Effect of UVA radiation on interactions of infusions obtained from teasel (Dipsacus fullonum L.) with free radicals

Introduction: Teasel (Dipsacus fullonum L.) extracts have antioxidant properties, which is of great importance in the treatment of many diseases. Herbal medicinal raw materials should be stored in conditions that guarantee the stability of their antioxidants. The aim of this study was to compare interactions with free radicals for infusions obtained from unexposed and UVA irradiated teasel plant materials. Material and methods: The nonirradiated and UVA irradiated plant raw materials as teasel (Dipsacus fullonum L.) herb and root, and the mixture of teasel (Dipsacus fullonum L.) herb, echinacea (Echinacea purpurea L.) herb, and elderberry (Sambucus nigra L.) fruit, were used in this study. Antioxidant properties of their infusions were compared. The examination was performed by the use od an X-band (9.3 GHz) electron paramagnetic resonance (EPR) spectrometer. The quenching of EPR spectra of the model DPPH free radicals by the infusions was determined. Results and discussion: UVA radiation increase and decrease interactions with free radicals for infusions of teasel herb and teasel root, respectively. UVA irradiation does not change free radicals interactions in case of infusion obtained from the mixture of teasel herb, echinacea herb, and elderberry fruit. Conclusions: Both teasel herb and root should be protect against UVA radiation during storage, because under these conditions change their interactions with free radicals, what which may be caused by changes in their antioxidant system. The effect of UVA radiation on antioxidative infusions of teasel depends on the type of raw material.