Antidiabetic Action of Mcy Protein: Studies on Gene Expression and Competitive Binding to Insulin Receptors.

Mcy protein, isolated from the fruits of Momordica cymbalaria, was shown to have antihyperglycemic, antihyperlipidemic activities along with renal as well as hepatoprotective activities in streptozotocin-induced diabetic rats. Mcy protein was shown to have insulin-like structure and/or function and/or insulin secretagogue activity. Hence, the present study was conducted to elucidate the molecular mechanism whereby Mcy protein elicits its therapeutic role and also to know whether the Mcy protein has any structural and functional similarity with insulin. Results of our experiments revealed that the Mcy protein is insulin-like protein. Furthermore, we assessed the effect of treatment with Mcy protein on the glucose transport (levels of glucose transporter, GLUT-2) and on the levels of key regulators of glucose and lipid metabolisms like hepatic glucokinase (GK) and sterol regulatory element-binding protein-1c (SREBP-1c). Our findings demonstrated that Mcy protein elevated the expressions of GK, SREBP-1c, and GLUT-2 that were decreased in diabetic animals. Insulin-receptor binding studies using rat erythrocytes demonstrated that mean specific binding of insulin with insulin receptors was significantly increased in Mcy-treated diabetic rats when compared to diabetic control rats. Scatchard analyses of insulin binding studies yielded curvilinear plots, and the number of receptor sites per cell was found to be 180 ± 21.1 in Mcy-treated diabetic animals and found to be significantly superior to those of diabetic control animals. Kinetic analyses also revealed an increase in the average receptor affinity of erythrocytes of Mcy-treated rats compared to diabetic control rats suggesting acute alteration in the number and affinity of insulin receptors on the membranes of erythrocytes.

Nano-ellagic acid: inhibitory actions on aldose reductase and α-glucosidase in secondary complications of diabetes, strengthened by in silico docking studies.

Increased blood sugar levels in prolonged diabetes lead to secondary complications such as retinopathy, neuropathy, and nephropathy, which gradually end in death. Synthesis of nano-phytomedicines from active phytoconstituents for novel emerging applications in the field of pharmaceuticals is of huge interest among researchers. In the present investigation, encapsulated ellagic acid (NEA) was synthesized at four different concentrations (0.2%, 0.3%, 0.4%, 0.5%) using ZnO nanoparticles as encapsulating agent. The surface morphology (fiber-like structures) of the nanoparticles were determined by scanning electron microscopy (SEM) and particle size (161-297 nm) and zeta potential (- 54.9-38.4 mV) were determined by dynamic light scattering technique. Further, the α-glucosidase and aldose reductase enzymes were significantly inhibited by the 0.4% of NEA compared to the other concentrations which strengthened our studies in overcoming the secondary complications of diabetes. The interaction analysis between ellagic acid and insulin receptor found Hit 1 among 10 executed ∆G score and energy of - 5.76, - 4.63 kcal/mol and formed polar bond with Arg 113 with - 1.175 Å distance. The residues Arg115, Lys116, Phe118, Ile115, Arg1131, Arg1155, Ile1157, Lys1165 and Phe1186 were found in ligand-protein interactions. ADME/T analysis of hit 1 was within the acceptable range without any toxic functional groups, providing a framework for developing novel therapeutics.

Diabetes affects hepatic and renal glycoproteins: effect of Boswellia ovalifoliolata on glycoproteins proportions in diabetes induced hepatic and renal injury.

PURPOSE: Chronic hyperglycemia and deficiency of insulin are peculiar features of diabetes mellitus alters glycoprotein levels in various tissues leads to impaired metabolism of glycoproteins which play a major role in the pathogenesis of diabetic complications. Boswellia ovalifoliolata is a medicinal plant known for its many medicinal properties including diabetes. In this background our study was aimed to evaluate the effect of aqueous extract of stem bark of Boswellia ovalifoliolata (AESBBO) on antidiabetic and glycoprotein metabolism. METHODS: Diabetes was induced in rats by intraperitoneal administration of streptozotocin at a dose of 50 mg/kg bw. After induction of diabetes rats were treated with AESBBO at dosage of 200 mg/kg for a long term treatment of 40 days. Finally, by the end of study all the rats were dissected blood, liver, and kidney tissue samples were collected to investigate the long term effects of AESBBO on diabetes and glycoprotein metabolism. RESULTS: Treatment with AESBBO significantly reduced the fasting blood glucose levels whereas the levels of insulin and hemoglobin were increased with decreased levels of glycosylated hemoglobin. The long term treatment of AESBBO significantly decreased the levels of plasma, liver and kidney tissue glycoproteins such as fucose, hexose, hexosamine and sialic acid. CONCLUSIONS: This study concludes that the aqueous extract of stem bark of Boswellia ovalifoliolata possesses a protective role on abnormal glycoprotein metabolism in addition to its antihyperglycemic activity.

Evaluation of biochemical mechanisms of anti-diabetic functions of Anisomeles malabarica.

