Composition and Antimicrobial Activity ofEuphrasia rostkovianaHayne Essential Oil

Abstract

Eyebright, Euphrasia rostkoviana Hayne (Scrophulariaceae), is a medicinal plant traditionally used in Europe for the treatment of various health disorders, especially as eyewash to treat eye ailments such as conjunctivitis and blepharitis that can be associated with bacterial infections. Some Euphrasia species have been previously reported to contain essential oil. However, the composition and bioactivity of E. rostkoviana oil are unknown. Therefore, in this study, we investigated the chemical composition and antimicrobial activity of the eyebright essential oil against some organisms associated with eye infections: Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, and Candida albicans. GC-MS analysis revealed more than 70 constituents, with n-hexadecanoic acid (18.47%) as the main constituent followed by thymol (7.97%), myristic acid (4.71%), linalool (4.65%), and anethole (4.09%). The essential oil showed antimicrobial effect against all organisms tested with the exception of P. aeruginosa. The best activity was observed against all Gram-positive bacteria tested with the minimum inhibitory concentrations of 512 µg/mL. This is the first report on the chemical composition of E. rostkoviana essential oil and its antimicrobial activity.

Antimicrobial Properties of Plant Essential Oils against Human Pathogens and Their Mode of Action: An Updated Review

“…The MIC values for these pathogens ranged from 0.097 to 6.25  μ L/mL. The antibacterial activity of Euphrasia rostkoviana essential oil against E. faecalis , E. coli , K. pneumoniae , S. aureus , S. epidermidis , and P. aeruginosa was reported by Novy et al [35]. In the study, all Gram-positive bacteria were effectively inhibited with an MIC of 512  μ g/mL.…”

HISTOCHEMICAL INVESTIGATION OF TRICHOMES AND CHEMICAL COMPOSITION OF ESSENTIAL OIL FROM Euphrasia stricta D. Wolff ex J.F. Lehm. (OROBANCHACEAE)

“…The content of essential oil in the drug eyebright was 0.257%, whereas the level of the oil content in Euphrasia stricta reported by Miladinovic et al [2014] and E. rostkoviana analysed by Novy et al [2015] reached 0.02%. The GC-MS analysis revealed 28 constituents representing 99.96% of total oil content.…”

“…In addition, our phytochemical analysis confirmed that substances such as pinene, linalool, terpineol, pulegone, caryphyllene, chamazulene, and cembrene, which represent various types of terpenes, were found in the essential oil in the eyebright. The data reported by other authors also showed that these substances are volatile constituents in Euphrasia stricta and E. rostkoviana [Miladinovic et al 2014, Novy et al 2015. The terpene compounds are responsible for the antioxidant, antiviral, antibacterial, and antifungal properties [Thoppil and Bishayee 2011].…”

“…Analyses performed by Miladinovic et al [2014] and Novy et al [2015] revealed that eyebright herb contained fatty acids (mostly palmitic acid) and their derivatives as main constituents. Similar results of trichome histochemistry in Calceolaria adscendens (Scrophulariaceae) [Sacchetti et al 1999] or Orobanche ramose (Orobanchaceae) [Sacchetti et al 2003] have been reported.…”

“…Miladinovic et al [2014] indicated the presence of 47 compounds. In turn, Novy et al [2015] identified 70 different compounds in the essential oil from E. rostkoviana. The biosynthesis of essential oils depends on a number of factors such as the cultivation method, fertilization, irrigation, weather conditions, type of soil, or date of harvest.…”