A natural plant mite removal emulsion and its preparation method and application

Abstract

The present invention discloses a natural plant mite removal emulsion, a preparation method, and an application thereof. The natural plant mite removal emulsion of the present invention comprises, by mass percentage, 5%-10% of volatile oil from Litsea cubeba, 5%-10% of total saponins from Eclalphia chinensis, 4%-8% of an emulsifier, 3%-5% of an auxiliary emulsifier, 15%-25% of triglycerides, and the balance of water. The above components are added with distilled water to make up to 100% to form a uniform emulsion. The activity of the volatile oil and saponins is utilized to kill dust mites. The emulsion allows the medicinal ingredients to evaporate slowly, exerting a long-lasting insecticidal effect. The product can be used in the fields of daily necessities, cosmetics, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation of traditional Chinese medicine compositions and mite removal in daily chemical products, and in particular to a natural plant mite removal emulsion containing litsea cubeba volatile oil and eclipta saponin, as well as a preparation method and application thereof. Background Art

[0002] As we all know, mites are widely distributed in our environment. They can inhabit damp places, clothing, fabrics, and household items that humans come into contact with daily. Prolonged exposure to mites can easily lead to allergies and various skin diseases, causing problems for people. Currently used mite removal agents are mostly chemical, which are prone to residues, pose health risks after prolonged contact or inhalation, and can easily lead to drug resistance. Therefore, the development of green, safe, and natural plant-based mite removal agents is of great significance.

[0003] Numerous studies have shown that various components in plant extracts have significant repellent and killing effects against mites. However, currently, there are only a limited number of pure Chinese herbal miticide formulations. Existing botanical miticides are complex due to the large number of raw materials, including numerous medicinal herbs, making their composition difficult to control. Alternatively, some active ingredients are volatile, resulting in a short duration of action. While volatile oil from Litsea cubeba has antibacterial and mite-killing properties (CN105039016A, CN108103607A, and CN101278681A), single-use Litsea cubeba oil has limited mite-killing efficacy and evaporates rapidly, preventing long-term effects. Therefore, there is a need to develop a natural botanical mite-killing formulation with high biosafety and long-term efficacy. Summary of the Invention

[0004] The purpose of the present invention is to provide a natural plant mite removal emulsion and its preparation method and application. The natural plant mite removal emulsion provided by the present invention can effectively kill mites for a long time.

[0005] The first aspect of the present invention provides a natural plant mite removal emulsion, which comprises, by weight percentage: 5%-10% of volatile oil of Litsea cubeba, 5%-10% of total saponins of Eclalphia lappa, 4%-8% of emulsifier, 3%-5% of auxiliary emulsifier, 15%-20% of triglyceride, and the balance is water.

[0006] Furthermore, the volatile oil of Litsea cubeba was prepared by the following method: fresh Litsea cubeba fruit was taken, placed in a round-bottom flask, deionized water with a solid-liquid ratio of 1:10~1:20 (W / V) was added, ultrasonic pretreatment was performed for 10 minutes, and then heated to boiling. The volatile oil was extracted by steam distillation for 2~4 hours, and the upper oily liquid in the volatile oil extractor was collected to obtain the volatile oil of Litsea cubeba.

[0007] Furthermore, the total saponins of Eclalaria japonica were prepared by the following method: (1) Extraction: Take the dried whole herb of Eclalaria japonica, add 8 to 12 times (V / W) of 80% ethanol, reflux extract twice, each time for 60 minutes, filter, combine the filtrates, and recover the solvent under reduced pressure until there is no alcohol smell to obtain a concentrated solution. (2) Macroporous resin purification: Take the concentrated solution of step (1) and purify it by AB-8 macroporous resin column chromatography. The loading ratio is: V 浓缩液 / W 大孔树脂 =2:1, repeat the sample loading twice, let it stand for 20 minutes after the sample loading, first elute with 30% (V / V) ethanol for 2 column volumes, and discard; then elute with 80% (V / V) ethanol for 4 column volumes, collect the eluate, recover the solvent, and put it into a freeze dryer for lyophilization to obtain the dry powder of total saponins of Eclaluddin.

[0008] Furthermore, the emulsifier is selected from one or more of polysorbate 20 and polysorbate 80; preferably polysorbate 80.

