This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with... more
This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/authorsrights
Overcoming the phenomenon of insecticides resistance in malaria vectors in Sub-Saharan tropics remains a great challenge to stop the burden of malaria disease. We tested the efficacy of Zingiber officinale as an alternative insecticide to... more
Overcoming the phenomenon of insecticides resistance in malaria vectors in Sub-Saharan tropics remains a great challenge to stop the burden of malaria disease. We tested the efficacy of Zingiber officinale as an alternative insecticide to synthetic pesticides and as a vector control tool against Anopheles coluzzii, the main malaria vector in Cameroon. The biotoxicity of Z. officinale essential oil on aquatic stages of An. coluzzii was assessed using WHO guidelines, and the essential oil active compounds were identified using Gas Chromatography coupling Mass Spectrometry (GC-MS). The essential oil of Z. officinale revealed an ovicidal and larvicidal property against developmental stages of An. coluzzii. A median inhibitory concentration (IC50) of 17.81 ppm was obtained for eggs hatching potentials, while LC50 of 12.20, 12.12, 12.77 and 13.67 were obtained after exposure to first, second, third and fourth instars larvae respectively. All larval stages exhibited similar and full susceptibility to Z. officinale essential oil at 25 ppm. Overall, the essential oil extraction yield was 0.301% and 26 compounds were identified from their retention indices and mass spectra. Hydrocarbon monoterpenes (24.52%), oxygenated monoterpenes (44.93%) and hydrocarbon sesquiterpenes (30.54%) constituted the major classes of the essential oil. β-curcumene (15.24%), geranial (15.16%), camphene (13.79%), neral (11.88%) and α-zingiberene (6.18%) were the most abundant oil compounds. In summary, Z. officinale essential oil revealed important ovicidal and larvicidal properties and stands as a promising tool to manage the phenomenon of insecticides resistant vectors in malaria endemic regions.
Context: The blowfly Chrysomya putoria is widely distributed throughout the Neotropical region and, besides transmitting pathogens; they could cause secondary myiasis. Botanical insecticides provide an alternative to synthetic pesticides... more
Context: The blowfly Chrysomya putoria is widely distributed throughout the Neotropical region and, besides transmitting pathogens; they could cause secondary myiasis. Botanical insecticides provide an alternative to synthetic pesticides because the excessive use of synthetic insecticides resulted in a progressive resistance of the pests to these chemicals, diminishing their effectiveness and generating consequences with negative environmental impact. The essential oil extracted from Ocimum sanctum (basil) has showed insecticidal activity against some insects but has no reported studies on the activity of this plant against flies.
Aims: To evaluate the insecticidal effects of Ocimum sanctum var. cubensis Gomes essential oil on the post embryonic development of Chrysomya putoria.
Methods: The colonies of Chrysomya putoria were established and maintained at the Laboratório de Entomologia Médica e Forense (FIOCRUZ), Rio de Janeiro, Brazil. The basil essential oil was tested in six concentrations (4.13, 8.25, 20.63, 41.25, 61.87 and 80,25 mg/mL). Mortality and changes in life cycle were recorded daily.
Results: β-caryophyllene, β-selinene and eugenol, were the main constituents of the basil essential oil. The experiments demonstrated that in all concentrations tested, this essential oil shortening the duration of all post embryonic stages having a direct impact in the viability of this fly estimating the LC50 in 7.47 mg/mL of concentration. In addition, the essential oil caused morphological alterations in abdomen, wings and ptilinum at lower concentrations.
Conclusions: This essential oil emerge as a good option for the control of the disease vector blowfly Chrysomya putoria.
