STUDIES ON ANTIOXIDANT PROPERTIES BEFORE AND AFTER UV-AND γ-IRRADIATION OF BULGARIAN LAVENDER ESSENTIAL OIL ISOLATED FROM LAVANDULA ANGOSTIFOLIA MILL.

At present there is not enough data about different types of radiation on Bulgarian essential oils isolated from medicinal plants. Here we report for the first time our studies on the effects of UV-radiation (290 nm to 320 nm) and gamma-radiation (doses of 5 Gy, 10 Gy, 20 Gy and 30 Gy) on Bulgarian lavender essential oil isolated from Lavandulla angustifolia Mill. A spectrophotometry method was used for evaluation of the changes in the reducing power of the Bulgarian lavender oil before and after radiation. The electron donation potential of non-irradiated oil was found to be lower (0.268 +/- 0.0244) than those of both, UV-irradiated (0.336 +/- 0.0121) and gamma-irradiated, oil samples (0.427 +/- 0.0251 at 5 Gy radiation, 0.341 +/- 0.0371 at 10 Gy; 0.328 +/- 0.0173 at 20 Gy). By direct electron paramagnetic resonance (EPR) spectroscopy, single almost symmetrical EPR signals with different values of the g-factor were registered in non-irradiated (g = 2.0047 +/- 0.0002), UV-irradiated (g = 2.01050 +/- 0.00005) and gamma-irradiated oil samples (g = 2.0017 +/- 0.0002), respectively. EPR spectroscopy was used for assessment of the radical scavenging capacity of the non-irradiated and UV- and gamma-irradiated samples of the Bulgarian lavender oil towards the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH). Excellent DPPH radical scavenging capacities were found for UV- and 30 Gy-irradiated lavender oil samples. Based on these preliminary results, we consider that, after proper UV- or gamma-radiation treatment, Bulgarian lavender oil might find application as a good radioprotector and antioxidant in cosmetics and medicine.