HK1135030B - Composition useful for the treatment of type 2 diabetes - Google Patents

Description

Composition for treating type 2 diabetes

Technical Field

The invention relates to an application of L-carnitine or alkanoyl L-carnitine and statins in combination in treating type 2 diabetes and clinical complications thereof.

Background

Diabetes is a disease that is widespread throughout the world and is associated with major clinical complications involving the microvascular region, such as diabetic retinopathy, diabetic neuropathy and nephropathy, and the macrovascular region, such as atherosclerosis, peripheral vasculopathy, myocardial infarction and stroke.

Insulin resistance, which is characteristic of type 2 diabetes and its microvascular and macrovascular complications, also involves syndrome X, polycystic ovary syndrome, obesity, hypertension, hyperlipidemia and hypercholesterolemia (j.am. osteopath.assoc, 2000 oct., 100 (10): 621-34; Jama, 2002nov., 27; 288 (20): 2579-88).

It is well known that hyperlipidemia, hypercholesterolemia and hypertension play a crucial role in the onset of Coronary Heart Disease (CHD). It is known that increased glycosylation of proteins is associated with all of the above-mentioned diabetic complications (Diabetologia 2001 Feb, 44 (2): 129-46).

The complications constitute a serious threat to the life and health of the individual.

Various clinical forms of diabetes are known, the most common being type 2 and type 1 diabetes. Type 2 diabetes is characterized by a decreased sensitivity to the action of insulin (insulin resistance) and causes an increase in insulin levels in the body in an attempt to compensate for this deficiency and the subsequent increase in glucose levels.

Persons with higher than normal blood glucose levels but who are not in the diabetic range are "prediabetic".

Insulin resistance is an asymptomatic condition that increases the likelihood of developing diabetes. In the case of insulin resistance, muscle, fat, and liver cells cannot properly utilize insulin. The pancreas attempts to meet the demand for insulin by producing more insulin. Overweight also contributes to insulin resistance because too much fat hinders the ability of the muscle to utilize insulin. Lack of exercise further reduces the ability of the muscle to utilize insulin.

Insulin resistance and obesity-related prediabetes may be an enhanced risk factor for hypertension, one of the most important risk factors for cardiovascular disease, which may lead to heart attack or stroke. Hypertension, if untreated, can also lead to a variety of other life-threatening conditions such as kidney damage and congestive heart failure.

Diabetes or pre-diabetes can be detected using one of the following tests:

fasting glucose test, which measures blood glucose after not eating overnight. This test is most reliable when performed in the morning. Fasting glucose levels of 100-125mg/dL are above normal, but not high enough to be termed diabetes. This condition is known as prediabetes or Impaired Fasting Glucose (IFG) and suggests that the patient may have developed insulin resistance for some time. IFG is considered a pre-diabetic state, meaning that the patient is likely to develop diabetes but is not yet diabetic.

Glucose tolerance test, which measures blood glucose after an overnight fast and 2 hours after the patient drinks a sweet liquid provided by a doctor or laboratory. If the patient's blood glucose falls within the range of 140-199mg/dL after 2 hours of drinking the fluid, the patient's glucose tolerance is greater than normal, but not high enough to be diabetic. This condition is also a form of prediabetes, known as Impaired Glucose Tolerance (IGT), which, like IFG, indicates a history of insulin resistance and a risk of developing diabetes.

Insulin resistance can be assessed using measurements of fasting insulin.

Numerous reports have demonstrated the implications of insulin resistance to a number of disease state values other than type 2 diabetes itself, such as dyslipidemia, obesity, arterial hypertension, and certain macrovascular and microvascular manifestations that are characteristic of diabetes itself. The combination of insulin resistance with obesity, hypertension and dyslipidemia is called syndrome X.

The drugs available on the market for the treatment of type 2 diabetes include drugs that have been used for many years, such as biguanides and sulfonylureas. Many of these (such as, for example, metformin) produce the following side effects: gastrointestinal disorders, the risk of acidosis in cases of renal, cardiac, hepatic, pulmonary insufficiency, etc. Sulfonylureas have an acute onset of hypoglycemia as a possible side effect. The drugs newly introduced into the market are thiazolidinediones (thiazolidinediones), which have side effects such as hepatotoxicity, increased LDL cholesterol, weight gain, and edema that are feared to humans.

