A novel 11ß-hydroxysteroid dehydrogenase type1 inhibitor CNX-010-49 improves hyperglycemia, lipid profile and reduces body weight in diet induced obese C57B6/J mice with a potential to provide cardio protective benefits.

BACKGROUND: 11ß-hydroxysteroid dehydrogenase type1 (11ß-HSD1) converts inactive glucocorticoids to active glucocorticoids which, in excess, leads to development of the various risk factors of the metabolic syndrome. Recent studies clearly suggest that both increased expression and activity of 11ß-HSD1 in metabolically active tissues such as liver, muscle and adipose are implicated in tissue specific dysregulation which collectively contribute to the whole body pathology seen in metabolic syndrome. In the present study we have evaluated CNX-010-49, a highly potent, selective and 'pan tissue' acting 11ß-HSD1 inhibitor, for its potential to modulate multiple risk factors of the metabolic syndrome. METHODS: Male C57B6/J mice on high fat diet (DIO mice) were orally dosed with CNX-010-49 (30 mg/kg twice daily; n = 8) or vehicle for 10 weeks. Fasting glucose, triglycerides, glycerol, free fatty acids, body weight and feed intake were measured at selected time points. At the end of the treatment an OGTT and subsequently organ histology was performed. In vitro, CNX-010-49 was evaluated in 3T3-L1 preadipocytes to assess impact on adipocytes differentiation, hypertrophy and lipolysis whereas in fully differentiated C2C12 cells and in primary mouse hepatocytes to assess the impact on glucose metabolism and hepatic glucose output respectively. RESULTS: CNX-010-49 a highly potent and selective pan tissue acting 11ß-HSD1 inhibitor (EC50 = 6 nM) significantly inhibits glucocorticoids and isoproterenol mediated lipolysis in mature 3T3-L1 adipocytes, improves muscle glucose oxidation, reduces proteolysis and enhances mitochondrial biogenesis. Also a significant inhibition of gluconeogenesis in primary mouse hepatocytes was observed. The treatment with CNX-010-49 resulted in a significant decrease in fasting glucose, improved insulin sensitivity and glucose tolerance. Treatment also resulted in a significant decrease in serum triglycerides levels and a complete inhibition of body weight gain without affecting feed consumption. A significant reduction in the serum biomarkers like Plasminogen activator inhibitor-1 (PAI-1), interleukin 6 (IL-6) and Fetuin-A with CNX-010-49 treatment was observed indicating a potential to modulate processes implicated in cardiovascular benefits. CONCLUSIONS: These results indicate that inhibition of 11ß-HSD1 with CNX-010-49 can give a potential benefit in the management of metabolic dysregulations that are seen in type 2 diabetes.

CNX-013-B2, a unique pan tissue acting rexinoid, modulates several nuclear receptors and controls multiple risk factors of the metabolic syndrome without risk of hypertriglyceridemia, hepatomegaly and body weight gain in animal models.

BACKGROUND: In addition to their role in growth, cellular differentiation and homeostasis Retinoid X Receptors (RXR) regulate multiple physiological and metabolic pathways in various organs that have beneficial glucose and lipid (cholesterol) lowering, insulin sensitizing and anti-obesity effects. Rexinoids, compounds that specifically binds and activate RXR, are therefore considered as potential therapeutics for treating metabolic syndrome. Apparently many of the rexinoids developed in the past increased triglycerides, caused hepatomegaly and also suppressed the thyroid hormone axis. The aim of this study is to evaluate CNX-013-B2, a potent and highly selective rexinoid, for its potential to treat multiple risk factors of the metabolic syndrome. METHODS: CNX-013-B2 was selected in a screening system designed to identify compounds that selectively activated only a chosen sub-set of heterodimer partners of RXR of importance to treat insulin resistance. Male C57BL/6j mice (n = 10) on high fat diet (HFD) and 16 week old ob/ob mice (n = 8) were treated orally with CNX-013-B2 (10 mg/kg twice daily) or vehicle for 10 weeks and 4 weeks respectively. Measurement of plasma glucose, triglyceride, cholesterol including LDL-C, glycerol, free fatty acids, feed intake, body weight, oral glucose tolerance and non-shivering thermogenesis were performed at selected time points. After study termination such measurements as organ weight, triglyceride content, mRNA levels, protein phosphorylation along with histological analysis were performed. RESULTS: CNX-013-B2 selectively activates PPARs- α, ß/δ and γ and modulates activity of LXR, THR and FXR. In ob/ob mice a significant reduction of 25% in fed glucose (p < 0.001 ), a 14% (p < 0.05) reduction in serum total cholesterol and 18% decrease (p < 0.01) in LDL-C and in DIO mice a reduction of 12% (p < 0.01 ) in fasting glucose, 20% in fed triglyceride (p < 0.01) and total cholesterol (p < 0.001) levels, coupled with enhanced insulin sensitivity, cold induced thermogenesis and 7% reduction in body weight were observed. CONCLUSION: CNX-013-B2 is an orally bio available selective rexinoid that can be used as a novel therapeutic agent for management of multiple risk factors of the metabolic syndrome without the risk of side effects reported to be associated with rexinoids.

