ArticlePDF Available

Abstract and Figures

The aim of this study is to compare the use of plant-based insect repellents that are environment friendly with the use of insect repellents based on chemical substances which can be harmful to the environment and human health. The plant studied here is " tea tree " ; its scientific name is Melaleuca alternifolia. Essential oil from this plant is extracted by steam distillation method. Based on the previous research, tea tree oil has antimicrobial, antifungal, anti-inflammatory, and insect repellent properties. Some experiments were done on tea tree oil to determine its insect repellent properties and the suitable concentration that can be used to make sure its repelling effect is optimum. The purpose of this determination is to avoid its harmful effect on humans because it can be toxic if it is used at high concentration. The results showed that tea tree oil repelled Tribolium castaneum. Furthermore, the toxicity assays also gave positive result where the tea tree oil has toxic properties against Solenopsis invicta. The lethal dose (LD) of tea tree oil to kill 50% of a group of S. invicta is 23.52 μL/mL. This LD 50 is determined by using the arithmetic method of Karber. Broadly, the results showed that M. alternifolia has insect repellent properties and shows toxicity against certain insects.
Content may be subject to copyright.
Recent Advances in Biology
and Medicine
Original
Research
Article
Insect Repellent Properties
of Melaleuca alternifolia
HATASO, USA
E-ISSN: 2378-654X
Recent Advances in Biology and Medicine, Vol. 2, Pages 57-61, 2016 57
ID: 293742 dx.doi.org/10.18639/RABM.2016.02.293742
Insect Repellent Properties of Melaleuca alternifolia
Mohamad Adib Bin Edris, Awang Soh Yusuff Mamat, Muhammad Shahzad Aslam*,
Muhammad Syarhabil Ahmad
School of Bioprocess Engineering, Universiti Malaysia Perlis,
Kompleks Pusat Pengajian Jejawi 3, 02600 Arau, Perlis, Malaysia.
*Correspondence: aslammuhammadshahzad@gmail.com
Received: Jun 24, 2016; Accepted: Jul 25, 2016; Published: Aug 6, 2016
Abstract
The aim of this study is to compare the use of plant-based insect repellents that are environment friendly with the use of insect repellents based
on chemical substances which can be harmful to the environment and human health. The plant studied here is “tea tree”; its scientific name
is Melaleuca alternifolia. Essential oil from this plant is extracted by steam distillation method. Based on the previous research, tea tree oil has
antimicrobial, antifungal, anti-inflammatory, and insect repellent properties. Some experiments were done on tea tree oil to determine its insect
repellent properties and the suitable concentration that can be used to make sure its repelling effect is optimum. The purpose of this determina-
tion is to avoid its harmful effect on humans because it can be toxic if it is used at high concentration. The results showed that tea tree oil repelled
Tribolium castaneum. Furthermore, the toxicity assays also gave positive result where the tea tree oil has toxic properties against Solenopsis invicta.
The lethal dose (LD) of tea tree oil to kill 50% of a group of S. invicta is 23.52 μL/mL. This LD50 is determined by using the arithmetic method of
Karber. Broadly, the results showed that M. alternifolia has insect repellent properties and shows toxicity against certain insects.
Keywords: Melaleuca alternifolia; Steam distillation; Repellency assay; Toxicity assay.
1. INTRODUCTION
A long time ago, plant-based insect repellents were used in “old style” practice, especially as protective mediums. In recent
times, the wide marketing of a repellent product partially produced by a plant-based ingredient has shown increasing popularity
among users. Most plants have a compound that can be used as an insect repellent.
As known, M. alternifolia, simply called “tea tree,” is a small tree, is quite a beauty, can grow up to 5 m in height, and
can have a narrow and thin bark and fine leaves that can grow up to 20 mm in length [1]. Generally, M. alternifolia live along
narrow rivers, marshy flats, beaches and “next to” the ranges. M. alternifolia is Australia’s native plant, and because of its
vigorous growth in Australia and its properties, this plant has been widely used in Australia. We can conclude that each part of
this plant can be used. In olden days, this plant was used to make medicinal ingredients, and sometimes it was used directly
on the human body. Despite its usefulness, wide use of M. alternifolia oil did not officially begin until early this century when its
antiseptic and eradicate properties were reported [1].
In recent years, an essential oil that has been extracted from the M. alternifolia has become increasingly used in medi-
cine. This essential oil, which can be called tea tree oil, is a whitish yellow viscous liquid with a distinctive spicy odour and is a
combination of a complex mixture of monoterpenes, 1-terpinen-4-01, cineole, and another hydrocarbon [1]. This oil that has
been extracted is yielded by steam distillation process. The oil produced is comparatively low in concentration, and it is obtained
at a concentration estimated at 1%-2% of the weight of wet plant material.
