Mixtures from extracts of stinging nettle and ginger root

Abstract

The present invention generally relates to a mixture formed from extracts of stinging nettle and ginger root, the mixture comprising zingiberene, 6-gingerol and caffeoylmalic acid, and a weight ratio of the stinging nettle extract to the ginger root extract ranging from 1 :10 to 10:1.

Description

[0001] Eisenfiihr Speiser

[0002] Munich, 9 October 2024

[0003] Our Ref.: SM 6975-01 WO SOE / TWS

[0004] Applicant: Symrise AG

[0005] Serial Number: New Application

[0006] Symrise AG

[0007] MuhlenfeldstraBe 1 , 37603 Holzminden,

[0008] Germany

[0009] Mixtures from extracts of stinging nettle and ginger root

[0010] The present invention mainly relates to mixtures from extracts of stinging nettle and ginger root, and their uses in cosmetics and therapy, in particular cosmetic and / or therapeutic skincare.

[0011] Latest studies show that consumers’ perception of skin sensitivity including itching, tingling 5 sensation and skin redness has increased. Many examples exist of medicaments designed to relieve or sooth irritated skin. These ingredients, whilst on the whole successful, are sometimes considered by consumers as “over the top”. A need exists for novel cosmetic ingredients with soothing and skin redness reducing efficacy.

[0012] Thus, an object of the present invention is to provide cosmetically accepted ingredients that0 can be incorporated into topical cosmetic formulations and are capable to sooth skin and / or reduce skin redness when applied topically. In addition to their effectiveness they should be price competitive and, if possible, a “green” alternative, to current soothing agents.

[0013] The object is achieved by the present invention. According to a first aspect of the present invention, a mixture formed from extracts of stinging nettle and ginger root comprises5 zingiberene, 6-gingerol and caffeoylmalic acid, and a weight ratio of the stinging nettle extract to the ginger root extract ranges from 1 :10 to 10:1 , preferably from 1 :6 to 6:1 , more preferably 1 :4 to 4:1 . In case the weight ratio of the stinging nettle extract to the ginger root extract in a mixture of the invention is not known, the weight ratio is an approximation determined according to the following approach:

[0014] 1 . Determine the average content of 6-gingerol in the dry matter of a representative number of ginger extracts. 2. Determine the average content of caffeoylmalic acid in the dry matter of a representative number of stinging nettle extract. 3. Calculate a first ratio of the determined 6-gingerol and caffeoylmalic acid content. 4. Determine the 6-gingerol and caffeoylmalic acid content in the mixture in which the weight ratio is to be deteremined, and calculate a second ratio in the same way. 5. Determine the ratio of the first and second ratios to obtain an aproximation forthe weight ratio of the dry extracts of ginger and stinging nettle in the mixture.

[0015] For example, if the ratio of 6-gingerol and caffeoylmalic acid in dry extracts from ginger and stinging nettle is 1 :2, and the corresponding ratio of 6-gingerol and caffeoylmalic acid in the mixture is 1 :10, then the weight ratio of the dry extracts of ginger and stinging nettle in the mixture is approximately 1 :5.

[0016] The present invention is based on the inventors’ observation that an extract of ginger root as described herein in combination with an extract of stinging nettle is capable to inhibit cytokine production in the form of interleukin 6 (IL-6) and interleukin 8 (IL-8) in keratinocyte cells in a synergistic manner. Based on this observation the inventors hypothesize that the mixture of the invention exhibits a synergistic efficacy with respect to soothing skin and / or reducing skin redness.

[0017] Therefore, a preferred mixture contains the stinging nettle and ginger root extracts in an amount sufficient to inhibit IL-6 biosynthesis and / or IL-8 biosynthesis in keratinocytes by at least 25%, as determined using the assay described in the Example section.

[0018] The effects associated with the combined extracts can be exploited in cosmetic skincare and / or therapeutic skincare. Advantageously, the extracts of ginger root and stingle nettle are considered safe and well tolerated by the skin. They are thus not only effective, but due to their safety can be rapidly included in cosmetic and / or therapeutic skincare products that may be used even daily.