CNX-011-67, a novel GPR40 agonist, enhances glucose responsiveness, insulin secretion and islet insulin content in n-STZ rats and in islets from type 2 diabetic patients.

BACKGROUND: GPR40 is a G-protein coupled receptor regulating free fatty acid induced and also glucose induced insulin secretion. We generated neonatally-streptozotocin-treated female rats (n-STZ) and treated them with CNX-011-67, a GPR40 agonist to examine the role of GPR40 in modulation of glucose metabolism, insulin secretion and content. METHODS: Female n-STZ animals were orally administered with CNX-011-67 (15 mg/kg body weight, twice daily) or with vehicle for 8 weeks (n = 8 per group). Glucose tolerance in treated animals and insulin secretion, islet insulin content and gene expression in isolated islets were determined. Islets from type 2 diabetic mellitus (T2DM) patients were treated with different concentrations of glucose in presence or absence of CNX-011-67 and insulin secretion was measured. RESULTS: Treatment of n-STZ rats with GPR40 agonist CNX-011-67 enhanced insulin secretion in response to oral glucose load on day 0 and this response persisted during the treatment period. The treatment also produced a 'memory effect' during which insulin secretion in response to oral glucose load remained enhanced, for a week, even in absence of the agonist. Activation of GPR40 enhanced responsiveness of islets to glucose and increased glucose induced insulin secretion and islet insulin content. An increase in islet mRNA expression of GCK, PDX1, insulin and PC was also observed. Acute treatment of islets from n-STZ rats with GPR40 agonist enhanced cellular ATP content. Activation of GPR40 enhanced mitochondrial calcium level in NIT-1 insulinoma cells. CNX-011-67 increased insulin secretion in islets from T2DM patients which were non-responsive to increased glucose concentration CONCLUSIONS: Our data provide evidence that activation of GPR40 with CNX-011-67 stimulates glucose metabolism, enhances glucose responsiveness, increases insulin secretion and content and that pharmacological activation of GPR40 will prove beneficial for treatment of T2DM.

Treatment with CNX-011-67, a novel GPR40 agonist, delays onset and progression of diabetes and improves beta cell preservation and function in male ZDF rats.

BACKGROUND: The role of G protein-coupled receptor (GPR40), which is highly expressed in pancreatic beta cells, has been studied extensively in the amelioration of beta cell dysfunction in T2D using rat and mouse islets, beta cell lines and in animal models of diabetes. But its potential as a therapeutic target has not been fully explored. This aim of the study is to evaluate the therapeutic potential of CNX-011-67, a highly selective, potent and orally bioavailable GPR40 agonist, in controlling diabetes and other metabolic parameters. METHODS: Seven week old male ZDF rats were treated with either vehicle or CNX-011-67, 5 mg/kg twice daily, for seven weeks. The animals were subjected to oral glucose tolerance and insulin tolerance tests. Plasma glucose, insulin, triglyceride, HbA1c, fructosamine and free fatty acids were measured at selected time points. Pancreas from control and treated animals were subjected to insulin and pancreatic and duodenal homeobox 1 (PDX1) immunohistochemistry and were also evaluated by electron microscopy. Also the potential impact of CNX-011-67 on islet insulin secretion, content, ATP levels and markers of both glucose oxidation, beta cell health in rat islets under chronic glucolipotoxic conditions was evaluated. RESULTS: Treatment of male ZDF rats with CNX-011-67 for 7 weeks significantly enhanced insulin secretion in response to oral glucose load, delayed the onset of fasting hyperglycemia by 3 weeks, reduced nonfasting glucose excursions, fasting free fatty acids and triglyceride levels. A significant increase in PDX1 expression and insulin content and reduction in plasma fructosamine, HOMA-IR, and beta cell apoptosis were observed. CNX-011-67 improves glucose mediated insulin secretion, insulin gene transcription and islet insulin content in cultured rat islets under chronic glucolipotoxic condition. Also enhanced glucose oxidation in the form of increased islet ATP content and overall improvement in beta cell health in the form of reduced expression of stress markers (TXNIP and CHOP mRNA) were observed. CONCLUSIONS: These findings, suggest that long-term oral therapy with CNX-011-67 could be of clinical value to provide good glycemic control and improve islet beta cell function.

Evaluation of beneficial effects of antioxidant properties of aqueous leaf extract of Andrographis paniculata in STZ-induced diabetes.

The beneficial effects of antioxidant properties Andrographis paniculata (Andrographis) were studied in the diabetic animals. Hyperglycemia, characteristic feature of diabetes mellitus leads to decreased antioxidant defense and hence development of oxidative stress, which in involved in the etiology of development of diabetic complications. The evidences suggest that good glycemic control and/or use of antioxidants may play an important role in the prevention of complications associated with diabetes. Diabetes was induced with single intraperitoneal injection of streptozotocin (45 mg/kg, i.p) dissolved in freshly prepared citrate buffer (pH 4.5), resulted in elevation of blood glucose levels, decrease in the superoxide dismutase and catalase activity. Oral administration of Andrographis (400 mg/kg, p.o) resulted in significant decrease in the blood glucose levels and increase in the activity of SOD and catalase. In conclusion Andrographis decreased the blood glucose levels in diabetic animals may be due to its antioxidant properties.