Oral care compositions comprising theanine and uses thereof

Abstract

This invention discloses an oral care composition containing theanine and its application. The oral care composition comprises: 1) theanine; 2) an orally acceptable carrier; wherein the theanine has a weight ratio of 0.01-1.2% in the oral care composition. This invention also discloses the application of theanine in inhibiting acid production by oral bacteria in the oral care composition. The theanine in the oral care composition of this invention has the effect of inhibiting the release of organic acids by oral acid-producing bacteria, and the combination of theanine with a fluoride ion source or a stannous ion source in the composition has a synergistic effect in inhibiting the release of organic acids by oral acid-producing bacteria.

Description

Technical Field

[0001] This invention relates to the field of oral care technology, and in particular to an oral care composition containing theanine and its application. Background Technology

[0002] The oral microecological system is one of the most complex ecosystems in the human body, second only to the gut. This system contains over 700 types of microorganisms, some of which are pathogenic bacteria that metabolize sugars from food and release organic acids. For example, when Streptococcus mutans is exposed to sucrose, the bacteria release large amounts of lactic acid, lowering the pH of the oral environment. This acidic pH further promotes the growth of acid-producing bacteria, creating a vicious cycle. In addition, lactic acid can damage or demineralize tooth enamel, leading to early tooth decay, and also irritates the oral mucosa, causing discomfort.

[0003] In existing technologies, the inhibition of organic acid release is typically achieved by reducing the concentration of pathogenic bacteria in the oral ecosystem by inhibiting bacterial growth. For example, Table 2 on page 43 of patent WO2021067992A shows that CrestPro-Health Advanced toothpaste, Crest Gum Care toothpaste, and 1% chlorhexidine, containing stannous ion sources, achieved acid production inhibition rates of 43.14%, 68.49%, and 75.12%, respectively. The second paragraph on page 43 of the specification further mentions that because both stannous ion sources and chlorhexidine are well-known antibacterial agents, the inhibition of bacterial acid production was expected. (This was an expected result as the stannous ion is known to act as an antibacterial, which can reduce the number of bacteria producing acid in the biofilm. Treatment with chlorhexidine resulted in a mean acid inhibition of 75.12%, which was not unexpected because chlorhexidine is known as an extremely effective antibacterial agent.) While this approach can effectively inhibit the release of organic acids, the antibacterial agent, while inhibiting harmful bacteria, also inhibits the growth of neutral or beneficial bacteria in the environment, posing a risk of disrupting the oral microecological environment.

[0004] Another method for inhibiting the release of organic acids in the prior art is to reduce the release of organic acids by inhibiting the ability of pathogenic bacteria to release organic acids themselves. For example, patent WO2021116873A discloses an oral care composition containing N-acetyl amino acids. Table 3 on page 29 of the specification shows that N-acetylated alanine, valine, cysteine, glutamic acid, glycine, leucine, proline, tyrosine, isoleucine, tryptophan, and phenylalanine all have a good inhibitory effect on lactic acid release. However, Table 3 also shows that TC6-CA-6, i.e., N-acetyl-glutamine, not only fails to inhibit but actually increases the release of lactic acid. Summary of the Invention

[0005] The first technical problem this invention aims to solve is to provide an oral care composition containing theanine. The theanine in this oral care composition can effectively inhibit the release of organic acids by oral acid-producing bacteria without inhibiting bacterial growth.

[0006] The second problem to be solved by the present invention is to provide an application of theanine in oral care compositions to inhibit acid production by oral bacteria.

[0007] To solve the first technical problem mentioned above, the present invention adopts the following technical solution:

[0008] An oral care composition comprising theanine, comprising:

[0009] 1) Theanine;

[0010] 2) Oral-acceptable carriers;

[0011] The theanine in the oral care composition is 0.01-1.2% by weight.

[0012] In some embodiments, the theanine accounts for 0.05-1% by weight in the oral care composition;

[0013] In some preferred embodiments, the theanine accounts for 0.1-0.6% by weight in the oral care composition;

[0014] In some embodiments, the oral care composition further includes a fluoride ion source.

[0015] In some preferred embodiments, the fluoride ion source is one or more of stannous fluoride, sodium fluoride, potassium fluoride, amine fluoride, sodium monofluorophosphate, olafon, and zinc fluoride;

[0016] In some embodiments, the fluoride ions in the fluoride ion source account for 0.05-0.3% by weight in the oral care composition;

[0017] In some embodiments, the oral care composition further includes a stannous ion source;

[0018] In some preferred embodiments, the stannous ion source is one or more of stannous pyrophosphate, stannous phosphate, stannous bromide, stannous iodide, stannous oxide, stannous sulfide, stannous metaphosphate, stannous acetate, stannous tartrate, stannous citrate, stannous malate, stannous gluconate, and stannous oxalate.

[0019] In some embodiments, the stannous ions in the stannous ion source account for 0.05%-1.2% by weight in the oral care composition.

