Addition of a surfactant to water increases the acaricidal activity of extracts of some plant species used to control ticks by Zimbabwean smallholder farmers

Abstract Background Many studies have revealed that bioactive compounds for different indications are not extracted from plants with water, the only extractant practically available to rural communities. We compared the acaricidal activity of acetone extracts of 13 species used traditionally to prot...

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Main Authors: Emmanuel T. Nyahangare, Brighton M. Mvumi, Lyndy J. McGaw, Jacobus N. Eloff
Format: Article
Language:English
Published: BMC 2019-11-01
Series:BMC Veterinary Research
Subjects:
Online Access:http://link.springer.com/article/10.1186/s12917-019-2078-3
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spelling doaj-2852c47f89aa4143a0aa7175a2ed6de82020-11-25T04:07:22ZengBMCBMC Veterinary Research1746-61482019-11-011511710.1186/s12917-019-2078-3Addition of a surfactant to water increases the acaricidal activity of extracts of some plant species used to control ticks by Zimbabwean smallholder farmersEmmanuel T. Nyahangare0Brighton M. Mvumi1Lyndy J. McGaw2Jacobus N. Eloff3Department of Animal Science, Faculty of Agriculture, University of ZimbabweDepartment of Soil Science & Agricultural Engineering, Faculty of Agriculture, University of ZimbabwePhytomedicine Programme, Faculty of Veterinary Science, University of PretoriaPhytomedicine Programme, Faculty of Veterinary Science, University of PretoriaAbstract Background Many studies have revealed that bioactive compounds for different indications are not extracted from plants with water, the only extractant practically available to rural communities. We compared the acaricidal activity of acetone extracts of 13 species used traditionally to protect cattle against ticks. We also investigated if the extraction of biologically active compounds against Rhipicephalus (Boophilus) decoloratus ticks could be enhanced by adding a liquid soap that is locally available to smallholder farmers. Methods A total of 13 plant species selected based on reported traditional use in Zimbabwe, were dried and finely ground before extraction with water, or water plus a surfactant, or acetone. The adapted Shaw Larval Immersion Test (SLIT) method was used to determine the activity of acetone and crude water extracts with or without liquid soap against the tick larvae. The activity of four fractions of crude acetone extracts (extracted using solvents of different polarity), of the most active plant species, Maerua edulis (tuber and leaf) was also compared to identify the most active fraction. Results Aqueous plant extracts were not toxic to ticks, but the addition of 1% liquid soap as a surfactant increased mortality of the R. (B) decoloratus larvae significantly. With the Maerua edulis tuber extract, the efficacy of the 1% liquid soap was comparable to that of the amitraz based commercial synthetic acaricide. The use of acetone as an extractant, also increased the mortality of the tick larvae in all the plant species. With M. edulis (tuber and leaf), Monadenium lugardae and Kleinia sp. acetone extracts, the activity was comparable to that of the positive control (a commercially available amitraz-based synthetic acaricide). The non-polar fractions of the acetone extract of leaf and tuber of M. edulis caused up to 100% mortality. This indicates that non-polar to intermediate polarity compounds are responsible for the acaricidal activity. Conclusion Organic solvents such as acetone extracted active compounds but water did not. By adding commonly available dishwashing soap to water active compounds were extracted leading to a high acaricidal activity of the plant extracts. In some cases, it was as active as non-polar extracts and a synthetic commercial acaricide (positive control). This approach makes it possible for the smallholder farmers and traditional healers to extract biologically active compounds from plants by using water.http://link.springer.com/article/10.1186/s12917-019-2078-3Water extractsAcetoneSolvent-solvent fractionationCattle tickSLIT bioassayTick larvae mortality
collection DOAJ
language English
format Article
sources DOAJ
author Emmanuel T. Nyahangare
Brighton M. Mvumi
Lyndy J. McGaw
Jacobus N. Eloff
spellingShingle Emmanuel T. Nyahangare
Brighton M. Mvumi
Lyndy J. McGaw
Jacobus N. Eloff
Addition of a surfactant to water increases the acaricidal activity of extracts of some plant species used to control ticks by Zimbabwean smallholder farmers
BMC Veterinary Research
Water extracts
Acetone
Solvent-solvent fractionation
Cattle tick
SLIT bioassay
Tick larvae mortality
author_facet Emmanuel T. Nyahangare
Brighton M. Mvumi
Lyndy J. McGaw
Jacobus N. Eloff
author_sort Emmanuel T. Nyahangare
title Addition of a surfactant to water increases the acaricidal activity of extracts of some plant species used to control ticks by Zimbabwean smallholder farmers
title_short Addition of a surfactant to water increases the acaricidal activity of extracts of some plant species used to control ticks by Zimbabwean smallholder farmers
title_full Addition of a surfactant to water increases the acaricidal activity of extracts of some plant species used to control ticks by Zimbabwean smallholder farmers
title_fullStr Addition of a surfactant to water increases the acaricidal activity of extracts of some plant species used to control ticks by Zimbabwean smallholder farmers
title_full_unstemmed Addition of a surfactant to water increases the acaricidal activity of extracts of some plant species used to control ticks by Zimbabwean smallholder farmers
title_sort addition of a surfactant to water increases the acaricidal activity of extracts of some plant species used to control ticks by zimbabwean smallholder farmers
publisher BMC
series BMC Veterinary Research
issn 1746-6148
publishDate 2019-11-01
description Abstract Background Many studies have revealed that bioactive compounds for different indications are not extracted from plants with water, the only extractant practically available to rural communities. We compared the acaricidal activity of acetone extracts of 13 species used traditionally to protect cattle against ticks. We also investigated if the extraction of biologically active compounds against Rhipicephalus (Boophilus) decoloratus ticks could be enhanced by adding a liquid soap that is locally available to smallholder farmers. Methods A total of 13 plant species selected based on reported traditional use in Zimbabwe, were dried and finely ground before extraction with water, or water plus a surfactant, or acetone. The adapted Shaw Larval Immersion Test (SLIT) method was used to determine the activity of acetone and crude water extracts with or without liquid soap against the tick larvae. The activity of four fractions of crude acetone extracts (extracted using solvents of different polarity), of the most active plant species, Maerua edulis (tuber and leaf) was also compared to identify the most active fraction. Results Aqueous plant extracts were not toxic to ticks, but the addition of 1% liquid soap as a surfactant increased mortality of the R. (B) decoloratus larvae significantly. With the Maerua edulis tuber extract, the efficacy of the 1% liquid soap was comparable to that of the amitraz based commercial synthetic acaricide. The use of acetone as an extractant, also increased the mortality of the tick larvae in all the plant species. With M. edulis (tuber and leaf), Monadenium lugardae and Kleinia sp. acetone extracts, the activity was comparable to that of the positive control (a commercially available amitraz-based synthetic acaricide). The non-polar fractions of the acetone extract of leaf and tuber of M. edulis caused up to 100% mortality. This indicates that non-polar to intermediate polarity compounds are responsible for the acaricidal activity. Conclusion Organic solvents such as acetone extracted active compounds but water did not. By adding commonly available dishwashing soap to water active compounds were extracted leading to a high acaricidal activity of the plant extracts. In some cases, it was as active as non-polar extracts and a synthetic commercial acaricide (positive control). This approach makes it possible for the smallholder farmers and traditional healers to extract biologically active compounds from plants by using water.
topic Water extracts
Acetone
Solvent-solvent fractionation
Cattle tick
SLIT bioassay
Tick larvae mortality
url http://link.springer.com/article/10.1186/s12917-019-2078-3
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