• Toxicological Research
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• v.21 no.3
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• pp.249-253
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• 2005

The present study was carried out to investigate the skin irritation potential of lemon grass essential oil in rabbits. A volume of 0.5 ml of test article was applied to intact and abraded skins, respectively, for 24 h in 6 healthy male New Zealand White rabbits. Parameters measured during 72 h observation period were mortality, clinical signs, body weight changes, and local irritation. All rabbits showed severe edema at both 24 h and 72 h after the application of test article. These animals also showed very slight to severe erythema and/or slight eschar formation at both 24 h and 72 h. The edema and erythema induced by lemon grass essential oil were recovered on day 7 of additional 11-day recovery period, but the eschar formation was not recovered at the end of recovery period. On the other hands, there were no treatment-related adverse effects on clinical sign, body weight and gross finding in rabbits. Based on these results, it was concluded that a single dermal application of the undiluted lemon grass essential oil caused very slight to severe edema, erythema and eschar formation in rabbits and showed a primary irritation index score of 5.63 indicating severe irritation. The results of this study strongly suggest that lemon grass essential oil should be used with care and in highly diluted forms especially when directly applied to the skin.

• Journal of Life Science
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• v.23 no.5
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• pp.637-642
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• 2013

This study was performed to evaluate the rodent repellency and antimicrobial activity of natural oils. Thirteen natural essential oils were evaluated for repellent efficacy against rodent feed intake suppression activity. Salvia sclarea (sage), Cinnamomum zeylanicum (cinnamon) Cymbopogon citratus (lemon grass), and Syzygium aromaticum (clove) showed the best repellent efficacy among tested natural oils. Antimicrobial activity against Gram-negative (four strains) and Gram-positive (four strains) bacteria were evaluated using four natural oils, which showed high efficacy on the rodent repellent test. Syzygium aromaticum showed antimicrobial activity against all tested bacteria and Cymbopogon citratus, Cinnamonum zeylanicum, and Salvia sclarea showed antimicrobial activity against some tested bacteria.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.376-382
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• 2012

Environment-friendly agro-materials are are likely to be preferred to chemical insecticides recently. For this reason, many studies are conducted to develop environment-friendly insecticides containing natural materials. This study was also conducted so as to assess ecotoxicity for Emulsifiable concentrate (EC) containing 30% of garlic extract or two plant essential oils (Zanthoxylum, Lemongrass) expected to prevent from pests and be used for agro-materials. Target species used to assess acute toxicity were invertebrate (Daphina magna), fish (Oryzias latipes), honeybee (Apis mellifera L.) and earthworm (Eisenia fetida). The $EC_{50}$ values for of garlic extract 30% EC, Zanthoxylum oil 30% EC and lemongrass oil 30% EC to Daphina magna were 3.3, 10, and $10mg\;L^{-1}$, respectively. The category of garlic extract 30% EC was moderately toxic, while those of Zanthoxylum oil 30% EC and lemongrass oil 30% EC were slightly toxic according to standard of USEPA. $EC_{50}$ for both of Zanthoxylum oil 30% EC and lemongrass oil 30% EC were more than $10mg\;L^{-1}$ then they were considered as slightly toxicity. In case of acute toxicity test to fish, $LC_{50}$ of garlic extract 30% EC was $3.3mg\;L^{-1}$. Zanthoxylum oil 30% EC and lemongrass oil 30% EC indicated $LC_{50}$ > $10mg\;L^{-1}$. Classification of acute toxicity to all test substances was in Korea criteria. Acute contact and oral toxicity test to Honeybee were conducted. As a result, $LD_{50}$ of all test substances were more than 100 a.i. ${\mu}g\;bee^{-1}$ in the acute contact test while $LD_{50}$ of garlic extract 30% EC was 4.4 a.i. ${\mu}g\;bee^{-1}$ and $LD_{50}$ of Zanthoxylum oil 30% EC and lemongrass oil 30% EC were more than 100 a.i. ${\mu}g\;bee^{-1}$. In case of acute toxicity test to earthworm, $LC_{50}$ of garlic extract 30% EC, Zanthoxylum oil 30% EC and lemongrass oil 30% EC were 267, 592, and $430mg\;kg^{-1}$, respectively. In conclusion, if the safety for earthworm is confirmed, these substances are expected to be use for environment-friendly insecticide materials with low risk against ecosystem and contribute to developing environment-friendly agro-materials.