| 1. |
- Ashitani, Tatsuya, et al.
(författare)
-
Activity studies of sesquiterpene oxides and sulfides from the plant Hyptis suaveolens (Lamiaceae) and its repellency on Ixodes ricinus (Acari:Ixodidae)
- 2015
-
Ingår i: Experimental & applied acarology. - : Springer Science and Business Media LLC. - 0168-8162 .- 1572-9702. ; 67:4, s. 595-606
-
Tidskriftsartikel (refereegranskat)abstract
- Hyptis suaveolens (Lamiaceae), a plant traditionally used as a mosquito repellent, has been investigated for repellent properties against nymphs of the tick Ixodes ricinus. Essential oils and volatile compounds of fresh and dried leaves, from plants originating from Laos and Guinea-Bissau, were identified by GC-MS and tested in a tick repellency bioassay. All the essential oils were strongly repellent against the ticks, even though the main volatile constituents differed in their proportions of potentially tick repellent chemicals. (+)/(-)-sabinene were present in high amounts in all preparations, and dominated the emission from dry and fresh leaves together with 1,8-cineol and alpha-phellandrene. 1,8-Cineol and sabinene were major compounds in the essential oils from H. suaveolens from Laos. Main compounds in H. suaveolens from Guinea-Bissau were (-)-sabinene, limonene and terpinolene. Among the sesquiterpene hydrocarbons identified, alpha-humulene exhibited strong tick repellency (96.8 %). Structure activity studies of oxidation or sulfidation products of germacrene D, alpha-humulene and beta-caryophyllene, showed increased tick repellent activity: of mint sulfide (59.4 %), humulene-6,7-oxide (94.5 %) and caryophyllene-6,7-oxide (96.9 %). The substitution of oxygen with sulfur slightly lowered the repellency. The effects of the constituents in the oils can then be regarded as a trade off between the subsequently lower volatility of the sesquiterpene derivatives compared to the monoterpenes and may thus increase their potential usefulness as tick repellents.
|
|
| 2. |
|
|
| 3. |
- Elmhalli, Fawzeia, PhD, et al.
(författare)
-
Acaricidal activity against Ixodes ricinus nymphs of essential oils from the Libyan plants Artemisia herba alba, Origanum majorana and Juniperus phoenicea
- 2021
-
Ingår i: Veterinary Parasitology. - : Elsevier BV. - 2405-9390. ; 24
-
Tidskriftsartikel (refereegranskat)abstract
- Ixodes ricinus (L.) (Acari: Ixodidae) is a major vector for the transmission of several important human pathogens. The aim of the present study was to evaluate the in vitro efficacy of different concentrations of essential oils (Eos) on I. ricinus tick nymphs. Oils were obtained from the leaves of three plants native to Libya: white wormwood (Artemisia herba alba Asso), marjoram (Origanum majorana L.) and Arar (Juniperus phoenicea L., English common name Phoenician juniper). Assays were done using the "open filter paper method". Two concentrations from each oil, 0.5 and 1 mu l/cm, were tested. The acaricidal effect was measured in terms of the lethal concentrations (LC50, LC95) and lethal time (LT50, LT95). Mortality rates were obtained by counting the surviving nymphs every 30 min for the first five hours and then at 24, 48 and 72 h. A mortality of 100% was recorded at the higher concentration of oils (1 mu l/cm(2)) from A. herba alba and J. phoenicea at the first 2 h of exposure. Exposure to O. majorana led to 100% mortality on the third day (72 h), and this effect decreased noticeably with 0.5 mu l/cm(2) oil at the same exposure time. However, 50% of ticks showed a paralysis effect and less movement after 2 h. The LC50 of mortality was reached within the first 24 h of exposure time at 0.5 mu l/cm(2) of O. majorana, which produced 60% tick's mortality. Chemical composition of the essential oils was elucidated by gas chromatography-mass spectrometry analyses. These results suggest that essential oils deserve further investigation as components of alternative approaches for I. ricinus tick control.
|
|
| 4. |
- Elmhalli, Fawzeia, PhD, et al.
(författare)
-
The repellency and toxicity effects of Essential oils from the Libyan plants Salvadora persica and Rosmarinus officinalis against nymphs of Ixodes ricinus.
