In this study we investigated the underlying mechanism of anti-inflammatory effect of an ethanol extract of SOL roots (ESOL).
The ability of ESOL to inhibit inflammatory skin disorder was tested in human keratinocyte HaCaT cells.
Viability test using MTT assay were used to determine non-cytotoxic concentrations of ESOL on HaCaT cells. ESOL-mediated inhibition of the tumor necrosis factor (TNF)-α/interferon (IFN)-γ-induced production of pro-inflammatory chemokines—such as macrophage-derived chemokine (MDC), regulated on activation, normal T-cell expressed and secreted (RANTES), interleukin (IL)-8, and thymus and activation regulated chemokine (TARC)—at the mRNA level was determined by real-time reverse transcription-polymerase chain reaction (RT-PCR). The ability of ESOL to reduce the expression of pro-inflammatory marker proteins was evaluated by Western blot analysis and immunocytochemistry.
ESOL reduced the production of MDC, RANTES, IL-8, and TARC in HaCaT cells stimulated with TNF-α/IFN-γ at both protein and mRNA levels. ESOL also suppressed the phosphorylation of signal transducer and activator of transcription (STAT)-1, extracellular signal-regulated kinase (ERK), and inhibited both nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha (IκB-α) degradation and the nuclear translocation of NF-κB/p65. ESOL exerts anti-inflammatory effects by suppressing the expression of TNF-α/IFN-γ-stimulated chemokines and pro-inflammatory molecules via a blockade NF-κB, STAT-1, and ERK activation.
Our results suggest the preventive potential of ESOL as a herbal medicine for the treatment of inflammatory skin diseases.