FIELD OF INVENTION

This invention relates generally to the treatment of Metabolic Syndrome (MetS) and related conditions. More particularly, the present invention is directed to N-benzylbenzamides that act as dual soluble soluble epoxide hydrolase (sEH)/peroxisome proliferator-activated receptor γ (PPARγ) modulators and are useful as medications in the treatment of MetS cluster diseases, including diabetes.

BACKGROUND OF THE INVENTION

The metabolic syndrome (MetS) is the name for a group of risk factors such as central obesity, atherogenic dyslipidemia, insulin resistance and endothelial dysfunction leading to arteriosclerotic cardiovascular diseases (ASCVD) such as coronary heart disease, stroke and peripheral vascular disease as well as type 2 diabetes (T2D)1-4. In addition, patients affected by T2D develop long-term microvascular complications: Two thirds of the individuals suffer from neuropathic pain5and one third develops diabetic nephropathy6. The MetS has a very complex pathophysiology which is only partially understood. SeeFIG. 1. Epidemiological evidence shows that the rising prevalence of the MetS in western societies is due to western lifestyle factors such as misbalanced, high caloric food intake, sedentary lifestyle and stress3. Up to now, the first-line treatment of the MetS covering all risk factors at once is a change in lifestyle meaning weight reduction, increased physical activity and an anti-atherogenic diet3,7,8. Nevertheless, already developed individual disorders such as endothelial dysfunction and T2D cannot be completely reversed by this approach and symptoms will worsen with advancing age. Therefore, patients accumulating various risk factors with time also accumulate quite a number of medications to treat each disorder separately9.

Obesity forms the basis of several risk factors in MetS and is therefore an important target. Pharmacological weight control can be achieved altering either appetite or calorie absorption. An altered appetite can be achieved by interfering with the central nervous system (CNS) but many drugs were already withdrawn from the market due to severe side effects10,11. Orlistat the only approved drug directly altering calorie absorption, inhibits pancreatic and gastric lipases and acts outside the CNS8.

Another facet of the MetS, atherogenic dyslipidemia, is based on an abnormal lipoprotein metabolism leading to plaque formation and atherosclerosis. Here, 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors (statins)12and PPARα agonists (fibrates) are used today to lower plasma cholesterol and triglyceride levels13. Partly initiated by atherogenesis, long-term high blood pressure provokes macrovascular events such as cardiovascular disease (CVD) and stroke, the main causes of death in MetS patients14. Hypertension therapy usually involves a combination of drugs such as diuretics and beta-blockers. However, this might not be an option in the treatment of MetS patients since insulin resistance and dyslipidemia may worsen during therapy15. Here, other blood pressure lowering medications such as angiotensin converting enzyme antagonists and angiotensin-II-receptor blockers are preferentially used.

The probably most relevant disorder caused by the MetS is T2D. Here, peripheral insulin resistance is induced by metabolic dysfunction leading to hyperinsulinemia and elevated blood glucose. As disease progresses pancreatic β-islet cell function is gradually lost resulting in global insulin deficiency and hyperglycemia16,17. In the advanced state, poorly treated T2D patients develop a plethora of microvascular complications such as retinopathy, painful neuropathy and nephropathy and strict glycemic control and adjusted blood-pressure levels are the only way for prevention18. So far, the established therapies to treat or ameliorate T2D are less effective or successful compared to the treatment of other risk factor of the MetS18. The increase of available insulin is one way to compensate the peripheral insulin-resistance in muscle and liver cells. This can be accomplished either by application of sulfonylureas or biguanides which trigger pancreatic insulin release or by insulin therapy (external injection)19,20.

To sum up, the treatment of the MetS risk factors and follow-up diseases requires a tremendous amount of drugs leading to the phenomenon of polypharmacy. Here, the pharmacokinetic and pharmacologic situation in patients reaches an unfavorable complexity and unpredictable drug-drug interactions can occur. In addition, medical compliance is at risk. While therapy costs rise, the probability for medication errors increases3. In this situation it is advisable to focus drug research on compounds capable of treating more than one aspect of the MetS. Therefore, multi-target ligands addressing more than one risk factor at once may find a reasonable application in this case21.

