A plant polysaccharide with moisturizing and elasticity-enhancing activities and its use in preparing cosmetics

Abstract

The present invention discloses a plant polysaccharide with moisturizing and elasticity-increasing activities and its use in preparing cosmetics. The plant polysaccharide is prepared in three steps: in the first step, crude polysaccharide is prepared by water extraction and alcohol precipitation; in the second step, protein is removed by the Sevag method to prepare deproteinized crude polysaccharide; in the third step, dialysis and refinement are carried out. The present invention makes full use of the resource advantages of Osbeckia chinensis, and prepares a refined plant polysaccharide therefrom. The refined plant polysaccharide not only has excellent moisturizing activity, but also has a good effect of increasing skin elasticity, and has the development prospect of being further developed into a cosmetic with both moisturizing and skin elasticity-increasing functions.

Description

Technical Field

[0001] The present invention belongs to the field of chemistry, relates to polysaccharides and their applications, and particularly relates to a plant polysaccharide with moisturizing and elasticity-enhancing activities and its use in preparing cosmetics. Background Art

[0002] With the continuous improvement of economic development and living conditions, people's demand for natural and healthy cosmetics is increasing day by day, and the group purchase trend is gradually changing from basic products to functional products with composite functions. In recent years, with the continuous in-depth research on plant polysaccharides, we have found that they have extremely high application value in the daily chemical field. On the one hand, plant polysaccharides have rich biological activities and comprehensive functions, and possess a variety of natural pharmacological effects such as moisturizing, anti-wrinkle, anti-acne, antioxidant, whitening, antibacterial, anti-allergic, anti-inflammatory, acaricidal, sunscreen, wound healing, etc. They are safe to use, mild in action, significant in effect, and have no side effects. On the other hand, due to the presence of hydrophilic groups, plant polysaccharides have strong hydrophilicity, gelation, emulsification and film-forming properties, and low exclusivity. When added to daily chemicals, they can ensure high affinity with human skin. Compared with chemically synthesized cosmetics on the market, plant polysaccharide-based cosmetics have a broader development and utilization space.

[0003] Although the research on plant polysaccharides in China started relatively late, due to the rich plant resource reserves in China, a large number of representative scientific research achievements have been obtained at present. Currently, research has been carried out on nearly a hundred plant polysaccharides such as bletilla striata polysaccharide, ginseng polysaccharide, glycyrrhiza polysaccharide, tremella polysaccharide, cordyceps polysaccharide, dictyophora indusiata polysaccharide, poria cocos polysaccharide, wolfberry polysaccharide, polygonum multiflorum polysaccharide, etc. A considerable part of these polysaccharides have been developed for the production of cosmetics.

[0004] Osbeckia chinensis Linn.exWalp is the dried whole herb of Osbeckia chinensis, a plant of the genus Osbeckia in the family Melastomataceae. It is mainly distributed in Guangdong, Guangxi, Guizhou, Hubei, Fujian, Jiangxi, Sichuan and other places, and is also distributed in Vietnam, Australia, Japan and other places, and its resource reserves are very large. Research shows that Osbeckia chinensis contains rich flavonoid compounds, which have a variety of pharmacological activities such as antibacterial, anti-inflammatory, antioxidant, anti-tumor and cardiovascular protection. Currently, there are few reports on the development of high-molecular compounds such as polysaccharides in various parts of Osbeckia chinensis.

[0005] The present invention is proposed based on the research on the protective activity of Osbeckia chinensis polysaccharide on the skin to make full use of the resource advantages of Osbeckia chinensis. Summary of the Invention

[0006] The purpose of the present invention is to provide a plant polysaccharide with moisturizing and elasticity-enhancing activities and its use in preparing cosmetics.

[0007] The purpose of the present invention is achieved by the following technical solutions:

[0008] A plant polysaccharide is prepared by the following steps:

[0009] First step, preparing crude polysaccharide by water extraction and alcohol precipitation

[0010] Crush the dried whole herb of Osbeckia chinensis, add water, heat for extraction, filter, repeat the extraction of the filter residue with water for 1 to several times, combine the extraction solutions for multiple times, concentrate under reduced pressure, then add 4 times the volume of 95% ethanol, stand at 4°C for more than 12 h, centrifuge, collect the precipitate, wash successively with absolute ethanol, acetone, and ether, and dry to obtain crude polysaccharide;

[0011] Second step, removing protein by Sevag method to prepare deproteinized crude polysaccharide

[0012] Dissolve the above-mentioned crude polysaccharide with appropriate distilled water, add appropriate Sevag reagent to the polysaccharide solution, shake well, stand for layering, and remove the lower-layer organic solvent and the middle-layer protein precipitate; repeat the treatment of the upper-layer polysaccharide solution with Sevag reagent until there is no obvious middle-layer protein precipitate, centrifuge, collect the supernatant, then add 4 times the volume of 95% ethanol, stand at 4°C for more than 12 h, centrifuge, collect the precipitate, wash successively with absolute ethanol, acetone, and ether, and dry to obtain deproteinized crude polysaccharide;

[0013] Third step, dialysis and purification

[0014] Dissolve the above-mentioned deproteinized crude polysaccharide with appropriate distilled water, load it into a dialysis bag for dialysis to remove small molecular compounds including monosaccharides, organic reagents, and organic salts in the polysaccharide; after dialysis, freeze-dry.

