Aloe extract with high O-acetyl content and preparation method and application thereof

Abstract

The present invention relates to an aloe extract with a high O-acetyl content, a preparation method and an application thereof. The aloe extract with a high O-acetyl content is prepared from aloe as a raw material, peeled and pulped to obtain a crude aloe extract A1, which is then purified by ethanol and impurities removed by activated carbon, and then treated by ultraviolet irradiation. The present invention enhances the level of acetylation in the aloe extract by means of physical ultraviolet light technology, and the obtained highly acetylated aloe extract can effectively treat or alleviate the symptoms of colitis.

Description

Technical Field

[0001] The invention relates to the technical field of plant extraction, and in particular to an aloe extract with a high O-acetyl content and a preparation method and application thereof. Background Art

[0002] Inflammatory bowel disease (IBD) is a chronic autoimmune disease characterized by gastrointestinal ulcers. Patients suffer from gastrointestinal bleeding, perforation, intestinal obstruction and other diseases for a long time. Studies have found that intestinal flora disorders are closely related to the occurrence and development of inflammatory bowel disease. The treatment of IBD mainly includes aminosalicylic acid drugs, glucocorticoid drugs, immunosuppressants and biological therapeutic drugs. However, the efficacy is low, the recurrence rate is high, and the side effects are large during the treatment process. At the same time, in the long-term treatment process, patients have to bear high drug costs, which is a disadvantage in the clinical application of such drugs. The adverse reactions and side effects of glucocorticoids and immunosuppressants also limit the application of the above drugs. The research and application of biological therapeutic drugs have received increasing attention. They can treat ulcerative colitis by anti-inflammatory and regulating immune responses, but their expensive drug costs also limit the application of the above drugs. Therefore, screening drugs with clear therapeutic effects, fewer adverse reactions and moderate treatment costs, and studying the main mechanism of action of related drugs and their active ingredients have become an important part of current scientific research and drug development.

[0003] Aloe vera is a medicinal plant with broad development and application prospects. Aloe vera extract has a variety of biological activities and is widely used in food, medicine, life sciences and other fields. Acetyl plays an important role in plant active substances. Studies have found that acetylated aloe vera extract can effectively enhance biological activity, improve its biological regulation, reduce side effects to a certain extent, and even produce new activities. In 2007, the light industry standard of the People's Republic of China included the O-acetyl content in the "Aloe vera products for food raw materials" standard. However, the content of acetylated aloe vera extract in aloe vera gel is low, and its processing difficulties and low activity have greatly limited its application in biomedicine. Acetylation modification of aloe vera extract, as an important means of developing and utilizing aloe vera, can enhance the value of aloe vera in the fields of food and biomedicine. Therefore, it is of great significance to obtain acetylated aloe vera extracts with good processing properties and high biological activity through physical or chemical modification for the research and development of innovative plant drugs. Summary of the invention

[0004] The purpose of the present invention is to provide an aloe extract with a high O-acetyl content, which has high acetylation, good biological activity, better stability, and can effectively alleviate the symptoms of colitis and the intestinal flora and metabolism.

[0005] The technical solution adopted by the present invention is as follows:

[0006] The invention discloses an aloe extract with high O-acetyl content. The aloe extract is obtained by peeling and pulping aloe vera as raw material, purifying the aloe vera extract with ethanol, removing impurities with activated carbon and then treating the extract with ultraviolet irradiation.

