Acaricidal activity of Egyptian crude plant extracts against Haemaphysalis longicornis ticks

TL;DR

Researchers tested Egyptian plant extracts against ticks and found that Artemisia judaica was highly effective at killing Haemaphysalis longicornis ticks.

Contribution

The study identifies Artemisia judaica as a potent acaricidal plant extract and characterizes its active compounds using mass spectrometry.

Findings

Artemisia judaica extract achieved 100% tick mortality at 48 hours with high and moderate concentrations.

Liquid chromatography–mass spectrometry identified camphor as the major component in Artemisia judaica extract.

The extract's LT50 values were 30.37 hours for high doses and 55.08 hours for moderate doses.

Abstract

Haemaphysalis longicornis is a common Ixodida tick species found in temperate areas of Asian countries. An anti-tick assay was conducted on adult female H. longicornis ticks. Plant extract solutions were prepared at concentrations of 50, 25, and 10 mg/mL. Tick survival and mortality were assessed by counting the number of dead and live ticks at 24 h, 48 h, 72 h, and 96 h posttreatment. Out of 11 plant extracts screened, Artemisia judaica extract exhibited the highest potency with 100% mortality (5/5) at 48 h when applied at high and moderate concentrations (50 and 25 mg/mL). Similar results were observed at 96 h for the 10 mg/mL group compared to the untreated ticks. Cleome droserifolia extract demonstrated partial activity with 60% (3/5) and 20% (1/5) mortality at 96 h posttreatment at concentrations of 50 and 25 mg/mL, respectively. Forsskaolea tenacissima extract showed a weak effect with 100% tick mortality (5/5) only at the highest treatment concentration after 96 h. To confirm the activity of A. judaica, trial 2 was conducted. A. judaica demonstrated potency within 48 h in high dose and 72 h in moderate dose, with 100% mortality (15/15) at 96 h posttreatment compared to untreated ticks. The median lethal time 50 (LT50) values were 30.37 h for the high and 55.08 h for the moderate doses. Liquid chromatography‒mass spectrometry was performed on the most potent candidate (A. judaica) to identify its phytochemical components. The results revealed the presence of 9 compounds identified through manual annotation and 74 compounds from the Global Natural Products Social library. These compounds included terpenoids, steroids, phenylpropanoids, flavonoid glycosides, flavonoids, and benzenoids. Camphor was identified as the major component via both approaches. These findings suggest the potential use of A. judaica extract in the future development of acaricidal therapeutics.

Figures