[0019] Generally, the technology disclosed herein is applicable for non-therapeutic, e.g., cosmetic purposes, or therapeutic purposes. In the context of the present invention, both therapeutic and non-therapeutic aspects, in particular cosmetic skincare and therapeutic skincare, are envisaged.

[0020] The ginger root extract used in the mixture of the invention is characterized by the presence of 6-gingerol and zingiberene. Zingiberene is an essential oil and included in the ginger root extracts as a main component. The presence of the zingiberene in combination with the 6-gingerol characterizes an extract fraction that is used in the present invention as the ginger root extract.

[0021] The ginger root extract may be further characterized by comprising one or more of 8- gingerol, 10 gingerol, 6-shoagaol and 8-shoagaol. This means, one or more of 8-gingerol, 10 gingerol, 6-shoagaol and 8-shoagaol may be further incorporated into the mixture of the invention by way of the ginger root extract.

[0022] Zingiberene means 2-Methyl-5-(6-methylhept-5-en-2-yl)cyclohexa-1 ,3-diene (ILJPAC), registered by the Chemical Abstracts Service (CAS) under Number 495-60-3.

[0023] 6-gingerol is (S)-(+)-5-Hydroxy-1-(4-hydroxy-3-methoxy-phenyl)-decan-3-on (ILJPAC), registered under CAS number 23513-14-6.

[0024] 8-Gingerol is (S)-5-Hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-dodecanon (ILJPAC), registered under CAS number 23513-08-8.

[0025] 10-Gingerol is (S)-5-Hydroxy-1-(4-hydroxy-3-methoxy-phenyl)-3-tetradecanon (ILJPAC), registered under CAS number 23513-15-7.

[0026] 6-shogaol is (E)-1-(4-Hydroxy-3-methoxyphenyl)-4-decen-3-on (ILJPAC), registered under CAS number 555-66-8.

[0027] 8-Shogaol is (E)-1-(4-hydroxy-3-methoxyphenyl)dodec-4-en-3-one (ILJPAC), registered under CAS number 36700-45-5.

[0028] The ginger root extract may further comprise one or more of sesquiphellandrene (CAS 20307-83-9), beta-bisabolene (CAS 495-61 -4), farnesene (CAS 26560-14-5) and Ar- Curcumene (CAS 4176-06-1). Their amount(s), if present, may range from 7 to 26% for sesquiphellandrene, 4 to 16% for beta-bisabolene, 3 to 13% for farnesene and 2 to 10% for Ar-Curcumene (amounts on a dry weight basis relative to the total dry weight of the ginger root extract).

[0029] Further optional constituents of the ginger root extract include one or more of the following: camphene (CAS 79-92-5, 5794-04-7) in an amount ranging from 1.5 to 6.0%; phellandrene (CAS 4221-98-1 , 2243-33-6, 6153-17-9, 6153-16-8) in an amount ranging from 1 .0 to 5.0%;

[0030] 1 ,8-cineol (470-82-6) in an amount ranging from 1 .0 to 4.0%; and neral / geranial (CAS 106-26-3 / 141-27-5) in an amount ranging from 1.5 to 6.0% (amounts on a dry weight basis relative to the total dry weight of the ginger root extract).

[0031] The mixture of the invention may be principally provided in liquid or solid form. From the perspective of stability, it is preferred that the mixture is solid. For example, the mixture may be formed from liquid extract(s), and then dried. The drying techniques is not limited, but may include any form known to the skilled person including spray drying, freeze drying, air drying, oven drying, vacuum drying, drum drying, fluidized bed drying, rotary drying, convection drying, radiation drying and the like. A preferred drying technique is spray drying. Alternatively, the mixture may be formed from dry extracts. A particular preferred mixture is in the form of a powder, in particular spray-dried powder.

[0032] The mixture may comprise one or more auxiliarty agents such as a carrier. The carrier serves to stabilize the components in the mixture during drying and is therefore preferentially contained in a solid mixture. A preferred carrier is maltodextrin. In a preferred embodiment, the mixture being in solid form, preferably in powder form, comprises, in addition to the ginger root and stinging nettle extracts, maltodextrin and / or Arabic gum.

