THE EFFECT OF UV-B ON FATTY ACID CONTENT AND RADICAL SCAVENGING ACTIVITY OF METHANOLIC EXTRACTS FROM Hypericum retusum Aucher GROWN UNDER IN VITRO CONDITIONS

The study was aimed to evaluate the effects of UV-B radiation on fatty acid content and antioxidant activity of a methanolic extract of Hypericum retusum Aucher plantlets grown under in vitro conditions. Therefore, the plantlets were exposed to UV-B radiation for different durations (Ti: 15, T-2: 30, T-3: 45, T-4: 60 min) The UV-B application led to increase in linolenic (42.84%), oleic (6.92%) and linoleic acid (28.48%) in H. retusum. The methanol extracts of plantlets grown in vitro conditions showed the strongest free radical scavenging activities at concentrations of 50, 100, and 300 mu g/mL(-1). It has been found that UV-B radiation and in vitro growth conditions have a significant effect on the accumulation of fatty acids. However, the free radical scavenging ability of H. retusum extract was decreased after UV-B application.