UVB PROTECTIVE, ANTI-AGING, AND ANTI-INFLAMMATORY PROPERTIES OF AQUEOUS EXTRACT OF WALNUT (JUGLANS REGIA L.) SEEDS

Walnut (Juglans regia L., fam. Juglandaceae) fruit is found to be very rich in phenolic compounds and thus to show wide spectrum of biological activities like antioxidant, anti-inflammatory, or antitumour properties. Ethanol or methanol are preferentially used for preparation of walnut extracts for cosmetic applications. However, it is commonly known that alcohol causes dehydration and redness of the skin. The aim of this work was to prepare aqueous extract of undamaged walnut seeds rich in pellicles and to evaluate its antioxidant, anti-apoptotic, anti-inflammatory, and anti-aging properties in vitro. Conducted research clearly demonstrated that simple water extraction of undamaged kernels with pellicles allows to obtain rich in phenolic compounds (36-38 mg per g of lyophilisate) walnut extract, which protects fibroblasts and keratinocytes against oxidative stress induced by UVB dose of 35 mJ/cm2 (5-6-h exposure on a sunny day), protects keratinocytes against UVB-induced apoptotic death, limits the development of the inflammation in epidermis, and also possesses ability to inhibit collagenase and elastase. Thus, obtained aqueous walnut extract (at relatively low concentration of 5 µg/ml) is found to be a promising compound of sunscreen and anti-aging cosmetic formulations.