Several factors affect the efficiency of the distillation process, and optimizing these factors is necessary to produce a
high yield of oil. Each year, the level of oil is different, and the harvesting time is an important thing that needs to be considered
for the best oil-level yield. The period from November to May is the time when the level of oil yield is high.
Moreover, one of the factors that effect the final quality of oil yield is the duration of the distillation process. The oil
has a number of properties which suggest its potential for use in wound treatments or as a protectant against flies. Besides,
it has documented insecticidal effects by which it can be used in the treatment of strikes by larvae, a repellent effect that can
help in protecting against new strikes or restrikes, and antimicrobial and anti-inflammatory effects that can help in healing
wounds [2].
2. MATERIALS AND METHODS
2.1. Preparation of Essential Oil
The raw materials that have been used in this project are parts of the tea tree; its scientific name is M. alternifolia. The parts that
were used in this experiment were the leaves from which the essential oil was extracted. The leaves were placed in the upper
container of distillation apparatus with fair and tight packing. Some spaces were left to allow the steam to pass through the raw
material. A low flow of water was allowed into the condenser. This allowed the oil to flow into the tube. The heating mantle
58 Original Research Article
HATASO rabm.scholasticahq.com
was turned on, and steam distillation began. The heating mantle was allowed to heat the water, and the water vapour passed
through the leaves. The process was carried out for a period of 30 minutes to 3 hours. The temperature was maintained at
165°C, as the boiling point of tea tree oil is 165°C. The heating mantle was turned off after the distillation process ended. The
distillate was extracted further by using “liquid-liquid extraction” technique. The essential oil obtained was poured into a small
bottle [3].
2.2. Repellency Assays
Several test samples were prepared by dissolving different volumes of the essential oil in 1 mL of acetone (5, 10, 20, and 30 μL).
A Whatman filter paper was divided into two sections. Then, oil solution was applied on one half of the filter paper as uniformly
as possible using a micropipette. Acetone was placed on the other half of the filter paper as a controlling agent. The essential
oil–treated and acetone-treated halves were dried to completely evaporate the solvent.
After that, both treated and untreated halves were joined again by using tape and placed at the bottom of a Petri dish.
Twenty insects (stored-product beetle, T. castaneum) were placed at the center of the filter-paper disc, and then the petri dish
was covered and kept in a dark environment. For each concentration of the solution, this procedure was replicated about four
times. A number of the insects on both the treated and untreated halves were recorded after four hours in dimmer light [4].
2.3. Toxicity Assays
Disposable Petri dishes (100 25 mm2) were prepared by covering the Petri dishes with a white cloth to prevent the escape of
the ant under study and force the ant to remain on the treated paper. Several test samples were prepared by dissolving different
volumes of essential oil in 1 mL of hexane (25, 30, 40, and 50 μL).
Each concentration of the essential oil was applied to the Whatman filter-paper circle (90 mm in diameter). The paper
was then dried under a fume hood for 1 hour and placed in the bottom of a Petri dish. Control filter papers were treated with
1 mL of hexane. In each of five replicates, five S. Invicta ants were placed on top of the treated filter paper. The dish was left
covered with white cloth. This method allowed assessment of mortality due to contact toxicity, as opposed to fumigation. To
prevent desiccation while forcing ants to remain on the treated filter paper, water was provided in a plastic cap, cut from the top
of a 0.5 mL microcentrifuge tube and placed on top of the filter paper. Mortality was assessed after every 15 min for 2 h, then
finally after 24 h [5]. Plates 3.5 and 3.6 show the toxicity assay test and S. Invicta ant preparation, respectively.
3. RESULTS AND DISCUSSION
3.1. Extraction of Essential Oil Using Steam Distillation
The product from the steam distillation will undergo a further process, that is, liquid-liquid separation technique. When solvent
(20 mL of diethyl ether) is added to the distillate (150 mL), three layers are formed—diethyl ether, essential oil, and water. From
Table 1: The productivity of tea tree oil by steam distillation apparatus.
Batch
Raw material
input (g)
Extraction
time (min)
Oil volume
(mL)
Productivity %
(mL/100 g)
1
2
3
4
100
100
100
100
195
200
210
215
1.03
1.07
1.11
1.14
1.03
1.07
1.11
1.14
Figure 1: Tea tree oil volume yield over time.
