On the other hand, diverse flavonoids present in the chemical composition of propolis have anti-psoriatic activity; this activity is related to the reduction of inflammation through the decrease of different cytokines and mediators that include TNF-α, NF-κB, IL-1β, IL-17, Il-6, IL-22, IL-23, PGE2, and COX enzymes; the inhibition of transcriptional expression of HSP90 subunits; as well as the induction of their antioxidant activity to increase the activity of enzymes SOD, and CAT, and by increasing of GSH levels, which all together increases the orthokeratosis in damaged skin by psoriasis. Here, IL17A is linked to psoriasis.