Grant: Collaborative Health Research Projects (NSERC partnered)

Psoriasis is an incurable skin disorder characterized by abnormal differentiation and inflammation. Taking into account that clinically approved anti-psoriatic treatments present many undesirable effects, it has been estimated that 51 % of patients use natural health products. Natural polyphenols are multifunctional molecules that can act through the modulation of multiple signaling pathways. This characteristic could be advantageous for the treatment of multi-causal diseases, such as psoriasis. So far, in vitro studies using natural polyphenols have been conducted on isolated enzymes and on normal or immortalized keratinocytes, which show significant differences regarding psoriatic samples. Thus, in this project, it is proposed to study the polyphenolic extract from black spruce bark on psoriatic cells and on a new psoriatic skin model produced by tissue engineering. This proposal has been divided in four major tasks: 1) to determine the chemical structure of polyphenolic compounds present in the purified extract from black spruce bark, 2) to evaluate the toxicological properties polyphenolic compounds of this extract, 3) to evaluate the influence of polyphenols on the TNF-alpha/NF-kappaB signaling pathway involved in psoriasis pathogenesis and lastly 4) to measure the percutaneous absorption of polyphenols on normal or psoriatic skin substitutes prepared by tissue engineering. This project will determine, for the first time, the pharmacological activity of natural polyphenols on signaling pathways involved in psoriasis pathogenesis by using psoriatic samples. Additionally, it will be possible to establish associations between the production of reactive oxygen species induced by TNF-alpha, the production of inflammatory