Pseudotsuga menziesii (Pinaceae): Volatile Profiles, Antimicrobial Activity and Toxicological Evaluation of Its Essential Oil

Abstract

The present article investigates the chemical composition of volatiles of essential oil (EO) and headspace (HS) fraction, as well as biological activities of EO obtained from needles with twigs of Pseudotsuga menziesii var. menziesii cultivated in Serbia. The major class of compounds was monoterpene hydrocarbons with α‐terpinolene, sabinene and β‐pinene (EO), and sabinene, α‐terpinolene and β‐pinene (HS) as the dominant volatiles. Tested EO exhibited mostly low antimicrobial potential against investigated strains (ATCC and respiratory isolates), where MICs ranged 1.25–20.00 mg/mL. Nevertheless, based on presented results, where antimicrobial testing was done for the first time on human respiratory system isolates, there is a potential of this EO to be used as an adjuvant in the treatment of human respiratory infections, especially those caused by Pseudomonas aeruginosa or Candida albicans strains. Regarding toxicological evaluation, EO showed moderate toxicity in Artemia salina toxicity bioassay (LC50=347.41, after 24 h) as well as week toxicity against Drosophila melanogaster with the ability only to moderately delay larval and pupal development.

Essential Oils of Three Balkan Abies Species: Chemical Profiles, Antimicrobial Activity and Toxicity toward Artemia salina and Drosophila melanogaster

“…Furthermore, just like Abies EOs, Pinus EOs from the mentioned study significantly influenced developmental times from larvae to pupae and larvae to adults. Nevertheless, the more recent study by Mitić et al [36] . has shown weak toxicity of EO of another species from Pinaceae family, particularly Pseudotsuga menziesii var.…”

“…Moreover, considering the other genera of the Pinaceae family, the Abies EOs seems to be more toxic against A. salina compared to EO of Pseudotsuga menziesii var. menziesii (Douglas fir) that showed moderate toxicity with LC 50 value of 347.41 μg/mL [36] . However, Douglas fir EO had a quite different chemical profile with α‐terpinolene (22.7 %), sabinene (17.9 %), β‐pinene (15.2 %), and terpinen‐4‐ol (9.2 %) as the dominant volatile compounds, while α‐pinene was detected in concentration below 5 % [36] …”

“…Nevertheless, the more recent study by Mitić et al [36] has shown weak toxicity of EO of another species from Pinaceae family, particularly Pseudotsuga menziesii var. menziesii, which had capacity only to moderately delay the development of D. melanogaster.…”

“…menziesii (Douglas fir) that showed moderate toxicity with LC 50 value of 347.41 μg/mL. [36] However, Douglas fir EO had a quite different chemical profile with α-terpinolene (22.7 %), sabinene (17.9 %), β-pinene (15.2 %), and terpinen-4-ol (9.2 %) as the dominant volatile compounds, while αpinene was detected in concentration below 5 %. [36] Insect Larvicidal Activity…”

Relaxing Effects of Breathing Pseudotsuga menziesii and Lavandula angustifolia Essential Oils on Psychophysiological Status in Older Adults

“…Pseudotsuga menziesii ( P. menziesii ) EO is extracted from Douglas firs, which are conifer trees originally grown in North America. The antimicrobial activity of P. menziesii EO has been reported [ 31 , 32 ]; however, its other function has not yet been examined. We wondered if the soothing and relaxing effect of a forest bath is attributed to the breathing of the aromas of EO derived from conifer trees such as Douglas firs.…”