[0020] In some preferred embodiments, the stannous ions constitute 0.1%-1.0% by weight in the oral care composition;

[0021] In some embodiments, the oral care composition includes toothpaste, gel, mouthwash, or tooth powder.

[0022] To address the second technical problem of this invention, this invention provides an application of theanine in oral care compositions to inhibit acid production by oral bacteria.

[0023] Unless otherwise specified, all raw materials used in this invention can be obtained commercially, and the equipment used in this invention can be conventional equipment in the relevant field or refer to existing technology in the relevant field.

[0024] Beneficial effects of the present invention

[0025] The theanine in the oral care composition of the present invention has the effect of inhibiting the release of organic acids by oral acid-producing bacteria, and the combination of theanine with the fluoride ion source or stannous ion source in the composition has a synergistic effect on inhibiting the release of organic acids by oral acid-producing bacteria. Detailed Implementation

[0026] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0027] Unless otherwise stated, all percentages and ratios used herein are based on the total weight of the composition. Unless otherwise stated, all percentages, proportions, and contents of ingredients mentioned herein are based on the actual content of the ingredient and do not include solvents, fillers, or other substances that can be combined with these ingredients in commercially available products.

[0028] The term "includes / contains" in this article refers to other steps and components that may be added without affecting the final result.

[0029] The term "preferred" and its variations herein refer to embodiments of the invention that provide specific beneficial effects under particular conditions. However, other embodiments may also be preferred under the same or other conditions. Furthermore, the detailed description of one or more preferred embodiments does not imply that other embodiments are useless, nor is it intended to exclude other embodiments from the scope of the invention.

[0030] Unless otherwise specified in the embodiments of the present invention, the conditions shall be performed in accordance with conventional conditions or conditions recommended by the manufacturer; if the manufacturers of the reagents or instruments used are not specified, they are all conventional products that can be purchased commercially.

[0031] As one aspect of the present invention, an oral care composition comprising theanine is characterized in that the oral care composition comprises:

[0032] 1) Theanine;

[0033] 2) Oral-acceptable carriers;

[0034] The theanine in the oral care composition is 0.01-1.2% by weight.

[0035] The present invention unexpectedly discovered that theanine, namely N-ethyl-L-glutamine, can effectively inhibit the release of organic acids by oral acid-producing bacteria without inhibiting bacterial growth.

[0036] Theanine

[0037] In the late 1960s, Japanese scientists extracted a natural amino acid from green tea and named it theanine. Theanine is a characteristic amino acid in tea and an important substance that contributes to the flavor of tea, primarily characterized by its umami and sweetness. It is the main component responsible for the tea's refreshing and sweet taste. Twenty-six amino acids have been identified in tea, 20 of which are protein-related amino acids, or protein amino acids. The remaining six amino acids are not related to protein synthesis and are called non-protein amino acids. These six are the most important in tea, with theanine being the most crucial, accounting for more than 50% of the total free amino acids in tea.

[0038] This application unexpectedly discovered that although theanine cannot inhibit the growth of oral acid-producing bacteria, when the weight ratio of theanine in the oral care composition is ≥0.01%, the oral care composition can effectively inhibit the release of organic acids by oral acid-producing bacteria, and when the concentration of theanine reaches 1.2%, the acid production inhibition rate can also reach 98.01% after 4 hours, which is close to 100%.

[0039] In some embodiments of the present invention, the theanine accounts for 0.01-1.2% by weight in the composition, for example, but not limited to, 0.03-1.2%, 0.05-1.2%, 0.08-1.2%, 0.1-1.2%, 0.15-1.2%, 0.2-1.2%, 0.3-1.2%, 0.4-1.2%, 0.5-1.2%, 0.6-1.2%, 0.8-1.2%, 1.0-1.2%, 0.01-1%, 0.03-1.0%, 0.05-1.0%, 0. 0.8-1.0%, 0.1-1.0%, 0.15-1.0%, 0.2-1.0%, 0.4-1.0%, 0.5-1.0%, 0.6-1.0%, 0.8-1.0%, 0.01-0.8%, 0.03-0.8%, 0.05-0.8%, 0.08-0.8%, 0.1-0.8%, 0.15-0.8%, 0.2-0.8%, 0.3-0.8%, 0.4-0.8%, 0.5-0.8%, 0.6-0.8%, 0.01-0.6%, 0 0.03-0.6%, 0.05-0.6%, 0.08-0.6%, 0.1-0.6%, 0.15-0.6%, 0.2-0.6%, 0.3-0.6%, 0.4-0.6%, 0.5-0.6%, 0.01-0.5%, 0.03-0.5%, 0.05-0.5%, 0.08-0.5%, 0.1-0.5%, 0.15-0.5%, 0.2-0.5%, 0.3-0.5%, 0.4-0.5%, 0.01-0.4%, 0.03-0.6%. 4%, 0.05-0.4%, 0.08-0.4%, 0.1-0.4%, 0.15-0.4%, 0.2-0.4%, 0.3-0.4%, 0.01-0.3%, 0.03-0.3%, 0.05-0.3%, 0.08-0.3%, 0.1-0.3%, 0.15-0.3%, 0.2-0.3%, 0.01-0.2%, 0.03-0.2%, 0.05-0.2%, 0.08-0.2%, 0.1-0.2%, 0.15-0.2%.

