Genetic variations of renin-angiotensin and fibrinolytic systems and susceptibility to coronary artery disease: a population genetics perspective.

BACKGROUND: Genetic predisposition is an important risk factor in coronary artery disease (CAD).This study was conducted to determine the polymorphism frequencies of the plasminogen activator inhibitor-1(PAI-1) gene 4G/5G, angiotensin-converting enzyme (ACE) gene I/D, and angiotensin II type 1 receptor (AT1) gene A1166C genotypes and to examine the role of these polymorphisms in CAD. METHODS: Genomic DNAs obtained from 260 subjects (130 CAD patients and 130 control) were used in the study. ACE I/D and PAI-1 4G/5G polymorphism genotypes were determined using polymerase chain reaction (PCR) and electrophoresis. AT-1 A1166C polymorphism was determined using the PCR, restriction fragment length polymorphism (RFLP) and electrophoresis. The products amplified from AT1 gene by PCR were cut with HindIII restriction endonuclease and then analyzed by 2% agarose gel electrophoresis. The results were statistically analyzed with the chi-square test, Mann-Whitney U test, and independent two-sample t-test. RESULTS: Allele frequencies showed statistically significant differences between the patient and control groups. There was no statistically significant difference in ACEI/D genotype frequencies between the twogroups. Likewise, no statistically significant difference was found in the AT1 A1166C genotype frequencies; however, a statistically significant difference was found in allele frequencies. The PAI-1 4G/5G genotype frequency was significantly higher in the patient group. CONCLUSIONS: While there is a relationship between of PAI-1 gene 4G/5G polymorphism and CAD, ACE gene I/D and AT1 gene A1166C polymorphisms are not related. PAI-1 gene homozygous genotypes may be considered as a prognostic marker for CAD patients.

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 effects of lycopene on hepatic ischemia/reperfusion injury in rats.

There is a very little information about the protective effect of lycopene (LYC) against hepatic ischemia-reperfusion injury. The present study was designed to examine the possible protective effect of the strong antioxidant and anti-inflammatory agent, LYC, on hepatic ischemia/reperfusion injury. For this purpose, rats were subjected to 45 min of hepatic ischemia followed by 60 min of reperfusion period. LYC at the doses of 2.5 and 5 mg/kg body weight (bw) were injected intraperitoneally, 60 min prior to ischemia. Upon sacrification, hepatic tissue samples were used for the measurement of catalase (CAT) activity and malondialdehyde (MDA) levels. Also, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) were assayed in serum samples. As a result of the use of LYC at the doses of 2.5 and 5 mg/kg bw; while improvements of the ALT, AST, LDH and MDA values were partial and dose-dependent, the improvement of CAT activity was total and dose-independent (p < 0.05). Our findings suggest that LYC has a protective effect against ischemia/reperfusion injury on the liver.

Preventive role of gallic acid on hepatic ischemia and reperfusion injury in rats.

There is little information about the hepatoprotective effects of gallic acid against ischemia-reperfusion (I/R) damage. Animals were subjected to I/R. Gallic acid at doses of 50 and 100 mg/kg body weight (bw) were injected as a single dose prior to ischemia. Liver tissue homogenates were used for the measurement of malondialdehyde (MDA), catalase (CAT) and glutathione peroxidase (GPx) levels. At the same time alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were assayed in serum samples and compared statistically. While the ALT, AST, LDH activities and MDA levels were significantly increased, CAT and GPx activities significantly decreased in only I/R-induced control rats compared to normal control rats (P < 0.05). Treatment with gallic acid at a dose of 100 mg/kg bw significantly decreased the ALT, AST, LDH activities and MDA levels, and markedly increased activities of CAT and GPx in tissue homogenates compared to I/R-induced rats with no treatment group (P < 0.05). In oxidative stress generated by hepatic ischemia-reperfusion, gallic acid contributes partially an alteration in the delicate balance between the scavenging capacity of antioxidant defense systems and free radicals in favour of the antioxidant defense systems in the body.

Carvacrol partially reverses symptoms of diabetes in STZ-induced diabetic rats.

