Application of amomum tsao-ko oil in preparation of mosquito repellent

Abstract

The invention discloses application of amomum tsao-ko oil to preparation of a mosquito repellent. The invention finds that the amomum tsao-ko oil and the combination of the amomum tsao-ko oil and the eucalyptus oil have mosquito repelling activity, in order to further improve the mosquito repelling activity and solve the defect that plant essential oil is easy to volatilize, the amomum tsao-ko oil and the eucalyptus oil are compounded in a certain proportion to achieve a synergistic effect, and the mosquito repelling activity is high.

Description

Technical Field

[0001] The invention belongs to the field of sanitary pest control, and particularly relates to the application of tsaoko oil and eucalyptus oil in combination for preparing mosquito repellent. Background Art

[0002] Tsaoko oil is extracted from the fruit of the plant Tsaoko. Tsaoko (Amomum tsaoko Crevost et Lemarie) is a perennial herbaceous plant of the ginger family. The whole plant can be used to extract aromatic oil. Tsaoko is one of the major varieties of Chinese medicinal materials for both medicinal and edible purposes. The fruit has the functions of drying dampness, strengthening the spleen, removing phlegm and stopping malaria (Chinese Pharmacopoeia 2020 Edition. Part 1. 2020: 249-250).

[0003] Eucalyptus oil is extracted from the eucalyptus plant. Eucalyptus (Eucalyptus globules Labill), also known as eucalyptus, is a plant of the genus Eucalyptus in the Myrtaceae family. Its essential oil has antibacterial and analgesic properties and is often widely used as the main raw material for mosquito repellents.

[0004] The results of current research on the use of plant essential oils to repel mosquitoes show that most plant essential oils have a certain repellent effect on mosquitoes, and there are certain differences in their repellent effects. Due to the shortcomings of plant essential oils, which are strong volatility and short lasting effect, plant essential oils are prepared into corresponding mosquito repellent preparations by using nano-slow-release materials, thereby extending the lasting effect of plant essential oils. There are relatively few research reports on the use of plant essential oils in mosquito repellent preparations. As a plant-derived substance, plant essential oils have a broad development space for the preparation of mosquito repellent preparations due to their low environmental pollution, low resistance to drug resistance, and safety to human health. Summary of the invention

[0005] The present invention has found that tsaoko oil and its combination with eucalyptus oil have repellent activity against mosquitoes. Based on this, the present invention first provides an application of tsaoko oil in preparing a mosquito repellent. At the same time, the present invention provides an application of tsaoko oil and eucalyptus oil in preparing a mosquito repellent. Optionally, the mosquito repellent is a mosquito repellent essential oil, a mosquito repellent lotion, a mosquito repellent incense, a mosquito repellent patch, a mosquito repellent ointment or other mosquito repellent products.

[0006] The present invention also provides a corresponding mosquito repellent. The mosquito repellent is a mosquito repellent nanoemulsion, the active ingredients of the mosquito repellent nanoemulsion are tsaoko oil and eucalyptus oil, and the volume ratio of tsaoko oil to eucalyptus oil is 1-9:9-1. Optionally, the volume ratio of tsaoko oil to eucalyptus oil is 3-7:7-3. Further optionally, the volume ratio of tsaoko oil to eucalyptus oil is 5:5.

[0007] In a specific embodiment, the mosquito repellent is made of the following raw materials in volume percentage: 5% to 10% of compound essential oil of grass fruit oil and eucalyptus oil, 2% to 5% of synergist, 5% to 10% of surfactant, 0% to 5% of co-surfactant, and the remainder is deionized water, and the sum of the volume percentages of each raw material is 100%. Optionally, the synergist is a mixture of one or more of vanillin, citral, cuminaldehyde, cinnamaldehyde or citronellal; the surfactant is a mixture of one or more of Tween20, Tween80, Span20 and Span80, and the co-surfactant is a mixture of one or more of anhydrous ethanol, n-propanol, n-butanol and isobutanol.

[0008] The present invention also provides a method for preparing the mosquito repellent, which comprises the following steps:

[0009] S1, the compound essential oil of tsaoko oil and eucalyptus oil is mixed with a synergist to obtain an oil phase A;

[0010] S2, deionized water, surfactant and co-surfactant are mixed to obtain aqueous phase B;

[0011] S3, adding the oil phase A while stirring the aqueous phase B, and mixing to form a crude emulsion;

[0012] S4, the crude emulsion is treated with ultrasound to obtain mosquito repellent nanoemulsion.