1.02
1.04
1.06
1.08
1.1
1.12
1.14
1.16
190 195 200 205 210 215
220
Oil volume
Extraction time (min)
Recent Advances in Biology and Medicine, Vol. 2, Pages 57-61, 2016 59
ID: 293742 dx.doi.org/10.18639/RABM.2016.02.293742
top to bottom are diethyl ether, essential oil, and water, respectively. This is due to the densities of each of them, which are
0.713 g/mL, 0.885-0.906 g/mL, and 1.000 g/mL, respectively. Water is discharged from the bottom of the separating funnel
(250 mL), and the process of liquid-liquid separation is repeated once again to make sure all the water is removed. Although,
there will be a small amount of water in the solution, most of the solution is solvent and essential oil. Anhydrous sodium hydrox-
ide is added to remove the small amount of water, and the solvent in the solution is removed by using a hot water bath because
of the low boiling point of the solvent. In steam distillation, typically the essential oil’s yield is in the range of 1% to 2% of weight
of wet plant material [1]. Table 1 and Figure 1 show the productivity of tea tree oil by steam distillation apparatus and the graph
of tea tree oil volume yield per time, respectively.
As seen in Figure 1, the volume of essential oil yield increases as the time extraction increases, although the yield of
essential oil also depends on the moisture content of the raw material (leaves). Although the volume of essential oil yield increases
as the extraction time increases, it also depends on the temperature at which the mixture of raw material and steam is heated,
and the temperature of the surrounding also affects the yield of essential oil. Other than that, as you can see, the extraction speed
is fast at the beginning, slows down with time, and increase in the end. The average time needed to yield essential oil in this
experiment is 205 min, and the average volume of essential oil yield is 1.09 mL. The total amount of tea tree oil yield is 4.35 mL.
As we know, tea tree oil has more than 100 components; the main components are monoterpenes, sesquiterpenes and
their alcohols [6]. These components have been identified using gas chromatography-mass spectrometry [7]. But in the present
study, all of these components have not been identified because it is not compulsory to identify them in this project. One of the
objectives of this project is to extract the essential oil from M. alternifolia using steam distillation. Based on the result, we have
achieved the objective. The present study also proves that the yield of tea tree oil is in the range of 1% to 2% of the weight of
wet plant material which has been reported in the earlier journal [1].
3.2. Repellency Assays
This test was performed to determine the repellent activity of the tea tree oil. Chi-square test was performed to determine the
repellent activity of the essential oil tested. Table 2 shows the filter paper–repellency assays using M. alternifolia essential oil
against T. castaneum adults.
In this filter paper repellency assay, adults of T. castaneum were used. Four replications were carried out for each
concentration of essential oil, and 20 T. castaneum adults were used per replicate. The results were expressed as mean on the
untreated and treated halves in the assay. The essential oil of M. alternifolia tested as a repellent to T. castaneum adults can be
indicated by Chi-square distribution analysis. Figure 2 shows the graph for repellency assay.
Line Series 1 indicates the untreated section of filter paper, and line Series 2 indicates the treated section of filter paper
with tea tree oil.
From the result, it is obviously shown that M. alternifolia essential oil is a repellent to T. castaneum adults. This repels the
beetles sufficiently, even at very low concentration, and the hypothesis of the ratio 1:1 was rejected. Major constituents that have
Table 2: Filter paper repellency assays using M. alternifolia essential oil against T. castaneum adults.
Concentration (%)
(vol:vol)
Mean of insects SE
in untreated (%)
Mean of insects SE in
treated (%) χ2 value
0.05
0.10
0.20
0.30
51.25 0.5
55.00 0.5
51.25 0.5
58.75 0.5
48.75 0.5
45.00 0.5
48.75 0.5
41.25 0.5
21.5
36
43.3
44.5
Figure 2: Repellency assay.
0
10
20
30
40
50
60
70
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35
Percentage mean of insect
Concentration of tea tree oil (%) vol:vol
Series
1
Series
2
60 Original Research Article
HATASO rabm.scholasticahq.com
repellent activity against insects are Terpinen-4-ol, y-terpinene, and α-terpinene. For repellent and insecticidal action against
T. castaneum, 1,8-cineole is the major constituent that is responsible for insecticidal action against T. castaneum. Based on Table
2, the χ2 value is the Chi-square test value, and it indicates the repellent activity of tea tree oil against T. castaneum. As you
can see that as the concentration of tea tree oil increases, the χ2 value also increases. The result means that as the concentra-
tion of tea tree oil used increases, the repellent activity of the tea tree oil against T. castaneum also increases. Tea tree oil has
been reported for its repellent behaviour against T. castaneum [7]. These earlier reports have clearly supported the result of the
present study.