[0007] The aloe extract with a high O-acetyl content of the present invention is prepared by the following method:

[0008] (1) soaking, washing, peeling and beating aloe leaves to obtain aloe extract A1, wherein the growth period of the aloe leaves is not less than 6 months, and the selected aloe is preferably Aloe vera;

[0009] (2) adding 50% by volume ethanol aqueous solution to the aloe extract A1 at a volume ratio of 1:5 and stirring at 20° C. for 24 hours; further concentrating to obtain aloe polysaccharide crude extract A2;

[0010] (3) Adding 15% by volume of activated carbon to the crude extract of aloe polysaccharide A2 to obtain a feed solution, wherein the activated carbon particle size is 2-3 mm;

[0011] (4) Immerse a submersible ultraviolet lamp in the liquid and continue stirring under ultraviolet light for 24 to 48 hours until the liquid is clarified, thereby obtaining a crude extract of aloe polysaccharide A3; wherein the wavelength of the ultraviolet light is 365 nm, and the ultraviolet light intensity at a distance of 5 cm from the ultraviolet lamp is not less than 1500 lux (at least 1500 lux);

[0012] (5) Filtering the obtained aloe polysaccharide crude extract A3 twice to remove fine residues and activated carbon, and taking clarified liquid;

[0013] (6) The clarified liquid obtained by filtering the crude aloe polysaccharide extract A3 was further stirred at 90° C. for 8 h to obtain a further concentrated aloe polysaccharide extract A4;

[0014] (7) The aloe polysaccharide extract A4 was sterilized at high temperature and high pressure to obtain the product aloe extract; the obtained aloe extract was subjected to O-acetyl detection, and the results showed that the O-acetyl content in the aloe extract treated with UV was significantly increased.

[0015] The advantages of the present invention are:

[0016] 1. The present invention uses physical ultraviolet light technology to enhance the acetylation level in the aloe extract.

[0017] 2. The highly acetylated aloe extract obtained by the present invention can effectively treat or alleviate the symptoms of colitis. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a bar graph of the O-acetyl content in the aloe extracts of the examples and comparative examples;

[0019] Figure 2 The colon length of mice in the control group, comparative example group and embodiment group;

[0020] Figure 3 Microscopic photos of crypt hyperplasia in the colon segments of mice in the control group, comparative example group and embodiment group;

[0021] Figure 4 These are microscope photos of the intestinal mucosal marker E-cadherin staining of the mouse colon segments in the control group, comparative example group and example group. The expression level of E-cadherin is represented by the color depth. DETAILED DESCRIPTION

[0022] In order to make the technical personnel in the field understand the present invention more clearly and intuitively, the present invention will be further described below in conjunction with the accompanying drawings. The experimental methods without specific conditions in the following examples are selected according to conventional methods and conditions, or according to the product instructions.

[0023] Example (UV irradiation)

[0024] The aloe extract with high O-acetyl content in this embodiment is prepared by the following method:

[0025] (1) 100 kg of Aloe vera leaves were soaked, washed, peeled and pulped to obtain 60 kg of crude aloe extract A1, wherein the growth period of the aloe vera leaves is not less than 6 months. In this embodiment, the same batch of Aloe vera with a growth period of 10 months was selected as the raw material;

[0026] (2) adding 50% by volume ethanol aqueous solution to the aloe extract A1 at a volume ratio of 1:5 and stirring at 20° C. for 24 h; further concentrating to obtain about 300 L of aloe polysaccharide crude extract A2;

[0027] (3) Adding 15% by volume of activated carbon to the crude extract of aloe polysaccharide A2 to obtain a feed solution, wherein the activated carbon particle size is 2-3 mm;

[0028] (4) Immerse a submersible ultraviolet lamp in the liquid, and continue stirring under ultraviolet light for 24 to 48 hours until the liquid is clear, thereby obtaining a crude extract of aloe polysaccharide A3; wherein the wavelength of the ultraviolet light is 365 nm, and the ultraviolet light intensity at a distance of 5 cm from the ultraviolet lamp is not less than 1500 lux;

[0029] (5) Filtering the crude extract A3 of aloe polysaccharide after UV irradiation twice to remove fine residues and activated carbon, and obtaining about 250 L of clear liquid;

[0030] (6) The clarified liquid obtained by filtering the crude aloe polysaccharide extract A3 was further stirred at 90°C for 20 h to obtain a further concentrated aloe polysaccharide extract A4, about 60 L;

[0031] (7) The aloe polysaccharide extract A4 is sterilized at high temperature and high pressure to obtain an aloe extract with biological activity.

