I. Karpouhtsis et al., INSECTICIDAL AND GENOTOXIC ACTIVITIES OF OREGANO ESSENTIAL OILS, Journal of agricultural and food chemistry, 46(3), 1998, pp. 1111-1115
The essential oils (EOs) obtained from the oregano plants Origanum vul
gare subsp. hirtum, Coridothymus capitatus, and Satureja thymbra were
examined by a combination of GC and GC-MS and found to be rich in carv
acrol, thymol, gamma-terpinene, and p-cymene. These EOs and their main
constituents, carvacrol and thymol, were tested for insecticidal and
genotoxic activities on Drosophila. The EO of S. thymbra was found to
be the most effective as an insecticide, while carvacrol was found to
be more toxic than thymol. The toxicities of carvacrol and thymol do n
ot correspond to their participation in the EOs, and mixtures of these
two phenols in levels resembling their content in the three oils show
ed that the toxicity of carvacrol was reduced in the presence of thymo
l, thus suggesting antagonistic phenomena. The somatic mutation and re
combination test on Drosophila revealed that, among the five compounds
studied, only thymol exhibits genotoxic activity.