[0013] Tsaoko oil and eucalyptus oil are natural plant-derived active substances. The present invention compounds tsaoko oil and eucalyptus oil in a certain proportion to achieve a synergistic effect, and has high mosquito repellent activity. DETAILED DESCRIPTION

[0014] Unless otherwise specified, the scientific and technical terms used herein are understood according to the knowledge of ordinary technicians in the relevant fields.

[0015] The applicant's research found that tsaoko oil showed high mosquito repellent activity against Aedes albopictus at different concentrations, and it can be compounded with eucalyptus oil, which has been proven to have good mosquito repellent activity, to prepare mosquito repellent nanoemulsion with better mosquito repellent effect.

[0016] In order to more clearly understand the present invention and the efficacy of the medicament of the present invention, the present invention is further described in detail below by the specific embodiments completed according to the technical solution of the present invention provided by the inventor, which are only preferred embodiments of the present invention, but are not limited to these embodiments. The essential oils, reagents, etc. used in the following examples are all commercially available products.

[0017] Example 1: Comparison of mosquito repellent activity of various plant essential oils

[0018] The repellent activity of plant essential oils against female adults of Aedes albopictus was determined by a "Y"-type olfactometer. The determination system consists of a "Y"-type tube, a drying tower, a vacuum pump, a water tower, a sample chamber and an odorless silicone tube. Under the conditions of room temperature of 26±1℃, relative humidity of 65±10%, and light intensity of 140Lux, the outside air was purified by activated carbon adsorption in the drying tower, entered the water tower for humidification, and then entered the sample determination chamber, entered the main pipe through the arm pipe of the "Y"-type tube, and the gas flow rate was 160mL / min for the main pipe, and finally discharged to the outside through the silicone tube. After the "Y"-type olfactometer equipment was installed, a certain amount of essential oil was sucked onto a filter paper strip with a microinjector and placed in the sample chamber on one side, and a filter paper strip of the same size without essential oil was placed in the sample chamber on the other side as a control. After 20s, 20 female mosquitoes were put into the insect throwing port, and the number of mosquitoes in the two arm pipes at 5, 10, 15 and 20min was recorded respectively. Each group of experiments was repeated 3 times. The formula for calculating the repellency (PR) is as follows:

[0019] PR(%)=(Nc-Nt) / (Nc+Nt)×100

[0020] Nc: number of mosquitoes in the control arm;

[0021] Nt: number of mosquitoes in the treatment group.

[0022] Table 1 Preliminary screening of mosquito repellent activity of 10 plant essential oils (5.0 μL)

[0023]

[0024] Note: The above data are the results of three parallel determinations (mean ± error); 20 female mosquitoes in each group.

[0025] Table 1 Preliminary screening of mosquito repellent activity of 10 plant essential oils (5.0 μL)

[0026]

[0027]

[0028] Note: The above data are the results of three parallel determinations (mean ± error); 20 female mosquitoes in each group.

[0029] The preliminary screening results of the mosquito repellent activity of 10 plant essential oils are shown in Table 1. As can be seen from Table 1, when the dosage of the essential oil is 5.0 μL, most of the plant essential oils show good repellent activity. Among them, eucalyptus oil and grass fruit oil show better repellent activity, and the repellent rate reaches more than 90% after five minutes; secondly, clove basil also shows better repellent activity, reaching more than 80% in the 5th minute, but the repellent rate at other times is slightly reduced.

[0030] Example 2: Screening of compounding ratio of tsaoko oil and eucalyptus oil

[0031] According to the preliminary screening results of the mosquito repellent activity of the above plant essential oils, the two plant essential oils with relatively good repellent effects are tsaoko oil and eucalyptus oil. Therefore, these two essential oils can be selected for compounding [V (tsaoko oil): V (eucalyptus oil)], with the ratio set to 1:9, 3:7, 5:5, 7:3, 9:1, and the mosquito repellent activity of plant essential oils with different ratios is determined by using the human skin protection test (the test method of GB / T 13917.9-2009 is carried out in a mosquito cage).