Little is known about the protective effects of carvacrol on the symptoms of streptozotocin induced diabetes in rats. Hence, this present study was designed to evaluate the protective effect of the strong antioxidant, carvacrol, on the symptoms of streptozotocin induced diabetes in rats. Carvacrol at the doses of 25 and 50 mg/kg body weight were orally administered to diabetic rats for a period of 7 days after the onset of diabetes. Food-water intake and body weight changes were daily recorded. Biochemical parameters such as serum glucose, insulin, total cholesterol, alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase were measured. Although treatment of diabetic rats with oral administration of carvacrol resulted in a slight reduction in serum glucose level and significant reduction in serum total cholesterol, alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase in comparison with diabetic control rats, there were no significant differences in serum insulin levels, food-water intake values and body weight changes. Despite the inadequacy of carvacrol on diabetes treatments, it was determined to have at least a partially protective role on liver enzymes.

The hepatoprotective effects of Hypericum perforatum L. on hepatic ischemia/reperfusion injury in rats.

Little is known about the effective role of Hypericum perforatum on hepatic ischemia-reperfusion (I/R) injury in rats. Hence, albino rats were subjected to 45 min of hepatic ischemia followed by 60 min of reperfusion period. Hypericum perforatum extract (HPE) at the dose of 50 mg/kg body weight (HPE50) was intraperitonally injected as a single dose, 15 min prior to ischemia. Rats were sacrificed at the end of reperfusion period and then, biochemical investigations were made in serum and liver tissue. Liver tissue homogenates were used for the measurement of malondialdehyde (MDA), catalase (CAT) and glutathione peroxidase (GPx) levels. At the same time alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were assayed in serum samples and compared statistically. While the ALT, AST, LDH activities and MDA levels were significantly increased, CAT and GPx activities significantly decreased in only I/R-induced control rats compared to normal control rats (p < 0.05). Treatment with HPE50 significantly decreased the ALT, AST, LDH activities and MDA levels, and markedly increased activities of CAT and GPx in tissue homogenates compared to I/R-induced rats without treatment-control group (p < 0.05). In oxidative stress generated by hepatic ischemia-reperfusion, H. perforatum L. as an antioxidant agent contributes an alteration in the delicate balance between the scavenging capacity of antioxidant defence systems and free radicals in favour of the antioxidant defence systems in the body.

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.

Preventive role of gallic acid on alcohol dependent and cysteine protease-mediated pancreas injury.

In order to investigate an association between alcohol consumption and lysosomal cysteine protease induced pancreatic injury and preventive effect of gallic acid as dose-dependent, we determined myeloperoxidase and malondialdehyde levels, serum amylase activities and cathepsin B and L activities in the cytosolic and lysosomal fractions of pancreatic tissue in the ethanol (8 g/kg) and ethanol plus gallic acid (at different doses 50, 100 and 200 mg/kg) given rats. Absolute ethanol (8 g/kg) was given by oral gavage. Gallic acid was dissolved in the saline (2 ml/kg) and administered before 30 min the oral administration of ethanol. Pancreatic myeloperoxidase and also malondialdehyde levels and serum amylase activities were measured. Besides, histological investigations were made. Cathepsin B activities in the cytosolic fraction were decreased by gallic acid (200 mg/kg) and increased in ethanol given rats. Cytosolic/lysosomal ratio of cathepsin B and L were found to be low in the all doses of gallic acid as compared to ethanol group. Serum amylase, pancreatic myeloperoxidase activities and malondialdehyde levels in the ethanol group were higher than in the control group. These were not statistically significant for myeloperoxidase and malondialdehyde. Also, our histopathologic results indicated that ethanol administration increased pancreatic tissue injury. Gallic acid especially at 200 mg/kg improved ethanol-mediated pancreatic tissue damage.In conclusion, gallic acid treatments were decreased release of lysosomal cathepsin B and L enzymes into cytoplasmic fraction and prevented alcohol mediated pancreatic tissue injury. Preventive effect of gallic acid might be dose-dependent.

Protective effect of seleno-L-methionine on cyclophosphamide-induced urinary bladder toxicity in rats.