[0040] Fluoride ion source

[0041] In some embodiments of the present invention, the oral care composition further includes a fluoride ion source.

[0042] The fluoride ion source is derived from one or more of the following: stannous fluoride, sodium fluoride, potassium fluoride, amine fluoride, sodium monofluorophosphate, olafluridine, and zinc fluoride. The olafluridine is sourced from Yizhan (Shanghai) Chemicals Co., Ltd.

[0043] In this invention, the fluoride ion source itself has antibacterial properties and can inhibit the release of organic acids by suppressing the growth of acid-producing bacteria. This invention unexpectedly discovered that the combination of the fluoride ion source and theanine has a synergistic effect in inhibiting the release of organic acids by acid-producing bacteria, and that while inhibiting the release of organic acids by acid-producing bacteria, it does not inhibit the growth of oral bacteria.

[0044] In some embodiments of the present invention, the fluoride ions in the fluoride ion source constitute 0.05-1.2% of the composition by mass, for example, but not limited to, 0.08-1.2%, 0.1-1.2%, 0.15-1.2%, 0.2-1.2%, 0.3-1.2%, 0.4-1.2%, 0.5-1.2%, 0.6-1.2%, 0.8-1.2%, 1.0-1.2%, and 0.05-1.0%. 0.08-1.0%, 0.1-1.0%, 0.15-1.0%, 0.2-1.0%, 0.3-1.0%, 0.4-1.0%, 0.5-1.0%, 0.6-1.0%, 0.8-1.0%, 0.05-0.8%, 0.08-0.8%, 0.1-0.8%, 0.15-0.8%, 0.2-0.8%, 0.3-0.8%, 0.4-0.8%, 0 0.5-0.8%, 0.6-0.8%, 0.05-0.6%, 0.08-0.6%, 0.1-0.6%, 0.15-0.6%, 0.2-0.6%, 0.3-0.6%, 0.4-0.6%, 0.5-0.6%, 0.05-0.5%, 0.08-0.5%, 0.1-0.5%, 0.15-0.5%, 0.2-0.5%, 0.3-0.5%, 0. 4-0.5%, 0.05-0.4%, 0.08-0.4%, 0.1-0.4%, 0.15-0.4%, 0.2-0.4%, 0.3-0.4%, 0.05-0.3%, 0.08-0.3%, 0.1-0.3%, 0.15-0.3%, 0.2-0.3%, 0.05-0.2%, 0.08-0.2%, 0.1-0.2%, 0.15-0.2%.

[0045] Tin ion source

[0046] In some embodiments of the present invention, the oral care composition further includes a stannous ion source.

[0047] The stannous ion source of the present invention is derived from one or more of the following: stannous pyrophosphate, stannous phosphate, stannous bromide, stannous iodide, stannous oxide, stannous sulfide, stannous metaphosphate, stannous acetate, stannous tartrate, stannous citrate, stannous malate, stannous gluconate, and stannous oxalate.

[0048] Stannous ion sources themselves have antibacterial properties and can inhibit the release of organic acids by suppressing the growth of acid-producing bacteria. This invention unexpectedly discovered that the combination of stannous ion sources and theanine has a synergistic effect in inhibiting the release of organic acids by acid-producing bacteria, and that while enhancing the inhibition of organic acid release by acid-producing bacteria, it does not enhance the effect of inhibiting the growth of oral bacteria.

[0049] In some embodiments of the present invention, the mass percentage of stannous ions in the stannous ion source in the composition is 0.05-1.2%, for example, but not limited to 0.08-1.2%, 0.1-1.2%, 0.15-1.2%, 0.2-1.2%, 0.3-1.2%, 0.4-1.2%, 0.5-1.2%, 0.6-1.2%, 0.8-1.2%, 1.0-1.2%, 0.05-1 0.0%, 0.08-1.0%, 0.1-1.0%, 0.15-1.0%, 0.2-1.0%, 0.3-1.0%, 0.4-1.0%, 0.5-1.0%, 0.6-1.0%, 0.8-1.0%, 0.05-0.8%, 0.08-0.8%, 0.1-0.8%, 0.15-0.8%, 0.2-0.8%, 0.3-0.8%, 0.4-0.8% 0.5-0.8%, 0.6-0.8%, 0.05-0.6%, 0.08-0.6%, 0.1-0.6%, 0.15-0.6%, 0.2-0.6%, 0.3-0.6%, 0.4-0.6%, 0.5-0.6%, 0.05-0.5%, 0.08-0.5%, 0.1-0.5%, 0.15-0.5%, 0.2-0.5%, 0.3-0.5%, 0 0.4-0.5%, 0.05-0.4%, 0.08-0.4%, 0.1-0.4%, 0.15-0.4%, 0.2-0.4%, 0.3-0.4%, 0.05-0.3%, 0.08-0.3%, 0.1-0.3%, 0.15-0.3%, 0.2-0.3%, 0.05-0.2%, 0.08-0.2%, 0.1-0.2%, 0.15-0.2%.