[0009] Furthermore, the co-emulsifier is ethanol with a mass concentration of 70-100%, preferably anhydrous ethanol.

[0010] The second aspect of the present invention provides a method for preparing the above-mentioned natural plant mite removal emulsion, comprising the following specific steps:

[0011] According to the mass fraction, the volatile oil of Litsea cubeba is dispersed in triglyceride and completely dissolved to obtain an oil phase; the total saponins of Eclalphia lappa are added to anhydrous ethanol and dispersed, and then added together with the emulsifier polysorbate 80 to distilled water, and the mixture is used as the aqueous phase; at a water bath temperature of 50°C and a stirring speed of 450 rpm, the above-mentioned oil phase is added to the aqueous phase while stirring, so that the oil phase and the aqueous phase are evenly mixed to prepare a uniform emulsion.

[0012] The natural plant mite removal emulsion prepared by the invention has uniform particle size and good stability.

[0013] The natural plant mite removal emulsion of the present invention can be used in the fields of cleaning daily necessities, cosmetics, clothing or environmental mite removal.

[0014] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0015] The present invention combines the extracted volatile oil from Litsea cubeba with the total saponins extracted and purified from Eclaleuca alternifolia. This formulation leverages the acaricidal properties of Litsea cubeba oil and the cytotoxic effects of Eclaleuca alternifolia saponins. Furthermore, Eclaleuca alternifolia saponins act as surfactants, promoting insect absorption of the volatile oil. To address the drawbacks of rapid volatilization and short efficacy of volatile oil components, the present invention incorporates a carefully designed formulation of the two compositions. Litsea cubeba volatile oil is encapsulated in an aqueous phase containing Eclaleuca alternifolia saponins to form an emulsion, achieving sustained-release, long-lasting acaricidal efficacy. In an exemplary embodiment of the present invention, the prepared plant emulsion achieved a mite-killing rate of 80.14% on the first day of use, demonstrating a strong acaricidal effect as evaluated according to T / CHCIA 002-2022 standards. The mite-killing rates were 76.09% on the second day and 62.92% on the third day, still meeting the product's efficacy criteria. This demonstrates that the product can still effectively kill mites three days after use, demonstrating its long-lasting efficacy compared to other products. The process of the present invention is green, environmentally friendly, and can be promoted for use. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figures are the 5-day mite-killing effects of each group of Examples and Comparative Examples. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the examples, but is not limited thereto. Example 1

[0018] Extraction of volatile oil from Litsea cubeba using different solvents: Fresh Litsea cubeba fruit was placed in a round-bottom flask and deionized water was added at a solid-to-liquid ratio of 1:8 to 22 (w / v). After ultrasonic pretreatment for 10 minutes, the mixture was heated to boiling and the volatile oil was extracted by steam distillation for 3 hours. The upper oily liquid in the volatile oil extractor was collected to obtain the volatile oil from Litsea cubeba. The yield of volatile oil from Litsea cubeba under different extraction conditions is shown in Table 1.

[0019] Table 1 Yield of volatile oil from Litsea cubeba under different extraction conditions

[0020]

[0021] As shown in Table 1, a solid-to-liquid ratio (W / V) of 1:8 yielded relatively low levels of essential oil from Litsea cubeba. As the amount of extraction solvent increased, the volume of essential oil also increased. At a solid-to-liquid ratio (W / V) of 1:20, the yield of essential oil from Litsea cubeba reached 3.84%. However, the yield did not improve significantly when the solid-to-liquid ratio (W / V) of 1:22 was used. Therefore, the present invention sets the solid-to-liquid ratio of the solvent used for extracting essential oil from Litsea cubeba to between 1:10 and 1:20 (W / V). Example 2

[0022] Extraction of volatile oil from Litsea cubeba at different extraction times: Fresh Litsea cubeba fruit was placed in a round-bottom flask and deionized water was added at a solid-to-liquid ratio of 1:20 (w / v). After ultrasonic pretreatment for 10 minutes, the mixture was heated to boiling and the volatile oil was extracted by steam distillation for 1-5 hours. The supernatant oil in the volatile oil extractor was collected to obtain the volatile oil from Litsea cubeba. The specific yields of volatile oil from Litsea cubeba at different extraction times are shown in Table 2.

