The Ameliorating Effect of Oral Paquinimod Administration against Imiquimod Induced Psoriasis-like Inflammation in Mice

Abstract

Psoriasis is a chronic, inflammatory condition that primarily affects the skin, hair, and joints and is associated with significant humanistic and economic consequences. Psoriasis was induced in mice in this work using an imiquimod 5% cream, an immune response modifier that can cause psoriasis-like skin inflammation when given orally. Paquinimod is prepared as a suspension and has been orally given to mice before imiquimod application.In this study, albino mice were allocated into five groups and treated as follows: the control group received only daily application of cream based on shaved back (62.5mg/2cm) with a daily oral dose of vehicle for 14 consecutive days with the oral vehicle. Imiquimod group received a daily oral dose of vehicle one hour before imiquimod 5%application on shaved back (62.5mg/2cm) for 14 consecutive days.The paquinimod-treated group received different daily oral doses of paquinimod one hour before imiquimod 5% application on shaved back (62.5mg/2cm) for 14 consecutive days. Dexamethasone -treated group received a daily oral dose of dexamethasone oral solution (2mg/5ml) one hour before imiquimod 5% application on shaved back (62.5mg/2cm) for 14 consecutive days. Paquinimod only group received a daily oral dose of paquinimod for 14 consecutive days. The current study found that the administration of paquinimod suspension resulted in a significant decline in TNF-α,IL-23, IL17 level, reduced psoriasis area and severity index, spleen index, skin thickness, and gene expression of TNF-α, Nf-KB, IL-1B, IL-17in the (Paquinimod suspension+imiquimod) group substantially more than that in the (vehicle suspension+imiquimod) groups. In conclusion, paquinimod has a strong ameliorating effect as compared with dexamethasone against imiquimod-induced psoriasis-like inflammation in mice.