Grape pomace and quercetin: a synergistic approach using PG-PEVs for Psoriasis treatment

Psoriasis is a chronic inflammatory skin disorder that affects millions worldwide and poses significant therapeutic challenges due to the adverse effects of conventional treatments. In this study we explored a sustainable approach based on Cannonau grape pomace extract, a winemaking side-stream rich in antioxidant polyphenols, combined with quercetin, to develop effective treatments for psoriasis. The extract was obtained using an eco-friendly extraction process and incorporated into phospholipid vesicles containing propylene glycol (PG-PEVs), which exhibited favourable physicochemical features: small size (∼77–172nm), homogeneously dispersed (PDI ∼0.29), highly negative zeta potential (∼−45 mV), high entrapment efficiency (≥82 %), and long-term stability over 18 months. Biological evaluations revealed the high biocompatibility of the formulations (≥80 %), and their ability to protect keratinocytes from oxidative stress and hyperproliferation, hallmarks of psoriasis. In a psoriasis-like murine model, PG-PEVs significantly reduced inflammation, neutrophil infiltration, and epidermal hyperplasia, as confirmed by decreased MPO levels (from ∼353 to ∼179 ng/mL) and improved skin architecture observed through histological analysis, which outperformed the effects of the natural chemicals in dispersion. These findings highlight the therapeutic potential of Cannonau pomace extract-loaded PG-PEVs as a promising, sustainable dermatological strategy. Moreover, this study supports the valorisation of agricultural side-streams into high-value cosmeceuticals, aligning with circular economy principles.