Essential Oils of Six Achillea Species: Chemical Profiles, Antimicrobial Potential and Toxicity toward Crustaceans

Abstract

This is the first comparative study on antimicrobial activity of essential oils (EOs) of six Achillea species (A. crithmifolia, A. distans, A. grandifolia, A. millefolium, A. nobilis, and A. lingulata) against ATCC and clinical microbial strains isolated from human swabs and on their toxicological potential on crustaceans. Oxygenated monoterpenes represented the major compound class in all six EOs, ranging from around 50 % (A. millefolium, A. nobilis, and A. lingulata) up to over 80 % (A. crithmifolia and A. grandifolia). Specific phytochemical profiles of the major volatiles were determined for each species. Still, borneol was the dominant compound in EOs of three yarrow species: A. distans, A. lingulata, and A. millefolium. Other major compounds were 1,8-cineole in A. crithmifolia, camphor in A. grandifolia, and artemisia ketone in A. nobilis EO. Antimicrobial activities of EOs were examined by a microdilution method revealing inhibitory action against all 15 studied strains in the range of 0.07 -20.00 mg/mL (MICs). High toxicity (LC 50 < 100 μg/mL) in Artemia salina acute toxicity bioassay was a shared characteristic, appearing in five out of six tested EOs, i. e., those isolated from A. lingulata, A. millefolium, A. distans, A. nobilis, and A. grandifolia. In both types of biological tests, A. lingulata EO has shown the highest and A. crithmifolia EO the lowest potential. The strongest activities, recorded for EO of A. lingulata, which was the only studied species from the section Anthemoideae, may be explained by its somewhat unusual chemical composition. According to the obtained results, the second dominant compound of this EO is γ-palmitolactone, which may be a significant agent regarding the antimicrobial activity and toxicity to crustaceans, either on its own or in union with other components, and it may be a suitable topic for further research.

Variability in the Essential Oil Composition ofAchillea erba‐rottasubsp.moschata(Wulfen) I. Richardson Growing in the Eastern Italian Alps

“…Most of the main compounds we found in A. moschata, were also previously identified as the major components in the essential oil extracted from different species of the genus Achillea L., including cis and trans-thujones, [35 -39] camphor, [28,[32][33]38,[40][41][42][43] and 1,8-cineole. [28,32,36,40,42,43] A high variability in the volatile oil composition resulted among the investigated accessions.…”

“…Most of the main compounds we found in A. moschata, were also previously identified as the major components in the essential oil extracted from different species of the genus Achillea L., including cis and trans-thujones, [35 -39] camphor, [28,[32][33]38,[40][41][42][43] and 1,8-cineole. [28,32,36,40,42,43] A high variability in the volatile oil composition resulted among the investigated accessions. Variability was observed particularly considering the most abundant components (on average > 2 % of the total oil, Table 3), as indicated by the coefficient of variability (CV) of their relative amount, calculated among investigated accessions: trans-thujone, chrisantenone and bornyl acetate (CV over 100 %), cis-thujone (CV = 72.8 %), camphor (CV = 61.4 %), 1,8-cineole (CV = 54.3 %), terpinen-4-ol (CV = 50.4 %), sabinene (CV = 41.9 %) and p-cymene (CV = 34.3 %).…”

Exploring the Medicinal Potential of Achillea grandifolia in Greek Wild-Growing Populations: Characterization of Volatile Compounds, Anti-Inflammatory and Antioxidant Activities of Leaves and Inflorescences

“…There is no other study reporting such a high amount of cis -thujone and trans -thujone in A. grandifolia essential oils. Previous phytochemical analysis of A. grandifolia essential oil from Serbia [ 15 , 16 , 17 , 18 ] and Greece [ 14 ] also report that cis -thujone (α-thujone) is among the main compounds, but in moderate quantities, i.e., 7.5%, 14.0%, and 11.9%, respectively. Furthermore, none of the samples examined from wild-growing plant material collected in Turkey (n = 3) has been reported to detect thujone in noteworthy quantities, except some traces (amounts not more than 0.05%) found in a sample from Aydin province [ 21 ].…”

“…To date, literature data reporting the composition of the essential oils extracted from aerial parts of A. grandifolia are limited. All previous studies have investigated plant material from wild-growing populations [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ], as well as from cultivated plants in Kazakhstan [ 22 ], and most of the extant information is related with the wild populations of Turkey [ 20 , 21 ] or Serbia [ 15 , 16 , 17 , 18 , 19 ]. There is only one study concerning the essential oil of wild-growing A. grandifolia from Greece, originating from the deciduous Carpinus forest of Vikos Gorge (Pindus Mountain range, Epirus) at an altitude of 500 m [ 14 ].…”

“…From Greece [ 24 ]. The investigation herein is aimed to update and amend an old phytochemical study that examined plant material originating from Greece [ 14 ], and to complement or contrast with other similar studies from Serbia [ 15 , 16 , 17 , 18 , 19 ] and Turkey [ 20 , 21 ].…”