Hyperlipidemia is a serious condition of diabetes mellitus and, together with frequent hypertension, constitutes a risk factor for atherosclerosis and cardiovascular disease, which are the leading causes of death from diabetes mellitus.

Cardiovascular disease is considered to be a leading cause of death in developed countries with high living standards. Social costs are enormous, both in terms of the patient's incapacity and incapacity, and in terms of the actual costs of health agencies and insurance.

Dyslipidemia is also often associated with diabetes as a consequence.

In WO 99/01126 a combination of a statin and an alkanoyl L-carnitine is described, useful for the treatment of diseases due to altered lipid metabolism.

The use of carnitine for reducing the toxicity caused by the administration of statins is described in WO 0074675.

In Clin ter.1992Jan, 140(1Pt 2): 17-22 describe the triglyceride lowering effect of L-carnitine in combination with simvastatin in patients with renal failure (hypotriglycemic action).

The combination of L-carnitine and simvastatin to reduce the potency of lipoprotein (a) in type 2 diabetes patients is described in Atherosclerosis 188, 2006, 455-461.

The use of L-carnitine for the treatment of hypertension in type 2 diabetic patients is described in Minerva Medica, Vol.80, N.degree.3.

In Muscle & Nerves 34: the use of statins in patients with fatty acid oxidation defects including carnitine abnormalities and mitochondrial disorders has been reported by August 2006, 153-162 to cause higher incidence of metabolic muscle disease than expected in the general population.

In these documents, insulin resistance or reduction of protein glycosylation is never mentioned.

There is an increasing interest in so-called risk factors, which are regarded as potential factors for these diseases, and there is still a clear need for drugs which can act on various sources of these pathological conditions and at the same time do not involve serious side effects, which may even require discontinuation of the treatment, for example in the case of certain antidiabetics.

Brief description of the invention

It has now surprisingly been found that certain combinations of substances known to have specific pharmacological effects are particularly suitable for the treatment of type 2 diabetes, for reducing protein glycosylation and the pathological conditions associated with these conditions.

The compositions of the present invention comprise L-carnitine and/or one or more alkanoyl L-carnitine or pharmaceutically acceptable salts thereof, and a statin.

Pharmaceutically acceptable salts of L-carnitine refer to any salt of L-carnitine with an acid that does not cause toxicity or side effects.

These acids are well known to those skilled in the art of pharmacologists and pharmaceutics. Non-limiting examples of such salts are: chloride, bromide, orotate, aspartate, acid citrate, magnesium citrate, phosphate, acid phosphate, fumarate and acid fumarate, magnesium fumarate, lactate, maleate and acid maleate, oxalate, acid oxalate, pamoate, acid pamoate, sulfate, acid sulfate, glucose phosphate, tartrate and acid tartrate, glycerophosphate, mucate, magnesium tartrate, 2-amino-ethanesulfonate, magnesium 2-amino-ethanesulfonate, methanesulfonate, choline tartrate, trichloroacetate, and trifluoroacetate.

Pharmaceutically acceptable salts of L-carnitine also represent salts approved by the FDA and listed in the publication int.J. of pharm.33(1986), 201-217, which is incorporated herein by reference.

The compositions of the present invention exert a surprising synergistic effect on insulin resistance and reduction of protein glycosylation, which is not predictable based on our knowledge of its individual components.

Thus, the advantages of such compositions will be readily apparent to those skilled in the art. In fact, it has the potential to be used in the treatment of insulin resistance, in the reduction of protein glycosylation and of the pathological forms associated therewith, such as microvascular and macrovascular complications associated with diabetes.

Accordingly, an object of the present invention is the use of L-carnitine and/or one or more alkanoyl L-carnitines selected from the group consisting of acetyl, propionyl, valeryl, isovaleryl, butyryl, and isobutyryl L-carnitine, or one or more pharmaceutically acceptable salts thereof in combination with a statin selected from the group consisting of simvastatin, lovastatin, fluvastatin, pravastatin, atorvastatin, cerivastatin, rosuvastatin and rosuvastatin, preferably simvastatin, for the preparation of a medicament for the treatment of type 2 diabetes, for the reduction of protein glycosylation and the pathological forms associated therewith.