3.3. Toxicity Assays
In this test, the toxicity of the essential oil from tea tree was determined by its toxic effect against red imported fire ant,
S. invicta. Four different concentrations were used, and each concentration was replicated five times. Table 3 shows the
mean standard error (SE) cumulative mortality of red imported fire ants continuously exposed to filter paper treated with five
different concentrations of essential oil.
Toxicity was evaluated in continuous exposure tests with treated filter paper. Based on Table 3, the filter paper treated
with 50 μL concentration of essential oil is the most effective against S. invicta compared to the other concentrations. The
mortality of S. invicta has been determined by calculating the percentage mean death of the insects. As you can see in Table 3,
there is no insect death at the beginning. But the number of dead insects increases as the time increases. At 1440 min, for
the concentrations of 25 μL and 30 μL, 24% of the insects died, and for the concentration of 40 μL, 28% of the insects died.
Furthermore, at the concentration of 50 μL, the mean percentage of dead insects is about 44%. There is no dead insect in
control. From the earlier study, it is seen that the mortality of tea tree oil on S. invicta is not very efficient [5]. The percentage
mean of dead insects is about 3.3% at the concentration of 25 μl [5]. Even though the result from the earlier study is different
from the present study, it is also indicated that the toxicity of tea tree oil against S. invicta is not very efficient. Tables 4 and 5
show the mean of dead insects at different concentrations of tea tree oil and the mean mortality of tea tree oil, respectively.
Based on Tables 4 and 5, we can find the lethal concentration (LC50) using the arithmetic method of Karber. In this
toxicity assay, LC50 of tea tree oil against S. invicta is 23.52 μL/mL. From this result, we can assume that the lethal concentration
of tea tree oil needed to kill 50% of a certain number of insects is 23.52 μL/mL. Lee et al. [8] stated that the LC50 of tea tree oil
Table 3: Mean SE cumulative mortality of red imported re ants continuously exposed to treated lter paper.
Time (min)
Concentration
(μL) 15 30 45 60 75 90 105 120 1440
25
30
40
50
Blank
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.2
0.0
0.0
0.0
0.2
0.2
0.0
0.6
0.0
0.4
0.2
0.2
0.8
0.0
0.4
0.2
0.2
0.8
0.0
0.4
0.2
0.2
1.0
0.0
0.6
0.4
0.4
1.2
0.0
1.2
1.2
1.4
2.2
0.0
Table 4: Mean of dead insects at different concentration of tea tree oil.
Group Concentration (μl/mL) Mean of dead insects
1 Blank 0
2 25 1.2
3 30 1.2
4 40 1.4
5 50 2.2
Table 5: Mean mortality of tea tree oil.
Group
Concentration
difference (a)
Mean mortality (b)
(second rst)/2
Probit
(a b)
1 0 0 0
2 0 0.6 0
3 5 1.2 6
4 10 1.3 13
5 10 1.8 18
Recent Advances in Biology and Medicine, Vol. 2, Pages 57-61, 2016 61
ID: 293742 dx.doi.org/10.18639/RABM.2016.02.293742
against S. invicta is 22.8 μL/mL. Although the result is quite different, we can make a conclusion that the previous report has
strongly supported the present study. The overall result, we can say, is that tea tree oil has a toxic effect on S. invicta.
4. CONCLUSION
Steam distillation is the best method to extract essential oil from M. alternifolia. The yield of essential oil depends on three fac-
tors: temperature, extraction time, and moisture content. As the extraction time increases, the yield of essential oil also increases.
The lower the moisture content, the greater is the yield of essential oil. In the repellency assays, the result shows that essential
oil from M. alternifolia is repellent and insecticidal against T. castaneum even at a low concentration of essential oil. The major
constituent that is responsible for the repellent and insecticidal actions is 1,8-cineole. It takes times for the essential oil to affect
the red flour beetle, T. castaneum. For the toxicity assay, the result indicates that essential oil from M. alternifolia is toxic against
red imported fire ants, S. invicta. In the beginning, there is no effect on the insect, but the effect becomes clearly visible in the
second hour. From these assays, it can be concluded that tea tree oil is toxic to S. invicta.
Author Contributions
Each author has contributed equally in this study.
Source of Funding
None.
Conflict of Interest
None.
References
1. Carson CF, Riley TV. Antimicrobial activity of the essential oil of Melaleuca alternifolia. Lett Appl Microbiol. 1993; 16(2):49-55.