[0023] Table 2 Yield of volatile oil from Litsea cubeba at different extraction times

[0024]

[0025] As can be seen from Table 2, when the extraction time is 1 h, the yield of volatile oil from Litsea cubeba is low, and when the extraction time is further increased to 4 h, the yield reaches 3.95, and when the extraction time exceeds 3 h, the yield does not increase much. Considering that a long extraction time has a certain impact on the stability of the volatile oil components and the time cost of extraction, the present invention sets the extraction time of volatile oil from Litsea cubeba to 2-4 hours. Example 3

[0026] Effect of extraction solvent on total saponin content of Eclaleuca alternifolia: Dry the whole herb of Eclaleuca alternifolia and add 6-14 times the volume (V / W) of 70-90% ethanol. Reflux and extract twice, each for 60 minutes. Filter and combine the filtrates. Reduce pressure and recover the solvent until the alcohol odor is gone to obtain a concentrate. The concentrate was purified by AB-8 macroporous resin column chromatography. The loading ratio was: V 浓缩液 / W 大孔树脂 =2:1, repeat the sample loading twice, let it stand for 20 minutes after the sample loading, first elute with 30% (V / V) ethanol for 2 column volumes, and discard; then elute with 80% (V / V) ethanol for 4 column volumes, collect the eluate, recover the solvent, and put it into a freeze dryer for lyophilization to obtain the dry powder of total saponins of Eclaluddin.

[0027] The total saponin content of Ecliptaecarpa extracts obtained under specific extraction conditions of different ethanol concentrations and volumes is shown in Table 3. As shown in Table 3, when the extraction solvent volume was 6 times the medicinal material (V / W), the total saponin content of Ecliptaecarpa was lower than that of other extracts. When the solvent volume was 14 times the medicinal material volume, the total saponin content did not change significantly compared to 12 times the volume. Therefore, the present invention sets the solvent volume for Ecliptaecarpa extraction to 8-12 times the volume (V / W). Furthermore, the ethanol solvent concentration was examined and it was found that extraction with 70% and 90% ethanol was not as effective as with 80% ethanol, so the ethanol concentration was set to 80%.

[0028] Determination of Total Saponins in Eclampsia chinensis Extract: The total saponins content in freeze-dried powder of Eclampsia chinensis extract was determined using UV-visible spectrophotometry. Weigh the Eclampsia chinensis A reference standard and add methanol to a 0.1 mg / mL reference solution. Accurately pipette 0.5 mL, 1.0 mL, 1.5 mL, 2.0 mL, 2.5 mL, and 3.0 mL of the reference standard stock solution into stoppered test tubes. Evaporate the solvent in a waterbath. Add 0.5 mL of 1% vanillin-perchloric acid solution to each tube. Heat in a 60°C waterbath for 15 minutes. Remove from the tube and cool on ice for 5 minutes. Add 5 mL of 70% sulfuric acid, shake well, and measure the absorbance at 550 nm. Prepare a standard curve using the absorbance and concentration. Dissolve an appropriate amount of freeze-dried powder of the test sample in methanol. Measure the absorbance at 550 nm using the same method as for the reference standard. Substitute the absorbance into the standard curve equation to calculate the total saponins content in the test sample.

[0029] Table 3 Content of total saponins of Eclalphia chinensis in each group of samples

[0030] Example 4

[0031] Effect of elution solvent on the total saponin content of Eclaleuca alternifolia: Take the dried whole herb of Eclaleuca alternifolia and add 10 times the volume (V / W) of 80% ethanol. Reflux and extract twice, each for 60 minutes. Filter and combine the filtrates. Recycle the solvent under reduced pressure until the alcohol taste is gone to obtain a concentrate. The concentrate is purified by AB-8 macroporous resin column chromatography. The loading ratio is: V 浓缩液 / W 大孔树脂 =2:1, repeat the sample loading twice. After loading, let it stand for 20 minutes. First, elute with 30% (v / v) ethanol for 2 column volumes and discard. Then, elute with 70-90% (v / v) ethanol for 2-5 column volumes. The eluate was collected, the solvent was recovered, and lyophilized in a freeze dryer to obtain a dry powder of total saponins from Eclampsia chinensis. The specific total saponin contents obtained under different ethanol elution conditions are shown in Table 4.