Anisomeles malabarica (AM) is an aromatic plant traditionally used for the treatment of diabetes mellitus in India. Following bioassay guided fractionation, we recently identified an active fraction of AM (AMAF, with potential mix of active principles) that showed significant antihyperglycemic and antihyperlipidemic activities. In addition, AMAF treatment improved insulin levels. However, the biochemical mechanism/s through which AMAF demonstrates the antidiabetic effects is largely unknown. Based on its beneficial effects we investigated the biochemical mechanism of the anti-diabetic activity of A.malabarica active fraction (AMAF) in streptozotocin (STZ) induced diabetic rats. Streptozotocin induced diabetic rats were treated with AMAF (50 mg AMAF/kg/day) for 30 days and alterations in the body weights, glycogen and protein content of tissues, functional markers of hepatic and renal tissues, carbohydrate metabolic enzymes and their genes expression were evaluated. Lipid peroxides levels and activities of antioxidant enzymes of hepatic and renal tissues were also measured. The AMAF treatment resulted in increase in body weights, hepatic and renal protein and tissue glycogen levels in diabetic treated rats compared to diabetic rats. In addition, the treatment improved activities of carbohydrate metabolic enzymes, antioxidant enzymes and, liver and renal functional markers in the AMAF treated diabetic rats. Gene expressions of key carbohydrate metabolic enzymes/factors glucokinase, glucose transporter protein (GLUT-2) and phosphoenolpyruvate carboxykinase (PEPCK) were also normalized up on AMAF treatment in diabetic rats. Our studies indicate that the isolated active fraction of AM (AMAF) from the leaves of A.malabarica positively regulated the glucose homeostasis and oxidative stress through carbohydrate metabolism and antioxidant enzyme activities respectively in hepatic and renal tissues.

Nanotechnological approaches for the development of herbal drugs in treatment of diabetes mellitus - a critical review.

Diabetes mellitus (DM) is a chronic illness that requires continuing medical care and patient self-management education to prevent acute complications and to reduce the risk of long-term complications. The number of people with diabetes is increasing due to population growth, ageing, urbanisation and increasing prevalence of obesity and physical inactivity. Apart from currently available therapeutic options, many herbal medicines have been recommended for the treatment of diabetes. Herbal drugs are prescribed widely because of their effectiveness, less side effects and relatively low cost. Several pharmacopoeias have provided parameters to maintain quality and standardise procedures in identification/authentication of herbal inputs and their products. Available literature related to folklore medicine used in the treatment of diabetes extended to nanoformulation of herbal drugs up to date was cited. The use of bioactive compounds leads to new hope to improve the life expectancy and health status of the population for the formulation of novel drugs. Recently, many studies have shown that nanotechnology has the potential to be used in different biological and medical applications, mainly as targeted drug delivery systems to minimise and delay the chronic effects of diabetes. Herein, the authors presented a thorough review of the available herbal medicines and the possibilities of developing their nanoformulations in the treatment of DM.

Mcy protein, a potential antidiabetic agent: evaluation of carbohydrate metabolic enzymes and antioxidant status.

The objective of the present study is to elucidate the long-term effects of anti-hyperglycemic active principle, Mcy protein (MCP), isolated from the fruits of Momordica cymbalaria on carbohydrate metabolism and oxidative stress in experimental diabetic rats. We used streptozotocin induced diabetic rats for the current studies. Our studies showed that MCP (2.5mg/kg.b.w) treatment significantly normalized the deranged activities of critical carbohydrate metabolizing enzymes, hexokinase, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase and fructose-1,6-bis phosphatase. In addition MCP showed inhibitory activity on α-glucosidase and aldose reductase enzymes in in vitro assays. Further MCP treatment improved the antioxidant defensive mechanism by preventing deleterious oxidative products of cellular metabolism, which initiates the lipid peroxidation and by normalizing the antioxidant enzyme (catalase, superoxide dismutase, glutathione peroxidase) activities. Additional structural studies using circular dichroism spectroscopy indicate that MCP contains majorly α-helix. Our findings suggest MCP regulates blood glucose and better manage diabetes mellitus associated complications by regulating carbohydrate metabolism and by protecting from the deleterious effects of oxidative stress.

Antihyperlipidemic and biochemical activities of Mcy protein in streptozotocin induced diabetic rats.

BACKGROUND: This study was aimed to evaluate the protective effects of a novel anti-hyperglycemic "Mcy protein" isolated from the fruits of Momordica cymbalaria in streptozotocin induced- diabetes rat model. MATERIALS AND METHODS: Wild type and Streptozotocin induced diabetic male wistar albino rats were either treated with single intraperitoneal injection of 2.5 mg Mcy protein/kg body weight or acetate buffer daily for 30 days. Fasting blood glucose and, serum and tissue lipid levels were measured along with biochemical analysis for hepatic and renal function tests. RESULTS: Mcy protein significantly reduced the fasting blood glucose and, serum as well as tissue lipid levels (p<0.05), besides normalizing the levels of liver and kidney function markers in the treated diabetic rats when compared to the diabetic controls. Our studies also showed the pancreatic islet regeneration in Mcy treated rats. CONCLUSION: Mcy protein can alleviate hyperlipidemia and help manage diabetes by stimulating insulin secretion without evident toxic effects on liver and kidney.