[0032] The mosquito repellent activity results of different ratios of grass fruit oil and eucalyptus oil are shown in Table 2. As can be seen from Table 2, when the dosage of the compound essential oil is 24.0 μL, the effective protection time of the compound essential oil of grass fruit oil: eucalyptus oil = 5:5 is significantly better than the protection time of the two essential oils alone, and its effective protection time is 82.5 minutes. Therefore, the ratio of 5:5 is a better choice for compound essential oils.

[0033] Table 2 Mosquito repellent activity of different ratios of tsaoko oil and eucalyptus oil (GB / T 13917.9-2009 test method carried out in a mosquito cage, 24.0 μL)

[0034]

[0035]

[0036] Note: A represents V (tsaoko oil): V (eucalyptus oil); the sample size is 2 males and 2 females; the effective protection time is the average value of four repetitions.

[0037] Example 3: Preparation of mosquito repellent nanoemulsion containing compound plant essential oil

[0038] The formula of the mosquito repellent nanoemulsion of this embodiment is, in percentage terms, 9.6% grass fruit oil + 9.6% eucalyptus oil + 0.8% vanillin (synergist) + 5% Span80 + 2.5% n-propanol + 72.5% distilled water. The preparation method is:

[0039] S1, the compound essential oils of tsaoko oil and eucalyptus oil and vanillic aldehyde are fully stirred and evenly mixed, and this system is used as oil phase A;

[0040] S2, deionized water, surfactant and co-surfactant were measured and placed in a conical flask, and magnetically stirred at 600 rpm for 15 min at room temperature. This system is the aqueous phase B;

[0041] S3, slowly adding the oil phase A while stirring the aqueous phase B, and homogenizing for a certain period of time at a speed of 10000 rpm using a high-speed shearing machine to form a crude emulsion;

[0042] S4, placing the crude emulsion in a centrifuge tube, and breaking it by an ultrasonic cell disruptor to obtain a milky white mosquito repellent nanoemulsion, the whole process is carried out under ice bath conditions. The operating parameters of the ultrasonic cell disruptor are as follows: working time: 4s, rest time: 2s.

[0043] Example 4: Determination of the repellent effect of plant essential oil mosquito repellent nanoemulsion on Aedes albopictus

[0044] 1. Materials and methods

[0045] 1.1 Test materials

[0046] 1.1.1 Test insects

[0047] Aedes albopictus, cultured in the sanitary pest insectary room of the Pollution-free Pesticide Research and Service Center of Northwest A&F University.

[0048] 1.1.2 Test reagents

[0049] 20% tsaoko oil and eucalyptus oil mosquito repellent nanoemulsion prepared in Example 3; 20% tsaoko oil and eucalyptus oil alcohol solution [V (tsaoko oil): V (eucalyptus oil) = 5:5]; Longliqi mosquito repellent; Frog Prince mosquito repellent.

[0050] The substance and formula of 20% amomum villosum oil and eucalyptus oil alcohol solution are specifically: 10% amomum villosum oil+10% eucalyptus oil+80% ethanol.

[0051] 1.2 Biotest method (human skin protection test)

[0052] The test is carried out in accordance with the test method specified in the National Standard of the People's Republic of China GB / T 13917.9-2009.

[0053] 1.2.1 Attack power test

[0054] 300 test insects are placed in a mosquito cage. The tester exposes a 40mm×40mm skin area on the back of his hand, and the rest of the body is tightly covered. Put the arm into the mosquito cage for 2 minutes, and observe if the mosquitoes land. Shake the arm to drive them away before their mouthparts pierce the skin, which is counted as one test insect landing. If more than 30 test insects land on the tester and the test insects, the attack power is qualified, and this person and the mosquitoes in this cage can be used for the repellent test.

[0055] 1.2.2 Repellency test

[0056] Select 4 or more testers with qualified attack power (half male and half female, and should not drink alcohol, tea or coffee before and during the test, and should not use products containing flavors), draw a 50mm×50mm skin area on the back of each hand, and evenly apply the repellent to be tested at a dose of 1.5μL / cm2 on one hand, exposing 40mm×40mm of skin, and tightly covering the rest. The other hand is a blank control. 2h after applying the repellent, put the hand into a mosquito cage with qualified attack power for 2min, and observe whether there are mosquitoes coming to land and suck blood. After that, test once every 1h. As long as one mosquito comes to suck blood, the repellent is judged to be ineffective. Record the effective protection time of the repellent (h). Each time, the control hand is tested first. The test insects with qualified attack power can continue the test. If the test insects have unqualified attack power, they need to be replaced with qualified test insects for testing.