[0033] The amount of maltodextrin, if present, may range from 10 to 95% by weight, preferably from 30% to 90% by weight, more preferably from 40 to 85% by weight, relative to the weight of the mixture. The amount of Arabic gum, if present, may range from 0.5 to 20% by weight, preferably from 1 .0% to 10% by weight, more preferably from 8 to 11 % by weight, relative to the weight of the mixture. According to a preferred embodiment, the stinging nettle extract in the mixture ranges from 0.5 to 20% by weight, preferably from 1.0 to 10% by weight, more preferably 2.0 to 5.0% by weight, relative to the weight of the mixture, on a dry weight basis.

[0034] Caffeoylmalic acid is a main constituent of the stinging nettle extract used in the invention and is therefore incorporated into the mixture of the invention as part of the stinging nettle extract. In addition to the caffeoylmalic acid, the stinging nettle extract may further comprise neochlorogenic acid, cryptochlorogenic acid and / or chlorogenic acid. Preferably, the stinging nettle extract comprises one or more of the following (amounts on a dry weight basis relative to the total weight of the stinging nettle extract): neochlorogenic acid in an amount ranging from 0.2 to 4.0% by weight, preferably 0.3 to 2.0% by weight, more preferably 0.4 to 1 .5% by weight; cryptochlorogenic and chlorogenic acids in an amount ranging from 0.5 to 4.0% by weight, preferably 0.8 to 3.0% by weight, more preferably 1 .0 to 2.0% by weight; and caffeoyl malic acid in an amount ranging from 1 .0 to 8.0% by weight, preferably 2.0 to 6.0% by weight, more preferably 3.0 to 5.0% by weight.

[0035] According to a preferred embodiment, the ginger root extract in the mixture ranges from 2 to 40% by weight, preferably from 3 to 25% by weight, more preferably 5 to 15% by weight, relative to the weight of the mixture, on a dry weight basis.

[0036] In one specific embodiment, the mixture is in solid form, preferably in powder form, and comprises the ginger root extract in an amount ranging from 2 to 40% by weight, preferably from 3 to 25% by weight, more preferably 5 to 15% by weight, relative to the weight of the mixture. The stinging nettle extract may be comprised in the mixture being in solid form, preferably in powder form, in an amount ranging from 0.5 to 20% by weight, preferably from 1 .0 to 10% by weight, more preferably 2.0 to 5.0% by weight, relative to the weight of the mixture.

[0037] In another specific embodiment, the mixture is in liquid form and the dry matter content (dry weight) of the ginger root extract ranges from 2 to 40% by weight, preferably from 3 to 25% by weight, more preferably 5 to 15% by weight, relative to the dry matter content (dry weight) of the mixture. The dry matter content of the stinging nettle extract in the liquid mixture may range from 0.5 to 20% by weight, preferably from 1 .0 to 10% by weight, more preferably 2.0 to 5.0% by weight, relative to the dry matter content (dry weight) of the mixture.

[0038] A preferred ginger root extract used in the mixture of the present invention is characterized in that it comprises the zingiberene in an amount ranging from 10 to 50% by weight, preferably 15 to 45% by weight, more preferably 20 to 40% by weight. A preferred ginger root extract comprises the 6-gingerol in an amount ranging from 0.5 to 8.0% by weight, preferably 1 .0 to 5.5% by weight, more preferably 1 .5 to 4.0% by weight (amounts on a dry weight basis). In addition to the 6-gingerol and zingiberene, the ginger root extract may further comprise (other) essential oils, (other) gingerols and / or shogaols. Preferably, the amount of essential oils in the ginger root extract ranges from 50 to 99% by weight, preferably 70 to 97% by weight, more preferably 85 to 95% by weight (amounts on a dry weight basis). Preferably, the amount of gingerols and shogaols in the ginger root extract ranges from 0.5 to 10% by weight, preferably 1 .0 to 8.0% by weight, more preferably 2.0 to 5.0% by weight (amounts on a dry weight basis).

