Abstract
Essential oils (EOs) are chemical products produced by odoriferous glands from a variety of plants. These essential oils have many health benefits: antiseptic, anti-inflammatory and antimicrobial activities. So due to these medicinal properties, the present study was designed to analyze essential oils of Thymus zygis L. and Thymus willdenowii Boiss. for their chemical composition and biological activities. These two thyme species were collected from the region of Ifrane, Middle Atlas of Morocco. The EO was obtained by hydrodistillation, and the yields were 5.25% for T. zygis and 3.00% for T. willdenowii. The chemical composition of the EOs was analyzed by gas chromatography coupled with mass spectrometry (GC-MS), and the results showed that T. zygis EO is dominated by carvacrol (52.5%), o-cymene (23.14%), and thymol (9.68%), while the EO of T. willdenowii contains germacrene D (16.51%), carvacrol (16.19%), and geranyl acetate (8.35%) as major compounds. The antioxidant activity assessed by Diphenylpicrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays revealed that both EOs have excellent antioxidant activities; by DPPH it resulted in IC50 = 6.13 ± 0.11 for T. zygis and 6.78 ± 0.3 µg/mL for T. willdenowii, while the one by FRAP yielded EC50 = 2.46 ± 0.01 (T. zygis) and 5.17 ± 0.2 (T. willdenowii) µg/mL. The antimicrobial activity of the two essential oils was evaluated against six bacterial strains and five fungal strains by the disk diffusion method to determine the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC). The EOs revealed variable antimicrobial activities against the different tested microbial strains and showed strong antimicrobial activities, even against strains known as multi-resistant to antibiotics (Acinetobacter baumannii) at low concentrations (2 µL/mL). T. zygis EO showed the most powerful activity against all the studied bacteria, while that of T. willdenowii recorded moderate activity when tested against Shigella dysenteriae and Salmonella Typhi. With inhibition diameters that vary between 75 mm and 84 mm for concentrations of 2 µL/mL up to 12 µL/mL, S. aureus was shown to be the most sensitive to T. zygis EO. For the antifungal activity test, T. zygis EO showed the best inhibition diameters compared to T. willdenowii EO. These results showed that T. zygis EO has more powerful antioxidant and antimicrobial activities than T. willdenowii EO, therefore, we deduce that thyme EOs are excellent antioxidants, they have strong antimicrobial properties, and may in the future represent new sources of natural antiseptics that can be used in pharmaceutical and food industry.
Highlights
In recent years, there has been increasing interest in natural substances of plant origin with therapeutic potential
With 5.25%, the T. zygis sample provided the highest yield against only 3.00% obtained with T. willdenowii
The latter remains higher compared to that obtained by El Idrissi and Idrissi (0.28%) [18] and when compared to other thyme species in Morocco such as Thymus bleicherianus collected in Meknes (Center of Morocco) (1.71%), Thymus capitatus collected in Tetouan (North of Morocco) (1.43%) and Thymus satureioides collected in Agadir (0.69%) [19]
Summary
There has been increasing interest in natural substances of plant origin with therapeutic potential This increase has been linked to several factors, including beneficial health effects, in particular with the extracts and products derived from higher plants, which have led to the discovery, and the development of useful therapeutic agents [1,2]. These products are relatively low-toxic, inexpensive, available, and have effects against many pathologies (bacteria, fungus, viruses, parasites, etc.) that pose infection risks to the human body. A wild aromatic plant belonging to the Lamiaceae family, is found mainly in the Mediterranean region, Asia, Southern Europe, and North Africa [7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
