Gokhan Bayramoglu

Hypoglycemic effect of Lentinus strigosus (Schwein.) Fr. crude exopolysaccharide in streptozotocin-induced diabetic rats.

ABSTRACT This study reports the hypoglycemic effects of the crude exopolysaccharide (EPS) produced from submerged mycelial culture of Lentinus strigosus (Schwein.) Fr. (Family Polyporaceae) in streptozotocin (STZ)-induced diabetic rats. In a dose-dependent study, diabetic rats were treated with EPS at doses of 50-150 mg/kg of body weight for 7 days. Serum glucose and plasma insulin levels were measured in normal, STZ-induced diabetic, and EPS-treated diabetic rats. Following oral administration of EPS dosages for 7 days, the serum glucose levels in the STZ-induced diabetic rats were reduced up to 21.1% at the dose of 150 mg/kg of body weight. The results revealed that orally administered L. strigosus EPS, at the dose of 150 mg/kg, exhibited a considerable hypoglycemic effect in STZ-induced diabetic rats. Plasma insulin levels of STZ-induced diabetic rats decreased as compared to control group rats (P < .05). Although insulin levels slightly increased in the EPS-treated groups the increase was not statistically significant. The hypoglycemic potential of the EPS was further supported by histological observations of pancreatic islets of Langerhans.

Lycopene Partially Reverses Symptoms of Diabetes in Rats with Streptozotocin-Induced Diabetes

In the present study, we describe the effects of lycopene on the symptoms of streptozotocin (STZ)-induced diabetes in rats. Lycopene at the dose of 2.5 mg/kg body weight (bw) per day was orally administered to STZ-induced diabetic rats for a period of 7 days after onset of diabetes. At the same time, food-water intake and body weight change were recorded daily. Upon sacrifice, biochemical parameters, such as the serum glucose, insulin, total cholesterol (TC), triglyceride (TG), alanine aminotransferase (ALT), and aspartate aminotransferase (AST), were measured in all experimental groups. Administration of lycopene at the dose of 2.5 mg/kg bw per day significantly reduced serum glucose, TC, TG, ALT, and AST levels, and increased serum insulin levels, but there were no improvements in food-water intake and body weight change parameters in lycopene-treated diabetic rats. The results suggest that orally administrated lycopene exhibits a potent hypoglycemic effect in STZ-induced diabetic rats and that lycopene may be useful for the management of diabetes mellitus.

Investigation of the possible protective role of gallic acid on paraoxanase and arylesterase activities in livers of rats with acute alcohol intoxication

Gallic acid, a polyphenyl class natural product from gallnut and green tea, is known to be antioxidant, anti‐inflammatory and radical scavenger. In this study, we aimed to investigate the possible protective effects of gallic acid on paraoxonase and arylesterase activities in liver exposed to acute alcohol intoxication. Paraoxonase and arylesterase activities in liver tissue and serum aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels were measured. Histological investigations were also made. In our study, we observed a significant increase of serum alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase activities, which are indicators of liver damage after acute ethanol consumption. Gallic acid therapy has significantly reduced the increase in these biomarkers, indicating a possible hepatoprotective effect of gallic acid. Ethanol consumption caused a significant decrease in liver paraoxonase activity (P < 0.001). Gallic acid treatment partly restored this decreased paraoxonase activity, which resulted from ethanol administration. A gallic acid dose of 100 mg/kg was observed as highest restoring effect for paraoxonase activity (P < 0.05). The activity of arylesterase was decreased in the ethanol group as compared with the control group, but this was not significant. However, 50 mg/kg of gallic acid treatment restored the loss of this activity due to ethanol exposure (P < 0.001). We observed that gallic acid ameliorates the liver damage caused by excessive alcohol consumption in a dose‐dependent way. Our results in this study showed that gallic acid might have a protective effect against alcoholic liver disease. Copyright

Effects of Black Hoof Medicinal Mushroom, Phellinus linteus (Agaricomycetes), Polysaccharide Extract in Streptozotocin-Induced Diabetic Rats.

In this article we report the healing effects of a Phellinus linteus fruiting body hot water extract (PLE) in streptozotocin (STZ)-induced diabetic rats. PLE was given before and after STZ. The preprotective, protective, and postprotective effects of PLE on STZ-induced oxidative stress were studied using biochemical (caspase 3 activity, cytosolic-to-lysosomal ratio of cathepsin B and L, DNA fragmentation levels), ordinary histological and immuno-histochemical investigation parameters. Following oral administration of PLE after STZ application, the serum glucose concentration significantly decreased up to 41.13% compared with the control group (P < 0.05). The hypoglycemic potential of the PLE was further supported by an increase of insulin secretion in the islets of Langerhans. In addition, the number of cells in Langerhans islets increased by 45.89% when PLE was given after STZ application. On the other hand, the use of PLE before oxidative stress could not prevent the onset of diabetes. This is, to our knowledge, the first study of the effect of application time of orally administered Ph. Linteus hot water extract on STZ-induced diabetes.

The protective effect of Hypericum origanifolium in experimental renal ischemia/reperfusion injury in rats

1 Department of Biology, Faculty of Arts and Science, Eskisehir Osmangazi University, Eskisehir, Turkey. 2 Department of Urology, Treating and Research Hospital, Dumlupınar University Kütahya, Kütahya, Turkey. 3 Department of Anatomy, Faculty of Medicine, Eskisehir Osmangazi University, Eskisehir, Turkey. 4 Department of Medical Biology, Faculty of Medicine, Eskisehir Osmangazi University, Eskisehir, Turkey. 5 Department of Pharmacognasy, Faculty of Pharmacy, Anadolu Universty, Eskişehir, Turkey. 6 Department of Medical Genetic, Faculty of Medicine, Eskisehir Osmangazi University, Eskisehir, Turkey.