Chemical Composition and Biological Screening of the Essential Oils of Micromeria macrosiphon and M. arganietorum (Lamiaceae)

The chemical composition and in vitro biological activities of the essential oil (EO) of Micromeria macrosiphon Coss. and M. arganietorum (J. Emb.) R. Morales, two Lamiaceae endemic to south Morocco, were investigated. GC/MS analysis resulted in the identification of 36 metabolites from the EO of M. macrosiphon, 45 from M. arganietorum. Borneol was the major metabolite in both oils and together with related derivatives such as camphor, accounted for 2/3 of the EO of M. macrosiphon, 1/3 of those of M. arganietorum. Pinene and terpinene derivatives were also present in high proportions. From a chemotaxonomic point of view, the composition of the examined samples may be related to those of other species endemic to Macaronesia. Both EOs showed significant toxicity towards liver HepG2 and melanoma B16 4A5 tumor cell lines at 100 mu g/mL; however, they were also cytotoxic towards S17 normal cell lines, with a selectivity index <1. No antibacterial activity was noticed against 52 strains at 100 mu g/mL.

Automated summary

The chemical composition and biological activities of the essential oil of Micromeria macrosiphon and M. arganietorum were investigated in this study, revealing similarities with other species endemic to Macaronesia. Both oils exhibited significant toxicity towards liver HepG2 and melanoma B16 4A5 tumor cell lines, but also showed cytotoxicity towards normal cell lines. Antibacterial activity was not observed against 52 strains at 100 μg/mL.