- 2019
-
Ingår i: Experimental & applied acarology. - : Springer Science and Business Media LLC. - 0168-8162 .- 1572-9702. ; 77:4, s. 585-599
-
Tidskriftsartikel (refereegranskat)abstract
- Essential oils extracted from the leaves of Libyan Rosemary (Rosmarinus officinalis L.), and Miswak (Salvadora persica L.) were evaluated for their acaricidal and repellent effects on Ixodes ricinus L. nymphs (Acari: Ixodidae) using a bioassay based on an “open filter paper method". R. officinalis leaf essential oil diluted to 0.5 and 1µl/cm ² in acetone exhibited, respectively, 20% and 100% tick mortality after about 5 hours of exposure. A total of 50% and 95% of I. ricinus nymphs were killed by direct contact with the oil when exposed to lethal concentrations (LC) of 0.7µl/cm² (LC50) and 0.95 µl/cm² (LC95), respectively. The LC50 (0.5µl/cm²) was reached before the end of the first 24 hours of exposure time (ET), as tick mortality at 24 hours was 60%. S. persica leaf essential oil at 1µl/cm² showed a significant repellency effect against I. ricinus nymphs at 1.5 hours ET. A 95% repellency was observed at a repellent concentration (RC95) of 1µl/cm² of S. persica, but no significant mortality was recorded at this dose of S. persica oil. Gas chromatography-mass spectrometry analyses showed that the main monoterpenes in both oils were 1,8-cineol, α-pinene, and β-pinene, although in markedly different proportions. These results suggest that essential oils have substantial potential as alternative approaches for I. ricinus tick control.
|
|
| 5. |
- Elmhalli, Fawzeia, et al.
(författare)
-
Toxicity against Ixodes ricinus nymphs of essential oils from the Libyan plants Artemisia herba alba, Origanum majorana and Juniperus phoenicea
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- ABSTRACT Ixodes ricinus (L.) (Acari: Ixodidae) is a major vector for the transmission of several important human pathogens. The aim of the study was to evaluate the in vitro efficacy of different concentrations of essential oils (Eos) on I. ricinus tick nymphs. Oils were obtained from the leaves of three plants native to Libya: white wormwood (Artemisia herba alba Asso), marjoram (Origanum majorana L.) and Arâr (Juniperus phoenicea L., English common name Phoenician juniper). Assays were done using the “open filter paper method". Two concentrations from each oil, 0.5 and 1µl/cm, were tested. And the toxic effect was measured in terms of the lethal concentrations (LC50, LC95) and lethal time (LT50, LT95). Mortality rates were obtained by counting the surviving nymphs every 30 minutes for the first five hours and then at 24, 48 and 72 h. A mortality of 100% was recorded at the higher concentration of oils (1µl/cm²) from A. herba alba and J. phoenicea at the first 2 hours of exposure. With O. majorana 100% mortality was only reached on the third day (72h), and this effect decreased noticeably with 0.5µl/cm² oil at the same exposure time. However, 50% of ticks showed a paralysis effect and less movement after 2 hours. Whereas the LC50 of mortality was reached within the first 24h of ET at 0.5µl/cm² of O. majorana, which produced 60% tick’s mortality. Chemical composition of the essential oils was elucidated by gas chromatography-mass spectrometry analyses. These results suggest that essential oils merit further investigation as components of alternative approaches for I. ricinus tick control.
|
|
| 6. |
- Garboui, Samira, et al.
(författare)
-
Repellency of MyggA® Natural spray (para-menthane 3, 8-diol) and RB86 (neem oil) against the tick Ixodes ricinus (Acari: Ixodidae) in the field in east-central Sweden
- 2006
-
Ingår i: Experimental & applied acarology. - : Springer Science and Business Media LLC. - 0168-8162 .- 1572-9702. ; 40:3-4, s. 271-277
-
Tidskriftsartikel (refereegranskat)abstract
- In the field in south-central Sweden, we tested by randomised, standardised methodology the potential anti-tick repellent activity of two concentrations of MyggA® Natural spray (containing PMD) (4.2 and 3.2 g/m2) and one of RB86 (with 70% neem oil containing azadirachtin)(3 g/m2) to host seeking nymphs of Ixodes ricinus. Each substance was applied separately to 1 m2 cotton flannel cloths. Nymphal ticks on the cloths, pulled over the vegetation, were recorded at 10-m stops. Nymphal numbers recorded differed significantly between treated cloths [4.2 or 3.2 g MyggA® Natural spray/m2 and 3 g RB86/m2] and the untreated control (df = 3, χ2 = 112.74, P < 0.0001). Nymphal numbers also differed significantly among collectors (df = 3, χ2 = 15.80, P < 0.001). Repellency of treated cloths, i.e., 4.2 or 3.2 g MyggA® Natural spray/m2 and 3 g RB 86/m2 declined from day 0 (i.e. the day of impregnation) to day 3 after impregnation from 77 to 24%, 58 to 16% and 47 to 0.5%, respectively. This study suggests that all three treatments have significant repellent activities against I. ricinus nymphs.
|
|
| 7. |
- Garboui, Samira S., et al.