[0032] Table 4 Content of total saponins of Eclalphia chinensis in each group of samples

[0033]

[0034] As shown in Table 4, when the Eclipta prostrata extract was purified by macroporous resin, elution with 70% ethanol may have insufficient solubility, resulting in a lower amount of total Eclipta prostrata saponins than that obtained with 80% ethanol. Elution with 90% ethanol also resulted in an unsatisfactory amount of total Eclipta prostrata saponins due to the presence of impurities such as chlorophyll. Therefore, 80% ethanol was selected as the elution solvent, and elution was performed for 4 column volumes. Example 5

[0035] The natural plant mite removal emulsion was prepared using the dried powder of total saponins of Eclaleuca alternifolia obtained by steam distillation of the volatile oil of Litsea cubeba obtained by extraction for 3 hours at a solid-liquid ratio of 1:20 in Example 1 and the dried powder of total saponins of Eclaleuca alternifolia obtained by extraction with 10 times the amount (V / W) of 80% ethanol added in Example 3 and elution with 80% ethanol for 4 column volumes.

[0036] Emulsion formula: 10% volatile oil of Litsea cubeba, 10% total saponins of Eclalphia chinensis, 8% polysorbate 80, 5% anhydrous ethanol, 20% triglyceride, and 47% distilled water.

[0037] The preparation method of the emulsion comprises the following steps: dispersing volatile oil from Litsea cubeba in triglyceride according to a formula and dissolving the oil phase completely; dispersing total saponins from Eclalaria japonica in anhydrous ethanol, adding the saponins together with an emulsifier, polysorbate 80, into distilled water, and mixing them to form the aqueous phase; adding the oil phase to the aqueous phase while stirring at a water bath temperature of 50°C and a stirring speed of 450 rpm to uniformly mix the oil phase and the aqueous phase to prepare a uniform light green emulsion. Example 6

[0038] A natural plant-based mite-removing emulsion was prepared using the volatile oil from Litsea cubeba obtained by steam distillation for 3 hours at a solid-to-liquid ratio of 1:20 in Example 1, and the dry powder of total saponins from Eclaleuca alternifolia obtained by extraction with 12 times the volume (v / w) of 80% ethanol in Example 3, followed by elution with 80% ethanol for 4 column volumes. The eluate was eluted with 80% ethanol to obtain the resulting eluate. The emulsion formulation and preparation method were the same as those in Example 5. Example 7

[0039] The preparation method of this embodiment is the same as that of embodiment 5, except that the emulsion formula is: 5% volatile oil of Litsea cubeba, 10% total saponins of Eclalphia lappa, 6% polysorbate 80, 5% anhydrous ethanol, 16% triglyceride, and 58% distilled water. Example 8

[0040] The preparation method of this embodiment is the same as that of embodiment 5, except that the emulsion formula is: 10% of volatile oil of Litsea cubeba, 5% of total saponins of Eclalphia lappa, 4% of polysorbate 80, 3% of anhydrous ethanol, 25% of triglyceride, and 53% of distilled water. Comparative Example 1

[0041] The preparation method of this comparative example is the same as that of Example 5, except that the emulsion formula is: 10% of Litsea cubeba essential oil, 8% of polysorbate 80, 5% of anhydrous ethanol, 20% of triglyceride, and 57% of distilled water. Comparative Example 2

[0042] The preparation method of this comparative example is the same as that of Example 5, except that the emulsion formula is: 10% total saponins of Eclalaria japonica, 8% polysorbate 80, 5% anhydrous ethanol, 20% triglyceride, and 57% distilled water. Comparative Example 3

[0043] This comparative example is prepared in the same manner as Example 5, except that the raw material for extracting Litsea cubeba is the leaves of Litsea cubeba. Comparative Example 4

[0044] This comparative example is prepared in the same manner as in Example 5, except that the total saponins of Eclalphia lappa were not purified with a macroporous resin. Comparative Example 5

[0045] This comparative example is prepared by the same method as Example 5, except that when the total saponins of Eclalphia lappa were purified by macroporous resin, elution with 30% (v / v) ethanol for 2 column volumes and then discarded was performed, but elution was performed directly with 80% (v / v) ethanol for 4 column volumes, and the eluate was collected, concentrated, and dried to prepare the product. Comparative Example 6

[0046] The preparation method of this comparative example is the same as that of Example 5, except that the emulsion formula is: 10% of Litsea cubeba volatile oil, 10% of Eclalphia truncatula total saponins, 8% of polysorbate 80, 20% of triglyceride, and 52% of distilled water.