[0057] 1.2.3 Calculation

[0058] Add up the effective protection time of the drug for 4 or more subjects, and take the average (retain one decimal place) as the effective protection time (h) of the drug.

[0059] 1.2.4 Evaluation

[0060] The efficacy of the repellent was evaluated based on the effective protection time (h) of the test persons.

[0061] The efficacy results are divided into two levels, A and B. Products that do not meet the B level standard are considered unqualified products.

[0062] Class A: effective protection time ≥ 6h; Class B: effective protection time ≥ 4h

[0063] 2 Results and analysis

[0064] The human protection test method was used to systematically determine the effective protection time of the compound essential oil nanoemulsion on the human body. The results are shown in Table 3.

[0065] Table 3 Effective protection time of plant essential oil nano mosquito repellent ointment

[0066]

[0067]

[0068] As shown in Table 3, the 20% compound essential oil nanoemulsion has a good mosquito repellent effect, and the effective protection time of mosquito repellent is 240 minutes, which meets the national B-level standard of repellent. Compared with the commercially available mosquito repellent, its effective protection time of mosquito repellent is longer.

[0069] In the human skin protection test, the compound essential oil nanoemulsion not only has good quick effect, but also has a longer lasting effect than the alcohol solution of compound essential oil. It is also environmentally friendly and safe for human health. It has a certain slow-release effect and prolongs the mosquito repellent effect. Therefore, it is very suitable for the prevention and control of household pests and mosquitoes, and has great application and promotion value.

[0070] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, these modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. Application of tsaoko oil in preparing mosquito repellent.

2. The application of tsaoko oil and eucalyptus oil in the preparation of mosquito repellent.

3. The use according to claim 1 or 2, characterized in that: The mosquito repellent is mosquito repellent essential oil, mosquito repellent lotion, mosquito repellent coil, mosquito repellent patch, mosquito repellent ointment or other mosquito repellent products.

4. A mosquito repellent, characterized in that: The mosquito repellent is a mosquito repellent nanoemulsion, the active ingredients of the mosquito repellent nanoemulsion are tsaoko oil and eucalyptus oil, and the volume ratio of the tsaoko oil to the eucalyptus oil is 1-9:9-1.

5. The mosquito repellent according to claim 4, characterized in that: The volume ratio of tsaoko oil to eucalyptus oil is 3-7:7-3.

6. The mosquito repellent according to claim 4, characterized in that: The volume ratio of cardamom oil and eucalyptus oil is 5:

5.

7. The mosquito repellent according to any one of claims 4 to 6, characterized in that: The mosquito repellent is prepared from the following raw materials in volume percentage: 5% to 10% of compound essential oil of tsaoko oil and eucalyptus oil, 2% to 5% of synergist, 5% to 10% of surfactant, 0% to 5% of co-surfactant, and the balance is deionized water, and the sum of the volume percentages of the raw materials is 100%.

8. The mosquito repellent according to claim 7, characterized in that: The synergist is one of vanillin, citral, cuminaldehyde, cinnamaldehyde or citronellal, or a mixture of two or more thereof; the surfactant is one of Tween20, Tween80, Span20 and Span80, or a mixture of two or more thereof; and the co-surfactant is one of anhydrous ethanol, n-propanol, n-butanol and isobutanol, or a mixture of two or more thereof.

9. The method for preparing the mosquito repellent according to claim 7, characterized in that: The preparation method comprises the following steps: S1, the compound essential oil of tsaoko oil and eucalyptus oil is mixed with a synergist to obtain an oil phase A; S2, deionized water, surfactant and co-surfactant are mixed to obtain aqueous phase B; S3, adding the oil phase A while stirring the aqueous phase B, and mixing to form a crude emulsion; S4, the crude emulsion is treated with ultrasound to obtain mosquito repellent nanoemulsion.

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