(författare)
-
Repellency of methyl jasmonate to Ixodes ricinus nymphs (Acari : Ixodidae)
- 2007
-
Ingår i: Experimental & applied acarology. - : Springer Science and Business Media LLC. - 0168-8162 .- 1572-9702. ; 42:3, s. 209-215
-
Tidskriftsartikel (refereegranskat)abstract
- In our search for tick repellents of plant origin, to be used as alternatives to commercial arthropod repellents, we investigated the effect of the well known plant signaling compound methyl jasmonate (MJ) using nymphs of the tick Ixodes ricinus. In laboratory tests, pieces of cloth with MJ at 0.075, 0.15, 0.30 and 0.75 mg/cm(2) yielded increasing repellencies against the nymphs: 57%, 71%, 92% and 99%, respectively, of the nymphs did not cling to the cloth. Repellency of MJ was also investigated in a tick-infested woodland area in central Sweden. Cotton flannel cloths sprayed with 0.05, 0.1 or 0.2 mg/cm(2) MJ dissolved in acetone were dragged over the ground vegetation. The numbers of nymphs on the treated cloths were significantly lower than those on the untreated cloth. Thus, MJ has, at the concentrations tested, significant repellent activity against I. ricinus nymphs.
|
|
| 8. |
- Garboui, Samira, et al.
(författare)
-
Tick repellent properties of three Libyan plants
- 2009
-
Ingår i: Journal of medical entomology. - : Oxford University Press (OUP). - 0022-2585 .- 1938-2928. ; 46:6, s. 1415-1419
-
Tidskriftsartikel (refereegranskat)abstract
- Specimens of Salvadora persica Wallich (Salvadoraceae), Pistacia atlantica Desfontaines (Anacardiaceae), and Juniperus phoenicea L. (Cupressaceae) were collected at The Green Mountain in northeastern Libya. The tick-repellent effects of the essential oils from the plants were evaluated using host-seeking nymphs of Ixodes ricinus L. (Acari: Ixodidae) in the laboratory. Significant tick repellent effects were observed for the oils of all three species, but the duration of action was short. The oils were obtained by steam distillation. Volatile compounds of the essential oils were collected by solid phase microextraction and the constituents were identified by gas chromatography-mass spectrometry.
|
|
| 9. |
|
|
| 10. |
|
|
| 11. |
- Sadek Garboui, Samira, 1972-
(författare)
-
Plant-Derived Chemicals as Tick Repellents
- 2008
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Ixodes ricinus is the main vector of Lyme borreliosis and Tick-borne encephalitis in Europe. Repellents provide a practical means of protection against tick bites and can therefore reduce transmission of tick-borne diseases. In laboratory tests, pieces of cloth treated with MyggA Natural® (a commercial insect repellent) or with the essential oils of Corymbia citriodora (30%), Lavandula angustifolia (1 and 30%), Pelargonium graveolens (1 and 30%), Hyptis suaveolens (10%), Salvadora persica, Pistacia atlantica, Juniperus phoenicea (20%) and methyl jasmonate (MJ) (0.5%, 1.0%, 2.0% and 5.0%) showed strong repellent activity against I. ricinus nymphs. In a tick-infested woodland in east-central Sweden, we tested by randomized, standardised methodology the potential anti-tick repellent activity of MyggA Natural® (roll-on), two concentrations of MyggA Natural® spray, RB86 (a commercially available insect repellent for horses), the essential oil of C. citriodora and three concentrations of MJ. Each substance was dissolved in acetone and applied separately to 1 m2 cloths which were then pulled over vegetation. Nymphal tick numbers on the cloths were recorded at 10-m intervals and differed significantly between treated cloths and the untreated control and also between collectors. Volatile compounds from fresh and dried leaves of H. suaveolens and the essential oils of H. suaveolens (from Laos and Guinea Bissau) and S. persica, P. atlantica and J. phoenicea (from Libya) were collected by solid phase micro-extraction (SPME) and the constituents were identified by gas chromatography - mass spectrometry (GC-MS). Two main sesquiterpene hydrocarbons in the H. suaveolens oil were β-caryophyllene and humulene. These were modified by oxidation and sulphidation to obtain effective tick repellent compounds with lower volatility. In all three oils from Libyan plants the main monoterpene hydrocarbons were α-pinene, sabinene, β-pinene, myrcene, α-phellandrene, 4-carene, β-phellandrene and γ-terpinene. The selected plant species contained numerous volatiles known to have insecticidal, acaricidal, and/or insect repellent properties.
|
|
