Antibacterial and Antifungal Effects of Essential Oils from Coniferous Trees

Abstract

Essential oils are generally not only antibiotic and anticarcinogenic, 1,2) but also have a sedative effect on stress. It has been shown that these essential oils contain ketone, terpene, and phenolic ether for sedation.3) Although essential oils have been regarded as useful sedatives, 4) there is little information on the antimicrobial or antifungal activities of essential oils extracted from coniferous trees. Essential oils with antimicrobial properties from medicinal as well as other edible plants have been recognized since antiquity.2) In addition, essential oils are used as food flavoring agents, and have a broad spectrum of in vitro antimicrobial activities attributed to the high content of phenolic derivatives. 5) More recently, plant extracts have been developed and proposed for use in foods as natural antioxidants. 6) In the present study, we investigated the antimicrobial and antifungal activities of several essential oils extracted from the coniferous trees Pinus densiflora, Pinus koraiensis, and Chamaecyparis obtusa against bacteria and fungi that commonly cause foot rot and other diseases. The essential oils were quantified using gas chromatography (GC) and identified in gas chromatography-mass spectrometric (GC-MS) analysis. In addition, the antibacterial effects against grampositive and gram-negative bacteria and antifungal effects against fungi were assayed using essential oils distilled from the needles of coniferous trees. MATERIALS AND METHODS Essential Oil ExtractionThe needles of the Japanese red pine (P. densiflora), Korean pine (P. koraiensis), and Japanese cypress (C. obtusa) were collected at the Reforestation Experiment Site of Chungbu Forest Experiment Station, Gyeonggi province, Korea. The essential oil from freshly cut needles of each species was obtained by steam distillation using a manufactured apparatus with a condenser. Distillation continued for 2-3 h at 100°C, and the volatile compounds containing the water-soluble fraction were allowed to settle for 20 min. The essential oil layer was separated and finally purified through a microfiltering and dehydration process.Measurement of Refractive Index The refractive index of chemical compounds is considered important because it indicates characteristic physical properties. We determined the index of the oils using an Abbe refractometer equipped with a sodium lamp (Bausch & Lomb, GD8804, U.S.A.).Quantification and Identification Each essential oil compound was quantified using a gas chromatograph (GC, Shimadzu GC-14A, Japan) equipped with a Shimadzu CPB-20 capillary column (0.2 mm inner diameterϫ50 m length). First, the calibration curves for several standard essential oils were obtained, and the calibration equation of each compound was used for quantification. GC analysis was carried out using helium carrier gas with an FID detector, and the injection and detection temperatures were 150 and 200°C, respectively. The oven temperature was increased from 50 to 200°C at intervals of 2°C/min over 75 min. Some other essential oils were id...

Literature-Related Discovery (LRD)

“…(2004). [35] Srinivasan P., Libbus B. and Sehgal A. K. Mining MEDLINE: Postulating a beneficial role for curcumin longa in retinal diseases. HLT Biolink.…”

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“…The higher the score, the stronger the recommendation made by the system. The 'A' MeSH terms within each semantic type are ranked by combined weight.In the initial paper [33] and subsequent publications [34,35], using the technique above, the authors start with curcumin and look for ailments this substance could potentially benefit. Three ailments identified are "retinal pathologies including diabetic retinopathies, ocular inflammation and glaucoma", Crohn's Disease /Ulcerative Colitis (both members of Irritable Bowel Syndrome), and EAE/Multiple Sclerosis.…”

“…A rise or a fall in cell hydration resulted in a decrease in cell deformability ….. Maximal arm blood flow was reduced by nearly 50% in hypohydration. [34,35] By far, the highest frequency concept was fish oil and its constituents, and there were many articles on the different expressions of fish/ fish oil (e.g., fish oil, marine oil, herring oil, sardine oil, mixed fish, seafood, mackerel, menhaden, cod liver oil, etc). Very few of these articles are displayed in the table above.…”

Active antifungal substances from natural sources

“…was also reported. 81 The oil had antifungal effects and the main component was bornyl acetate. Examples of other antifungal essential oils from the Cupressaceae family also included Juniperus comunis L. essential oil which was active against the dermatophyte Aspergillus and Candida strains.…”