A. Sivropoulou et al., ANTIMICROBIAL AND CYTOTOXIC ACTIVITIES OF ORIGANUM ESSENTIAL OILS, Journal of agricultural and food chemistry, 44(5), 1996, pp. 1202-1205
Three Origanum essential oils, Origanum vulgare ssp. hirtum, Origanum
dictamnus, and a commercially available Origanum oil, were analyzed by
gas chromatography-mass spectrometry (GC-MS) and showed a high conten
t-of carvacrol, thymol, gamma-terpinene, and p-cymene representing 73.
7%, 92.8%, and 87.78% of the total oil, respectively. The three essent
ial oils exhibited high levels of antimicrobial activity against-eight
strains of Gram-positive and Gram-negative bacteria. Among the major
components of the three oils, carvacrol and thymol exhibited the highe
st levels of antimicrobial activity, while their biosynthetic precurso
rs gamma-terpinene and p-cymene were inactive. The essential oil of O.
vulgare ssp. hirtum was extremely bactericidal at 1/4000 dilution and
even at dilutions as high as 1/50000 caused considerable decrease in
bacterial growth rates. The same essential oil also exhibited high lev
els of cytotoxicity against four permanent animal cell lines including
two derived from human cancers.