Acaricidal activity of Foeniculum vulgare against Rhipicephalus annulatus is mainly dependent on its constituent from trans-anethone

Abstract

Globally, the economic losses due to hard ticks infestation and the control of the associated diseases have been calculated at USD $13.9–18.7 billion per year. The economic impact is related to its direct damage to the skins, blood loss, anemia, severe immunological reactions and indirect losses that related to the effects of hemoparasites, cost of treatment for clinical cases and expenses incurred in the control of ticks. The current study evaluated the acaricidal activities of fennel Foeniculum vulgare essential oil and its main components; trans-anethole and fenchone; against R. annulatus. GC–MS analysis revealed that this oil contained 16 components representing 99.9% of the total identified compounds with E-anethole being the predominant component(64.29%), followed by fenchone (9.94%). The fennel oil and trans-anethole showed significant acaricidal activities. The LC50 of the fennel oil was attained at concentrations of 12.96% for adult ticks and 1.75% for tick larvae meanwhile the LC50 of trans-anethole was reached at concentrations of 2.36% for adult tick and 0.56% for tick larvae. On the contrary, fenchone showed no any significant adulticidal activities and its LC50 attained at a concentration of 9.11% for tick larvae. Regarding repellence activities, trans-anethole achieved 100% repellency at the concentration of 10% while fennel showed 86% repellency at the same concentration. Fenchone showed no repellency effect. Treatment of larvae with fennel, trans-anethole, and fenchone LC50 concentrations significantly inhibited the acetylcholinesterase activity. Meanwhile, glutathione s-transferase activity was significantly decreased in fennel treated larvae but no significant effect was found in the larvae of trans-anethole and fenchone groups. These results indicate that the acaricide effect of fennel oil may attributed to its high content of trans-anethole. This was supported by potent adulticidal, larvicidal, and repellency effects of trans-anethole against Rhipeciphalus annulatus tick and therefore it could be included in the list of acaricide of plant origin.

Phytochemical Profile of Foeniculum vulgare Subsp. piperitum Essential Oils and Evaluation of Acaricidal Efficacy against Varroa destructor in Apis mellifera by In Vitro and Semi-Field Fumigation Tests

“…Analysis of the phytochemical profiles, however, revealed more abundant chemicals to which the greatest acaricide effect can be ascribed. As evidenced by other research, the acaricidal effect of fennel oil can be related to its high anethole amount [27], which is present in much higher concentrations (percentages) in the EO of the whole plant (49.90) than in the EOs of the leaves (29.18), achenes (24.16) and flowers (27.40). Considering that only vapours were tested, it can be concluded that anethole showed good acaricide action.…”

“…EO is known to contain compounds such as terpenes, coumarins, flavonoids and sterols, mainly from trans-anethole, fenchon, estragon and α-fellandrene [25]. These constituents have shown pharmacological activity against mites, diptera, fleas, lepidoptera and ticks [26][27][28]. The presence and concentration of EO constituents is variable and mainly depends on the phenological stage and the geographical area in which the plant or its parts are harvested, as well as the extraction method.…”

Design, Synthesis, and Biological Evaluation of Pyrido [1,2-α] Pyrimidinone Mesoionic Derivatives Bearing Propenylbenzene as the Vector Control Insecticide

“…9−11 Also, the nAChRs play a central role in fast excitatory synaptic transmission in the insect central nervous system 12 and have been an important neuronal target for the control of vector insects. 13,14 As a highly efficient pharmacophore, anethole has a broad range of biological activities against vector insects, including mosquitoes, 15−19 Rhipicephalus microplus, Rhipicephalus annulatus, and Dermacentor nitens, 20,21 Myzus persicae, 22,23 Musca domestica, 24 Bemisia tabaci, 25 and Periplaneta americana, 26 with neurotoxic actions of acetylcholinesterase, GABA receptors, and octopamine receptors. 27−29 lead candidate for the development of insect vector control agents.…”

“…In order to optimize the mesoionic lead compound, 2,2,2-trifluorethyl and (2-chlorothiazol-5-yl)­methyl group replace the n -propyl group at the 1-position of the mesoionic core based on bioisosteric replacement strategy (compounds 2 and 3 ) showing excellent insecticidal activity against many kinds of pests . Further optimization based on compound 3 led to the discovery of triflumezopyrim ( 4 ) and dicloromezotiaz ( 5 ) as a hemiptera and lepidoptera insecticide by the bioisosteric replacement strategy (Figure ), , which exert their insecticidal action by inhibiting nicotinic acetylcholine receptors (nAChRs). − Also, the nAChRs play a central role in fast excitatory synaptic transmission in the insect central nervous system and have been an important neuronal target for the control of vector insects. , As a highly efficient pharmacophore, anethole has a broad range of biological activities against vector insects, including mosquitoes, − Rhipicephalus microplus, Rhipicephalus annulatus, and Dermacentor nitens, , Myzus persicae, , Musca domestica, Bemisia tabaci, and Periplaneta americana, with neurotoxic actions of acetylcholinesterase, GABA receptors, and octopamine receptors. − It is a potential chemical probe and a lead candidate for the development of insect vector control agents …”

D‐limonene nanoemulsion: lousicidal activity, stability, and effect on the cuticle of Columbicola columbae

“…In addition, the overuse of such chemical insecticides leads to the development of resistance (Abdel‐Ghaffar et al, 2009) which could lead to great difficulty in the lice treatment. Consequently, plant essential oils could be an effective and safe alternative for the synthetic insecticides (Aboelhadid et al, 2021; Khater et al, 2014).…”