RETRACTED: Combination of carvacrol and rosiglitazone ameliorates high fat diet induced changes in lipids and inflammatory markers in C57BL/6J mice.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. Following concerns raised by Dr. E. Bik, the journal conducted an investigation and found evidence that there had been improper manipulation and duplication of images in Figure 4. The editors would like to thank Dr. Bik for her valuable insight in this matter. The authors have not responded to requests for an explanation of these irregularities so this article is retracted without their approval.

Antihyperglycemic effect of carvacrol in combination with rosiglitazone in high-fat diet-induced type 2 diabetic C57BL/6J mice.

Thiazolidinediones constitute a family of antidiabetic drugs, and rosiglitasone (RSG) has an extensive usage in treating the complications of type 2 diabetes mellitus. Carvacrol (CVL), a monoterpenic phenol that occurs in many essential oils of the family Labiatae including Origanum, Satureja, Thymbra, Thymus, and Corydothymus species, possess a wide variety of pharmacological properties including antioxidant potential. We hypothesized that carvacrol in combination with RSG would prove beneficial to ameliorate the dysregulated carbohydrate metabolism in high-fat diet (HFD)-induced type 2 diabetic C57BL/6J mice. Mice were divided into six groups and fed HFD, for 10 weeks. CVL (20 mg/kg BW) and RSG (4 mg/kg BW) were administered post-orally, daily for 35 days. HFD mice showed an elevation in plasma glucose, insulin, glycosylated hemoglobin and a decrease in hemoglobin. The activities of carbohydrate metabolic enzymes such as glucose-6-phosphatase and fructose-1,6-bisphosphatase increased whereas glucokinase and glucose-6-phosphate dehydrogenase activities decreased in the liver of HFD mice. The activities of hepatic marker enzymes such as aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and gamma-glutamyl transpeptidase increased in HFD mice. Combination of CVL and RSG prevented the above changes toward normalcy. Histopathological analysis of H&E stained pancreas was also in agreement with the biochemical findings. These major findings provide evidence that combination of CVL with RSG has better antidiabetic properties.

Effect of ursolic acid treatment on apoptosis and DNA damage in isoproterenol-induced myocardial infarction.

The present study was designed to evaluate the protective effect of ursolic acid (UA) against isoproterenol-induced myocardial infarction. Myocardial infarction was induced by subcutaneous injection of isoproterenol hydrochloride (ISO) (85 mg/kg BW), for two consecutive days. ISO-induced rats showed elevated levels of cardiac troponins T (cTn T) and I (cTn I) and increased activity of creatine kinase-MB (CK-MB) in serum. Lipid peroxidative markers (thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD) and lipid hydroperoxides (HP)) elevated in the plasma and heart tissue whereas decreased activities of enzymatic antioxidants (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR)) in erythrocytes and heart tissue of ISO-induced rats. Non-enzymatic antioxidants (vitamin C, vitamin E and reduced glutathione (GSH)) levels were decreased significantly in the plasma and heart tissue of ISO-induced rats. Furthermore, ISO-induced rats showed increased DNA fragmentation, upregulations of myocardial pro-apoptotic B-cell lymphoma-2 associated-x (Bax), caspase-3, -8 and -9, cytochrome c, tumor necrosis factor-α (TNF-α), Fas and down-regulated expressions of anti-apoptotic B-cell lymphoma-2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-xL). UA-administered rats showed decreased levels/activity of cardiac markers, DNA fragmentation and the levels of lipid peroxidative markers in the plasma and heart tissue. Activities of enzymatic antioxidants were increased significantly in the erythrocytes and heart tissue and also non-enzymatic antioxidants levels were increased significantly in the plasma and heart tissue in UA-administered rats. UA influenced decreased DNA fragmentation and an apoptosis by upregulation of anti-apoptotic proteins such as Bcl-2, Bcl-xL and down-regulation of Bax, caspase-3, -8 and -9, cytochrome c, TNF-α, Fas through mitochondrial pathway. Histopathological observations were also found in line with biochemical parameters. Thus, results of the present study demonstrated that the UA has anti-apoptotic properties in ISO-induced rats.

Antihyperglycemic effect of biochanin A, a soy isoflavone, on streptozotocin-diabetic rats.

The study was designed to investigate the antihyperglycemic effect of biochanin A on streptozotocin-diabetic rats. Diabetes was induced in adult male albino rats of the Wistar strain, weighing 180-200 g, by administration of streptozotocin (40 mg/kg of body weight) intraperitoneally. Diabetic rats showed increase in plasma glucose and glycosylated hemoglobin and a decrease in plasma insulin and hemoglobin. Activities of gluconeogenic enzymes such as glucose 6-phosphatase, fructose 1,6-bisphosphatase increased and glucokinase, glucose 6-phosphate dehydrogenase decreased in the liver of diabetic rats along with glycogen. Oral administration of biochanin A (10mg/kg body weight) or glibenclamide (600 µg/kg body weight) in 0.5% dimethyl sulfoxide, for 45 days, prevented the above changes and improved towards normality. In addition, protection against body weight loss of diabetic animals by biochanin A was also observed. No significant effect was observed in normal rats treated with biochanin A (10mg/kg bodyweight). These results showed that biochanin A has potential antihyperglycemic activity at a dose of 10mg/kg bodyweight in streptozotocin induced diabetic rats.