scholarly journals Toxicity of Ocimum basilicum and Ocimum gratissimum Extracts against Main Malaria Vector, Anopheles gambiae (Diptera: Culicidae) in Nigeria

Author(s):  
Kayode David Ileke ◽  
Jacobs Mobolade Adesina

  Background: Anopheles gambiae (Diptera: Culicidae) transmit malaria parasite that causes malaria fever in humans, causing millions of deaths every year among infants in tropical countries. This study was undertaken to assess the tox-icity of Ocimum basilicum and Ocimum gratissimum against pre-adult stages and adult malaria vector, An. gambiae and non-targeted aquatic organism, fingerlings of Clarias garipienus. Methods: Ethalonic extracts of O. basilicum and O. gratissimum were prepared according to the method described by WHO. The larvae and pupae of An. gambiae were exposed to plant extracts for 24h and their mortality was recorded. Toxicity of Ocimum species on non-targeted organism, fingerlings of C. garipienus was also investigated. Results: Ocimum basilicum showed remarkably potency against pre-adult stages and adults An. gambiae causing 100% mortality at 0.4% concentration within 24h of treatment. The LC50 and LC90 of O. basilicum were lower than O. gratti-simum in all stages of An. gambiae studied. Ocimum basilicum and O. gratissimum extracts significantly reduced the number of bites by the vector given a range of 72.25% to 81.75% protection. Ocimum species at the tested concentra-tions did not significantly reduce the number of fingerlings introduced. Conclusion: Ocimum species at the tested concentrations did not significantly reduce the numbers of non-targeted or-ganisms, fingerlings introduced. Therefore, O. basilicum and O. gratissimum

2014 ◽  
Vol 7 (1) ◽  
pp. 312 ◽  
Author(s):  
Sabina Wachira ◽  
Sabar Omar ◽  
Julia Jacob ◽  
Martin Wahome ◽  
Hans T Alborn ◽  
...  

Author(s):  
Daniel Edward Callies ◽  
Yasha Rohwer

Each year, over 200 million people are infected with the malaria parasite, nearly half a million of whom succumb to the disease. Emerging genetic technologies could, in theory, eliminate the burden of malaria throughout the world by intentionally eradicating the mosquitoes that transmit the disease. In this paper, we offer an ethical examination of the intentional eradication of Anopheles gambiae, the main malaria vector of sub-Saharan Africa. In our evaluation, we focus on two main considerations: the benefit of alleviating the malaria burden, and the loss of value that would accompany the eradication of the species. We outline a typology of the different ways in which species are valued or could be valuable, then use that typology to appraise the value of the species in question. We argue that Anopheles gambiae has minor (and redundant) instrumental value, little final subjective value and no objective final value.


2013 ◽  
Vol 31 (No. 2) ◽  
pp. 195-202 ◽  
Author(s):  
S. Saha ◽  
T.D. Dhar ◽  
C. Sengupta ◽  
P. Ghosh

The essential oils and methanol extracts of Ocimum basilicum L., Ocimum kilimandscharicum Guerke, Ocimum gratissimum L, Ocimum canum Sims, and Ocimum tenuiflorum L. (green type) were examined for their potential antibacterial activities. The chemical composition of essential oils of Ocimum species was analysed by GC-MS. The inhibitory effects of essential oils and methanol extracts were studied on two Gram-positive (Bacillus subtilis, Micrococcus luteus) and five Gram-negative (Pseudomonas aeruginosa, Shigella dysenteriae, Escherichia coli, Vibrio cholera, and Shigella flexneri) bacteria using disc-diffusion method. Minimum inhibitory concentration (MIC) was assessed by micro broth dilution method. The antibacterial test results showed that the essential oils of Ocimum basilicum L., Ocimum kilimandscharicum Guerke, and Ocimum gratissimum L. strongly inhibited the growth of all of the microorganisms studied, especially of the Gram-negative strains, whereas other two essential oils showed moderate activities. The result may suggest that the essential oils of Ocimum possess compounds with antibacterial activities, and therefore could be used as natural preservative ingredients in food and/or pharmaceutical industries.  


