No abstract

Genus Mentha, a member of Lamiaceae family, encompasses a series of species used on an industrial scale and with a well-described and developed culture process. Extracts of this genus are traditionally used as foods and are highly valued due to the presence of significant amounts of antioxidant phenolic compounds. Many essential oil chemotypes show distinct aromatic flavor conferred by different terpene proportions. Mint extracts and their derived essential oils exert notable effects against a broad spectrum of bacteria, fungi or yeasts, tested both in vitro or in various food matrices. Their chemical compositions are well-known, which suggest and even prompt their safe use. In this review, genus Mentha plant cultivation, phytochemical analysis and even antimicrobial activity are carefully described. Also, in consideration of its natural origin, antioxidant and antimicrobial properties, a special emphasis was given to mint-derived products as an interesting alternative to artificial preservatives towards establishing a wide range of applications for shelf-life extension of food ingredients and even foodstuffs. Mentha cultivation techniques markedly influence its phytochemical composition. Both extracts and essential oils display a broad spectrum of activity, closely related to its phytochemical composition. Therefore, industrial implementation of genus Mentha depends on its efficacy, safety and neutral taste.

No abstract

The present study describes the total phenolic content, concentrations of flavonoids and in vitro antioxidant and antimicrobial activity of methanol extracts from Seseli pallasii Besser, S. libanotis (L.) Koch ssp. libanotis and S. libanotis (L.) Koch ssp. intermedium (Rupr.) P. W. Ball, growing wild in Serbia. The total phenolic content in the extracts was determined using Folin-Ciocalteu reagent and their amounts ranged between 84.04 to 87.52 mg GA (gallic acid)/g. The concentrations of flavonoids in the extracts varied from 4.75 to 19.37 mg Qu (quercetin)/g. Antioxidant activity was analyzed using DPPH reagent. Antioxidant activity ranged from 0.46 to 4.63 IC50 (mg/ml) and from 1.98 to 2.19 mg VitC (vitamin C)/g when tested with the DPPH and ABTS reagents, respectively, using BHA and VitC as controls. The antimicrobial activity of the extracts was investigated using a micro-well dilution assay for the most common human gastrointestinal pathogenic bacterial strains: Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 9027, Salmonella enteritidis ATCC 13076, Bacillus cereus ATCC 10876, Listeria monocytogenes ATCC15313, Staphylococcus aureus ATCC 25923 and Candida albicans ATCC 10231. This finding suggests that Seseli species may be considered as a natural source of antioxidants and antimicrobial agents.

In this paper, the chemical composition and biological activity of the essential oil of Artemisia absinthium was studied. The aim of this study was to investigate the potential of ethnopharmacological uses of this plant species in the treatment of gastrointestinal diseases and wounds, and as an insect repellent. The aerial part of the plant was hydrodistilled, and the chemical composition of the essential oil was analyzed by gas chromatography and gas chromatography/mass spectrometry. Forty-seven compounds, corresponding to 94.65 % of the total oil, were identified, with the main constituents being sabinene (24.49 %), sabinyl acetate (13.64 %), and α-phellandrene (10.29 %). The oil yield was 0.23 % (v/w). The antimicrobial activity of the oil was investigated against ten bacterial isolates (from patients wounds and stools) and seven American Type Culture Collection strains using a microwell dilution assay. The minimal inhibitory/bactericidal concentration of the oil ranged from < 0.08 to 2.43 mg/mL and from 0.08 to 38.80 mg/mL, respectively. The antioxidant activity of the essential oil was evaluated using 2,2-diphenyl-1-picrylhydrazil and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical-scavenging methods and assessed as significant. Skin irritation potential and acute toxicity of the oil were also investigated. Results of the skin irritant reaction showed that none of the 30 volunteers developed a positive skin irritant reaction to undiluted A. absinthium essential oil. Acute oral exposure to the essential oil did not cause mortality in the treated mice, but it did cause neurological, muscle, and gastrointestinal problems. A subchronic toxicity test on Drosophila melanogaster showed that the essential oil of A. absinthium is toxic for developing insect larvae. Starting with the concentration of 0.38 % of essential oil in medium, significant mortality of larvae exposed to the oil was noted when compared to the control. Probit analysis revealed that the LC50 value of A. absinthium essential oil for D. melanogaster larvae after 15 days of exposure was 6.31 % (49 mg/mL). The essential oil also affected the development of D. melanogaster larvae and significantly delayed achievement of the pupa stadium.

No abstract

The objective of the present study to perform a comparative analysis of the chemical composition, antioxidant, and antimicrobial activities of the essential oils of plant species Hyssopus officinalis, Achillea grandifolia, Achillea crithmifolia, Tanacetum parthenium, Laserpitium latifolium, and Artemisia absinthium from Balkan Peninsula. The chemical analysis of essential oils was performed by using gas chromatography and gas chromatography-mass spectrometry. Monoterpenes were dominant among the recorded components, with camphor in T. parthenium, A. grandifolia, and A. crithmifolia (51.4, 45.4, and 25.4 %, respectively), 1,8-cineole in H. officinalis, A. grandifolia, and A. crithmifolia (49.1, 16.4, and 14.8 %, respectively), and sabinene in L. latifolium and A. absinthium (47.8 and 21.5 %). The antiradical and antioxidant activities were determined by using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging methods. The essential oil of A. grandifolia has shown the highest antioxidant activity [IC50 of 33.575 ± 0.069 mg/mL for 2,2-diphenyl-1-picrylhydrazyl and 2.510 ± 0.036 mg vitamin C/g for the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) assay]. The antimicrobial activity against 16 multiresistant pathogenic bacteria isolated from human source material was tested by the broth microdilution assay. The resulting minimum inhibitory concentration/minimum bactericidal concentration values ranged from 4.72 to 93.2 mg/mL. Therefore, the essential oils of the plant species included in this study may be considered to be prospective natural sources of antimicrobial substances, and may contribute as effective agents in the battle against bacterial multiresistance.

No abstract