PPARγ, a member of the PPAR nuclear receptor family, is activated endogenously by various lipophilic compounds such as long chain fatty acids and eicosanoids. After recruitment of co-activators, the receptor heterodimerizes with the retionid X receptor (RXR)22and influences ligand dependent as well as independent the transcription/transrepression of various target genes. PPARγ plays a key role in adipogenesis, regulation of lipid metabolism and glucose homeostasis as well as anti-inflammatory processes and is therefore used for the treatment of T2D23. Pharmacological activation of the receptor by thiazolidinediones (TZDs) such as rosiglitazone and pioglitazone displays beneficial effects on insulin action and blood-glucose levels24. In the “lipid steal hypothesis” these effects originate from free fatty acid (FFA) and triglyceride (TG) uptake into the white adipose tissue. This is maintained by the upregulation of several PPARγ target genes such as FABP4 (human adipocyte fatty acid binding protein 4, corresponds to murine ap4), LPL (lipoprotein lipase), fatty acid transport proteins (CD36, fatty acid translocase, FATP, glycerol transporter aquaporins) and PEPCK (phosphoenolpyruvat-carboxykinase)25-30In addition, the insulin-sensitizing effect of PPARγ is correlated with the upregulation of bioactive adipokines such as adiponectin leading to decreased hepatic glucose output and improved glucose uptake31-34and anti-inflammatory properties of PPAR□ activation such as suppression of tumor necrosis factor α (TNFα) and resistin negatively influence insulin-resistance35,36Recent studies also showed that TZDs may have a preventive effect on pancreatic β-cell function, stabilizing insulin-secretion and supporting whole-blood insulin action37-39. It is also of interest that PPARγ activation has been discussed to upregulate HDL-C lipoprotein and might be valuable in the treatment of dyslipidemia40,41.

However, the clinical use of TZDs is limited due to excessive weight gain, fluid retention and increased osteoporosis risk in treated patients42,43Meta-analyses of clinical trials have implicated rosiglitazone in increasing the risk of congestive heart failure, myocardial infarction, cardiovascular disease and all-cause mortality leading to tightly restricted access in the United States and a recommendation for market withdrawal in Europe. Troglitazone was withdrawn from the market due to hepatotoxicity and pioglitazone seems to trigger bladder cancer44. Another drawback is the poor effect of TZDs on the occurrence of macrovascular events, although the equilibration of blood glucose levels reduces microvascular complications45. In this context, it is important to mention that some of the adverse events seen with TZD such as cancer development and hepatotoxicity seem to be a compound characteristic instead of a class specific phenomenon46-48.

The soluble epoxide hydrolase (sEH) is abundantly expressed in adipose tissue and whose expression and activity increases with obesity49. The sEH is an enzyme of the arachidonic acid cascade, promoting the hydrolysis of cytochrome P450 derived epoxyeicosatrienoic acids (EETs) to their less bioactive corresponding diols, the dihydroxyepoxyeicosatrienoic acids (DHETs)50. Through sEH inhibition EET levels increase. Endothelial cell derived EETs activate calcium-activated-potassium channels on smooth muscle cells, leading to hyperpolarization and vascular relaxation51,52Numerous studies show EET-derived effects on various MetS associated disorders such as cardiovascular disease (CVD)53, dyslipidemia54, neuropathy55-57and nephropathy58. In animal models of hypertension EETs act as endothelial-derived relaxation factors and have multiple protective effects on the cardiovascular system. Recent studies have shown improved angiogenesis by endothelial progenitor cells derived from patients with acute myocardial infarction through sEH inhibition and subsequent activation of PPARγ by accumulating EETs59,60The relevance of sEH inhibition in dyslipidemia therapy was already shown by Hammock et al. In this study, sEH inhibition in LDL receptor knock-out mice increased ABCA1 (ATP-binding cassette transporter A1) expression, a cholesterol efflux regulatory protein facilitating cholesterol export from cells and subsequent formation of nascent HDL, in adipose tissue. This was accompanied by an increase in circulating HDL, which enhances the reverse cholesterol transport pathway. In addition, sEH inhibition reduced LDL-C levels, and reduced the size of established atherosclerotic plaques in the animals54. Furthermore, sEH inhibition showed analgesic effects in several in vivo diabetic neuropathic pain models56,61,62. As described previously, the impaired functionality of pancreatic islet β-cells is one of the underlying mechanisms leading to T2D. It was shown that sEH inhibition can prevent hyperglycemia and augments islet glucose stimulated insulin secretion in diabetic mice. In addition, sEH-knock-out mice displayed attenuated islet cell apoptosis in STZ-induced diabetes63. Furthermore, several mouse models could show that sEH inhibition has renoprotective effects58. At the moment no sEH inhibitors are on the market. Accordingly, as there is an unmet medical need for safer PPARγ modulating drugs that carry additional cardio and kidney protective properties, the combination of PPARγ agonism with sEH antagonism in one compound would have substantial advantages in the treatment of MetS and T2D.