Cyclophosphamide (CP) is a widely used antineoplastic drug, which could cause toxicity of the normal cells due to its toxic metabolites. Its urotoxicity may cause dose-limiting side effects like hemorrhagic cystitis. Overproduction of reactive oxygen species (ROS) during inflammation is one of the reasons of the urothelial injury. Selenoproteins play crucial roles in regulating ROS and redox status in nearly all tissues; therefore, in this study, the urotoxicity of CP and the possible protective effects of seleno-L: -methionine (SLM) on urinary bladder of rats were investigated. Intraperitoneal (i.p.) administration of 50, 100, or 150 mg/kg CP induced cystitis, in a dose-dependent manner, as manifested by marked congestion, edema and extravasation in rat urinary bladder, a marked desquamative damage to the urothelium, severe inflammation in the lamina propria, focal erosions, and polymorphonuclear (PMN) leukocytes associated with occasional lymphocyte infiltration determined by macroscopic and histopathological examination. In rat urinary bladder tissue, a significant decrease in the endogenous antioxidant compound glutathione, and elevation of lipid peroxidation were also noted. Pretreatment with SLM (0.5 or 1 mg/kg) produced a significant decrease in the bladder edema and caused a marked decrease in vascular congestion and hemorrhage and a profound improvement in the histological structure. Moreover, SLM pretreatment decreased lipid peroxide significantly in urinary bladder tissue, and glutathione content was greatly restored. These results suggest that SLM offers protective effects against CP-induced urinary bladder toxicity and could be used as a protective agent against the drug toxicity.

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.

Silymarin attenuates the renal ischemia/reperfusion injury-induced morphological changes in the rat kidney.

OBJECTIVES: Renal ischemia/reperfusion (I/R) injury is associated with increased mortality and morbidity rates due to acute renal failure (ARF). Oxidative stress induced with renal I/R injury directly affects glomerular and tubular epithelium through reactive oxygen species. Several studies have been directed to the treatment of renal I/R injury. The aim of this study was to test the attenuation with silymarin (SM) treatment of renal I/R injury-induced morphological changes in the rat kidney. METHODS: A total of 32 adult male Sprague-Dawley rats were evaluated in four groups. Group I (sham), Group II (renal I/R), Group III (renal I/R injury + SM 50 mg per kg) and Group IV (renal I/R injury + SM 100 mg per kg) were designed to evaluate the dose-dependent effects of SM on the morphological changes of renal I/R injury. Renal I/R injury were induced with left renal pedicle occlusion for 45 min followed with reperfusion for 6 h under anesthesia. After induction of I/R injury, left nephrectomies were performed for histopathological examinations. RESULTS: After renal I/R injury, significant tubular dilatation, tubular vacuolization, pelvic inflammation, interstitial inflammation, perirenal adipose infiltration, tubular necrosis and glomerular necrosis (cortical necrosis) were observed. However, even with low dose SM in Group III (50 mg per kg SM), histopathological changes due to I/R injury were prevented. CONCLUSIONS: The results of this study have demonstrated that SM significantly prevents renal I/R injury-induced renal tubular changes in the rat. SM in 50 mg/kg was observed to be sufficient to significantly prevent renal tubular necrosis. Further, to our literature knowledge, this is the first specific study to demonstrate the preventive effect of SM on renal I/R injury.

Effects of carvacrol on defects of ischemia-reperfusion in the rat liver.

Many plants found in nature have been used to treat various illnesses. One such plant is oregano (Kekik in Turkish). Health beneficial effects of carvacrol obtained from oregano oil have been shown scientifically. We have investigated the comparative effects of carvacrol in the liver of rats subjected to ischemia-reperfusion defect, with silymarin. To test the effects we formed four groups using male Wistar albino rats. Group I was control. The other three groups of animals were administered 60min prior to surgical operation single doses of physiological serum, carvacrol and silymarin, respectively. Group II, III and IV animal were subjected to 45min long liver ischemia and 60min reperfusion. Blood and tissue samples were collected for biochemical and histological analysis following the test. AST and ALT values obtained after biochemical analysis of the serums showed statistically significant difference in group II than the other three groups. A statistical evaluation of the serum AST levels among the groups II, III and IV showed that both groups III and IV which had no difference in between were significantly different in a positive way from group II (p<0.001). As to the serum ALT levels, difference between group II and group III (p<0.001) and group II and group IV (p<0.01) was found significant. No statistical difference was observed in groups I, III and IV for GSH, MDA and CAT levels of the liver. A statistical evaluation of the GSH level in group III and group IV was found to be significantly different from group II (p<0.001) without any difference between them. A similar evaluation for MDA and CAT levels among the revealed no difference between group III and group IV, however, group II showed difference with group II and group IV (p<0.05). Histological findings were in harmony with the biochemical results. We conclude that carvacrol protects the liver against defects caused by ischemia and reperfusion, and carvacrol is not hepatotoxic at the applied dosage.