2. Callander JT, James PJ. Insecticidal and repellent effects of tea tree (Melaleuca alternifolia) oil against Lucilia cuprina. Vet Parasitol. 2012;
184(2-4):271-78.
3. Stichlmair J, Fair JR. Distillation: principles and practices. Wiley-VCH, New York, USA (1998).
4. Nerio LS, Olivero-Verbel J, Stashenko E. Repellent activity of essential oils: a review. Bioresour Technol. 2010; 101(1):372-78.
5. Wiltz BA. Applied ecology and control of imported re ants and Argentine ants (Hymenoptera: Formicidae). PhD thesis (2005), University
of Georgia, Athens, GA.
6. Brophy JJ, Davies NW, Southwell IA, Stiff IA, Williams LR. Gas chromatographic quality control for oil of Melaleuca terpinen-4-ol type
(Australian tea tree). J Aric Food Chem. 1989; 37(5):1330-35.
7. Hammer KA, Carson CF, Riley TV, Nielsen JB. A review of the toxicity of Melaleuca alternifolia (tea tree) oil. Food Chem Toxicol. 2006;
44(5):616-25.
8. Lee BH, Choi WS, Lee SE, Park BS. Fumigant toxicity of essential oils and their constituent compounds towards the rice weevil, Sitophilus
oryzae (L.). Crop Prot. 2001; 20(4):317-20.
Citation: Aslam MS, Edris MAB, Mamat ASY, Ahmad MS. Insect repellent properties of Melaleuca alternifolia. Recent Adv Biol Med. 2016;
2:57-61.
... In a study by Edris et al., it was found that 1,8-cineole was the major constituent that was responsible for the insecticidal and repellent action against adult red floor beetles Tribolium castaneum and red imported fire ants Solenopsis invicta. The LC50 was determined to be 23.52 µL/mL [49]. Maguranyi et al. found that tee tree oil was one of the most effective essential oils studied by repelling Aedes aegypti, Culex annulirostris, and Culex quinquefasciatus for up to 38 min, 45 min, and 78 min, respectively. ...
... In a study by Edris et al., it was found that 1,8-cineole was the major constituent that was responsible for the insecticidal and repellent action against adult red floor beetles Tribolium castaneum and red imported fire ants Solenopsis invicta. The LC 50 was determined to be 23.52 µL/mL [49]. Maguranyi et al. found that tee tree oil was one of the most effective essential oils studied by repelling Aedes aegypti, Culex annulirostris, and Culex quinquefasciatus for up to 38 min, 45 min, and 78 min, respectively. ...
Article
Full-text available
Insect repellent textiles offer protection against disease-causing vectors such as mosquitoes, flies, and ticks. Protection is based on the incorporation of insect repellent compounds present in plant oil derivatives or synthetic oils. The effectiveness and application of natural insect repellents such as citronella grass, lemongrass, rosemary, peppermint, holy basil, tea tree, neem, lavender, thyme, lemon eucalyptus, clove, and cinnamon oils, as well as synthetic compounds permethrin, allethrin, malathion, DEET, DETA, IR3535, and picaridin, are compared here. The insect repellent and insecticidal effectiveness of natural compounds in their pure form are very low due to their high volatility. The effectiveness has been greatly improved through slow-release systems such as encapsulation of the essential oils and is comparable to synthetic compounds used for insect control purposes. Due to the lasting toxicity of synthetic compounds to humans and the environment, the use of natural compounds should become a more preferred method of insect control.
... Labelled products were tested at the highest label rate ( Table 2). Rates of unlabelled products were determined based on reports in the literature (Bekele et al. 1996;Bin et al. 2016 Table 2). Timorex Gold, potassium metabisulfite, and Fossil Shell Flower were tested at multiple rates in short-term trials to help determine potential use as a commercial repellent. ...
Article
Full-text available
The multicoloured Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), has become a pest in North American vineyards during harvest due to its adverse effects on wine quality. This study evaluated alternative products that may be suitable for use in vineyards as repellents to the beetle. Products were screened as repellent for multicoloured Asian lady beetle in short-term laboratory trials. Thirteen products significantly reduced the number of beetles on grapes, Vitis vinifera (Vitaceae). Products that showed a 50% or greater repellency were evaluated for residual repellency 24, 48, and 72 hours after application. In these trials, pine oil was highly repellent at each testing period, whereas the repellency of most other products decreased over time. Eight repellent compounds were evaluated in field trials in commercial vineyards that had high multicoloured Asian lady beetle populations. The number of beetles on vines was counted 2–6 and 24–28 hours after application. In the field, the most effective repellents overall were Biobenton and Buran, which reduced the number of multicoloured Asian lady beetles by 39 and 34%, respectively. The discovery of new repellents of multicoloured Asian lady beetle provides an opportunity to improve management of the pest in vineyards and to reduce risk of wine taint without using broad-spectrum insecticides.
