Protective effect of grape extract phospholipid vesicles against oxidative stress skin damages

Grape extract rich in polyphenols (∼129±32mg of gallic acid equivalents per g of dry extract) was obtained from the pomaces of Cannonau grapes by homogenization in an ethanol/water mixture. The efficacy of ultrasounds in speeding up the extraction kinetics of polyphenols was demonstrated. The extract was incorporated in liposomes and PEVs (penetration enhancer containing vesicles) with Labrasol® or Labrasol®/ethanol. All the vesicles were spherical and predominantly unilamellar: liposomes were large (∼927nm) and polydispersed (PI ∼0.56), while PEVs were small (∼140nm) and fairly homogeneous (PI ∼0.3). Moreover, PEVs were able to incorporate a high amount of the extract (∼98% of the extract used for their preparation, 50mg/ml). The formulations were highly cytocompatible and were able to promote the proliferation of keratinocytes and fibroblasts. In addition, thanks to their antioxidant activity, grape extract formulations provided a cytoprotective effect against oxidative stress damage.Therefore, an efficient, environmentally-friendly extraction strategy is proposed to obtain an extract with high phenolic content from waste grape pomaces, which was incorporated in vesicular systems to maximize the antioxidant power in a cell model of oxidative stress