Soothing and anti-itch effect of quercetin phytosome in human subjects: a single-blind study

BACKGROUND We evaluated the ability of quercetin, a natural antioxidant formulated in a specific delivery system, to reduce skin inflammation induced by a variety of stimuli, including UV radiation, stimulation with a histamine solution, or contact with chemical irritants. In particular, we tested the soothing and anti-itch effect of Quercevita(®), 1% cream for external use, a formulation characterized by a phospholipids-based delivery system. PATIENTS AND METHODS The study was a monocentric, single blind trial that enrolled a group of 30 healthy volunteers. The back of each subject was examined to identify four quadrants with no previous skin damage or naevi that were treated in order to induce a controlled and reversible form of skin stress. The areas were treated as follows: no product; Quercevita(®) 1% cream, 2 mg/cm(2); placebo; positive control (a commercially available topical formulation containing 1% dexchlorpheniramine). RESULTS Only quercetin phospholipids 1% and dexchlorpheniramine 1% achieved a significant reduction in erythema with comparable results: (-10.05% [P=0.00329] for quercetin phospholipids 1% vs -14.05% [P=0.00046] for the positive control). Moreover, quercetin phospholipids 1% and dexchlorpheniramine 1% were both associated with a significant decrease in mean wheal diameter: (-13.25% and -12.23% for dexchlorpheniramine 1%, respectively). Similar findings were reported for the other tested parameters. CONCLUSION Quercetin has a skin protective effect against damage caused by a variety of insults, including UV radiation, histamine, or contact with toxic chemical compounds. Indeed, quercetin is able to reduce redness, itching, and inflammation of damaged skin; it may also help restore skin barrier function, increasing hydration, and reducing water loss.