[0015] Preferably, in the first step, water is added for heating extraction according to a material-liquid ratio of 1:10.

[0016] Preferably, the heating extraction temperature is 90°C and the time is 3 h.

[0017] Preferably, the drying in the first and second steps is vacuum drying at 50°C.

[0018] Preferably, the Sevag reagent in the second step is composed of chloroform and n-butanol mixed according to a volume ratio of 4:1.

[0019] Preferably, the dialysis duration in the third step is 48 h.

[0020] Use of any of the above plant polysaccharides for preparing a cosmetic having both moisturizing and skin elasticity enhancing effects.

[0021] Beneficial technical effects:

[0022] The present invention makes full use of the resource advantages of Osbeckia chinensis, and prepares a refined polysaccharide therefrom. This refined polysaccharide not only has excellent moisturizing activity, but also has a good effect of increasing skin elasticity, and has the development prospect of being further developed into a cosmetic with both moisturizing and increasing skin elasticity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a photograph of the refined polysaccharide, which is a white powder with fine and uniform particles.

[0024] Figure 2 It is the expression levels of Collagen I and Elastin proteins in human dermal fibroblasts. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] Example 1: Isolation and purification of plant polysaccharide

[0026] The dried whole herb of Osbeckia chinensis was crushed, added with water according to a solid-liquid ratio of 1:10, heated and extracted at 90 °C for 3 h, filtered, the filter residue was added with water and extracted again, the two extraction solutions were combined, concentrated under reduced pressure, and then 4 times the volume of 95% ethanol (i.e., commercially available 95% ethanol, volume percentage concentration) was added, allowed to stand at 4 °C for more than 12 h, centrifuged at 5000 rpm for 15 minutes, the precipitate was collected, washed successively with absolute ethanol, acetone, and ether, and vacuum dried at 50 °C to obtain crude polysaccharide.

[0027] Since proteins may be mixed in the polysaccharide prepared by the water extraction and alcohol precipitation method, it is necessary to remove proteins for refinement. The Sevag method was used to remove proteins. This method has mild conditions and a low polysaccharide loss rate. The principle is to use Sevag reagent to denature proteins and then remove them. The above crude polysaccharide was dissolved in an appropriate amount of distilled water, 1 / 4 volume of Sevag reagent (chloroform: n-butanol = 4:1, V / V) was added to the polysaccharide solution, shaken well for 30 minutes, allowed to stand for stratification, and the lower organic solvent layer and the protein precipitate in the middle layer were removed. The upper polysaccharide solution was repeatedly treated with Sevag reagent 3 - 5 times until there was no obvious protein precipitate in the middle layer, centrifuged at 10000 rpm for 10 minutes, the supernatant was collected, then 4 times the volume of 95% ethanol (same as above) was added, allowed to stand at 4 °C for more than 12 h, centrifuged at 5000 rpm for 15 minutes, the precipitate was collected, washed successively with absolute ethanol, acetone, and ether, and vacuum dried at 50 °C to obtain deproteinized crude polysaccharide.

[0028] The above deproteinized crude polysaccharide was dissolved in an appropriate amount of distilled water, placed in a dialysis bag and dialyzed for 48 h to remove small molecular compounds such as monosaccharides, organic reagents, and organic salts in the polysaccharide. After dialysis, it was freeze-dried to obtain refined polysaccharide. Figure 1 It is a photograph of this refined polysaccharide, a white powder with fine and uniform particles. Store in dry condition.

[0029] Example 2: Moisturizing activity

[0030] The moisturizing activity of the refined polysaccharide prepared in Example 1 was evaluated by a common water absorption and volatilization test. Under normal temperature conditions, 5 portions of the refined polysaccharide and 5 portions of sodium alginate (positive control) were accurately weighed and placed in separate weighing bottles, with each sample being 1 g. Then, 0.4 g of distilled water was added to each weighing bottle. After the samples had fully absorbed water (about 30 minutes), the weighing bottles were transferred to a desiccator (containing silica gel desiccant particles). Starting from the time of transfer to the desiccator, the weighing bottles were weighed at 6, 12, 18, and 24 h, and each weighing bottle was weighed 3 times. The remaining water weight at each measurement time point was calculated, and the moisturizing rate of the test sample was calculated according to the formula. Moisturizing rate (%) = weight of water contained at the measurement time point / initial water weight × 100%.

