Essential oils (Eos) have historically served as a significant source of natural remedies, thanks to their diverse range of bioactive compounds (Kareem et al., 2025). They are used in traditional medicinal practices around the world. For instance, in Ayurveda, they have been employed for thousands of years to address numerous health conditions (Buckle, 2014). Similarly, because of their antiviral, analgesic and anti-inflammatory properties, essential oils are used in traditional Chinese medicinal practices (Oriola and Oyedeji, 2022). Essential oils have been used as antimicrobial agents in funerals and to prevent the propagation of infectious illnesses since the time of the pharaohs (Lis-Balchin, 2006). Thuja (Tetraclinis articulata (Vahl) Masters) is a tree in the Cupressaceae plant family, found naturally in North Africa. It is characterised by light, evergreen foliage. When young, it has a pyramidal habit. Its leaves are reduced to opposite scales, overlapping in pairs (Boudy, 1952). This species of plant is mostly found in the region of Maghreb, though it is occasionally seen near Cartagena on Spain’s southeast coast and in Malta, where it is considered endangered (Quézel and Médail, 2003). Previous research has examined the chemical contents of Tetraclinis articulata essential oils. These investigations have mainly focused on identifying the specific composition of the EO, whether it comes from a single part of the plant or a combination of various parts such as twigs, leaves, cones, branches, seeds, roots or sawdust. An examination of the chemical elements of T. articulata vital oil has revealed a variety of bioactive substances, mainly from the monoterpene group. These compounds include molecules such as α-pinene, bornyl acetate, camphor, limonene, borneol and α-terpineol (El jemli  et al., 2017; Djouahri et al., 2013; Djouahri et al., 2014). This species covers 73% of the area of the Beni Affene mountain (wilaya of Tiaret, Algeria) (CFT, 2015). The aim of this research was to identify the volatile compounds of T. articulata EO and its antibacterial, antifungal in vitro.

Botanical authenticity, essential oil extraction, gas chromatography analyses and antimicrobial and antifungal studies were carried out at the Ibn Khaldoun University’s Faculty of Natural and Life Sciences in Tiaret, Algeria.
 
Plant material and extraction of Eos
 
In March 2025, twenty samples of T. articulata leaves were taken from its native environment at Beni Affen. Geographically, this area is located to the north-west of the wilaya of Tiaret, in western Algeria. It covers an area of 4,018 hectares (CFT, 2015), with coordinates of 35° 17' north latitude and 1° 03' east longitude. Samples were then dried at 27°C, or room temperature.
               
Essential oils were obtained in the laboratory by hydrodistillation over a three-hour period using Clevenger-type equipment. For the process, 100 g portions of leaf powder were utilized. To maintain the physicochemical properties of the extracted oils, storage at a temperature of 4±1°C in a dark environment was advised.
 
Identification of compounds
 
The EOs were analysed by gas chromatography-mass spectrometry (GC-MS). The gas chromatographic characterisations were carried out via a Perkin-Elmer apparatus that included a splitter injector, a flame ionisation detector (FID), as well as two capillary columns (50 m x 0.22 mm; film thickness: 0.25 m), nonpolar (BP-1, PDMS) and polar (BP-20, PEG). The injector and detector have a temperature of 250°C. The temperature was set to increase from 60°C to 220°C at an amount of 2°C/min and it stayed at 220°C for 20 minutes. The infusion was carried out in divided mode via a divided ratio for 1/60 and the carrier gas used was helium (0.8 mL/min) at a pressure of 25 psi. 0.1 μL of EO was added. A group of alkanes (C8-C28) were used to compare the retention indexes (Ir) of the constituents. After that, linear interpolation was applied to the two columns.
 
Antimicrobial activity
 
To examine the antimicrobial and antifungal properties of thuja essential oil, we used five bacterial strains, two yeast species and two filamentous fungi using the disc diffusion technique. For cases showing positive activity, the minimum inhibitory concentration (MIC) was assessed through the direct contact technique on an agar medium.
               
The pathogenic strains used were chosen for their high frequency of contamination of foodstuffs, their current resistance to various antibiotics and their pathogenicity (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 13047 Bacillus cereus, Pseudomonas aeruginosa ATCC 27853, Candida tropicalis, Candida albicans, Aspergillus fumigatus MNHN 566 and Aspergillus flavus MNHN 994294).
 
Statistical analysis
 
SPSS software was used to analyse the data. Once the data was converted to mean standard deviations (SD), the means were compared using ANOVA. A probability value of below 0.05 was considered indicative of statistical significance.

Chemical composition
 
Table 1 provides a detailed breakdown of the T. articulata EOs chemical composition.


               
GC-MS analysis of the EO from Tetraclinis articulata, collected in Beni Affen Mountain (Tiaret, Algeria), revealed the presence of 37 compounds. These compounds represent 98.26% of the oil’s total composition. The chemical profile is dominated by oxygenated monoterpenes, which constitute 62.16% and monoterpene hydrocarbons, making up 32.49%. The most prominent bioactive component includes bornyl acetate (26.25%), camphor (21.3%) and α-pinene (19.2%). Notable quantities of limonene (5.92%) and borneol (4.62%) were also identified.
               