[0050] Oral acceptable carriers

[0051] The term "orally acceptable carrier" as used in this invention refers to any medium suitable for formulating the oral care compositions disclosed herein; an orally acceptable carrier is harmless to mammals when held in the mouth in the amount disclosed herein without being swallowed for a duration sufficient to allow effective contact with the tooth surface as required by the invention; generally, an orally acceptable carrier is not harmful even if unintentionally swallowed; suitable orally acceptable carriers include, for example, one or more of the following substances: water, thickeners, buffers, humectants, surfactants, abrasives, sweeteners, flavorings, visual aids (e.g., pigments, dyes or mixtures thereof), anti-caries agents, antibacterial agents, whitening agents, desensitizing agents, vitamins, preservatives, enzymes and mixtures thereof.

[0052] In some embodiments of the present invention, the oral care composition is toothpaste, gel, mouthwash, or tooth powder.

[0053] As another aspect of the invention, the present invention provides the application of theanine in oral care compositions to inhibit acid production by oral bacteria.

[0054] Evaluation methods for inhibiting the release of organic acids by acid-producing bacteria:

[0055] I. Preparations before the experiment

[0056] 1. Preparation of TSB medium: Weigh 15g of TSA medium into a 500ml glass bottle, add 500ml of pure water, shake well, and sterilize at 121℃ for 20min;

[0057] 2. Sterilized water: Pure water, sterilized at 121℃ for 20 minutes;

[0058] 3. Preparation of 50% sucrose solution: Weigh 25g of sucrose into a beaker, add pure water to 40ml, stir to dissolve, pour into a 50ml volumetric flask, make up to 50ml, pour into a 50ml glass bottle, and sterilize at 121℃ for 20min.

[0059] 4. Preparation of 2% sucrose solution: Add 1.5ml of 50% sucrose solution to 36ml of sterile pure water;

[0060] II. Experimental Procedures

[0061] 5. Inoculate Streptococcus mutans (Sm) into 20 ml of TSB medium and incubate for 20 h;

[0062] 6. Take 10g of sample, add 20g of deionized water, stir for 30 minutes, centrifuge at 7000rpm for 15 minutes, and take the supernatant;

[0063] 7. After centrifuging the bacterial culture from step 5 at 7000 rpm for 15 min, remove the supernatant, resuspend it in 20 ml of sterile water prepared in step 2 before the experiment, centrifuge it again at 7000 rpm for 15 min, remove the supernatant, resuspend it in sterile water and dilute it to an OD value of 0.5.

[0064] 8. Take 7 ml of the sample solution from step 6, 14 ml of the sucrose solution from step 4 of the pre-experiment preparation, and 7 ml of the bacterial culture from step 7 into 50 ml test tubes, vortex to mix, and dispense 2 ml into each well into a 24-well plate, with two replicates per group.

[0065] 9. After standing in an incubator at 37℃ for 4 hours, measure the pH value of the 24-well plate samples;

[0066] 10. Calculate the pH difference for each sample at each time point compared to the pH value at 0 min;

[0067] 11. Calculate the inhibition rate of organic acid release.

[0068]

[0069] Examples 1-11, Comparative Examples 1-2 :

[0070] The formulations of Examples 1-11 and Comparative Examples 1-2 in Table 1 below were used to prepare toothpaste. All data in the table are weight percentages.

[0071] Table 1:

[0072]

[0073] Continued from Table 1:

[0074]

[0075] As can be seen from Table 1:

[0076] Comparative Example 1 formulation did not contain theanine;

[0077] Comparative Example 2 was prepared by adding 0.005% theanine to Comparative Example 1;

[0078] Examples 1-11 were based on Comparative Example 1 with the addition of 0.01%, 0.03%, 0.05%, 0.1%, 0.15%, 0.2%, 0.3%, 0.5%, 0.6%, 1.0%, and 1.2% theanine, respectively.

[0079] Using Comparative Example 1 as a control, the inhibition rate of organic acid release in Examples 1-11 and Comparative Example 2 was evaluated according to the above-described evaluation method for inhibiting the release of organic acids by acid-producing bacteria. The results are shown in Table 2.

[0080] Table 2

[0081] Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Example 5 4h -2.93％ 2.59％ 5.66％ 10.68％ 20.37％ 26.39％

[0082] Continued from Table 2:

[0083]

[0084] As can be seen from Table 2:

[0085] Comparative Example 2, with the addition of 0.005 wt% theanine, showed an inhibition rate of -2.93% after 4 hours. This means that under the condition of 0.005% by weight, theanine did not show an inhibitory effect on the release of organic acids, but instead showed a counterproductive effect of promoting the release of organic acids.

