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Screening for adulticidal activity against Anopheles arabiensis in ten plants used as mosquito repellent in South Africa.

Mavundza EJ, Maharaj R, Chukwujekwu JC, Finnie JF, Van Staden J - Malar. J. (2014)

Bottom Line: Due to the development of resistance to synthetic insecticides, adverse effects to human health, non-target organisms and the environment, there is an urgent need to develop new insecticides, which are effective, safe, biodegrable and target-specific.The results of the present study showed that the DCM extract of A. ferox leaves may have the potential to be used as an insecticide against An. arabiensis.Further studies to isolate and identify active compounds are in progress.

View Article: PubMed Central - HTML - PubMed

Affiliation: Malaria Research Unit, Medical Research Council, 491 Peter Mokaba Ridge, Overport, Durban 4001, South Africa. edison.mavundza@mrc.ac.za.

ABSTRACT

Background: Due to the development of resistance to synthetic insecticides, adverse effects to human health, non-target organisms and the environment, there is an urgent need to develop new insecticides, which are effective, safe, biodegrable and target-specific. This study was undertaken to evaluate the adulticidal activity of 10 plants used traditionally as mosquito repellents in South Africa.

Methods: The dried plant materials were extracted with dichloromethane (DCM) and ethanol (EtOH). The extracts were evaluated for adulticidal activity against Anopheles arabiensis mosquitoes, a potent malaria vector in South Africa. Adult mortality was observed after 24 hours of exposure.

Results: All the extracts showed adulticidal activity. The highest activity was observed in both DCM and EtOH extracts of Aloe ferox leaves with 98 and 86% mosquito mortality, respectively. The DCM extract of A. ferox leaves was then subjected to a dose-dependent bioassay to determine the EC50 value. The extract exhibited an EC50 value of 4.92 mg/ml.

Conclusion: The results of the present study showed that the DCM extract of A. ferox leaves may have the potential to be used as an insecticide against An. arabiensis. Further studies to isolate and identify active compounds are in progress.

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Dose–response assay of DCM extract of A. ferox against An. arabiensis.
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Figure 2: Dose–response assay of DCM extract of A. ferox against An. arabiensis.

Mentions: Due to its high activity, the DCM extract of A. ferox leaves was then subjected to a dose-dependent bioassay to determine the EC50 value. The extract was tested at five concentrations ranging from 0.6 to 10 mg/ml. After 24 hours of exposure, mosquito mortality ranging from 5 to 100% was observed (Figure 2) and an EC50 value of 4.92 mg/ml was recorded. The activity of this extract may be due to various compounds, such as phenolics, terpenoids, and alkaloids that exist in plants, and they may jointly or individually contribute to the insecticidal, ovicidal, repellent and antifeeding activities against various insect species [34]. Aloe ferox has been reported to contain compounds such as chromones, anthraquinones, anthrones, anthone-C-glycosides [27]. Therefore, the observed adulticidal activity of the DCM extract of A. ferox leaves may be attributed to these compounds. The adulticidal activity of the DCM extract of A. ferox against An. arabiensis is reported for the first time in this study.


Screening for adulticidal activity against Anopheles arabiensis in ten plants used as mosquito repellent in South Africa.

Mavundza EJ, Maharaj R, Chukwujekwu JC, Finnie JF, Van Staden J - Malar. J. (2014)

Dose–response assay of DCM extract of A. ferox against An. arabiensis.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4016781&req=5

Figure 2: Dose–response assay of DCM extract of A. ferox against An. arabiensis.
Mentions: Due to its high activity, the DCM extract of A. ferox leaves was then subjected to a dose-dependent bioassay to determine the EC50 value. The extract was tested at five concentrations ranging from 0.6 to 10 mg/ml. After 24 hours of exposure, mosquito mortality ranging from 5 to 100% was observed (Figure 2) and an EC50 value of 4.92 mg/ml was recorded. The activity of this extract may be due to various compounds, such as phenolics, terpenoids, and alkaloids that exist in plants, and they may jointly or individually contribute to the insecticidal, ovicidal, repellent and antifeeding activities against various insect species [34]. Aloe ferox has been reported to contain compounds such as chromones, anthraquinones, anthrones, anthone-C-glycosides [27]. Therefore, the observed adulticidal activity of the DCM extract of A. ferox leaves may be attributed to these compounds. The adulticidal activity of the DCM extract of A. ferox against An. arabiensis is reported for the first time in this study.

Bottom Line: Due to the development of resistance to synthetic insecticides, adverse effects to human health, non-target organisms and the environment, there is an urgent need to develop new insecticides, which are effective, safe, biodegrable and target-specific.The results of the present study showed that the DCM extract of A. ferox leaves may have the potential to be used as an insecticide against An. arabiensis.Further studies to isolate and identify active compounds are in progress.

View Article: PubMed Central - HTML - PubMed

Affiliation: Malaria Research Unit, Medical Research Council, 491 Peter Mokaba Ridge, Overport, Durban 4001, South Africa. edison.mavundza@mrc.ac.za.

ABSTRACT

Background: Due to the development of resistance to synthetic insecticides, adverse effects to human health, non-target organisms and the environment, there is an urgent need to develop new insecticides, which are effective, safe, biodegrable and target-specific. This study was undertaken to evaluate the adulticidal activity of 10 plants used traditionally as mosquito repellents in South Africa.

Methods: The dried plant materials were extracted with dichloromethane (DCM) and ethanol (EtOH). The extracts were evaluated for adulticidal activity against Anopheles arabiensis mosquitoes, a potent malaria vector in South Africa. Adult mortality was observed after 24 hours of exposure.

Results: All the extracts showed adulticidal activity. The highest activity was observed in both DCM and EtOH extracts of Aloe ferox leaves with 98 and 86% mosquito mortality, respectively. The DCM extract of A. ferox leaves was then subjected to a dose-dependent bioassay to determine the EC50 value. The extract exhibited an EC50 value of 4.92 mg/ml.

Conclusion: The results of the present study showed that the DCM extract of A. ferox leaves may have the potential to be used as an insecticide against An. arabiensis. Further studies to isolate and identify active compounds are in progress.

Show MeSH
Related in: MedlinePlus