SUMMARY OF INVENTION

Here, the inventors present a multi-target approach to treat MetS cluster diseases, including diabetes, by administration of certain N-benzylbenzamides to affect the simultaneous modulation of soluble epoxide hydrolase (sEH) and peroxisome proliferator-activated receptor γ (PPARγ).

Accordingly, the invention encompasses, in a first aspect, certain compounds having the structure:


wherein: X—Y is CH═C or CH2—CH; R1is CH2CH3, CH3or H; and R3is a fluoro-substituted aryl group; or a salt thereof. The fluoro-substituted aryl group at R3is preferably a phenyl group comprising a trifluoromethyl- or trifluoromethoxy-substitution, even more preferably substituted at the phenyl group's ortho position.

In certain compounds according to the invention, R3is:



A preferred compound of the invention calls for R3to be



Compounds of the invention include those wherein: X—Y is CH2—CH and R1is CH2CH3; X—Y is CH═C and R1is CH2CH3; X—Y is CH2—CH and R1is H; and X—Y is CH═CH and R1is H.

A particularly preferred compound according to the invention calls for X-Y to be CH2CH, R1to be H, and R3to be



In particularly preferred embodiments, the inventive compound exhibits a half maximal inhibitory concentration (IC50) for soluble epoxide hydrolase (sEH) and a half maximal effective concentration (EC50) for peroxisome proliferator-activated receptor gamma (PPARγ) that are less than 1.0 micromolar when administered to a subject.

In another aspect, the invention provides a composition comprising: (a) an inventive N-benzylbenzadmide compound; and (b) a pharmaceutically acceptable carrier. In preferred embodiments, this composition is formulated as an oral dosage.

In yet another aspect, the invention provides a method of treating metabolic syndrome in a subject, comprising administering to a subject a therapeutically effective amount of an inventive N-benzylbenzamide compound, wherein soluble epoxide hydrolase (sEH) and peroxisome proliferator-activated receptor gamma (PPARγ) are simultaneously-modulated by the compound thereby treating metabolic syndrome in the subject.

In preferred embodiments, the therapeutically effective amount provides a half maximal inhibitory concentration (IC50) for sEH and a half maximal effective concentration (EC50) for PPARγ that are less than 1.0 micromolar in the subject.

In another embodiment, the invention encompasses the use of an inventive N-benylbenzamide compound for the manufacture of a medicament for treating MetS in a subject. As well, the invention further contemplates compounds according to the invention for use in treating MetS in a subject.

In yet another aspect, the invention provides a method of treating diabetes in a subject, comprising administering to a subject a therapeutically effective amount of an inventive N-benzylbenzamide compound, wherein soluble epoxide hydrolase (sEH) and peroxisome proliferator-activated receptor gamma (PPARγ) are simultaneously-modulated by the compound thereby treating diabetes in the subject.

In preferred embodiments, the therapeutically effective amount provides a half maximal inhibitory concentration (IC50) for sEH and a half maximal effective concentration (EC50) for PPARγ that are less than 1.0 micromolar in the subject.

In another embodiment, the invention encompasses the use of an inventive N-benylbenzamide compound for the manufacture of a medicament for treating diabetes in a subject. As well, the invention further contemplates compounds according to the invention for use in treating diabetes in a subject

In yet another aspect, the invention provides a method for simultaneously-modulating soluble epoxide hydrolase (sEH) and peroxisome proliferator-activated receptor gamma (PPARγ) activities in a subject, comprising administering to a subject a therapeutically effective amount of an inventive N-benzylbenzamide compound, wherein soluble epoxide hydrolase (sEH) and peroxisome proliferator-activated receptor gamma (PPARγ) are simultaneously-modulated by the compound in the subject.

In preferred embodiments, the therapeutically effective amount provides a half maximal inhibitory concentration (IC50) for sEH and a half maximal effective concentration (EC50) for PPARγ that are less than 1.0 micromolar in the subject.

In another embodiment, the invention encompasses the use of an inventive N-benylbenzamide compound for the manufacture of a medicament for simultaneously-modulating soluble epoxide hydrolase (sEH) and peroxisome proliferator-activated receptor gamma (PPARγ) activities in a subject. As well, the invention further contemplates compounds according to the invention for use in simultaneously-modulating soluble epoxide hydrolase (sEH) and peroxisome proliferator-activated receptor gamma (PPARγ) activities in a subject.

Other objects, features and advantages of the present invention will become apparent after review of the specification, claims and drawings.