[0086] However, in Example 1, when the weight ratio of theanine in the composition was increased to 0.01%, the composition began to show a certain inhibitory effect on the release of organic acids, with an inhibition rate of 2.59% after 4 hours. Subsequently, the inhibition rate continued to increase with the increase of the weight ratio of theanine in the composition. In particular, when the weight ratio of theanine was added to 1.2%, the inhibition rate reached 98.01% after 4 hours, which was close to 100%.

[0087] Therefore, when the theanine content in the composition is 0.01-1.2% by weight, theanine can inhibit the release of organic acids by oral bacteria in oral care compositions.

[0088] Comparative Examples 3-11 :

[0089] The formulations of Comparative Examples 3-11 in Table 3 below were used to prepare toothpaste. All data in the table are weight percentages.

[0090] Table 3:

[0091]

[0092] As can be seen from Table 3, Comparative Examples 3-11 were supplemented with 0.08%, 0.16%, 0.24%, 0.32%, 0.48%, 0.8%, 0.96%, 1.6%, and 1.92% stannous chloride (molecular weight 189.61), respectively, based on Comparative Example 1. That is, based on stannous ions (atomic weight 118.71), Comparative Examples 3-11 were supplemented with 0.05%, 0.1%, 0.15%, 0.2%, 0.3%, 0.5%, 0.6%, 1.0%, and 1.2% stannous ions, respectively, based on Comparative Example 1.

[0093] Using Comparative Example 1 as a control, the inhibition rate of organic acid release from Comparative Examples 3-11 was evaluated according to the above-mentioned evaluation method for inhibiting the release of organic acids by acid-producing bacteria. The results are shown in Table 4 below.

[0094] Table 4:

[0095]

[0096]

[0097] As can be seen from Table 4:

[0098] When the concentration of stannous ions in the composition is 0.05%, the composition exhibits a relatively significant inhibitory effect on the release of organic acids by acid-producing bacteria, and the inhibitory effect increases with the increase of stannous ion concentration.

[0099] In Comparative Example 9, the inhibition rate reached 93.27% when the stannous ion concentration was 0.8%.

[0100] Comparative Example 10 showed an inhibition rate of up to 96.91% when the stannous ion concentration reached 1.0%.

[0101] When the concentration of stannous ions was increased to 1.2%, the inhibition rate of Comparative Example 11 was 97.19%, which was comparable to that of Comparative Example 10.

[0102] Therefore, when the stannous ion source (calculated as tin) accounts for 0.05-1.2% of the weight in the composition, the stannous ions have the effect of inhibiting the release of organic acids by acid-producing bacteria.

[0103] Comparative Examples 12-16 :

[0104] The formulations of Comparative Examples 12-16 in Table 5 below were used to prepare toothpaste. All data in the table are weight percentages.

[0105] Table 5:

[0106]

[0107] As can be seen from Table 5:

[0108] Comparative Examples 12-16 were prepared by adding 0.11%, 0.22%, 0.33%, 0.44%, and 0.66% sodium fluoride (molecular weight 41.99) to Comparative Example 1, respectively; that is, Comparative Examples 12-16 were prepared by adding 0.05%, 0.1%, 0.15%, 0.2%, and 0.3% fluoride ions (atomic weight 19) to Comparative Example 1, respectively.

[0109] Using Comparative Example 1 as a control, the inhibition rate of organic acid release from Comparative Examples 12-16 was evaluated according to the above-mentioned evaluation method for inhibiting the release of organic acids by acid-producing bacteria. The results are shown in Table 6 below.

[0110] Table 6:

[0111]

[0112] As can be seen from Table 6, Comparative Examples 12-16 all showed a certain inhibitory effect on the release of organic acids.

[0113] Therefore, when the weight percentage of the fluoride ion source (calculated as fluoride) in the composition is 0.05-1.2%, the fluoride ions have the effect of inhibiting the release of organic acids by acid-producing bacteria.

[0114] Examples 12-16 :

[0115] The formulations of Examples 12-16 in Table 7 below were used to prepare toothpaste. All data in the table are weight percentages. The organic acid release inhibition rate of each composition was observed after 4 hours.

[0116] Table 7:

[0117]

[0118] As can be seen from Table 7:

[0119] Examples 12-16 were based on Comparative Example 1, with the addition of 0.05%, 0.1%, 0.15%, 0.3%, and 0.5% theanine by weight, respectively; and 0.08%, 0.16%, 0.24%, 0.48%, and 0.80% stannous chloride by weight, respectively. That is, Examples 12-16 had stannous ions added at weight ratios of 0.05%, 0.1%, 0.15%, 0.3%, and 0.5%, respectively.

[0120] In Examples 12-16, the total concentrations of theanine and stannous ions reached 0.1%, 0.2%, 0.3%, 0.6%, and 1.0%, respectively.

[0121] Using Comparative Example 1 as a control, the inhibition rate of organic acid release in Examples 12-16 was evaluated according to the above-described evaluation method for inhibiting the release of organic acids by acid-producing bacteria. The results showed that:

[0122] The organic acid release inhibition rate of Example 12 reached 25.77%, which exceeded that of Example 4 (20.37%) and Comparative Example 4 (19.82%).

