Description
The essential oils of Thymus caespititius, T. camphoratus, T. capitellatus, T. carnosus, T. pulegioides, T. zygis subsp.
zygis and T. zygis subsp. sylvestris collected in diff erent regions of Portugal, including the Azores islands, were evaluated for
preventing lipid peroxidation and scavenging free radicals, and hydroxyl and superoxide anions. T. zygis subsp. zygis oil possessed
the best capacity for preventing lipid peroxidation (IC50 = 0.030 ± 0.003 mg/ml), immediately followed by the oils isolated
from T. zygis subsp. sylvestris collected in diff erent regions of Portugal. IC50 values ranged from 0.066 ± 0.003 to 0.087 ±
0.001 mg/ml in oils isolated from samples from Alcanena and Duas Igrejas, respectively. The oils isolated from T. zygis subsp.
sylvestris, independent of the harvesting region, were shown to be the most eff ective for scavenging free radicals (0.358–
0.453 mg/ml). The best capacity for scavenging hydroxyl radicals was found in the oils of T. camphoratus collected in Espartal
and of T. caespititius of Lordelo, with IC50 < 0.5 mg/ml. The low oil amount did not allow IC50 values for the superoxide anion
scavenging determination, therefore considering a unique oil concentration (5 mg/ml), the highest inhibition percentages
(>50%) were registered with the essential oils of T. zygis subsp. sylvestris from Duas Igrejas and Covão do Coelho, and of T.
capitellatus from Sines. Copyright © 2010 John Wiley & Sons, Ltd.
; Lima, A. Sofia 