The compositions of the present invention may also include other useful ingredients, but which do not significantly impair the activity.

The composition of the invention may also be formulated as a food supplement, which constitutes another object of the invention.

Other objects of the present invention are the various uses of the above-mentioned compositions as medicaments, in particular for the preparation of medicaments for the treatment of insulin resistance and type 2 diabetes and its complications due to protein glycosylation.

In particular, the present invention provides the use of the above composition for the preparation of a medicament useful for the treatment of diseases involving insulin resistance, such as type 2 diabetes, syndrome X, polycystic ovary syndrome, obesity, hypertension, hyperlipidemia and hypercholesterolemia.

The medicaments of the invention may be used to treat individual disease states, or to exert a prophylactic or protective effect against them, or to treat complex pathological conditions involving one or more of the above-mentioned therapeutic aspects. For example, drugs with a combined effect of reducing protein glycosylation, treating type 2 diabetes and insulin resistance and anti-dyslipidemias, and protective action against the cardiovascular system, especially in certain severe cases of type 2 diabetes associated with obesity.

Detailed description of the invention

The compositions of the present invention comprise active ingredients known in the medical field and already used in clinical practice. They are therefore very readily available as products already on the market for some time and are of a grade suitable for human or animal administration.

Statins are a known class of drugs used to reduce cholesterol levels. Statins are commercially available or can be prepared according to known methods described in the literature.

L-carnitine and its alkanoyl derivatives are known compounds and their preparation is described in U.S. Pat. No. 4,254,053.

Several previous therapeutic uses of carnitine for the treatment of diabetes are known.

For example, WO 98/01128 discloses the use of acetyl L-carnitine, isovaleryl L-carnitine, propionyl L-carnitine for increasing the level of IGF-1.

It is stated in WO 98/01128 that diabetes is also included in a long list of treatable pathologies.

WO 98/41113 describes a therapeutic nutritional composition for diabetic patients comprising gamma linoleic acid, acetyl L-carnitine, inorganic salts and vitamins.

US 4362719 describes the use of L-carnitine and acetyl (acil) L-carnitine for the treatment of juvenile onset diabetes.

US 5430065 describes the use of L-carnitine and acetyl-idene L-carnitine for the long-term treatment of patients with non-insulin dependent diabetes mellitus.

In Journal of Cellular Physiology 203; 2005; 439-446 reported that the addition of acetyl L-carnitine to the culture medium significantly affected the ability of muscle cells to respond to insulin treatment.

None of the above publications describes that L-carnitine and/or one or more alkanoyl L-carnitine in combination with a statin has been used for the preparation of a medicament for the treatment of type 2 diabetes and diseases associated with protein glycosylation due to type 2 diabetes.

According to the present invention, it is also possible to combine a number of statins with one or more carnitine, depending on their pharmacological characteristics and on the general knowledge of the person skilled in the art.

This means that the dosages and proportions of the individual components can be determined by the person skilled in the art by means of routine preclinical and clinical trials or by routine considerations in connection with the formulation of dietetic products, in addition to the reasons for the synergistic effects shown herein below.

The recommended amounts of the respective compounds for the preparation of pharmaceutical compositions for human use are as follows. Simvastatin: 5mg to 80mg per day, preferably 15 to 40mg per day, most preferably 20mg per day.

L-carnitine and/or alkanoyl L-carnitine: 0.5-5 g/day, preferably 1.5-3 g/day, most preferably 2 g/day.

The pharmaceutical compositions may have a single form in which the active ingredients are present as a single pharmaceutical form (tablets, sachets, capsules, vials), or the active ingredients may be administered in a coordinated sequential manner. In the latter case, the components are provided in separate containers and the pharmaceutical composition is formulated according to instructions for their sequential administration. The compositions of the invention are entirely conventional and are obtained by methods routinely practiced by the pharmaceutical industry. Depending on the route of administration chosen, the compositions may be in solid or liquid form suitable for oral, parenteral or intravenous administration. The compositions of the invention comprise at least one pharmaceutically acceptable vehicle or excipient together with the active ingredient. Particularly useful may be formulation aids such as, for example, solubilizers, dispersants, suspending agents and emulsifiers. The general reference is Remington's pharmaceutical sciences Handbook, latest edition.