[0123] The organic acid release inhibition rate of Example 13 reached 55.56%, which exceeded that of Example 6 (38.91%) and Comparative Example 6 (50.46%).

[0124] The organic acid release inhibition rate of Example 14 reached 70.66%, which exceeded that of Example 7 (57.73%) and Comparative Example 7 (65.72%).

[0125] The organic acid release inhibition rate of Example 15 reached 95.36%, which exceeded that of Example 9 (88.23%) and Comparative Example 9 (93.27%).

[0126] The organic acid release inhibition rate of Example 16 reached 98.34%, which exceeded that of Example 10 (93.33%) and Comparative Example 10 (96.91%).

[0127] Therefore, under the same total concentration, the combination of theanine and stannous ions exhibits a superior inhibition rate against the release of organic acids by acid-producing bacteria. In other words, the combination of stannous ions and theanine has a synergistic effect in inhibiting the release of organic acids by acid-producing bacteria.

[0128] Examples 17-20

[0129] The formulations of Examples 17-20 in Table 8 below were used to prepare toothpaste. All data in the table are weight percentages. The organic acid release inhibition rate of each composition was observed after 4 hours.

[0130] Table 8:

[0131]

[0132]

[0133] As can be seen from Table 8:

[0134] Examples 17-20, based on Comparative Example 1, added 0.005%, 0.05%, 0.1%, and 0.15% theanine by weight, respectively, and added 0.11%, 0.11%, 0.22%, and 0.33% sodium fluoride, respectively. That is, Examples 17-20 added 0.05%, 0.05%, 0.1%, and 0.15% fluoride by weight, respectively. The total concentrations of theanine and fluorine in Examples 18-20 reached 0.1%, 0.2%, and 0.3%, respectively.

[0135] Using Comparative Example 1 as a control, the inhibition rate of organic acid release in Examples 17-20 was evaluated according to the above-described evaluation method for inhibiting the release of organic acids by acid-producing bacteria. The results showed that:

[0136] Although the inhibition rate of organic acid release in Comparative Example 2 (0.005% theanine by weight) was -2.93% and the inhibition rate of organic acid release in Comparative Example 8 (0.05% fluorine by weight) was 1.67%, the inhibition rate of organic acid release in Example 17 reached 3.52%. That is, 0.005% theanine did not reduce the inhibition rate of organic acid release in the fluorine-containing composition. On the contrary, the combination of 0.005% theanine by weight and 0.05% fluorine by weight had a positive effect on the inhibition rate of organic acid release.

[0137] The inhibition rate of organic acid release in Example 18 reached 21.10%, which exceeded that of Example 4 (20.37%) and Comparative Example 9 (4.82%).

[0138] The organic acid release inhibition rate of Example 19 reached 40.21%, exceeding that of Example 6 (38.91%) and Comparative Example 11 (15.48%); that is, the combination of theanine and fluorine showed a better inhibition rate than the single raw material.

[0139] Therefore, under the same total concentration, the combination of theanine and fluorine exhibits a superior inhibition rate of organic acid release from acid-producing bacteria compared to the single ingredient. In other words, the combination of fluoride ion source and theanine has a synergistic effect in inhibiting the release of organic acids by acid-producing bacteria.

[0140] Examples 21-22 :

[0141] The formulations of Examples 21-22 in Table 9 below were used to prepare toothpaste. All data in the table are weight percentages. The organic acid release inhibition rate of each composition was observed after 4 hours.

[0142] Table 9:

[0143]

[0144]

[0145] As can be seen from Table 9:

[0146] Examples 21-22 were based on Comparative Example 1, with the addition of 0.05% and 0.1% theanine by weight, respectively, and 0.11% and 0.22% sodium fluoride by weight, respectively. In other words, Examples 21-22 added 0.05% and 0.1% fluorine by weight, respectively, and 0.08% and 0.16% stannous chloride by weight, respectively. In other words, Examples 21-22 added 0.05% and 0.1% stannous ions, respectively.

[0147] Using Comparative Example 1 as a control, the inhibition rate of organic acid release in Examples 21-22 was evaluated according to the above-described evaluation method for inhibiting the release of organic acids by acid-producing bacteria. The results showed that:

[0148] The organic acid release inhibition rate of Example 21 reached 30.09%, which exceeded the sum of Example 12, Comparative Example 3 and Comparative Example 8 (10.68% + 9.75% + 1.67% = 22.1%).

[0149] The organic acid release inhibition rate of Example 22 reached 66.36%, which exceeded the total of Example 4, Comparative Example 4 and Comparative Example 9 (19.82% + 20.37% + 4.82% = 45.01%); that is, the combination of theanine, stannous ions and fluorine has a synergistic effect in inhibiting the release of organic acids.