[0047] Mite removal performance test:

[0048] The mite removal performance of the emulsions prepared in the examples and comparative examples was tested with reference to the method described in "Evaluation Method for Repellent, Inhibitory and Killing Mites of Daily Chemical Products" (T / CHCIA 002-2022). Take filter paper and spread it flat in a culture dish, drip the sample to be tested onto the filter paper to make it completely soaked, and take another filter paper and drip distilled water into it as a blank control. Put a specified number of dust mites and feed in each culture dish and culture them in an incubator with a temperature of 25°C and a relative humidity of 75%. Every 2 hours, observe the death of dust mites, and every 24 hours, count the mortality rate, remove all dust mites, put in a new batch of dust mites, and continue to observe and count. The results of the mite removal effect of each group of test products are shown in Table 5 and Figure 1 The T / CHCIA 002-2022 standard stipulates that a mite killing rate of ≥60% indicates that the product is effective, ≥80% indicates that the product has a strong mite killing effect, and ≥95% indicates that it has an extremely strong effect. Figure 1 It can be seen that the mite killing rates of Example 1 and Example 4 (80% ethanol, 12 times) exceeded 80% on the first day of use, achieving a strong mite killing effect. After 3 days of use, the mite killing rates still exceeded 60%, achieving an effective effect of the product, indicating that the product has a mite killing effect and a long duration of action.

[0049] Table 5 Mite removal effect of each group of samples

[0050]

[0051] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A natural plant mite removal emulsion, characterized in that: The composition comprises, by weight percentage: 5%-10% of volatile oil of Litsea cubeba, 5%-10% of total saponins of Eclalphia chinensis, 4%-8% of emulsifier, 3%-5% of auxiliary emulsifier, 15%-20% of triglyceride, and the balance of water; The volatile oil of Litsea cubeba is prepared by the following method: fresh Litsea cubeba fruit is placed in a round-bottom flask, deionized water with a solid-liquid ratio of 1:10 to 1:20 (W / V) is added, ultrasonic pretreatment is performed for 10 minutes, heating to boiling, and volatile oil is extracted by steam distillation for 2 to 4 hours, and the upper oily liquid in the volatile oil extractor is collected to obtain the volatile oil of Litsea cubeba; The total saponins of Eclalphia chinensis are prepared by the following method: (1) Extraction: Take the dried whole herb of Eclipta prostrata, add 8-12 times the volume (V / W) of 80% ethanol, reflux extract twice, each time for 60 minutes, filter, combine the filtrates, and decompress the filtrates to recover the solvent until there is no alcohol smell to obtain a concentrated solution; (2) Macroporous resin purification: The concentrated solution from step (1) was purified by AB-8 macroporous resin column chromatography, with the loading ratio being: V 浓缩液 / W 大孔树脂 =2:1, repeat the sample loading twice, let it stand for 20 minutes after the sample loading, first elute with 30% (V / V) ethanol for 2 column volumes, discard; then elute with 80% (V / V) ethanol for 4 column volumes, collect the eluate, recover the solvent, and freeze-dry in a freeze dryer to obtain the dry powder of total saponins of Eclaleuca alternifolia. The emulsifier is selected from one or more of polysorbate 20 and polysorbate 80; the auxiliary emulsifier is ethanol with a mass concentration of 70-100%.

2. The method for preparing the natural plant mite-removing emulsion according to claim 1, wherein: The method comprises the following specific steps: dispersing volatile oil of Litsea cubeba in triglyceride to completely dissolve the oil phase; taking total saponins of Eclalphia lappa, adding the saponins to an emulsifier, dispersing the saponins in distilled water, adding an emulsifier, and mixing the mixture to form an aqueous phase; adding the oil phase to the aqueous phase while stirring at a water bath temperature of 50°C and a stirring speed of 450 rpm to uniformly mix the oil phase and the aqueous phase to prepare the natural plant mite removal emulsion.

3. Use of the natural plant mite removal emulsion according to claim 1 in the field of cleaning daily necessities, cosmetics, clothing or environmental mite removal.

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