• Research in Plant Disease
• /
• v.12 no.1
• /
• pp.51-54
• /
• 2006

The effectiveness of four plant oils (garlic, ginger, cinnamon and lemongrass) against a range of plant pathogenic organisms was tested in vitro. Of the four oils, two oils (garlic and cinnamon) showed relatively good antimicrobial activities. Activity of garlic oil was shown against the plant pathogenic bacteria Agrobacterium tumefaciens, Ewinia carotovora, Ralstonia solanacearum, Xanthomonas campestris, and the fungi Phytophthora infestans, Fusarium oxysporum, Collectotricum sp., whereas Acidovorax avenae and Pythium sp. showed the resistance towards garlic oil. Results from the planta bioassays under greenhouse conditions indicated that garlic oil significantly reduced the cucumber powdery mildew (Sphaerotheca fusca) and tomato powdery mildew (Erysiphe cichoracearum) showing control value 70.0-74.6% and 71.2%, respectively.

• Journal of Food Hygiene and Safety
• /
• v.37 no.4
• /
• pp.285-295
• /
• 2022

The ability of volatile components of essential oils (EO) from cinnamon, clove, and lemongrass to inhibit biofilms formed on polyethylene and stainless steel by six types of food poisoning bacteria was investigated. The main components of cinnamon EO were identified as cinnamaldehyde (38.30%), linalool (9.61%), β-caryophyllene (8.90%), and 1,3,4-eugenol (8.19%). 1,3,4-Eugenol (61.84%) was the dominant component of clove EO. The major component of lemongrass EO was citral. Citral is a natural mixture of two isomeric acyclic monoterpene aldehydes: geranial (trans-citral, 19.11%) and neral (cis-citral, 19.23%). Among these major compounds, cinnamaldehyde, linalool, eugenol, and citral exhibited comparatively strong antimicrobial activity in the disc diffusion assay. Treatments with 0.1% eugenol and citral were highly effective on biofilm inhibition on both tested surfaces. Cinnamaldehyde (0.1%) was effective against biofilm formation by Listeria monocytogenes ATCC 19112 and Staphylococcus aureus KCCM 11812. These results suggested the potential of cinnamaldehyde, eugenol, and citral treatments in inhibiting the formation of biofilms by food poisoning bacteria.

• Weed & Turfgrass Science
• /
• v.4 no.4
• /
• pp.321-329
• /
• 2015

The present study aimed to evaluate the phytotoxic potential of essential oils. For this purpose, 18 essential oil samples extracted from Korean plants and 64 commercial essential oils were screened for their phytotoxic potential against the seedling growth of Brassica napus L. (rapeseed). Among the 82 samples, 11 commercial oils (cinnamon, citronella, clove, cumin seed, geranium, jasmine, lemongrass, palmarosa, pimento, rose otto and spearmint) strongly inhibited the seedling growth with $GR_{50}$ value < $150{\mu}g\;mL^{-1}$. Major components from these effective essential oils were identified by solid phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS). GC-MS analyses revealed that the effective samples mainly consist of benzyl benzoate, carvone, citral, citronellol, eugenol, geraniol, D-limonene and terpinene. Subsequently, bioactivity of these individual components was evaluated against the seedling growth of B. napus, Echinochloa crus-galli and Aeschynomene indica. The components from different chemical groups exhibited different potency in inhibiting the seedling growth with varied $GR_{50}$ values ranged from $29{\mu}g\;mL^{-1}$ to > $1000{\mu}g\;mL^{-1}$. In the greenhouse experiment, citral and geraniol completely suppressed the growth of all the tested 10 plants at $100kg\;ha^{-1}$. In conclusion, the individual essential oil components geraniol and citral could be used as natural herbicides for weed management.

• Journal of Applied Biological Chemistry
• /
• v.58 no.1
• /
• pp.61-64
• /
• 2015

As an edible coating, carnauba shellac wax (CSW) and lemongrass oil (LO) solution was prepared to extend the shelf life of 'Hongro' apples. During storage, there were significant differences in the populations of total aerobic bacteria, yeast, and molds between the coated apples and the control samples. The weight loss and vitamin C loss of apples coated with the CSW-LO solution were lower than those of the control. These results suggest that CSW-LO coating can be an effective method for improving quality of 'Hongro' apples.

• Parasites, Hosts and Diseases
• /
• v.59 no.5
• /
• pp.465-471
• /
• 2021

Culicoides biting midges (Diptera: Ceratopogonidae) are hematophagous arthropod vectors that transmit epizootic arthropod-borne viruses (arboviruses). Arboviruses are recognized as causes of pregnancy loss, encephalomyelitis, and congenital malformations in ruminants. Therefore, continuous monitoring and control of Culicoides, which causes significant damage to industrial animals are necessary. We performed attraction and repellent tests in Culicoides using various essential oils, cow dung, and carbon dioxide (CO₂). Culicoides tended to move more to cow dung (60.8%, P<0.0001) and CO₂ (63.8%, P<0.01). To the essential oils as repellents, 26.1% (P<0.0001), 18.7% (P<0.001), and 25.5% (P<0.01) of the Culicoides moved to the lavender, lemongrass, and eucalyptus chamber, respectively. The Culicoides that moved to the 3 essential oils chambers showed markedly low activity. Collectively, it was showed that Culicoides tended to be attractive to cow dung and CO₂, and repellent from the 3 essential oils.

• Journal of The Korean Society of Integrative Medicine
• /
• v.11 no.4
• /
• pp.73-82
• /
• 2023

Purpose : Cymbopogon citratus, also known as lemongrass, has widely spread around the world and its essential oil is usually applied in food, perfume, and other industrial purposes. In addition, C. citratus has also been used for the treatment of inflammation, digestive disorders, and diabetes in traditional medicine. In this study, the antioxidative activity of C. citratus ethanol extract (CCEE) was analyzed in RAW 264.7 cells through the induction of one of phase II enzymes, heme oxygenase (HO)-1 by nuclear factor-erythroid 2 p45-related factor (Nrf)2, mitogen-activated protein kinase (MAPK), and phosphoinositide 3-kinase (PI3K)/Akt. Methods : The antioxidative activity of CCEE against oxidative stress and its underlying molecular mechanisms were analyzed by the cell viability assay, intracellular reactive oxygen species (ROS) formation assay, and Western blot analysis in RAW 264.7 cells. Results : The results exhibited that CCEE potently attenuated tert-butyl hydroperoxide (t-BHP) induced intracellular ROS levels in a dose-dependent manner without any cytotoxicity. CCEE treatment significantly induced the expression of HO-1 which is known for its antioxidative capacity. In addition, CCEE treatment significantly upregulated the expression of Nrf2, a corresponding transcription factor for the regulation of antioxidative enzymes, which was in accordance with the HO-1 overexpression. MAPK and PI3K/Akt were also evaluated for their important roles in the regulation of cellular redox homeostasis against oxidative damage. As a result, the potent HO-1 expression was mediated by not extracellular regulated kinase (ERK), c-Jun NH2 terminal kinase (JNK), p38, but phosphoinositide 3-kinase (PI3K) phosphorylation. To confirm the antioxidative activity of CCEE-induced HO-1 expression, oxidative damage was initiated by t-BHP and attenuated by CCEE treatment, which was identified by HO-1 selective inhibitor and inducer. Conclusion : Consequently, CCEE potently induced the HO-1-mediated antioxidative potential through the modulation of Nrf2 and PI3K/Akt signaling pathways in RAW 264.7 cells. These results suggest that CCEE could be a promising strategy for the mitigation against cellular oxidative damage.