[0150] Evaluation methods for the inhibitory effect on bacterial growth:

[0151] This invention uses the minimum inhibitory concentration (MIC) method to evaluate the effect of samples on inhibiting bacterial growth.

[0152] The sample solution was prepared using culture medium to an initial concentration of 20,000 ppm, and a 4,000 ppm CPC solution was prepared as a positive control. CPC stands for Cetylpyridinium Chloride. The experimental steps are as follows:

[0153] 1) First, add 100 μL of culture medium to columns 2-12 of a 96-well plate, then inject 200 μL of sample and control solution into each well in the first row;

[0154] 2) Using an 8-channel pipette, slowly aspirate and mix the solution in each well of the first column. After mixing (repeated 10-15 times), transfer 100 μL of solution from the wells of the first column to the wells of the second column using the 8-channel pipette. Then continue mixing the solution in the wells of the second column using the 8-channel pipette. After mixing, transfer another 100 μL to the wells of the third column, repeating this process until all 12 columns of solutions are mixed. Finally, transfer 100 μL of solution from the well of the 12th column and discard it. This yields a series of sample and control solutions with gradient concentrations obtained through 2-fold dilution.

[0155] 3) Add 100 μL of the adjusted bacterial suspension to each well, so that each well in the 96-well plate should contain 200 μL of solution. Then place the 96-well plate in a microbial incubator and incubate for 18-24 hours.

[0156] 4) Prepare a 0.05% resporane solution. Pipette one drop of resporane solution into each well and observe the color change of the resporane to determine the bacterial activity in the well plate. Combine this with the data measured by the microplate reader to determine the MIC value (unit: ppm). The sample MIC results are shown in Table 10 below.

[0157] Table 10:

[0158]

[0159] Pathogenic bacteria:

[0160]

[0161]

[0162] Beneficial bacteria:

[0163] Bifidobacterium bifidum Bf Bifidobacteria streptococcus sanguis S.sa Blood streptococcus

[0164] As can be seen from Table 10:

[0165] Theanine and glycine themselves did not show good antibacterial effects against oral pathogens or beneficial bacteria. Stannous chloride and sodium fluoride had some inhibitory effects on the growth of the aforementioned pathogens and beneficial bacteria. However, when theanine and stannous chloride were mixed in a 1:1 ratio, the inhibitory effect of stannous chloride on bacterial growth weakened. Similarly, when theanine and sodium fluoride were mixed in a 1:1 ratio, or when theanine, sodium fluoride, and stannous chloride were mixed in a 1:1:1 ratio, the inhibitory effect of sodium fluoride or stannous chloride on bacterial growth also weakened. However, when glycine and stannous chloride were mixed in a 1:1 ratio, the MIC value of the mixture was comparable to that of stannous chloride.

[0166] Evaluation methods for in vitro inhibition of biofilm growth:

[0167] Artificial oral biofilm dynamic models are currently recognized as superior in vitro models for dental plaque research. They can simulate the human oral environment, observe the dynamic process of bacterial biofilm formation, and are an effective research method for plaque growth and control. The specific experimental steps are as follows:

[0168] 1) Collect irritating saliva from 3 people, centrifuge to obtain the supernatant, and sterilize by ultraviolet irradiation for 60 minutes;

[0169] 2) Place autoclaved hydroxyapatite (HAP) tablets into saliva and soak overnight to form an acquired membrane;

[0170] 3) Collect irritating saliva from the above 3 individuals (the subjects should have not engaged in oral hygiene activities for 24 hours prior to collection) and mix it into the culture medium;

[0171] 4) Draw the irritating saliva mixture into the flow chamber of the artificial oral cavity, and fully immerse the HAP tablets in the solution. Place in a 42.5℃ water bath, and culture the plaque using a pulsed flow mode.

[0172] 5) After 8 hours of plaque growth, pump out the nutrient medium from the flow chamber. Prepare a 1000 ppm solution of the sample to be tested, and place the sample tubing into the sample solution, allowing the sample solution to quickly fill the entire flow chamber at maximum flow rate;

[0173] 6) After timing for 1 minute, pump out all the test sample solution;

[0174] 7) Pump the culture medium solution into the flow chamber and continue culturing for 16 hours, then terminate the experiment;

[0175] 8) Processing experimental results using the OD method: Take out the HAP tablet with tweezers, wash it 5 times in distilled water, and then put it into a sterile test tube containing 2 mL of physiological saline. Use a vortex shaker to mix it thoroughly.

[0176] 9) Pipette 300 μL of the suspension from the previous step into a 96-well cell culture plate and use a microplate reader (Tecan, Infinite M200) to detect bacteria at a wavelength of 630 nm. The OD630 value represents the bacterial concentration. The smaller the OD630, the better the antibacterial effect.

[0177] Three subjects were selected and labeled as Subject 1, Subject 2, and Subject 3. The average OD630 of the artificial oral cavity was calculated for the three subjects, and the average values ​​are shown in Table 11 below.