[0039] In the mixture of the invention, the ginger root extract is preferably a supercritical CO2 extract from dried ginger roots, preferably dried ginger root from Madagascar. An advantage of the supercritical CO2 extraction is that no fluid or liquid solvent is needed, and that the CO2 can be of natural origin. One or more enrichment steps may be conducted after the supercritical CO2 extraction. A preferred stinging nettle extract is a press juice obtained from fresh plant material such as fresh leaves and / or stems. It is further preferred that the press juice is dried, in particular spray dried, and provided as a powder.

[0040] Another aspect of the invention pertains to a method for producing a mixture formed from extracts of stinging nettle and ginger root (as described herein). The method includes the steps: a) providing extracts of stinging nettle and ginger root and, optionally, one or more auxiliary agents such as one or more carriers, preferably selected from the group of Arabic gum, maltodextrin and combinations thereof; b) mixing the extracts and, optionally the one or more auxiliary agents, in appropriate relative proportions; and c) obtaining the mixture.

[0041] The extracts may be provided in a solid, e.g., powder, form, preferably a spray-dried powder form, in step a). If present, the one or more auxiliary agents may be provided in a solid form as well. Thereby, a solid mixture may be obtained in step c) without need of a drying step. Alternatively, if one or more components of the mixture obtained in step b) is liquid, a solid mixture may be obtained after carrying out a separate drying step. Moreover, the features and embodiments described in relation to the mixture of the invention shall be understood to define corresponding features and embodiments of the method of the invention. For instance, the ginger root extract used in the production method of the invention may be a supercritical CO2 extract from dried ginger root. The stinging nettle extract used in the method of the invention may be a press juice extract from fresh plant material.

[0042] Another aspect of the invention is a method for soothing skin, reducing skin redness or inhibiting cytokine production in keratinocyte cells. The method comprises: providing a mixture as described herein; and topically applying the mixture on a region of skin, where the skin is to be soothed, wherein the skin redness is to be reduced, or where the cytokine production in keratinocyte cells is to be inhibited.

[0043] In one embodiment, the region of the skin on which the mixture is affected by a pathological condition. In this embodiment, the mixture of the invention can be used in a therapeutic manner, in particular for therapeutic skincare. In another embodiment, the region of the skin on which the mixture is not affected by a pathological condition and / or free of signs of a pathological condition. According to this embodiment, the mixture of the invention is used cosmetically, in particular in cosmetic skincare, but not therapeutically.

[0044] The mixture of the invention is particularly suited for being used in a method for treating a skin condition associated with cytokine overproduction in keratinocyte cells. Hence, a further aspect of the invention is a mixture as defined herein for use in a method fortreating a skin condition associated with cytokine overproduction in keratinocyte cells by topically applying the mixture on regions of skin showing signs of cytokine overproduction.

[0045] It has been surprisingly turned out that the ginger root extract as described herein is stabilized by the presence of the stinging nettle extract. Therefore, the present invention also relates to the use of a stinging nettle extract (as described herein) for stabilizing a ginger root extract (as described herein).

[0046] In the following, the invention is explained in more detail with reference to representative examples and with reference to the drawings which show:

[0047] Fig. 1 Inhibition of IL-6 biosynthesis. Comparison of single extracts and combined extracts. The combined extracts were tested in two different weight ratios, namely a weight ratio of stinging nettle extract to ginger root extract of 6.3:1 and a weight ratio of stinging nettle extract to ginger root extract of 3:1. The x-axis indicates the concentration of the solution used in the test in %.

[0048] Fig. 2 Inhibition of IL-8 biosynthesis. Comparison of single extracts and combined extracts using the same extracts as in Fig. 1 .

[0049] Examples:

[0050] In the following experiments, SymVital® Ginfuse (CAS 84696-15-1) was used as exemplary ginger root extract. A spray dried powder of stinging nettle juice was used as exemplary stinging nettle extract. The stinging nettle juice is a press juice obtained from fresh plant material. The dry matter was determined by lyophilization to be 4.9%.

[0051] 1 . Inhibition of interleukin biosynthesis

[0052] IL-8 / IL-6 ELISA: According to the test procedure, the IL-8 and IL-6 produced and secreted by cells are determined in an Enzyme linked immunosorbance assay (ELISA) from cell supernatants utilizing antibodies detecting the I L-8 / IL-6. The assay is performed on HaCaT cells by addition of test substances and their incubation for 6h (37°C). Afterwards, inflammation is triggered with IL1a for 24h or 2h, respectively, and IL-8 / IL-6 is measured. Therefore, the quantitative sandwich enzyme immunoassay technique is employed. A monoclonal antibody specific for human IL-8 / IL-6 is pre-coated onto a microplate. Standards and samples / supernatants are pipetted into the wells and any IL-8 present is bound by the immobilized antibody. After washing away any unbound substances, an enzyme-linked polyclonal antibody specific for human IL-8 / IL-6 is added to the wells. Following washing away any unbound antibody-enzyme reagent, a substrate solution is added. A color develops in proportion to the amount of IL-8 bound in the initial step. Results are calculated as inhibition [%]. Therefore, the IL-8 / IL-6 concentrations for unknown samples are interpolated from a standard curve. Finally, the concentration of the nonstimulated control is subtracted of each determined IL-8 / IL-6 concentration. Afterwards the inhibition is determined in relation to the stimulated control.

[0053] As can be seen in Fig. 1 , the greatest inhibition of IL-6 biosynthesis was achieved with a weight ratio of stinging nettle extract to ginger root extract of 6.3:1. Fig. 2 shows the inhibition of IL-8 biosynthesis. Again, the greatest inhibition was achieved when the weight ratio of stinging nettle extract to ginger root extract was 6.3:1. Further, opposite effects have been observed for IL-6 and IL-8. One may speculate that this observation is due to different regulation kinetics, which seems to be altered by the synergy.

[0054] 2. Stabilization of 6-gingerol

[0055] Stability of raw materials and finished formulations upon storage and normal use is important. Normal use of finished formulations includes opening and closing the packaging over typically several months which leads to oxygen exposure or storage at different conditions such as e.g. elevated temperatures. Active ingredients delivering benefits need to be stable or have to be stabilized to deliver their activity also over longer times of use.

[0056] To evaluate the oxidative stability of ginger root extract, 6-gingerol was used as analyte. 6- gingerol is a known anti-inflammatory agent. Tests were performed in a simplified system consisting of water and dipropylene glycol (DPG), an organic solvent used in cosmetic and fragrance compositions.

[0057] The stability test was performed with an Oxipres device of Mikrolab. The device allows the determination of oxidative resistance and is a modification of the bomb method according to ASTM D941 , which is based on oxidation with oxygen. The test runs under elevated pressure and temperature, through which the degradation process is accelerated due to harder conditions such as temperature and pressure, allowing thus to simulate storage conditions for ingredients and investigate their behavior.

[0058] Test conditions used in this study were 5 bar oxygen, 70°C for 24 hours. The ginger root extract alone and in combination with the stinging nettle extract in DPG / water-based solution was stressed using the described conditions and 6-gingerol was analyzed by HPLC before and after oxipres treatment and modulation of its content was calculated.

[0059] Table 1 : Test samples and results

[0060] * The solution contained 50 ppm of 6-gingeriol before the oxipres treatment.

[0061] The experiments show that the stinging nettle extract stabilizes the ginger root extract ingredient 6-gingerol already at very low dry matter-based concentrations.

Claims

Claims:

1. A mixture formed from extracts of stinging nettle and ginger root, the mixture comprising zingiberene, 6-gingerol and caffeoylmalic acid, and a weight ratio of the stinging nettle extract to the ginger root extract ranging from 1 :10 to 10:1 , preferably 1 :6 to 6:1 , more preferably 1 :4 to 4:1 , on a dry weight basis.

2. The mixture of claim 1 being in the form of a powder, preferably a spray-dried powder.

3. The mixture of claim 1 or 2, further comprising one or more auxiliary agents selected from the group of maltodextrin, Arabic gum, and combinations thereof.

4. The mixture of claim 3, wherein the amount of maltodextrin ranges from 10 to 95% by weight, preferably 30 to 90%, more preferably 40 to 85%, on a dry weight basis relative to the total weight of the mixture.

5. The mixture of claim 3 or 4, wherein the amount of Arabic gum ranges from 1 to 25% by weight, preferably 3 to 20%, more preferably 5 to 15%, on a dry weight basis relative to the total weight of the mixture.

6. The mixture of any of the preceding claims, wherein the amount of the stinging nettle extract in the mixture ranges from 0.5 to 20% by weight, preferably 1 .0 to 10%, more preferably 2.0 to 5.0%, on a dry weight basis relative to the total weight of the mixture.

7. The mixture of any of the preceding claims, wherein the stinging nettle extract is characterized by a composition comprising, on a dry weight basis relative to the total weight of the ginger root extract, one or more of the following: neochlorogenic acid in an amount ranging from 0.2 to 4.0% by weight, preferably 0.3 to 2.0% by weight, more preferably 0.4 to 1 .5% by weight; cryptochlorogenic and chlorogenic acids in an amount ranging from 0.5 to 4.0% by weight, preferably 0.8 to 3.0% by weight, more preferably 1 .0 to 2.0% by weight; caffeoyl malic acid in an amount ranging from 1 .0 to 8.0% by weight, preferably 2.0 to 6.0% by weight, more preferably 3.0 to 5.0% by weight.

8. The mixture of any of the preceding claims, wherein the amount of the ginger root extract in the mixture ranges from 2 to 40% by weight, preferably 3 to 25%, more preferably 5 to 15%, on a dry weight basis relative to the total weight of the mixture.

9. The mixture of any of the preceding claims, wherein the ginger root extract is characterized by a composition comprising, on a dry weight basis relative to the total weight of the ginger root extract: zingiberene in an amount ranging from 10 to 50% by weight, preferably 15 to 45% by weight, more preferably 20 to 40% by weight, preferably with the proviso that the total amount of essential oils ranges from 50 to 99% by weight, preferably 70 to 97% by weight, more preferably 85 to 95% by weight.

10. The mixture of any of the preceding claims, wherein the ginger root extract is characterized by a composition comprising, on a dry weight basis relative to the total weight of the ginger root extract:6-gingerol in an amount ranging from 0.5 to 8.0% by weight, preferably 1 .0 to 5.5% by weight, more preferably 1 .5 to 4.0% by weight, preferably with the proviso that the total amount of gingerols and shogaols ranges from 0.5 to 10% by weight, preferably 1 .0 to 8.0% by weight, more preferably 2.0 to 5.0% by weight.11 . The mixture of any of the preceding claims, wherein the ginger root extract is a supercritical CO2 extract from dried ginger root and / or wherein the stinging nettle extract is a press juice extract from fresh plant material.

12. A method for producing a mixture formed from extracts of stinging nettle and ginger root as defined by any one of claims 1 to 11 , comprising: a) providing extracts of stinging nettle and ginger root and, optionally, one or more auxiliary agents selected from the group of maltodextrin, Arabic gum, and combinations thereof;b) mixing the extracts and, optionally, the one or more auxiliary agents, in appropriate relative proportions; and c) obtaining the mixture.

13. A method for soothing skin, reducing skin redness or inhibiting cytokine production in keratinocyte cells, comprising: providing a mixture as defined in any of claims 1 to 11 ; and topically applying the mixture on a region of skin, where the skin is to be soothed, wherein the skin redness is to be reduced, or where the cytokine production in keratinocyte cells is to be inhibited.

14. A mixture as defined in any of claims 1 to 11 for use in a method for treating a skin condition associated with cytokine overproduction in keratinocyte cells by topically applying the mixture on regions of skin showing signs of cytokine overproduction.

15. Use of a stinging nettle extract for stabilizing a ginger root extract.

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