... Tác dụng chống côn trùng được sơ bộ đánh giá trên loài kiến đường Camponotus consobrinus [9]. Cắt đôi một tờ giấy lọc đường kính 9 cm thành hai nửa bằng nhau, một nửa bôi 0,5 ml mẫu thử, nửa còn lại bôi một lượng tương đương mẫu trắng. ...
Article
Full-text available
Lemongrass oil derived from some species of grasses in the family of Poaceae (particularly Cymbopogon citratus) posses a highly effective insect repellent potential. In Vietnam, this product is widely commercially available but its quality is not strictly controlled. From a formulator's perspective, lemongrass essential oil is not suitable for direct application on the skin because high concentrations of citral, major chemical constituent of this oil, may cause local irritation. In addition, this compound is volatile, resulting in a short repellent effect. Contributing to solve these problems, a high-performance liquid chromatography with diode array detection was developed for the simultaneous quantification of neral and geranial, two geometric isomers of citral. This method was used to examine the quality of some lemongrass oil samples in order to choose material for the preparation of insect repellent cream. Experimental research demonstrated that the stability of the lemongrass oil cream containing 6% of citral was significantly improved when using β-cyclodextrin, a cyclic oligosaccharides capable of protecting substances by capturing them in conical structure. The obtained product showed insect repellent effect against banded sugar ant Camponotus consobrinus. This effect did not change after 6 months of storage in conventional conditions. Keywords Citral, high performance liquid chromatography, quantification, insect repellent cream, lemongrass oil. References [1] H.O. Lawal, G.O. Adewuyi, A.B. Fawehinmi, A.O. Adeogun, S.O. Etatuvie, Bioassay of herbal mosquito repellent formulated from the essential oil of plants, Journal of Natural Products. 5 (2012) 109-115. http://journalofnaturalproducts.com/Volume5/15_Res_paper-14.pdf.[2] New York State Integrated Pest Management Program, Lemongrass oil profile active ingredient eligible for minimum risk pesticide use. https://ecommons.cornell.edu/bitstream/handle/1813/56130/lemongrass-oil-MRP-NYSIPM.pdf, 2019 (accessed 5 November 2019).[3] Organisation for Economic Co-operation and Development, Citral CAS N°:5392-40-5. https://hpvchemicals.oecd.org/UI/handler.axd?id=0ea83202-3f4f-4355-be4f-27ff02e19cb9, 2001 (accessed 5 November 2019).[4] R. Arun, K.C.K. Ashok, V.V.N.S.S. Sravanthi, Cyclodextrins as drug carrier molecule: a review, Scientia Pharmaceutica 76 (2008) 567-598. http://dx.doi.org/10.3797/scipharm.0808-05.[5] O.I. Adeniran, E. Fabiyi, A cream formulation of an effective mosquito repellent: a topical product from lemongrass oil (Cymbopogon citratus) Stapf, Journal of Natural Product and Plant Resources, 2 (2012) 322-327. https://pdfs.semanticscholar.org/13bf/993de8f77462335ebc07365adb38e56e706f.pdf.[6] P. Borman, D. Elder, Q2(R1) Validation of analytical procedures: text and methodology, in: A. Teasdale, D. Elder, R.W. Nims (Eds), ICH quality guidelines: an implementation guide, John Wiley & Sons Inc., Hoboken, 2018, pp. 127-166.[7] S. Agrawal, N. Haldankar, A. Jadhav, Formulation of natural mosquito repellent, International Journal of Advance Research, Ideas and Innovations in Technology 4 (2018) 11-17. https://www.ijariit.com/manuscripts/v4i1/V4I1-1143.pdf.[8] Vietnamese pharmacopoeia commission, Vietnamese pharmacopoeia V part 2, Medical Publishing House Co., Ltd, Ha Noi, 2018 (in Vietnamese).[9] M.A.B. Edris, A.S.Y. Mamat, M.S. Aslam, M.S. Ahmad, Insect repellent properties of Melaleuca alternifolia, Recent Advances in Biology and Medicine 2 (2016) 57-61. http://dx.doi.org/10.18639/RABM.2016.02.293742.[10] R. Gaonkara, S. Yallappab, B.L. Dhananjayac, G. Hegde, Development and validation of reverse phase high performance liquidchromatography for citral analysis from essential oils, Journal of Chromatography B. 1036 (2016) 50–56. http://dx.doi.org/10.1016/j.jchromb.2016.10.001.[11] D. Miron, F. Battisti, C.S.T. Caten, P. Mayorga, E.E.S. Schapoval, Spectrophotometric simultaneous determination of citral isomers in cyclodextrin complexes with partial least squares supported approach, Current Pharmaceutical Analysis 8 (2012) 401-408. http://dx.doi.org/10.2174/157341212803341735.[12] L. Huber, Validation and qualification in analytical laboratories, Informa Healthcare USA Inc., New York, 2007.[13] N.D. Wilson, M.S. Ivanova, R.A. Watt, A.C. Moffat, The quantification of citral in lemongrass and lemon oils by near‐infrared spectroscopy, Journal of Pharmacy and Pharmacology 54 (2002) 1257-1263. http://dx.doi.org/10.1211/002235702320402107.[14] N. Dudai, O. Larkov, E. Lewinsohn, Simple colorimetric measurement of citral in lemon scented essential oils using Schiff’s reagent, Future for Medicinal and Aromatic Plants, 26 (2004) 499-504. http://dx.doi.org/10.17660/ActaHortic.2004.629.64.