[0178] Table 11:

[0179] sample OD630 water 1.424 Theanine 1.557 glycine 1.532 stannous chloride 0.967 Sodium fluoride 1.250 A 1:1 mixture of theanine and stannous chloride 1.210 A 1:1 mixture of theanine and sodium fluoride 1.305 A mixture of theanine, sodium fluoride, and stannous chloride in a 1:1:1 ratio 1.291 A 1:1 mixture of glycine and stannous chloride 0.823

[0180] Table 11 shows the following:

[0181] Theanine and glycine do not inhibit the growth of oral biofilms;

[0182] Stannous chloride and fluorides have a certain inhibitory effect on biofilm growth;

[0183] The mixture of theanine and stannous chloride did not show an enhanced inhibitory effect on biofilm growth;

[0184] Similarly, the mixture of theanine and sodium fluoride did not show an enhanced effect on biofilm growth inhibition.

[0185] The mixture of theanine, stannous chloride, and sodium fluoride did not show enhanced biofilm growth inhibition.

[0186] However, the OD630 value of the mixture of glycine and stannous chloride decreased, indicating that although glycine itself does not inhibit the growth of oral biofilms, it can enhance the effect of stannous chloride in inhibiting biofilm growth.

[0187] It is evident that although the combination of theanine / glycine and stannous ion source has the effect of inhibiting acid production by acid-producing bacteria, the two mechanisms are not the same.

[0188] In summary, theanine cannot inhibit the growth of oral acid-producing bacteria. However, when the mass ratio of theanine in the composition is ≥0.01, the composition can effectively inhibit the release of organic acids by oral acid-producing bacteria. Furthermore, when the theanine concentration reaches 1.2%, the inhibition rate of acid production after 4 hours can reach 98.01%, close to 100%. The combination of fluoride ion source and theanine has a synergistic effect in inhibiting the release of organic acids by acid-producing bacteria, and does not inhibit the growth of oral bacteria while inhibiting the release of organic acids. The combination of stannous ion source and theanine also has a synergistic effect in inhibiting the release of organic acids by acid-producing bacteria, and does not inhibit the growth of oral bacteria while inhibiting the release of organic acids. Moreover, the combination of theanine, stannous ions, and fluoride has a synergistic effect in inhibiting the release of organic acids.

[0189] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is impossible to exhaustively list all embodiments here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. An oral care composition comprising theanine, characterized in that, Comprising: 1) theanine; 2) an orally acceptable carrier; wherein the theanine is present in the oral care composition in a weight ratio of 0.01-1.2%; the oral care composition further comprises a stannous ion source, the stannous ion source comprising stannous ions present in the oral care composition in a weight percentage of 0.05-1.2%.

2. The oral care composition of claim 1, wherein: the theanine is present in the oral care composition in a weight percentage of 0.05-1%.

3. The oral care composition of claim 2, wherein: the theanine is present in the oral care composition in a weight percentage of 0.1-0.6%.

4. The oral care composition of claim 1, wherein: the oral care composition further comprises a fluoride ion source.

5. The oral care composition of claim 4, wherein: the fluoride ion source is one or more of stannous fluoride, sodium fluoride, potassium fluoride, amine fluoride, sodium monofluorophosphate, sodium oxyfluoride, zinc fluoride.

6. The oral care composition according to claim 4 or 5, wherein: the fluoride ion source comprises fluoride ions present in the oral care composition in a weight percentage of 0.05-0.3%.

7. The oral care composition of claim 1, wherein: the stannous ion source is one or more of stannous chloride, stannous pyrophosphate, stannous phosphate, stannous bromide, stannous iodide, stannous oxide, stannous sulfide, stannous metaphosphate, stannous acetate, stannous tartrate, stannous citrate, stannous malate, stannous malonate, stannous gluconate, stannous oxalate.

8. The oral care composition of claim 1, wherein: the stannous ion source comprises stannous ions present in the oral care composition in a weight percentage of 0.1-1.0%.

9. The oral care composition of claim 1, wherein: the oral care composition comprises a toothpaste, a gel, a mouthwash, or a dentifrice.

10. The use of theanine for the preparation of an oral care composition for inhibiting acid production by oral bacteria, characterized in that, the oral care composition comprises: 1) theanine; 2) an orally acceptable carrier; wherein the theanine is present in the oral care composition in a weight ratio of 0.01-1.2%.

11. Use according to claim 10, characterized in that: the theanine is present in the oral care composition in a weight percentage of 0.05-1%.

12. Use according to claim 11, characterized in that: the theanine is present in the oral care composition in a weight percentage of 0.1-0.6%.

13. The use according to claim 10, characterized in that: the oral care composition further comprises a fluoride ion source.

14. Use according to claim 13, characterized in that: the fluoride ion source is one or more of stannous fluoride, sodium fluoride, potassium fluoride, amine fluoride, sodium monofluorophosphate, sodium oxyfluoride, zinc fluoride.

15. The use according to claim 13, characterized in that: the fluoride ion source comprises fluoride ions present in the oral care composition in a weight percentage of 0.05-0.3%.

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