In Vitro Acaricidal Activity of Selected Medicinal Plants Traditionally Used against Ticks in Eastern Ethiopia

Abstract

A study was carried out to evaluate the acaricidal activities of crude methanolic extract of leaves of six medicinal plants, namely, Vernonia amygdalina, Calpurnia aurea, Schinus molle, Ricinus communis, Croton macrostachyus, and Nicotiana tabacum, against Rhipicephalus (Boophilus) decoloratus and Rhipicephalus pulchellus using an in vitro adult immersion test. Five graded concentrations of the crude extracts, 6.25, 12.5, 25, 50, and 100 mg/ml, were tested at different time intervals, and temporal changes in tick viability were recorded for 24 hours. Diazinon (0.1%) and distilled water were used as positive and negative controls, respectively. Standard procedures were applied to screen the phytochemical constituents of the tested plant parts. Phytochemical screening showed the presence of a condensed amount of tannins in all extracts. Starting from 30 min post exposure, the 100 mg/ml concentration of C. aurea and R. communis extracts has caused significantly higher mortality (P<0.05) compared to the diazinon. A significant increase in tick mortality started 2 hr post exposure with diazinon and 50 and 100 mg/ml concentrations of S. molle. Vernonia amygdalina extract and diazinon showed a significant increase in tick mortality 3 hr post exposure with 100 mg/ml concentration. Similarly, a significant increase in tick mortality started 2 hr post exposure with diazinon and 100 mg/ml concentrations of C. macrostachyus and N. tabacum. At 24 hr post exposure, diazinon and 50 and 100 mg/ml concentrations of all the extracts have caused significantly higher tick mortality than the rest of the concentrations (P<0.05). Higher concentrations of all the extracts had showed a comparable and strong acaricidal effect on Rhipicephalus (Boophilus) decoloratus and Rhipicephalus pulchellus having no significant difference with that of the positive control (P>0.05) at 24 hr post exposure period. Tick killing activity of all evaluated plant extracts increases with increasing exposure time and concentration as well. Thus, all the tested plants could be used against Rhipicephalus (Boophilus) decoloratus and Rhipicephalus pulchellus as a potential alternative to substitute commercially available drugs. We recommend further study on fractionating each component separately and validating the materials.

The First Study for The Acaricidal Activity of Alcoholic Extracts of Adiantum capillus-veneris and Funaria hygrometric against Argas persicus

“…Whereas, various alcoholic extracts (ethanolic and methanolic) of different parts for numerous plants, e.g. Acmella oleracea, Ageratum conyzoides, Aloe rupestris, Argemone mexicana, Artemisia absinthium, Berberis tinctoria, Caesalpinia gaumeri, Cissus quadrangularis, Clematis brachiata, Cleome gynandra, Dalbergia sissoo, Datura metel, D. stramonium, Dodonaea viscose, Eupatorium adenophorum, Euphorbia rothiana, Neoglaziovia variegata, Ficus sycomorus, Lobelia leschenaultiana, Monsonia angustifolia, Pelargonium luridium, Semecarpus anacardium, Solanum sisymbrifolium, Strobilanthes foliosus, Schkuhria pinnata, Sclerocarya birrea and Tabernaemontana elegans…..etc., recorded 10-100% efficiency against hard ticks within 24 hours to 14 days of treatment (Dantas et al, 2015;Ghosh et al, 2015a, b;Godara et al, 2015Godara et al, , 2018Banumathi et al, 2016;Cruz et al, 2016;Kumar et al, 2016;Muyobela et al, 2016;Singh et al, 2016;Anholeto et al, 2017;Rosado-Aguilar et al, 2017;Fouche et al, 2017Fouche et al, , 2019Vasconcelos et al, 2018;Figueiredo et al, 2019;Politi et al, 2019;Kemal et al, 2020;Upadhaya et al, 2020). Notably, the ticks killing activity of all extracts increases with increasing concentration and exposure time (Kemal et al, 2020).…”

“…It is not strange using plant extracts as pesticides, especially for the management of ticks; a lot of botanists dealing with this goal (Ghosh et al, 2015a;Adenubi et al, 2016;Islam et al, 2018;Kemal et al, 2020;Mahran et al, 2020), but it is rare to use Cryptogams (i.e. bryophytes and pteridophytes) in this regard.…”

Efficacy evaluation of methanolic extracts of Calpurnia aurea and Schinus molle plants against the cattle lice Linognathus vitulli

“…The differences on the yield of these extract materials could be attributed to the difference in chemical composition of the extracts, environmental conditions which create differences in phytochemical constitution, and harvest time. Furthermore, the solvents and test protocols used during extraction promote difference in concentrations and classes of secondary bioactive present in extracts (23).…”

Plant-Derived Natural Compounds for Tick Pest Control in Livestock and Wildlife: Pragmatism or Utopia?

“…Extracts from Nicotiana tabacum , the cultivated tobacco plant, are also potently acaricidal. While methanol extractions required greater concentrations (25–100 mg/mL) to kill 50% of Rhipicephalus decoloratus , Rhipicephalus pulchellus , or R. sanguineus adults within 24 h of exposure [ 144 , 145 ], hexane extractions proved more effective with an LC 50 of 0.6 mg/mL for female R. microplus . Ethanol extracts also appeared to produce a greater level of toxicity [ 146 ] than other extracts.…”

“…More recently, six medicinal plants ( Vernonia amygdalina , Calpurnia aurea , Schinus molle , Ricinus communis , Croton macrostachyus , and Nicotiana tabacum ) were used against R. decoloratus and R. pulchellus in an in vitro adult immersion test with five crude extract concentrations (6.25, 12.5, 25, 50, or 100 mg/mL) with diazinon (0.1%) as a positive control. Two of the concentrations (50 and 100 mg/mL) showed a comparable and strong acaricidal effect on both tick species compared with the positive control after a 24 h period [ 144 ].…”