As mentioned above, insulin resistance and diabetes may be enhanced risk factors for hypertension (which is one of the most important risk factors for cardiovascular disease), which may lead to heart attack or stroke. Hypertension, if untreated, can also lead to a variety of other life-threatening conditions such as kidney damage and congestive heart failure. The composition of the present invention may be administered with known drugs for treating hypertension, or with additional antidiabetics, depending on the prescription and experience of the doctor.

The following examples further illustrate the invention.

Detailed description of the preferred embodiments

Example 1

Antidiabetic and serum lipid lowering activity in db/db mice

Mutations in experimental animals make it possible to develop models that exhibit non-insulin dependent Diabetes mellitus associated with obesity, hyperlipidemia and insulin resistance and enable us to test the efficacy of novel antidiabetic compounds (Reed and Scribner, Diabetes, obesityand Diabetes 1: 75-86, 1999).

A widely used mouse model of hereditary diabetes is the C57BL/KsJ db/db mouse.

The genetic basis of this model is a deficiency in the leptin receptor gene which causes leptin resistance and leads to bulimia, obesity, hyperinsulinemia and insulin resistance, with subsequent symptoms of insulin hyposecretion and hyperglycemia (Kodama et al, Diabetologia 37: 739-495, 1994; Chen et al, Cell 84: 491-495, 1996).

Because hyperglycemia is accompanied by obesity and insulin resistance, the db/db mice have characteristics close to those of human type 2 diabetes patients and can be used to test insulin sensitizing compounds.

C57BL/KsJ db/db mice used for the experiments were supplied by Jackson Lab (by ch. Blood samples were taken from the tail vein with the help of a Jelco 22G catheter (Johnson and Johnson) under postabsorption conditions (fasting from 8.30 am to 4.30 pm) after adaptation for 10 days under standard conditions (22 ± 2 ℃ c; 55 ± 15% humidity; 15-20 air changes/hour; 12 hours day-dark cycle, day 7 pm to day 7 pm) given a standard 4RF21 diet (mucedo). Plasma glucose, insulin, triglyceride, cholesterol, free fatty acids and urea levels were examined to ensure proper distribution of mice in each treatment group. At the start of treatment, the weight of the animals was checked and a schedule was compiled to monitor the water and feed consumption of the animals. Mice were divided into groups and treated twice daily with oral administration of the following drugs:

simvastatin 100 mg/kg;

the L-carnitine inner salt is 400 mg/kg;

acetyl L-carnitine HCl 592mg/kg (in equimolar amounts relative to L-carnitine);

propionyl L-carnitine HCl 627mg/kg (equimolar amount relative to L-carnitine);

400mg/kg of L-carnitine inner salt and 100mg/kg of simvastatin;

acetyl L-carnitine HCl 592mg/kg + simvastatin 100 mg/kg;

propionyl L-carnitine HCl 627mg/kg + simvastatin 100 mg/kg.

Serum glucose levels, glucose tolerance (OGTT), numerous lipid state variables and weight gain were monitored during the course of the experiment. The composition of the present invention is capable of lowering serum glucose levels in: in fed (table 1), in postabsorbed (table 2), in fasted (table 3); and is capable of improving glucose tolerance (table 4); capable of reducing the level of fructosamine (table 5), an indicator of protein glycosylation, which, as mentioned above, plays an important role in the development of microvascular and macrovascular complications of diabetes.

The compositions of the present invention also show good ability to lower serum triglyceride levels (table 6) and raise HDL-cholesterol levels (table 7).

An increase in HDL-cholesterol values forms an indicator of a reduced risk of atherosclerosis and cardiovascular complications such as atherosclerosis and infarction.

TABLE 1

Blood glucose levels in db/db mice treated with the compounds shown in the table and the indicated doses orally twice daily for 12 days.

Samples were taken at meal age approximately 15 hours after the last treatment.

