Aims: In the present study, the chemical constituents, antimicrobial and larvicidal potentials of hydrodistilled essential oil from the rhizome of Zingiber zerumbet were evaluated.
Study Design: The study was designed in different phases which are: collection of mature rhizomes of Zingiber zerumbet, hydrodistillation of essential oils, chemical analysis of the essential oils, determination of the antimicrobial potential and evaluation of larvicidal activity.
Place and Duration of Study: The study was conducted at School of Natural Science, Vinh University, Vinh City, Nghệ An Province, Vietnam. The duration of the study was between August and December 2018.
Methodology: The rhizomes of Z. zerumbet were collected from Bến En National Park, Thanh Hóa Province, Vietnam, in August 2018. The air-dry sample was subjected to hydrodistillation process using Clevenger-apparatus to obtained essential oils. We evaluated the larvicidal potential of the oil against Culex quinquefasciatus and Aedes albopictus at 24 h and 48 h according to World Health Organisation protocol. The antimicrobial activity (MIC) was determined by microdilution broth susceptibility assay. Statistical analysis was performed using GraphPad Prism (version 7.02). The LC50 values, LC90 values and 95% confidence limits were obtained by using XLSTAT v. 2018.5.
Results: The most abundant compound of the essential oil was zerumbone (51.3%). The essential oil showed mortality of 98.3% (24 h) and 100% (48 h) against the Ae. albopictus at concentration of 100 µg/mL. In the same vein, mortality of 100% was displayed against Cx. quinquefasciatus under the tested time and concentration. The essential oil exhibited larvicidal activity towards Cx. quinquefasciatus showing minimum lethal concentrations, LC50, values of 33.28 mg/mL (24 h) and 21.81 mg/mL (48 h). The LC50 values of 55.75 µg/mL and 36.22 µg/mL at 24 h and 48 h respectively were obtained against Ae. albopictus. The result of the antimicrobial test indicated that Z. zerumbet oil inhibited the growth of Aspergillus niger (ATCC 9763) with MIC of 50.0 µg/mL.
Conclusion: Results demonstrated that the essential oil of Z. zerumbet was effective in the control of tested mosquitoes, Culex quinquefasciatus and Aedes albopictus and the microbe, Aspergillus niger.
Chemical Compositions of Crassocephalum crepidioides Essential Oils and Larvicidal Activities Against Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus
