HK1082404A - Therapeutic and dietary compositions - Google Patents

Description

Therapeutic and dietary compositions

no marking

The present application is a divisional application of a patent application having application number 98807550.4, filed on 1998 at 22.7.1998 entitled "therapeutic and dietary composition containing essential fatty acids and bioactive disulfides".

Technical Field

The present invention relates to therapeutic and dietary compositions.

Fatty acids

Gamma-linolenic acid (GLA), its immediate metabolite dihomogamma-linolenic acid (DGLA), and the DGLA metabolite Arachidonic Acid (AA) produced in some circumstances have a variety of beneficial biological effects which are active as essential nutrients and nutrients, or as therapeutic agents with specific prophylactic or therapeutic effects on a variety of diseases, including skin disorders (e.g., eczema and psoriasis), metabolic disorders (especially diabetes and its complications such as retinopathy, neuropathy, nephropathy and cardiovascular disease), inflammatory and autoimmune disorders (e.g., rheumatoid arthritis, osteoarthritis, Sjogren's syndrome, systemic lupus erythematosus, Crohn's disease, ulcerative colitis), respiratory disorders (including asthma, pulmonary arterial hypertension and pulmonary fibrosis), psychiatric and central nervous system disorders (e.g., schizophrenia, peripheral nerve disease, central nervous system disorders, and the like, Alzheimer's dementia and vascular dementia or other types of dementia, depression and multiple sclerosis), diseases of the cardiovascular system (such as hypertension, coronary artery disease and peripheral artery disease), diseases of the gastrointestinal system (such as glomerulonephritis and other inflammatory and autoimmune diseases), diseases of the gastrointestinal system (such as esophagitis, gastritis, peptic ulcer, crohn's disease and ulcerative colitis), and diseases of the endocrine system and its target organ system (such as benign breast disease and benign prostate disease). Cancer and precancerous conditions also respond to treatment with GLA and DGLA. GLA and DGLA have also been found to be beneficial in the care of animal diseases, diseased skin and normal skin, where they are beneficial for skin care by improving skin blood flow and skin smoothness.

Other essential fatty acids of the n-3 series, particularly Stearidonic Acid (SA), eicosapentaenoic acid (EPA), menhaden acid (DPA) and docosahexaenoic acid (DHA), also have many nutritional and therapeutic effects, and many of the previous patents filed by the applicant relate to the use of either or both of these two series in various situations, one example of which is EPA0218460, which relates to their use in diabetic complications.

Both series of essential fatty acids are well known per se, and their nomenclature and relationships are as follows:

TABLE I

n-6 EFAs 18: 2n-6 Linoleic Acid (LA) ↓18: 3n-6 γ -linolenic acid (GLA) ↓20: 3n-6 double high- γ -linolenic acid (DGLA) ↓20: 4n-6 Arachidonic Acid (AA) ↓22: 4n-6 adrenal acid ↓ 22: 5n-6

Elongation of delta-6-desaturase delta-5-desaturase elongation of delta-4-desaturase

n-3 EFAs 18: 3n-3 α -linolenic acid (ALA) ↓18: 4n-3 Stearidonic Acid (SA) ↓20: 4n-3 eicosatetraenoic acid ↓20: 5n-3 eicosapentaenoic acid (EPA) ↓22: 5n-3 ↓22: 6n-3 docosahexaenoic acid (DHA)

These acids, which are in essentially all-cis configuration, are systematically named as derivatives of the corresponding stearic, eicosanoic or docosaic acids, such as z, z-octadeca-9, 12-dienoic acid, or z, z, z, z-docosac-4, 7, 10, 13, 16, 19-hexaenoic acid, but numerical indications based on the number of carbon atoms, the number of unsaturated centers, and the number of carbon atoms from the end of the chain to the beginning of unsaturation, such as 18: 2n-6 or 22: 6n-3 is convenient to use. Acronyms such as EPA, and abbreviated forms of nomenclature such as eicosapentaenoic acid are used in some instances as colloquial names. Other acids that have undergone a 6-desaturation step are commonly referred to as "6-desaturated" acids.

Disulfide compounds

There are many different types of compounds that are alpha-lipoic acid, also known as lipoic acid (TA) and related compounds. In vivo, TA is converted to dihydrolipoic acid (DHL) during the formation of acetyl-CoA from pyruvate, or succinyl-CoA from alpha-oxoglutarate, and during other redox reactions. Lipoic acid dehydrogenase, which requires the cofactor NAD, can reconvert DHL to TA. TA and DHL have been considered equivalents because they are rapidly interconverting in vivo. The structure is as follows:

r, S and racemic form of lipoic acid or alpha-lipoic acid (TA)

And R, S and racemic form of dihydrolipoic acid (DHL)

In the present application, lipoic acid denotes isomerically pure D-or S- α -lipoic acid, the racemic form of α -lipoic acid or any mixture of R-and S-isomers, as well as the corresponding compounds involving lipoic acid, including the reduced form of lipoic acid.

The strongly lipophilic TA and the associated free disulfides are antioxidants capable of forming redox pairs in vivo, for example they have been found to be of therapeutic value in the control of diabetic complications, especially diabetic neuropathy. Diabetic complications are believed to be associated with an excessive rate of lipid and protein oxidation, and it has been found that the TA/DHL redox pair significantly neutralizes a variety of free radicals. In addition, the TA/DHL redox couple can "recycle" other important antioxidants such as alpha-tocopherol and ascorbate, and can increase intracellular glutathione levels. In addition to diabetic complications, there is evidence that TA can enhance sensitivity to insulin and thus be of therapeutic value for pre-diabetic syndrome X and obesity.

TA metabolites that function similarly to TA are tetranorlipoic acid (TALA), bisnorlipoic acid (BALA) and 8-hydroxybisnorlipoic acid (8BALA), which have the same R and S isomers as lipoic acid.

Antioxidant properties of alpha-lipoic acid and its reduced forms, and thus its proposed clinical applications in diabetes and other diseases, are discussed by Packer Witt and Tritschler in antioxidant Handbook (Handbook of antioxidants) (E cadana and L Packer, Marcel Dekkar, new york 1996), chapter 18, p 545-591. In addition, the applicant's prior patent application PCT GB 96/01053(WO96/34846) discloses fatty acid/antioxidant derivatives of 1, 3-propanediol, and their use in diseases where antioxidants can be beneficial, including cardiovascular disease, cancer and inflammation. The specific diesters disclosed therein are esters of GLA or DHA and alpha-lipoic acid. Other patent specifications PCT GB96/01052(WO96/34855) by the present applicant disclose related compounds, namely analogous derivatives of dihydroxymethane. However, in these patent applications, the applicant has emphasized the use of compounds containing fatty acid and lipoic acid moieties: there is no mention of the combined use of fatty acids and lipoic acid as separate molecules, nor of a specific use for such a combination. In hoechst usp 5043328, applicants mention the use of lipoic acid as an antioxidant in prostaglandin metabolism, gastrointestinal disorders, and skin and subcutaneous tissue dysfunction.

The invention

To date, the treatments and prevention available for most of the diseases mentioned, including diabetes, insulin resistance, syndrome X, and diabetic complications such as neuropathy and retinopathy, are far from satisfactory. It is felt that it would be worthwhile to test the therapeutic effect of the two different approaches described above on diabetic complications simultaneously. GLA is believed to act primarily on the microcirculation, whereas TA/DHL acts primarily on the oxidation mechanism, but it is reasonable to test whether the combined use of these agents would have at least a synergistic effect.

Indeed, in the determination of nerve conduction velocity and nerve blood flow, a large and unexpected synergistic effect was found, the effect of the two agents used in combination being much greater than the sum of the effects of their individual uses. These results are shown in FIGS. 1 and 2. In diabetic animals, both nerve conduction and nerve blood flow are significantly affected. By co-administering GLA and TA in amounts that produce only a weak effect when used alone, both nerve conduction and nerve blood flow in the animals were completely restored to normal.

The results of EFA and its synergy with TA were completely unexpected and we decided to continue their research. Vitamin E is a lipophilic antioxidant similar to TA and is generally thought to play a more important physiological role than TA. However, when vitamin E was administered in combination with GLA in diabetic animals, no enhancement was found for the effect of all GLA. Also, in several clinical trials, we found that the role of GLA in diseases such as atopic eczema, angina pectoris, rheumatoid arthritis and cardiovascular diseases was not enhanced by co-administration with vitamin E. Thus, there is no reason to suspect the unexpectedly large synergistic effect we observe, which we believe cannot be explained by antioxidant action.

To explore other effects, we have performed preliminary experiments with rats to determine the effect of GLA, EPA or DHA with or without the administration of the antioxidants vitamin E, vitamin C or TA. 0.1% by weight of each fatty acid was added to the food and the test was carried out for 2 weeks. The diet contained no other added substances (control) or 0.1% by weight of vitamin E, vitamin C or TA. After 2 weeks, the animals were sacrificed and the levels of fatty acids or their intermediary metabolites in plasma phospholipids and red blood cell membrane phospholipids were determined. Neither vitamin E nor vitamin C has any effect on the level of fatty acids in plasma or erythrocytes. From this we can conclude that antioxidants themselves have no effect on the metabolism of GLA, EPA or DHA in this case. Also, TA had no effect on the composition of plasma phospholipid fatty acids. In contrast, the concentration of the relevant fatty acids in the red cell phospholipids increased by 10-20% in each group. This demonstrates that TA has an unknown and unexpected effect on the entry of EFAs into the cell membrane. This effect appears to be independent of antioxidant activity.

We would show that TA can facilitate EFA entry into cell membrane phospholipids. This will affect cell membrane structure and affect the utilization of EFAs by the cell signaling system, which may be responsible for our observed synergy in neural function and neural blood flow in diabetic animals. This synergy is generally applicable to all EFAs, not just GLA.

Broadly, the present invention relates to compositions of GLA and/or other EFAs with TA or related compounds and their use in therapy, or nutrition, or in the manufacture of compositions for use in therapy or nutrition. The diseases involved are those listed in the present specification, but the present invention is particularly concerned with improving EFA concentration in cell membranes and/or improving impaired nerve function (e.g. motor nerve conduction velocity) and blood flow, particularly in diabetic complications. In other diseases, especially in cardiac and peripheral circulatory disorders, reduced blood flow may also be an important cause. In most of the listed diseases, the reduced ability of EPA to enter cell membranes may be an important cause.

Disclosure of Invention

The invention provides, inter alia:

1. the use of essential fatty acids, especially those which have undergone a 6-desaturation step in the n-6 and n-3 metabolic pathways, and a biologically active disulfide, especially TA or related compound, in the manufacture of a medicament for treatment to improve or maintain cell membrane EFA concentration in healthy individuals or individuals suffering from the diseases listed in this specification, or in the treatment itself, including the use of one active agent for administration in combination with another active agent, and each active agent being present as such or in a derivative which releases the active agent in vivo.

2. The use of essential fatty acids, especially those which have undergone a 6-desaturation step in the n-6 and n-3 metabolic pathways, and a biocompatible disulfide, especially TA or related compound, for the preparation of a medicament for the treatment or prevention of any disease where reduced blood flow to any tissue is important, and any pathogenic peripheral coronary or cerebrovascular disease and any cardiovascular disease, especially hypertension, coronary artery disease or peripheral arterial disease or thrombotic disease, including the use of one active agent for administration in combination with another active agent, and each active agent being present as such or in a derivative which releases the active agent in vivo.

3. The application is especially used for treating atherosclerotic vascular injury and coronary heart disease.

4. The use as described above, wherein the active agent comprises at least one active agent selected from GLA, DGLA and AA, and/or SA, EPA, DPA and DHA.

5. The use as described above, wherein the active agent comprises one or more active agents selected from TA, TALA, BALA or 8-BALA itself or their respective reduced forms.

6. The use as described above, wherein the active agent further comprises one or more other essential nutrients, especially vitamins A, D and E; b vitamins such as riboflavin, pyridoxine, niacin or niacinamide; folic acid; vitamin C; or assimilable zinc, chromium, magnesium or selenium.

7. The above use, wherein the fatty acid and the disulfide are present in respective amounts: i.e. both can be administered in an amount of 1mg to 100 g/day, preferably 10mg to 10 g/day, very preferably 50mg to 5 g/day, and in a weight ratio of 1: 20 to 20: 1, preferably 1: 5 to 5: 1, very preferably 1: 3 to 3: 1.

As mentioned above, the most effective EFA is 6-desaturated EFA, especially GLA, AA, DGLA, SA, EPA, DPA or DHA, suitably in a daily dose of 1mg to 100g, preferably 10mg to 10g, very preferably 50mg to 5g per day. Disulfides, such as TA, BALA, TAL, and 8BALA or reduced forms thereof, can be used in similar dosages. The weight ratio of EFA to disulfide may be, for example, from 1: 20 to 20: 1, but is preferably from 1: 5 to 5: 1, more preferably from about 1: 3 to 3: 1. In addition, EFA and disulfide may each be used in any suitable chemical form that is pharmaceutically acceptable and that enhances the concentration of EFA or disulfide related compounds in blood or other body tissues. Such prodrugs may include triglycerides, phospholipids, other glycerides, propylene glycol derivatives, germ glycol derivatives, and other prodrugs known to those skilled in the art. EFA and disulfide may even be loaded on the same molecule, which then functions as both an EFA prodrug and a disulfide prodrug. Specific examples are 1, 3-propanediol derivatives disclosed in the applicant's PCT application WO96/34836, and germ diol derivatives disclosed in the applicant's PCT application WO 96/34855.

The active agents may be present together in the same dosage form or separately in different dosage forms in the form of instructions for how they are to be administered. When present in separate dosage forms, the two active agents may be in the same package. They can be administered, for example, orally, enterally, parenterally, topically, rectally, or intravaginally in formulations known to those skilled in the art.

The active agent can be formulated into nutritional supplements, medicinal foods, functional foods, nutritional foods, or conventional foods, together with other essential nutrients including minerals and vitamins such as vitamins A, D and E; b vitamins such as riboflavin, pyridoxine, niacin or niacinamide; folic acid; vitamin C; or assimilable zinc, chromium, magnesium or selenium. These nutrients may be used in biologically assimilable chemical forms.

Experiment of

Preliminary experimental evidence was obtained from experiments performed on rats treated with streptozotocin to develop diabetes. In these rats, complications similar to those of human diabetes mellitus develop, which are characterized by a slow conduction rate of impulses along the sciatic nerve and a reduced blood flow to the sciatic nerve. The reduction in blood flow is particularly important and may be associated with a number of diabetic complications such as retinopathy, nephropathy, macrovascular arterial disease of the heart and peripheral arteries, impotence and leg ulcers. It may also be associated with other diseases that can be effectively treated with essential fatty acids, such as inflammation.

The test was performed with 5 groups of rats dosed with Streptozotocin (STZ). After administration with STZ, they were subjected to this experiment only if a clear blood glucose rise occurred. 10 rats were used as normal controls.

10 rats were diabetic but untreated. There were 8 treatments with TA alone. 11 were treated with GLA alone and 11 were treated with a combination of TA and GLA. GLA was added to the diet to provide a dose of about 20 mg/kg/day and TA was administered intraperitoneally at a dose of 20 mg/kg/day. Because fat metabolism is surface area dependent and because the surface area to volume ratio of small animals is much greater than that of large animals, these doses are approximately 2-3 mg/kg/day in adults.

Rats were made diabetic by intraperitoneal injection of 45mg STZ/kg. The rats used were Sprague Dawley male rats, 19 weeks in size at the time of STZ injection. After STZ injection, rats were left for 6 weeks to allow nerve damage and then were not treated with any treatment, or were treated with GLA or TA or GLA and TA for 2 weeks. At the end of 2 weeks, the rats were anesthetized and the motor conduction velocity was measured in the perineal branch of the sciatic nerve. Blood flow to sciatic nerve was measured by microelectrode hydrogen clearance polarography.

Data for motor conduction velocity and total neural blood flow are plotted. Treatment with TA alone and GLA alone resulted in a small improvement in nerve conduction velocity and total nerve blood flow, but the improvement obtained at these doses was far from returning to normal. The estimated additive effect obtained by adding the results obtained for these two compounds is also far from returning to normal. However, contrary to the expected additive effect, the two compounds, when administered in combination, effectively restored nerve conduction velocity and nerve blood flow to normal. According to previous dose/response experiments with GLA or ALA alone, GLA or TA taken together appeared to extend the effect of each other approximately 10-fold. This is in contrast to the experimental results of Packer et al (loc. cit., pp. 570-572) -no effect on nerve conduction with TA treatment alone.

The invention is exemplified above by the therapeutic examples of administering compounds to treat specific diseases. The following examples illustrate the invention with drugs and their formulations.

Examples

The following are examples of compositions that are effective for diabetic complications and other diseases listed in the present invention:

1. soft or hard gelatin capsules each containing 100mg TA, TALA, BALA or 8-BALA per se or their respective reduced forms and 100mg GLA, DGLA, AA, SA, EPA, DPA or DHA, for use at a dosage of 1-4 capsules per day.