Compound (I)

Glucose mg/dl

±S.D.

P (Student's t test)

	Mean value of
				Control	483.1	14.8
Simvastatin	465.0	19.4	NS
				L-carnitine	470.0	25.9	NS
Propionyl L-carnitine	475.5	28.8	NS
				Acetyl L-carnitine	468.0	25.7	NS
L-carnitine + simvastatin	294.1	33.1	P < 0.001, relative to control
				Propionyl L-carnitine + simvastatin	303.5	21.1	P < 0.001, relative to control
Acetyl L-carnitine + simvastatin	304.6	15.6	P < 0.001, relative to control

Number of animals per group: 6.

TABLE 2

Blood glucose levels in db/db mice treated with the compounds shown in the table and the indicated doses orally twice daily for 12 days.

Samples were taken in the post-absorption situation (fasting from 9 am to 5 pm) and 8 hours after the last treatment.

Compound (I)	Average value of glucose mg/dl	±S.D.	P (Student's t test)
				Control	410.8	10.4
Simvastatin	418.1	20.6	NS
				L-carnitine	416.5	22.6	NS
Propionyl L-carnitine	411	7.4	NS
				Acetyl L-carnitine	416.1	25.5	NS
L-carnitine + simvastatin	220.5	20.8	P < 0.001, relative to control
				Propionyl L-carnitine + simvastatin	218.0	14.9	P < 0.001, relative to control
Acetyl L-carnitine + simvastatin	215.5	16.1	P < 0.001, relative to control

Number of animals per group: 6.

TABLE 3

Blood glucose levels in db/db mice treated with the compounds shown in the table and the indicated doses orally twice daily for 18 days.

Samples were taken after 18 hours of fasting and 5 hours of the last treatment.

Compound (I)	Average value of glucose mg/dl	±S.D.	P (Student' st test)
				Control	342.5	20.1
Simvastatin	328.3	21.76	NS
				L-carnitine	324.8	18.6	NS
Propionyl L-carnitine	328.6	16.3	NS
				Acetyl L-carnitine	332.0	15.5	NS
L-carnitine + simvastatin	153.83	7.63	P < 0.001, relative to control
				Propionyl L-carnitine + simvastatin	143.8	6.5	P < 0.001, relative to control
Acetyl L-carnitine + simvastatin	147.8	4.3	P < 0.001, relative to control

Number of animals per group: 6.

TABLE 4

Area under the curve (AUC) of OGTT in blood of db/db mice treated with the compounds shown in the table and the indicated doses orally twice daily for 18 days.

The OGTT test (3 g/kg glucose) was performed in mice after 18 hours of fasting and 5 hours of the last treatment.

Compound (I)	AUC glucose u.a. mean	±S.D.	P (Student' st test)
				Control	52447.7	1950.6
Simvastatin	50973.3	2950.3	NS
				L-carnitine	50187.8	2557.7	NS
Propionyl L-carnitine	49005.5	3840.8	NS
				Acetyl L-carnitine	49332.3	366.3	NS
L-carnitine + simvastatin	36149.5	2367.1	P < 0.001, relative to control
				Propionyl L-carnitine + simvastatin	34695	2617.7	P < 0.001, relative to control
Acetyl L-carnitine + simvastatin	35786.5	1795.6	P < 0.001, relative to control

Number of animals: 6.

TABLE 5

Plasma fructosamine levels in db/db mice treated twice daily orally with the compounds shown in the table and at the indicated doses for 25 days.

Samples were taken in the post-absorption situation (fasting from 9 am to 4.30 pm) and 7.5 hours after the last treatment.

Compound (I)	Mean mM fructosamine	±S.D.	P (Student' st test)
				Control	0.82	0.03
Simvastatin	0.76	0.08	NS
				L-carnitine	0.81	0.06	NS
Propionyl L-carnitine	0.81	0.04	NS
				Acetyl L-carnitine	0.85	0.03	NS
L-carnitine + simvastatin	0.49	0.07	P < 0.001, relative to control
				Propionyl L-carnitine + simvastatin	0.54	0.05	P < 0.001, relative to control
Acetyl L-carnitine + simvastatin	0.56	0.04	P < 0.001, relative to control

Number of animals per group: 6.

