB level was observed.
Conclusion: These findings suggested that D. kotschyi with inhibition of NF-κB,
SAPK/JNK, STAT-3 and p-38 might have reduced the expression levels of key inflammatory
mediators and thus possibly have potential beneficial impact on inflammatory diseases.