Studies On The Mechanisms And Interactions Of Several Anti-psoriatic Drugs From The Aspect Of NF-κB Signaling Pathway

Objective To study the relationship between inhibition of keratinocyte growth by several anti-psoriatic drugs and NF-κ B signaling pathway on the basis of transcriptional factor NF-κB being an important regulator of keratinocyte proliferation, which could further reveal mechanisms of related drugs or compounds, and provide evidence for developing new anti-psoriatic drugs. At the same time, to evaluate the interaction and mechanism when anti-psoriatic drugs or compounds which inhibited the activation of NF-κB or activated NF- κB signaling pathway were taken together, exploring whether there are synergism or potential antagonism for instruction of clinical application.Methods HaCaT keratinocyte cell line was cultured in vitro, then different drugs or compounds were added, respectively. Using western blot analysis to study the expression of Ik Bα, a protein inhibitor binding with NF-κ B, and electrophoretic mobility shift assay to determine the ability of NF-κ B binding to DNA, so as to reflect the influence of drugs or compounds on NF-κB signaling pathway. MTT assay was used to measure the optical density which represented relative cell number of HaCaT keratinocyte, and made cell growth curve in order to show the influence on cell growth and proliferation. RT-PCR was used for determination of the mRNA expression of cytokine such as IL-8 and ICAM-1. Drugs or compounds treated with HaCaT cells included anthralin (ATL) which activated NF-κB signaling pathway and leflunomide (Lf) and triptolide (To) which inhibited the activation of NF- κB, sodium salicylate (NaSal) was used for positive control drug.Results I. Anti-psoriatic drug ATL was effective on induction of degradation of Iκ Bα, and in a dose dependent manner, IC₅₀ was about 13.8μM. Accordingly, further results indicated ATL also enhanced the DNA binding activity of NF-κ B, while Lf and T₀ had no influence on degradation of Ik Ba and DNA binding activity of NF-κ B. II. Further results...