[0032] The above preparation method was repeated for 6 times, and the aloe extracts obtained were labeled as UV1 to UV6. The O-acetyl group of the aloe extract preparations of UV1 to UV6 was detected respectively; then the aloe extracts of UV1 to UV6 were mixed and sampled for the enteritis treatment experiment.

[0033] Comparative example (without UV irradiation)

[0034] The aloe extract of this comparative example was prepared by the following method:

[0035] (1) 100 kg of Aloe vera leaves were soaked, washed, peeled and pulped to obtain 60 kg of aloe vera extract A1, wherein the leaves had a growth period of not less than 6 months. In this comparative example, the same batch of Aloe vera with a growth period of 10 months was selected as the raw material;

[0036] (2) adding 50% by volume ethanol aqueous solution to the aloe extract A1 at a volume ratio of 1:5 and stirring at 20° C. for 24 h; further concentrating to obtain about 300 L of aloe polysaccharide crude extract A2;

[0037] (3) Adding 15% by volume of activated carbon to the crude extract of aloe polysaccharide A2 to obtain a feed solution, wherein the activated carbon particle size is 2-3 mm;

[0038] (4) The feed liquid is stirred in the dark for 24 to 48 hours until the feed liquid becomes clear, thereby obtaining a crude extract of aloe polysaccharide A3;

[0039] (5) The aloe polysaccharide crude extract A3 was filtered twice to remove fine residues and activated carbon, and about 250 L of clear liquid was obtained;

[0040] (6) The clarified liquid obtained by filtering the crude aloe polysaccharide extract A3 was further stirred at 90° C. for 20 h to obtain about 60 L of further concentrated aloe polysaccharide extract A4;

[0041] (7) The aloe polysaccharide extract A4 is sterilized at high temperature and high pressure to obtain an aloe extract with biological activity.

[0042] The above preparation method was repeated for 6 times, and the aloe extracts obtained were labeled as B1 to B6. The O-acetyl group of the aloe extract preparations of B1 to B6 was tested respectively; and then the aloe extracts of B1 to B6 were mixed and sampled for the enteritis treatment experiment.

[0043] Detection of O-acetyl groups in aloe vera extracts from different sources

[0044] The aloe vera extracts of the examples and comparative examples were subjected to O-acetyl detection according to the Light Industry Standard of the People's Republic of China (QB / T 2489-2018) "Aloe vera products for food raw materials".

[0045] After testing, the results of the O-acetyl detection in the aloe extracts of the embodiment and the comparative example are shown in Table 1.

[0046] Table 1

[0047]

[0048] As can be seen from Table 1, the content of O-acetyl in the aloe extract obtained by ultraviolet light treatment is significantly increased. Compared with the comparative example, the content of O-acetyl in the aloe extract of the embodiment is increased by 5 to 10 times.

[0049] Colitis treatment trial

[0050] Experimental process:

[0051] Grouping: The mice were randomly divided into 3 groups: control group, comparative example group and embodiment group, with 10 mice in each group;

[0052] Mouse enteritis modeling: Each group of mice was given 2.5% DSS aqueous solution as drinking water for 7 consecutive days. The weight and stool-related symptoms of each group of mice were recorded every day;

[0053] Drug treatment: After the modeling, the control group, comparative group and example group were given normal saline, aloe extract without ultraviolet irradiation and aloe extract irradiated by ultraviolet by gavage, 300ul / mouse according to the stomach capacity of the mouse, once a day, for 1 week.

[0054] After the gavage, the mice were killed and the colon tissue was taken out. Its length was measured and recorded (persistent inflammation will shorten the colon of the mice, so the length can reflect the intestinal inflammation). The results are as follows: Figure 2 The colon tissue was then fixed in 4% paraformaldehyde. Figure 2 It can be seen that compared with the control group and the comparative example, the embodiment group can significantly alleviate intestinal inflammation and greatly reduce the effect of inflammation on colon length.