These results are consistent with those obtained in other regions of Algeria (Boussaïd, 2017), although different rankings and percentages were recorded. On the other hand, a sample taken in Messer (Sidi Bel Abbès) contains low α-pinene content (3.2%) (Larabi et al., 2015). The EO of T. articulata leaves gathered in the Oujlida region (Tlemcen) is mainly made up of α-pinene (32%), followed by cedrol (11%) and d-3-carene (9.5%), according to Bouayad Alam  et al. (2014). There is absolutely no camphor and a very small amount of bornyl acetate (0.7%). In fact, this study’s findings aligned with those from Morocco (El Hachlafi  et al., 2024). Whereas Herzi et al., (2013) documented a high proportion of α-pinene and linalyl acetate in their Tunisian study, they reported a complete lack of camphor and bornyl acetate. Furthermore, an analysis conducted on a Canadian essential oil sample revealed the significant presence of d-3-Carene 18.29% and β-myrcene 11.69%, in addition to α-pinene 32.69%. In contrast, bornyl acetate exists in low concentrations (5.9%). (Kiliç, 2014).
 
Antimicrobial activity
 
The agar disc diffusion method was employed to assess the antibacterial properties of T. articulata essential oil. Fig 1A summarises the antibacterial action and Fig 1B summarises the antifungal effect.
               
Fig 1 presents the test outcomes, interpretable based on inhibition zone (IZ): the action of the essential oil is classified as low for an IZ of 10 mm, moderate for an IZ of 10 to 15 mm and high for an IZ of more than 15 mm (Alrajhi et al., 2019). Consequently, the study area’s T. articulata essential oil demonstrated the strongest antibacterial activity against Staphylococcus aureus (24.42±0.87 mm), Bacillus cereus (22.25±1.01 mm) and Escherichia coli (16.65±0.74 mm). In contrast, it exhibited lower to moderate action against the two Gram-negative microbes, Salmonella enterica (9.75±0.78 mm) and Klebsiella pneumoniae (11.3±0.61 mm).


               
In terms of antifungal potential, T. articulata oil demonstrated high activity, according to the disc diffusion results from tests against Candida tropicalis (17.78±0.78 mm), Candida albicans (17.1±0.64 mm) and Aspergillus fumigatus (16.57±0.783 mm) strains, respectively. Nevertheless, a moderate effect was seen on Penicillium expansum (11.7±0.61 mm).
               
Table 2 and 3 present the efficacy of T. articulata essential oil against microbial and fungal strains, determined by MIC, CBM and CMF, as well as the calculated tolerance levels (CMF/CMI) for the tested microorganisms.




               
The most potent action was displayed by gram-positive bacteria (S. aureus, B. cereus and E. faecalis), with MIC values falling between 44.5, 60 and 122.5 μg/mL and MBC values starting at 44. 5, 60 and 310 µg/mL for MBC, while MIC and MBC levels for Gram-negative bacteria ranged from 125 to 310 µg/mL for E. coli, 125 to 500 µg/mL for K. pneumoniae, 150 to 600 µg/mL for P. aeruginosa and 212.5 to 850 µg/mL for S. enterica. These results confirm those obtained using the disk diffusion method. C. tropicalis (MIC and MFC = 27.75 µg/mL) and P. expansum (MIC and MFC = 100 µg/mL) were the fungal strains with the minimum MIC and MFC concentrations, A. fumigatus (MIC = 125 and FMC = 250 µg/mL) and C. albicans (MIC = 132.5 and FMC = 265 µg/mL), indicating the antifungal effectiveness of T. articulata EO (Table 3).
               
In comparison to the antibiotics mentioned, the MIC, MBC and MFC leads to were effective and competitive. Furthermore, the MBC/MIC and MFC/MIC proportions indicate that T. articulata oil from the study area has bactericidal and fungicidal properties. Furthermore, our research confirms widely discussed results indicating that certain bioactive EOs work better toward Gram-positive bacteria than Gram-negative ones (Walasek-Janusz  et al., 2022; Çelebi  et al., 2023), implying that EOs primarily target the bacterial cell wall and cytoplasm.
               
This knowledge provides us with a strong foundation for comprehending the functions of essential oils and their function in pharmaceutical products and drug development. It emphasises how crucial it is to search for antibiotic substitutes in a range of settings, including essential oils. Ultimately, this oil may be helpful as an organic antimicrobial agent to combat various infectious diseases brought on by harmful bacteria or fungi. A worldwide search for new, safe and potent antimicrobial compounds derived from conventional forms has been sparked by the concerning increase in antimicrobial resistance (Derradjia  et al., 2025). Additionally, several of the most prevalent pathogenic bacteria are developing increased resistance to first-line antibiotics (Shikha et al., 2026).

The chemical composition of thuja essential oil contained 37 different components, mostly from the monoterpene class. Bornyl acetate, camphor and α-pinene were the primary ingredients. Also, this oil has shown promising biological effects, such as antibacterial and antifungal qualities. The GC-MS analysis showed that these consequences were probably linked to multiple bioactive substances present in T. articulata’s volatile component. These results lend scientific credence to the potential applications of this oil. Additionally, it is highly advised to conduct regular clinical and in vivo research to validate the pharmacological traits of this species and assess its mildness to guarantee its safety.
 
Disclaimers
 
The views and conclusions expressed in this article are solely those of the authors and do not necessarily represent the views of their affiliated institutions. The authors are responsible for the accuracy and completeness of the information provided, but do not accept any liability for any direct or indirect losses resulting from the use of this content.

The authors declare that there are no conflicts of interest regarding the publication of this article. No funding or sponsorship influenced the design of the study, data collection, analysis, decision to publish, or preparation of the manuscript.