Unraveling the Potential of Organic Oregano and Tarragon Essential Oils: Profiling Composition, FT-IR and Bioactivities

Abstract

Oregano and tarragon are widely cultivated culinary herbs used for food seasoning, having familiar characteristic aromas appreciated by the wide public. The aim of this research was to characterize essential oils (EOs) from locally sourced organic oregano and tarragon (Cluj, Romania) and study their bioactivity potential. Results showed that oregano EO had a sesquiterpene dominant profile responsible for strong bands between 2800 and 3000 cm−1 on the Fourier transform infrared spectroscopy (FT-IR) spectrum and a composition consistent with reports from similar climatic regions. The tarragon EO profile was defined by phenylpropanoids responsible for the strong sharp peaks between 1000 and 1600 cm−1 on the FT-IR spectrum. In oregano EO, 22 compounds were identified with β-caryophyllene as a major constituent. In tarragon EO, 20 compounds were identified with eugenol as a major constituent. Oregano EO had a stronger antibacterial effect against both Gram-negative and Gram-positive bacterial strains, while tarragon EO had a slightly stronger cytotoxic effect on three types of cancer cell lines tested (skin melanoma, prostate carcinoma, and colorectal adenocarcinoma). It was concluded that, given the fact that a sufficient supply of high-quality plant material can be available for EO extraction, culinary herbs can become reliable candidates for many industries without the risk of discontinued supply. Therefore, research aiming to widen their potential applications is welcome and worth pursuing.

Agastache Species (Lamiaceae) as a Valuable Source of Volatile Compounds: GC–MS Profiling and Investigation of In Vitro Antibacterial and Cytotoxic Activities

“…One µL of injection was made at 250 • C in split mode (20:1). The acquisition range (m/z) of the detector was adjusted at 35 to 800 in scan mode, with the electron impact mode (EI, 70 eV) selected, at an acquisition rate of 500 ms [41].…”

“…A microtiter-plate-based antibacterial test with resazurin was used to determine the MIC. Stock solutions of the EOs were created by mixing 50% ethanol and Tween 80 (8:1) [41]. The first well of a 96-well microtiter plate contained 100 µL of sterile nutrition broth and 100 µL of the sample.…”

“…After incubation for 24 h at 37 • C, MBC was determined as the lowest concentration that inhibited bacterial growth. The experiment was performed in triplicate [41,45]. 4.5.…”