Hsiang-Ting Huang1, Chien-Chung Lin2, Tai-Chih Kuo3, Shiang-Jiuun Chen4, Rong-Nan Huang5. 1. Department of Entomology and Research Center for Plant Medicine, College of Bioresources and Agriculture, National Taiwan University, Taipei, 10617, Taiwan. 2. Department of Orthopedic Surgery, Taipei City Hospital, Taipei, 100, Taiwan. 3. Department of Biochemistry, Taipei Medical University, 250 Wu-Hsing Street, Taipei, 110, Taiwan. 4. Department of Life Science, College of Life Science, National Taiwan University, Taipei, 106, Taiwan. 5. Department of Entomology and Research Center for Plant Medicine, College of Bioresources and Agriculture, National Taiwan University, Taipei, 10617, Taiwan. rongent@ntu.edu.tw.
Abstract
MAIN CONCLUSION: The essential oils (EOs) of Plectranthus amboinicus showed the highest larvicidal activity among four herbal plants studied and β-caryophyllene might be the major component responsible for its differential toxicity to the larvae of Culex quinquefasciatus and Aedes Aegypti. Mosquitoes act as vectors for many life-threatening diseases, including malaria, dengue fever, and Zika virus infection. Management of mosquitoes mainly relies on synthetic insecticides, which usually result in the rapid development of resistance; therefore, alternative mosquito control strategies are urgently needed. This study characterized the major component of essential oils (EOs) derived from the vegetative parts of four herbal plants and their larvicidal activity toward important mosquito vectors. The EOs were extracted by hydro-distillation and subjected to gas chromatography-mass spectrometry (GC-MS) analysis and a larvicidal activity assay toward Aedes aegypti, Ae. albopictus and Culex quinquefasciatus. In total, 14, 11, 11 and 9 compounds were identified from the EOs of Plectranthus amboinicus, Mentha requienii, Vitex rotundifolia and Crossostephium chinense, respectively. The EOs derived from four herbal plants exhibited remarkable larvicidal activity against the three mosquito species. In particular, the EOs of P. amboinicus showed the highest larvicidal activity, and the larvae of Cx. quinquefasciatus were more sensitive to the P. amboinicus EOs than that of Ae. Aegypti. Although carvacrol (61.53%) was the predominant constituent of the P. amboinicus EOs, its precursors, γ-terpinene (8.51%) and p-cymene (9.42%), exhibited the most larvicidal activity toward Ae. aegypti and Cx. quinquefasciatus. However, β-caryophyllene (12.79%) might be the major component responsible for the differential toxicity of the P. amboinicus EOs, as indicated by the significant differences in its LC50 values toward both mosquitoes. Information from these studies will benefit the incorporation of EOs into integrated vector management.
MAIN CONCLUSION: The essential oils (EOs) of Plectranthus amboinicus showed the highest larvicidal activity among four herbal plants studied and β-caryophyllene might be the major component responsible for its differential toxicity to the larvae of Culex quinquefasciatus and Aedes Aegypti. Mosquitoes act as vectors for many life-threatening diseases, including malaria, dengue fever, and Zika virus infection. Management of mosquitoes mainly relies on synthetic insecticides, which usually result in the rapid development of resistance; therefore, alternative mosquito control strategies are urgently needed. This study characterized the major component of essential oils (EOs) derived from the vegetative parts of four herbal plants and their larvicidal activity toward important mosquito vectors. The EOs were extracted by hydro-distillation and subjected to gas chromatography-mass spectrometry (GC-MS) analysis and a larvicidal activity assay toward Aedes aegypti, Ae. albopictus and Culex quinquefasciatus. In total, 14, 11, 11 and 9 compounds were identified from the EOs of Plectranthus amboinicus, Mentha requienii, Vitex rotundifolia and Crossostephium chinense, respectively. The EOs derived from four herbal plants exhibited remarkable larvicidal activity against the three mosquito species. In particular, the EOs of P. amboinicus showed the highest larvicidal activity, and the larvae of Cx. quinquefasciatus were more sensitive to the P. amboinicus EOs than that of Ae. Aegypti. Although carvacrol (61.53%) was the predominant constituent of the P. amboinicus EOs, its precursors, γ-terpinene (8.51%) and p-cymene (9.42%), exhibited the most larvicidal activity toward Ae. aegypti and Cx. quinquefasciatus. However, β-caryophyllene (12.79%) might be the major component responsible for the differential toxicity of the P. amboinicus EOs, as indicated by the significant differences in its LC50 values toward both mosquitoes. Information from these studies will benefit the incorporation of EOs into integrated vector management.
Authors: Kai Liu; Paul-Georges Rossi; Bernard Ferrari; Liliane Berti; Joseph Casanova; Félix Tomi Journal: Phytochemistry Date: 2007-06-04 Impact factor: 4.072