search by
Copyright @ Pol J Cosmetol
Pol J Cosmetol 2017, 20(2): 158-162pl  The influence of UV radiation on the free radical scavenging activity by water extract from Mullein flowers (Verbascum thapsus L.)Małgorzata Stec, Paweł Ramos, Barbara Pilawa Katedra i Zakład Biofizyki, Wydział Farmaceutyczny z Oddziałem Medycyny Laboratoryjnej w Sosnowcu, Śląski Uniwersytet Medyczny w Katowicach Summary Introduction. The effect of ultraviolet radiation on antioxidative properties of the water extracts from mullein flowers (Verbascum thapsus L.) was examined. The free radical scavenging activities of the water extracts from mullein flowers before and after their exposition on UV radiation during 60 minutes, were compared. Aim. The aim of the research presented in this paper was to determine the ability of aqueous extracts of mullein flowers to capture free radicals using electron paramagnetic resonance spectroscopy (EPR) with a frequency of microwave radiation of 9.3 GHz. Material and methods. The UV lamp of Firm XY (Niemcy) was used. The water extracts were obtained after 15 minutes infuse as the infusion from mullein flowers. The kinetics of the interactions of the tested extracts with free radicals was determined. In this study the model DPPH free radicals were used and the EPR spectra were measured for them by the electron paramagnetic resonance spectrometer and the numerical system of data acquisition. Results. The antioxidative character of the extracts from the mullein flowers both nonirradiated and UV irradiated, was proved. The extracts quenched EPR lines of DPPH free radicals. The amplitudes of EPR lines of DPPH free radicals decreased with increasing of the time of interactions with infusion of mullein, next they reached the minimal value, which reflected the free radical scavenging activity by the tested extracts. The free radical scavenging activity decreased after exposition of the mullein flowers on UV radiation. However the faster interactions with free radicals were stated for the infusion of Mullein flowers exposed to UV. Conclusion. The spectroscopic analysis indicated that the mullein flowers should not be stored under UV radiation because it decreases antioxidative activity of the extracts. Key words: Mullein flowers, UV radiation, free radicals, antioxidants, EPR spectroscopy |