TABLE 6

Plasma triglyceride levels in db/db mice treated with the compounds shown in the table and the indicated doses orally twice daily for 25 days.

Samples were taken in the post-absorption situation (fasting from 9 am to 4.30 pm) and 7.5 hours after the last treatment.

Compound (I)	Mean value of mg/dl triglyceride	±S.D.	P (Student' st test)
				Control	90.6	4.1
Simvastatin	83.6	5.8	P0.05

L-carnitine	85.7	3.8	NS
				Propionyl L-carnitine	86.2	4.2	NS
Acetyl L-carnitine	85.6	4.4	NS
				L-carnitine + simvastatin	64.4	4.5	P < 0.001, relative to control
Propionyl L-carnitine + simvastatin	55.8	3.9	P < 0.001, relative to control
				Acetyl L-carnitine + simvastatin	49.4	2.3	P < 0.001, relative to control

Number of animals per group: 6.

TABLE 7

Plasma HDL-cholesterol levels in db/db mice treated with the compounds shown in the tables and the indicated doses orally twice daily for 25 days. Samples were taken in the post-absorption situation (fasting from 9 am to 4.30 pm) and 7.5 hours after the last treatment.

Compound (I)	Average HDL-cholesterol mg/dl	±S.D.	P (Student' st test)
				Control	80.9	3.9
Simvastatin	74.5	2.4	P0.01
				L-carnitine	84.0	4.4	NS
Propionyl L-carnitine	80.9	2.3	NS
				Acetyl L-carnitine	84.5	3.7	NS
L-carnitine + simvastatin	91.2	1.8	P < 0.001, relative to control
				Propionyl L-carnitine + simvastatin	91.4	2.3	P < 0.001, relative to control
Acetyl L-carnitine + simvastatin	91.4	2.8	P < 0.001, relative to control

Number of animals per group: 6.

the results reported above clearly demonstrate the unexpected synergistic effect of the compositions of the present invention with respect to the individual components.

Claims (7)

1. Use of L-carnitine and/or alkanoyl L-carnitine or their pharmaceutically acceptable salts in combination with simvastatin for the preparation of a medicament for the treatment of type 2 diabetes, wherein the alkanoyl L-carnitine is selected from the group consisting of acetyl L-carnitine, propionyl L-carnitine, valeryl L-carnitine, isovaleryl L-carnitine, butyryl L-carnitine and isobutyryl L-carnitine.
2. 2. The use of claim 1, wherein the pharmaceutically acceptable salt of L-carnitine or alkanoyl L-carnitine is selected from the group consisting of: chloride, bromide, orotate, aspartate, acid citrate, magnesium citrate, phosphate, acid phosphate, fumarate and acid fumarate, magnesium fumarate, lactate, maleate and acid maleate, oxalate, acid oxalate, pamoate, acid pamoate, sulfate, acid sulfate, glucose phosphate, tartrate and acid tartrate, glycerophosphate, mucate, magnesium tartrate, 2-amino-ethanesulfonate, magnesium 2-amino-ethanesulfonate, methanesulfonate, choline tartrate, trichloroacetate, and trifluoroacetate.
3. 3. The use of claim 1, wherein the medicament for administration comprises 5mg to 80 mg/day simvastatin; 0.5-5 g/day of carnitine and/or alkanoyl L-carnitine or a pharmaceutically acceptable salt thereof.
4. 4. The use of claim 3, wherein the medicament for administration comprises 15-40 mg/day simvastatin and 1.5-3 g/day carnitine and/or an alkanoyl L-carnitine or a pharmaceutically acceptable salt thereof.
5. 5. The use of claim 3, wherein the medicament for administration comprises 20 mg/day simvastatin and 2 g/day carnitine and/or an alkanoyl L-carnitine or a pharmaceutically acceptable salt thereof.
6. 6. Use according to any one of claims 3 to 5, wherein the medicament is in solid or liquid form suitable for oral and parenteral administration, in the form of tablets, sachets, capsules or vials.
7. 7. Use according to any one of claims 3 to 5 wherein the medicament is in the form of a single medicament or in separate containers for sequential administration.