[0055] The fixed colon tissues were paraffin-embedded, sectioned, and stained with HE and immunohistochemistry to analyze the changes in the intestinal crypt tissue structure and the expression of E-cadherin, a marker of mucosal epithelial cells.

[0056] Intestinal crypts are crucial structures for intestinal epithelial proliferation and repair, and their structural integrity reflects the function of the intestinal barrier. Figure 3 It can be seen that compared with the control group and the comparative example, the intestinal crypt structure of the embodiment group is more complete, orderly, and larger in number, while the intestinal crypt structure of the comparative example and the control group is destroyed, disordered, and reduced in number, indicating that the embodiment can significantly restore the intestinal barrier function.

[0057] E-cadherin is a marker of epithelial cells, and its content reflects the function of epithelial cells, such as Figure 4 As shown, the results of immunohistochemical staining showed that the expression level of E-cadherin in the intestinal epithelial cells of the embodiment group was significantly increased (brown) compared with the control group and the comparative example, indicating that the intestinal epithelial cell function of the embodiment group was better restored.

[0058] It can be seen from this that the high O-acetyl aloe extract obtained by ultraviolet light irradiation can effectively improve the symptoms of enteritis in mice with ulcerative colitis after gavage, effectively inhibit inflammation of the mouse intestine, thereby alleviating the symptoms of enteritis, effectively repairing the damaged intestinal barrier of mice with enteritis, and promoting the repair of intestinal mucosa.

[0059] The above description of the embodiments is to facilitate the understanding and application of the present invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the embodiments herein, and improvements and modifications made to the present invention by those skilled in the art based on the disclosure of the present invention should be within the scope of protection of the present invention.

Claims

1. A method for preparing an aloe extract with a high O-acetyl content, characterized in that: The steps include: (1) soaking, washing, peeling and beating aloe leaves to obtain aloe extract A1; (2) adding ethanol aqueous solution to the aloe extract A1 and stirring to obtain aloe polysaccharide crude extract A2; the ethanol aqueous solution uses an ethanol aqueous solution with a volume percentage of 50%, and the volume ratio of the aloe extract A1 to the ethanol aqueous solution is 1:5; (3) adding activated carbon to the aloe polysaccharide crude extract A2 to obtain a feed solution; (4) immersing a submersible ultraviolet lamp into the feed liquid, and continuing to stir the feed liquid under ultraviolet light until the feed liquid becomes clear, thereby obtaining a crude extract of aloe polysaccharide A3; wherein: the wavelength of the ultraviolet light is 365 nm, the ultraviolet light intensity in the feed liquid at a distance of 5 cm from the ultraviolet lamp is not less than 1500 lux, the ultraviolet light irradiation time is 24 h to 48 h, and stirring is performed during irradiation; (5) Filtering the obtained aloe polysaccharide crude extract A3 to remove fine residues and activated carbon, and taking clarified liquid; (6) The clarified liquid obtained by filtering the aloe polysaccharide crude extract A3 was further stirred at 90° C. for 8 h to obtain the aloe polysaccharide extract A4; (7) The aloe polysaccharide extract A4 is sterilized at high temperature and high pressure to obtain the product aloe extract.

2. The method for preparing an aloe extract with a high O-acetyl content according to claim 1, characterized in that: In step (3), the particle size of the activated carbon is 2-3 mm; the proportion of the activated carbon in the slurry is 15%.

3. Aloe extract with high O-acetyl content obtained according to the preparation method of claim 1 or 2.

4. Use of the aloe extract with a high O-acetyl content obtained by the preparation method according to claim 1 or 2 in the preparation of a drug for preventing or treating colitis.

5. A drug for preventing or treating colitis, characterized in that: The aloe extract with high O-acetyl content is prepared by the preparation method according to claim 1 or 2.

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