Extracts from Corylus avellana as a source of antioxidants useful in cosmetic preparations

Abstract Introduction: Human skin is constantly exposed to harmful external factors that are often the cause of premature aging. Anti-oxidants (including vitamins and flavonoids) are an important group of compounds that are necessary to scavenge harmful free radicals. As a result of the universally functioning cult of beauty, cosmetics manufacturers increasingly often add antioxidants to slow the aging process of the skin. In beauty salons, these preparations are used during cosmetics treatments to facilitate the penetration of active ingredients into the skin, including mesotherapy, iontophoresis, or sonophoresis. Researchers, on the other hand, are looking for new rich sources of antioxidants and for more effective methods of their isolation. Raw materials from common hazel (Corylus avellana L.) are characterized by a very high antioxidant potential, but they are relatively rarely used in the production of any cosmetic preparations. The aim of the study was to evaluate the impact of the hazel vegetation period as well as extraction conditions on the antioxidative activity of alcoholic extracts of selected parts of Corylus avellana L. Materials and methods: Ultrasound-assisted extraction was applied to obtain alcoholic extracts from male inflorescences and common hazel leaves in different vegetation phases. Ethanol, methanol, isopropanol, and n-propanol at concentrations of 40%, 70%, or 96/99% were applied as extractants. The antioxi-dative potential was assessed using the DPPH and ABTS methods. Absorbance measurements were made using a spectrophotometer. Results and conclusions: All the tested raw materials from Corylus avellana L. were characterized by a very high antioxidant activity. The highest scavenging capacity of free radicals was observed for dried leaves before and during fruiting determined using the DPPH and ABTS methods. The lowest activities were obtained in extracts in propan-1-ol and propan-2-ol from dried leaves during fruiting and male inflorescences. The results confirm the high content of antioxidants in the studied plant and suggest that raw materials derived from common hazel may be used in the production of cosmetics.