Article
Full-text available
Background Mosquito repellents can be an effective method for personal protection against mosquito bites that are a nuisance and carry the risk of transmission of mosquito-borne pathogens like plasmodia , dengue virus, chikungunya virus, and Zika virus. A multitude of commercially available products are currently on the market, some of them highly effective while others have low or no efficacy. Many home remedies of unknown efficacy are also widely used. Methods We conducted a survey study to determine what kind of mosquito repellents and other mosquito control strategies people use. Our online survey was focused on unconventional methods and was answered by 5,209 participants. Results The majority of participants resided in the United States, were female (67%), had higher education (81% had a university degree), and were 18 to 37 years old (50%). The most commonly used repellent was DEET spray (48%), followed closely by citronella candles (43%) and ‘natural’ repellent sprays (36%). We collected a plethora of home remedies and other strategies people use that warrant further research into their effectiveness. Discussion Our study lays the foundation for future research in alternative, unconventional methods to repel mosquitoes that may be culturally acceptable and accessible for people.
Article
Full-text available
Detailed GC and GC-MS analyses of oil of Melaleuca have identified several constituents not previously reported from Melaleuca alternifolia and clarified some earlier assignments. The range, mean, and coefficient of variation for the principle constituents in 800 typical samples are presented along with the compositions of several substandard oils. Isolation and storage procedures affecting the chemical composition of the oil are reported. Ethanolic extraction of mature leaves gave solutions suitable for direct injection into a gas chromatograph for the qualitative determination of tea tree oil. Comparison with conventional steam distillation showed that this technique was suitable for preliminary analysis of tea tree oil yield and quality.
Article
Full-text available
Currently, the use of synthetic chemicals to control insects and arthropods raises several concerns related to environment and human health. An alternative is to use natural products that possess good efficacy and are environmentally friendly. Among those chemicals, essential oils from plants belonging to several species have been extensively tested to assess their repellent properties as a valuable natural resource. The essential oils whose repellent activities have been demonstrated, as well as the importance of the synergistic effects among their components are the main focus of this review. Essential oils are volatile mixtures of hydrocarbons with a diversity of functional groups, and their repellent activity has been linked to the presence of monoterpenes and sesquiterpenes. However, in some cases, these chemicals can work synergistically, improving their effectiveness. In addition, the use of other natural products in the mixture, such as vanillin, could increase the protection time, potentiating the repellent effect of some essential oils. Among the plant families with promising essential oils used as repellents, Cymbopogon spp., Ocimum spp. and Eucalyptus spp. are the most cited. Individual compounds present in these mixtures with high repellent activity include alpha-pinene, limonene, citronellol, citronellal, camphor and thymol. Finally, although from an economical point of view synthetic chemicals are still more frequently used as repellents than essential oils, these natural products have the potential to provide efficient, and safer repellents for humans and the environment.