The composition of the essential oil (EO) obtained by hydro distillation from dry leaves of Heliotropium stenophyllum (Heliotropiaceae) was analyzed using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The... more
The composition of the essential oil (EO) obtained by hydro distillation from dry leaves of Heliotropium stenophyllum (Heliotropiaceae) was analyzed using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The insecticidal activity of the oil against the house fly Musca domestica was evaluated and the dose necessary to kill 50% of flies (LC50) in 2 h was determined at 25 ± 1 °C. The essential oil from Heliotropium stenophyllum showed potent insecticidal properties (LC50 = 1.09 mg/dm3) in comparison with other essential oils, in which at shorter times, the same bio-assay was used. According to GC and GC/MS analysis, junenol (19.08%); longiborneol (9.34%); (E, Z)-geranyl linalool (6.81%); selina-3,11-dien-6-α-ol (6.70%); α-cedrene epoxide (6.60%); heliofolen-12-al D (6.23%) and β-epi-bisabolol (4.83%) were the principal components of the EO. The Heliotropium stenophyllum essential oil, made up exclusively of sesquiterpenes, showed a composition very different from the EOs of the other species of Heliotropium, studied, and present a great potential as a natural insecticide against houseflies.
Context: The blowfly Chrysomya putoria is widely distributed throughout the Neotropical region and, besides transmitting pathogens; they could cause secondary myiasis. Botanical insecticides provide an alternative to synthetic pesticides... more
Context: The blowfly Chrysomya putoria is widely distributed throughout the Neotropical region and, besides transmitting pathogens; they could cause secondary myiasis. Botanical insecticides provide an alternative to synthetic pesticides because the excessive use of synthetic insecticides resulted in a progressive resistance of the pests to these chemicals, diminishing their effectiveness and generating consequences with negative environmental impact. The essential oil extracted from Ocimum sanctum (basil) has showed insecticidal activity against some insects but has no reported studies on the activity of this plant against flies. Aims: To evaluate the insecticidal effects of Ocimum sanctum var. cubensis Gomes essential oil on the post embryonic development of Chrysomya putoria. Methods: The colonies of Chrysomya putoria were established and maintained at the Laboratório de Entomologia Médica e Forense (FIOCRUZ), Rio de Janeiro, Brazil. The basil essential oil was tested in six conc...
Background: Plant-based traditional system of medicine continues to play an important role in healthcare. In order to find new potent source of bioactive molecules, we studied the cytotoxic activity of the essential oils from the flowers... more
Background: Plant-based traditional system of medicine continues to play an important role in healthcare. In order to find new potent source of bioactive molecules, we studied the cytotoxic activity of the essential oils from the flowers and leaves of Callistemon citrinus. This is the first report on anticancer potential of essential oils of C. citrinus.
Methods Cytotoxicity of essential oil was evaluated using sulfo-rhodamine B (SRB) assay against human lung carcinoma (A549), rat glioma (C-6), human colon cancer (Colo-205) and human cervical cancer (SiHa) cells. Apoptosis induction was evaluated by caspase-3/7 activity which was further confirmed by western blotting. Percentage cell apoptosis was determined by Annexin V based dead cell assay followed by DNA content as cell cycle analysis against A549 and C-6 cells. While 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to check the toxicity against normal human peripheral blood mononuclear cells (PBMCs), the immunomodulatory activity on mouse splenocytes was evaluated using SRB assay.
Results The GC and GC-MS analysis of these essential oils revealed high content of α-pinene (32.3%), limonene (13.1%) and α-terpineol (14.6%) in leaf sample, whereas the flower oil was dominated by 1,8-cineole (36.6%) followed by α-pinene (29.7%). The leaf oil contained higher amount of monoterpene hydrocarbons (52.1%) and sesquiterpenoids (14%) as compared to flower oil (44.6% and 1.2%, respectively). However, the flower oil was predominant in oxygenated monoterpenes (43.5%). Although both leaf and flower oils showed highest cytotoxicity on A549 cells (61.4%±5.0 and 66.7%±2.2, respectively), only 100 μg/mL flower oil was significantly active against C-6 cells (69.1%±3.1). Interestingly, no toxicity was recorded on normal cells.
Conclusion Higher concentration of 1,8-cineole and/or synergistic effect of the overall composition were probably responsible for the efficacy of flower and leaf oils against the tested cells. These oils may form potential source of natural anti-cancer compounds and play important role in human health.
