Anti- psoriatic effect and phytochemical evaluation of Iraqi Scabiosa palaestina ethyl acetate extract

The purpose of this study was to confirm the antipsoriasis activity of Scabiosa palaestina (S. palaestina) ariel component extract and identify the active compound(s) responsible for this activity using a developed RP-HPLC technology. The active ethyl acetate extract of S. palaestina was extracted and fractionated by the hot continuous Soxhlet apparatus method. Psoriasis was induced in experimental animals after 4 days of imiquimod (IMQ) cream application on dorsal skin rats of 3 treated groups (6 rats for each) and the normal group (6 rats) left without treatment. Two of the psoriatic-induced groups were treated with ethyl acetate (EA) extract or methotrexate (MTX) for 12 days, starting from day 4 of the IMQ application. Assessment of psoriatic lesions was done during the experiment, depending on the psoriasis area severity index (PASI). At the end of the study (day 15), animals were sacrificed and 2 skin specimens were collected for histopathological examination and cytokine measurement. Compared with the positive control group, ethyl acetate extract shows significant improvement in PASI (p-value < 0.05) and histopathological changes exerted by IMQ. On the other hand, no significant reduction has been seen in the psoriatic and angiogenic mediator (IL-17 and VEGF) with a P-value > 0.05 compared with the positive control group, which may be attributed to other cytokines that could be affected by the ethyl acetate extract of S. palaestina. These results suggest that the antipsoriasis properties of ethyl acetate extract may possibly be due to the presence of flavonoid compounds (luteolin, apigenin, quercetin, vitexin and kaempferol).