Article
The red imported fire ant, Solenopsis invicta Buren, and Argentine ant, Linepithema humile (Mayr), are invasive species that are major pests in urban, natural, and agricultural habitats. The goal of this dissertation was to study aspects the chemical sensitivity, behavior, and ecology of each species to enhance control options. In these studies, I: 1) provide recommendations for the optimal usage of various insecticides against each species, 2) evaluate deterrent and toxic effects of natural products, 3) develop a delivery system for ant toxicants that uses a pheromonal attractant to facilitate toxicant transfer by contact, and 4) determine which habitats within blackland prairies are most susceptible to invasion by imported fire ants. Bifenthrin had properties best suited for use as barrier or mound treatments against both species. In laboratory assays, it was the fastest acting of the chemicals tested and was the only chemical that acted as a barrier to ant movement. Fipronil exhibited high horizontal toxicity and delayed topical toxicity, properties that are desirable in a broadcast treatment. Chlorfenapyr and thiamethoxam appeared best suited to use as mound treatments, as they had low horizontal toxicity and did not impede ant movement in barrier tests.
Article
Melaleuca alternifolia has been used for medical purposes since Australia was colonized in 1788. Melaleuca alternifolia is commonly called tea tree, although this vernacular name is also given to many other species in the Leptospermum and Melaleuca genera. A small tree, it grows up to 5 m in height, has papery bark and narrow, tapered leaves up to 20 mm in length and flowers in summer. Melaleuca alternifolia is unique to Australia and its natural habitat is a relatively small area around the Clarence and Richmond rivers in the north-east coastal area of New South Wales where the terrain is generally low lying and swampy. The essential oil of M. alternifolia, or tea tree oil. has enjoyed increased medicinal use in recent years. It is a pale yellow viscous liquid with a distinctive pungent odour and is composed of a complex mixture of monoterpenes, 1-terpinen-4-ol, cineole and other hydrocarbons (Peña 1962).
Article
Toxicity of various essential oils and their volatile constituents towards the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), was determined. The most potent toxicity was found in essential oil from eucalyptus (LD50=28.9 μl/l air). GC-MS analysis of essential oil from eucalyptus showed it to be rich in 1,8-cineole (81.1%), limonene (7.6%) and α-pinene (4.0%). Treatment of S. oryzae with each of these terpenes showed 1,8-cineole to be most active (LD50=23.5 μl/l air). In addition to 1,8-cineole, benzaldehyde (LD50=8.65 μl/l air) occurring in peach and almond kernels had a potent fumigant toxicity towards the rice weevils. Therefore, benzaldehyde and other natural volatiles could be a safer fumigant to control stored-grain insect pests than those currently used.
Article
Laboratory studies were conducted to assess the effect of tea tree oil (TTO) from Melaleuca alternifolia (terpinen-4-ol chemotype) against different stages of the Australian sheep blowfly Lucilia cuprina. When applied to wool, 3% TTO formulation repelled gravid female L. cuprina and prevented oviposition for six weeks. Formulations containing 1% TTO caused 100% mortality of L. cuprina eggs and 1st instar larvae and 2.5% TTO caused mortality of most second and third instar larvae in agar feeding assays. In experiments where third instar larvae were dipped in TTO formulations for 60s, concentrations of up to 50% TTO gave less than 50% kill. TTO at concentrations of 0.5%, 2% and 5% was strongly repellent to third instar larvae and caused them to evacuate treated areas. Inclusion of TTO in formulations with diazinon, ivermectin and boric acid reduced mortality in comparison with the larvicides used alone, at least partially because of avoidance behaviour stimulated by the TTO. Addition of TTO to wound treatments may aid in wound protection and myiasis resolution by preventing oviposition by L. cuprina adults, insecticidal action against L. cuprina eggs and larvae, stimulating larvae to leave the wound and through antimicrobial and anti-inflammatory properties that aid in wound healing.
Article
The essential oil of Melaleuca alternifolia, also known as tea tree or melaleuca oil, is widely available and has been investigated as an alternative antimicrobial, anti-inflammatory and anti-cancer agent. While these properties are increasingly well characterised, relatively limited data are available on the safety and toxicity of the oil. Anecdotal evidence from almost 80 years of use suggests that the topical use of the oil is relatively safe, and that adverse events are minor, self-limiting and occasional. Published data indicate that TTO is toxic if ingested in higher doses and can also cause skin irritation at higher concentrations. Allergic reactions to TTO occur in predisposed individuals and may be due to the various oxidation products that are formed by exposure of the oil to light and/or air. Adverse reactions may be minimised by avoiding ingestion, applying only diluted oil topically and using oil that has been stored correctly. Data from individual components suggest that TTO has the potential to be developmentally toxic if ingested at higher doses, however, TTO and its components are not genotoxic. The limited ecotoxicity data available indicate that TTO is toxic to some insect species but more studies are required.
Distillation: principles and practices
  • J Stichlmair
  • J R Fair
Stichlmair J, Fair JR. Distillation: principles and practices. Wiley-VCH, New York, USA (1998).