[0031] The following table shows the moisturizing rates of the refined polysaccharide and sodium alginate. The refined polysaccharide is slightly better than sodium alginate.

[0032]

[0033] Example 3: Activity of increasing skin elasticity

[0034] Human dermal fibroblasts in good growth state (purchased from Procell, product number CP-H103, resuscitated, cultured, and passaged according to the instructions, and passaged 3 times for the experiment) were resuspended with a complete medium for human dermal fibroblasts (purchased from Procell, product number CM-H103) and then inoculated into a 6-well culture plate at 1 mL per well. They were cultured overnight at 37 °C and 5% CO2. The next day, 1 mL of the complete medium for human dermal fibroblasts containing the refined polysaccharide of Example 1 was added, such that the final concentration of the refined polysaccharide was 30 and 60 μg / mL. As a control, the complete medium for human dermal fibroblasts without the refined polysaccharide was added, and the culture continued. After 48 h, the cells were collected, lysed with a lysis solution, total protein was extracted, and quantified by the BCA method. Samples were loaded at 40 μg per well for SDS-PAGE electrophoresis, electrotransferred to a PVDF membrane, blocked with 5% skim milk powder, the membrane was washed, and primary antibodies against Collagen I, Elastin, and β-actin were added and incubated overnight at 4 °C. A horseradish peroxidase-labeled IgG secondary antibody was added and incubated at room temperature for 2 h. Color development was carried out by the ECL chemiluminescence method, and images were acquired by imaging.

[0035] The results are as Figure 2As shown, compared with the control group, the expression levels of Collagen I and Elastin proteins in the refined polysaccharide group were significantly increased, and the higher the concentration of the refined polysaccharide, the more obvious the increase in the expression levels of Collagen I and Elastin proteins, proving that the refined polysaccharide has the effect of promoting the expression of Collagen I and Elastin proteins in human dermal fibroblasts. Collagen I is type I collagen, and Elastin is elastin, and their expression in dermal fibroblasts is the two most important proteins for maintaining human skin elasticity. The above experiment shows that the refined polysaccharide prepared in Example 1 has the activity of increasing human skin elasticity.

[0036] The polysaccharide provided by the present invention has both moisturizing activity and the activity of increasing skin elasticity, and has further development value.

Claims

1. A plant polysaccharide, characterized in that: Prepared by the following steps: The first step is to prepare crude polysaccharide by water extraction and alcohol precipitation The dried whole herb of Jinjinxiang was crushed, water was added, and the mixture was heated for extraction. The mixture was filtered, and the residue was repeatedly extracted with water for one or more times. The multiple extracts were combined and concentrated under reduced pressure. Then, 4 volumes of 95% ethanol were added, and the mixture was allowed to stand at 4°C for more than 12 hours. The mixture was centrifuged, and the precipitate was collected and washed with anhydrous ethanol, acetone, and ether in sequence, and dried to obtain a crude polysaccharide. The second step is to remove protein by Sevag method to prepare deproteinized crude polysaccharide The crude polysaccharide is dissolved in an appropriate amount of distilled water, an appropriate amount of Sevag reagent is added to the polysaccharide solution, the solution is shaken thoroughly, and the solution is allowed to stand for separation to remove the lower organic solvent and the intermediate protein precipitate; the upper polysaccharide solution is repeatedly treated with the Sevag reagent until no obvious intermediate protein precipitate is present, the solution is centrifuged, the supernatant is collected, and then 4 times the volume of 95% ethanol is added, the solution is allowed to stand at 4°C for more than 12 hours, the solution is centrifuged, the precipitate is collected, and the solution is washed with anhydrous ethanol, acetone, and ether in sequence, and dried to obtain a deproteinized crude polysaccharide; The third step is dialysis purification The deproteinized crude polysaccharide is dissolved in an appropriate amount of distilled water, placed in a dialysis bag and dialyzed to remove small molecular compounds including monosaccharides, organic reagents and organic salts in the polysaccharide; after the dialysis is completed, the polysaccharide is freeze-dried.

2. The plant polysaccharide according to claim 1, characterized in that: The first step is to add water at a material-liquid ratio of 1:10 and heat for extraction.

3. The plant polysaccharide according to claim 2, characterized in that: The heating extraction temperature was 90°C and the time was 3 h.

4. The plant polysaccharide according to claim 1, characterized in that: The first and second drying steps are vacuum drying at 50°C.

5. The plant polysaccharide according to claim 1, characterized in that: In the second step, the Sevag reagent is prepared by mixing chloroform and n-butanol in a volume ratio of 4:

1.

6. The plant polysaccharide according to claim 1, characterized in that: The third step of dialysis lasts for 48 hours.

7. Use of the plant polysaccharide according to any one of claims 1 to 6 for preparing cosmetics having the functions of both moisturizing and increasing skin elasticity.

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