2. The capsule as described in 1, but the daily dose of the active ingredient is 0mg to 200mg for lipoic acid related compounds and 20mg to 200mg for fatty acids.

3. Capsules as described in 1 or 2, but with the fatty acids being derivatives, i.e. ethyl esters or other esters; a monoglyceride, diglyceride, or triglyceride; a phospholipid; amides or other derivatives which increase the in vivo activity of the fatty acid.

4. Capsules according to claim 1 or 2 containing a diester containing residues of fatty acids selected from GLA, DGLA, AA, SA, EPA, DPA and DHA and residues of lipoic acid or one of its related compounds TALA, BALA or 8-BALA itself or in their respective reduced forms, and the diester is a diester of 1, 3-propanediol prepared as described in example 5 or 17 of WO96/34846, or a diester of dihydroxymethane prepared as described in example 4 of WO96/34855, which specifications are incorporated herein by reference.

5. Tablets or capsules containing 50, 100 or 200mg of TA, TALA, BALA or 8-BALA per se or their respective reduced forms per tablet or capsule in a package, e.g. a blister pack, of soft or hard capsules containing 50mg, 100mg or 200mg of GLA, DGLA, AA, SA, EPA, DPA or DHA per capsule, each dosage form being taken at a dose of 1-4 units/day.

6. A nutritional supplement for use in a human or animal subject suffering from diabetes or other disorders, the supplement being provided in the form of capsules, each capsule containing 50mg TA, 100mg GLA or DGLA, 100mg DHA, 50mg ascorbic acid, a recommended daily dose of a B vitamin and 300mg chromium picolinate.

7. Functional food for people suffering from diabetes or other diseases, wherein each food contains 100mg GLA and 100mg TA in addition to calories and essential nutrients, and optionally DGLA, AA, SA, EPA, DPA or DHA.

8. A skin care or cosmetic preparation for eczema or psoriasis comprises 0.1-2.0% TA and 0.1-10.0% GLA or DGLA in an emollient base.

9. Food or drink for athletes or people doing sports exercise for any reason including injuries, heart diseases or recovery from stroke, wherein each serving contains 50-200mg TA and 50-200mg GLA or DGLA, and optionally other essential nutrients and fatty acids.

10. A food, drink or supplement for horse or dog comprises TA 1-50 mg/kg/day and GLA or DGLA 1-50 mg/kg/day, and optionally other essential nutrients and fatty acids.

Claims (9)

1. Use of essential fatty acids, especially those which have undergone a 6-desaturation step in the n-6 and n-3 metabolic pathways, and a biocompatible disulfide, especially TA or related compounds, for the manufacture of a medicament for the treatment or prevention of a disease having reduced blood flow to any tissue.

2. Use of essential fatty acids, in particular those which have undergone a 6-desaturation step in the n-6 and n-3 metabolic pathways, together with a biocompatible disulfide, in particular TA or related compound, for the preparation of a medicament for the treatment or prevention of peripheral coronary or cerebrovascular disease of any aetiology and of any cardiovascular disease.

3. The use of claim 1 for the treatment of atherosclerotic vascular injury.

4. Use according to claim 2 for the treatment of in particular hypertension, coronary artery disease or peripheral artery disease or thrombotic disorders.

5. The use of claim 1, 2, 3 or 4 wherein the active agent comprises at least one active agent selected from GLA, DGLA and AA, and/or SA, EPA, DPA and DHA.

6. The use of claim 1, 2, 3 or 4, wherein the active agent comprises one or more active agents selected from TA, TALA, BALA or 8-BALA per se or reduced forms of each.

7. Use according to claim 1 or 2, wherein the active agent further comprises one or more other essential nutrients, especially vitamins A, D and E; b vitamins such as riboflavin, pyridoxine, niacin or niacinamide; folic acid; vitamin C; or assimilable zinc, chromium, magnesium or selenium.

8. Use according to claim 1 or 2, wherein the fatty acid and the disulfide are present in respective amounts: i.e. both can be administered in an amount of 1mg to 100 g/day, preferably 10mg to 10 g/day, very preferably 50mg to 5 g/day, and in a weight ratio of 1: 20 to 20: 1, more preferably 1: 5 to 5: 1, very preferably 1: 3 to 3: 1.

9. The use according to any of the preceding claims, wherein the essential fatty acid and the biocompatible disulphide are provided together or separately.