2018 ◽  
Vol 5 (10) ◽  
pp. 347-358
Author(s):  
Kayode David Ileke

Anopheles gambiae (Giles, 1902) and Culex quinquefasciatus (Say, 1832) mosquitoes are the main vectors of human malaria and lymphatic filariasis, respectively. This study aims to analyze the larvicidal, pupicidal and adulticidal properties of Monodora myristica (Dunal, 1831) and Conyza sumatrensis (Retzius, 1742-1821) extracts against An. gambiae and Cx. quinquefasciatus. The experiment was conducted in the laboratory at ambient temperature of 28 oC +/- 2 oC and 75% +/- 5% relative humidity. The results showed that M. myristica and C. sumatrensis extracts significantly affect all stages of An. gambiae and Cx. quinquefasciatus tested. The mosquitocidal toxicity of the two plant extracts is dosage dependent. Anti-larval activity of M. myristica at rate 500 mg/L and 1,000 mg/L caused 100% mortality of An. gambiae larvae while it evoked 80% and 100% mortality of Cx. quinquefasciatus larvae. The same trend of results were also obtained on the anti-pupal and adulticidal toxicity of M. myristica and C. sumatrensis extracts. As larvicides, pupicides and adulticides, the LC50s and LC90s, after 24 h varied across plant extracts and mosquito species. C. sumatrensis attained LC50 and LC90 at higher concentration than M. myristica. On An. gambiae larvae, the LC50s after 24 h, varied from 86.95 mg/L (M. myristica) to 131.73 mg/L (C. sumatrensis). Similarly, the LC90s after 24 h on An. gambiae larvae, varied from 278.39 mg/L (M. myristica) to 131.73 mg/L (C. sumatrensis). For Cx. quinquefasciatus larvae, the LC50s after 24 h, varied from 391.41 mg/L (M. myristica) to 898.20 mg/L (C. sumatrensis). The seed extract of M. myristica exerted the best pupicidal activity among the two tested extracts with LC50 and LC90 values of 140.61 mg/L and 520.35 mg/L on An. gambiae, respectively, followed by leaf of C. sumatrensis with LC50 and LC90 values of 157.59 mg/L and 781.86 mg/L on An. gambiae, respectively. More concentrations were require to achieve 50% and 90% death of Cx. quinquefasciatus pupae. On adulticidal activity, seed of M. myristica exerted LC50 and LC90 values of 122.79 mg/L and 502.99 mg/L on An. gambiae, respectively, followed by leaf of C. sumatrensis with LC50 and LC90 values of 215.05 mg/L and 981.25 mg/L on An. gambiae, respectively. More concentrations were require to achieve 50% and 90% death of Cx. quinquefasciatus adults. The two tested plants can be integrated into pest management programmes to combat human malaria and lymphatic filariasis vectors breeding site in Nigeria. I recommend formulation of M. myristica seeds which have the lowest LC50 and LC90 after 24 h of exposure for field evaluation.


PLoS ONE ◽  
2013 ◽  
Vol 8 (12) ◽  
pp. e82103 ◽  
Author(s):  
Emilie Deletre ◽  
Thibaud Martin ◽  
Pascal Campagne ◽  
Denis Bourguet ◽  
Andy Cadin ◽  
...  

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Melina Campos ◽  
Luisa D. P. Rona ◽  
Katie Willis ◽  
George K. Christophides ◽  
Robert M. MacCallum

Abstract Background Whole genome re-sequencing provides powerful data for population genomic studies, allowing robust inferences of population structure, gene flow and evolutionary history. For the major malaria vector in Africa, Anopheles gambiae, other genetic aspects such as selection and adaptation are also important. In the present study, we explore population genetic variation from genome-wide sequencing of 765 An. gambiae and An. coluzzii specimens collected from across Africa. We used t-SNE, a recently popularized dimensionality reduction method, to create a 2D-map of An. gambiae and An. coluzzii genes that reflect their population structure similarities. Results The map allows intuitive navigation among genes distributed throughout the so-called “mainland” and numerous surrounding “island-like” gene clusters. These gene clusters of various sizes correspond predominantly to low recombination genomic regions such as inversions and centromeres, and also to recent selective sweeps. Because this mosquito species complex has been studied extensively, we were able to support our interpretations with previously published findings. Several novel observations and hypotheses are also made, including selective sweeps and a multi-locus selection event in Guinea-Bissau, a known intense hybridization zone between An. gambiae and An. coluzzii. Conclusions Our results present a rich dataset that could be utilized in functional investigations aiming to shed light onto An. gambiae s.l genome evolution and eventual speciation. In addition, the methodology presented here can be used to further characterize other species not so well studied as An. gambiae, shortening the time required to progress from field sampling to the identification of genes and genomic regions under unique evolutionary processes.


2016 ◽  
Vol 15 (1) ◽  
Author(s):  
Emmanuel Hakizimana ◽  
Corine Karema ◽  
Dunia Munyakanage ◽  
Gad Iranzi ◽  
John Githure ◽  
...  

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