In-vitro antimicrobial activity and identification of bioactive components using GC–MS of commercially available essential oils in Saudi Arabia

Abstract

This study was designed to evaluate antimicrobial activity and chemical composition of four different plant essential oils i.e. Ginger oil (GiO), Black seed oil (BSO), Oregano oil (OO) and Rose oil (RO) against different bacterial and fungal strains. Anti-microbial activities of selected essential oils were determined by the microbiological technique using Agar well diffusion assay. After in vitro study, most of the essential oils showed antimicrobial activity against all the selected pathogens. Among all the tested oils, GiO showed strong antimicrobial activity. GiO showed highest antimicrobial activity against (119.79%), (110.61%) and (106.02%), when compared with the tetracycline (50 µg/mL) activity. However, Antifungal activity of GiO was found to be present against and , when compared with clotrimazole (50 µg/mL) activity. Among all the selected bacteria, BSO showed maximum antimicrobial activity against the followed by Moreover, BSO had highest zone of inhibition against the (33.58%). OO indicated that, had the highest sensitivity (12.6 ± 0.58, 131.25%), followed by (19.1 ± 0.61, 96.46%) and (15.2 ± 0.27, 83.06%) when compared with tetracycline activity. OO showed poor sensitivity against all the selected fungal strains. Furthermore, Gas Chromatography analysis revealed that, Gingerol (10.86%) was the chief chemical constituents found in GiO followed by-Sesquiphellandrene (6.29%), Zingiberene (5.88%). While, BSO, OO and RO had higher percentage of p-Cymene (6.90%), Carvacrol (15.87%) and Citronellol (8.07%) respectively. The results exhibited that the essential oils used for this study was the richest source for antimicrobial activity which indicates the presence of broad spectrum antimicrobial compounds in these essential oils. Hence, essential oils and their components can be recommended for therapeutic purposes as source of an alternative medicine.

Ginger (Zingiber officinale) Antimicrobial Potential: A Review

“…Disk and well diffusion agar DMSO [16] Broth microdilution MIC and MBC DMSO 5% [21] MIC-diffusion agar Ethanol [29] Agar disk diffusion Acetone [30] MIC-broth microdilution Ginger essential oil [31] Agar disk diffusion Essential oil [32] MIC-broth microdilution Tween 80 [33] Agar disk diffusion Ginger essential oil [34] MIC-broth microdilution Tween 126 [35] Agar-agar diffusion DMSO [36] Broth microdilution MIC and MBC DMSO [37] DMSO, dimethyl sulfoxide; MIC, minimum inhibitory concentration; MBC, minimum bactericidal concentration. constitution of the Gram-negative cell wall [16], although the effect of high sensitivity on Gram-negative strains such as K. pneumonia has been observed [39].…”

“…As can be seen in Table 2, there is no standardization of ginger oil dilution, which can lead to uncertain results as it is an oil, and, because it is a less dense material than water, the oil cannot be diluted directly in the broth, which limits their miscibility in the test media. Therefore, a surfactant should be added, and we found that the most commonly used was DMSO [16,21,36,37], tween [33,35], some solvents like ethanol [29] and acetone [30], and even ginger oil [31,32,34]. The disk diffusion and well diffusion tests have been used to evidence antimicrobial activities, assuming that all components of the oil have the same solubility, but as verified in Tables 3 and 4, the diffusion of oil in the agar, during the test, may not diffuse into the agar, limiting the use of this method.…”

GC-MS Analysis of Commercially Available Allium sativum and Trigonella foenum-graecum Essential Oils and their Antimicrobial Activities

“…Both the samples were run for 30 minutes and analysis of obtained chromatograms was performed. Identification and characterization of various compounds were made by comparing relative retention time (RT) and mass spectra of samples with reference standards by using National Institute of Standards and Technology (NIST) library database 5 .…”

“…Antimicrobial activity of GEO and FEO were analyzed by using agar well diffusion assay techniques 5 . Muller-Hinton Agar and Sabouraud Dextrose Agar plates were used for antibacterial and antifungal activity, respectively.…”

“…Additionally, the antimicrobial properties of volatile components are known for decades and because of their potential microbial growth inhibition activity, these volatile components are being investigated as a substitute to synthetic chemical preservatives in food industries 4 . Since ancient times, herbs and spices are added in food and food products, not only as seasoning agent but also as a method of preservation 5 . Plant materials such as Garlic essential oil (GEO) and Fenugreek essential oil (FEO) with antibacterial properties could have a possible application in food preservation, for example, several studies have proved that garlic (Allium sativum) possesses a significant antimicrobial activity.…”