Search

Abstract In this paper, the chemical constituents, larvicidal and antimicrobial activities of hydrodistilled essential oils from Zingiber castaneum Škorničk. & Q.B. Nguyễn and Zingiber nitens M.F. Newman were reported. The main constituents of Z. castaneum leaf were bicyclogermacrene (24.8%), germacrene D (12.9%), cis-β-elemene (11.2%) and β-pinene (10.3%), while sabinene (22.9%) and camphene (21.2%) were the significant compounds in the rhizome. However, the dominant compounds in the leaf of Z. nitens includes β-pinene (45.8%) and α-pinene (10.7%). Terpinen-4-ol (77.9%) was the most abundant compound of the rhizome. Z. castaneum rhizome oil displayed larvicidal activity against Aedes aegypti and Culex quinquefasciatus with LC50 values of 121.43 and 88.86 µg/mL, respectively, at 24 h. The leaf oil exhibited activity with LC50 values of 39.30 µg/mL and 84.97 µg/mL, respectively. Also, the leaf and rhizome oils of Z. nitens displayed greater larvicidal action towards Ae. aegypti with LC50 values of 17.58 µg/mL and 29.60 µg/mL, respectively. Only the rhizome oil displayed toxicity against Cx. quinquefasciatus with LC50 value of 64.18 µg/mL. All the studied essential oils inhibited the growth of Pseudomonas aeruginosa ATCC25923 with minimum inhibitory concentration (MIC) value of 50.0 µg/mL. This paper provides information on the larvicidal and antimicrobial potentials of Z. castaneum and Z. nitens essential oils.

Abstract Herein the chemical constituents and the anti-pain properties of the essential oil from the stem bark of Casuarina equisetifolia L. (Casuarinaceae) grown in Nigeria were evaluated. The essential oil was obtained by hydrodistillation method in an all glass Clevenger-type apparatus, and characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The hot plate method was used to determine the anti-nociceptive property whereas the anti-inflammatory activity was evaluated by carrageenan-induced and formalin experimental models. The pale-yellow essential oil was obtained in yield of 0.21% (v/w), calculated on a dry weight basis. The main constituents of the essential oil were methyl salicylate (30.4%), a-zingiberene (15.5%), (E)-anethole (9.5%), b-bisabolene (8.6%), b- sesquiphellandrene (6.9%), and ar-curcumene (6.2%). In the anti-nociceptive study, the rate of inhibition increases as the doses of essential oil increases with optimum activity at the 30th and 60th min for all tested doses. The essential oil displayed anti-nociceptive activity independently of reaction time at the highest tested dose (200 mg/kg). The essential oil of C. equisetifolia moderately reduced pain responses in early and late phases of the formalin test. The oil inhibited the paw licking in the neurogenic phase (60-63%) compared to the late phase of the formalin test. The carrageenan- induced oedema model revealed the suppression of inflammatory mediators within the 1st - 3rd h. Thus, C. equisetifolia essential oil displayed both anti-nociceptive and anti-inflammatory activities independent of the dose tested. The anti-inflammatory and anti-nociceptive activities of C. equisetifolia essential oil are herein reported for the first time.

Mosquito-borne diseases are a large problem in Vietnam as elsewhere. Due to environmental concerns regarding the use of synthetic insecticides as well as developing insecticidal resistance, there is a need for environmentally-benign alternative mosquito control agents. In addition, resistance of pathogenic microorganisms to antibiotics is an increasing problem. As part of a program to identify essential oils as alternative larvicidal and antimicrobial agents, the leaf, stem, and rhizome essential oils of several Zingiber species, obtained from wild-growing specimens in northern Vietnam, were acquired by hydrodistillation and investigated using gas chromatography. The mosquito larvicidal activities of the essential oils were assessed against Culex quinquefasciatus, Aedes albopictus, and Ae. aegypti, and for antibacterial activity against a selection of Gram-positive and Gram-negative bacteria, and for activity against Candida albicans. Zingiber essential oils rich in α-pinene and β-pinene showed the best larvicidal activity. Zingiber nudicarpum rhizome essential oil showed excellent antibacterial activity against Enterococcus faecalis, Staphylococcus aureus, and Bacillus cereus, with minimum inhibitory concentrations (MIC) of 2, 8, and 1 μg/mL, respectively. However, the major components, α-pinene and β-pinene, cannot explain the antibacterial activities obtained.

Copyright of Boletín Latinoamericano y del Caribe de Plantas Medicinales y Aromáticas is the property of Universidad de Santiago de Chile and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)