Effects of carvacrol upon the liver of rats undergoing partial hepatectomy

The present study aims to investigate the possible effects of carvacrol obtained from origanum oil upon the regenerative feature of the liver subsequent to partial hepatectomy in rats.Male Wistar Albino rats, weighing 230±30 g, were divided into three experiment groups. Group I (n=8) were used as sham operation group. Group II (n=8) were applied saline solution and hepatectomy. Carvacrol and hepatectomy (73 mg/kg) were applied to Group III (n=8). One dose of test material was injected 1 h before 68% partial hepatectomy. At the end of the experiments, blood and organs were removed. The liver regeneration rate of the rats was calculated measuring the weights of their liver before and after the hepatectomy. Hematoxylin and eosin, interleukin-6 (IL-6) and proliferating cell nuclear antigen (PCNA) treatments were applied to liver sections. Aspartate transaminase (AST), alanine transaminase (ALT), tumor necrosis factor-alpha (TNF-α) and IL-6 levels were determined in serum samples.The liver regeneration, mitotic index and PCNA index increased significantly in rats of Group III over the Group II at the 72nd hour after partial hepatectomy. Histological evaluations were also similar with these results of PCNA and mitotic indexes. In AST, ALT, TNF-α and IL-6 levels, there was no statistically significant difference.According to these results, it is concluded that carvacrol increases the liver regeneration rate.     

Sustained Na+/H+ Exchanger Activation Promotes Gliotransmitter Release from Reactive Hippocampal Astrocytes following Oxygen-Glucose Deprivation

Hypoxia ischemia (HI)-related brain injury is the major cause of long-term morbidity in neonates. One characteristic hallmark of neonatal HI is the development of reactive astrogliosis in the hippocampus. However, the impact of reactive astrogliosis in hippocampal damage after neonatal HI is not fully understood. In the current study, we investigated the role of Na⁺/H⁺ exchanger isoform 1 (NHE1) protein in mouse reactive hippocampal astrocyte function in an in vitro ischemia model (oxygen/glucose deprivation and reoxygenation, OGD/REOX). 2 h OGD significantly increased NHE1 protein expression and NHE1-mediated H⁺ efflux in hippocampal astrocytes. NHE1 activity remained stimulated during 1–5 h REOX and returned to the basal level at 24 h REOX. NHE1 activation in hippocampal astrocytes resulted in intracellular Na⁺ and Ca²⁺ overload. The latter was mediated by reversal of Na⁺/Ca²⁺ exchange. Hippocampal astrocytes also exhibited a robust release of gliotransmitters (glutamate and pro-inflammatory cytokines IL-6 and TNFα) during 1–24 h REOX. Interestingly, inhibition of NHE1 activity with its potent inhibitor HOE 642 not only reduced Na⁺ overload but also gliotransmitter release from hippocampal astrocytes. The noncompetitive excitatory amino acid transporter inhibitor TBOA showed a similar effect on blocking the glutamate release. Taken together, we concluded that NHE1 plays an essential role in maintaining H⁺ homeostasis in hippocampal astrocytes. Over-stimulation of NHE1 activity following in vitro ischemia disrupts Na⁺ and Ca²⁺ homeostasis, which reduces Na⁺-dependent glutamate uptake and promotes release of glutamate and cytokines from reactive astrocytes. Therefore, blocking sustained NHE1 activation in reactive astrocytes may provide neuroprotection following HI.     

Protective effects of leptin on ischemia/reperfusion injury in rat bladder

The aim of the study was to evaluate protective effects of exogenous leptin on ischemia/reperfusion (I/R)-induced injuries to the urinary bladder tissue and to investigate the effect on tumor necrosis factor alpha (TNF-alpha) levels and apoptotic cells during I/R injury. Bladder I/R injury was induced by abdominal aorta occlusion by ischemia for 45 min, followed by 60 min of reperfusion in rats. The rats were divided into three groups: control (n = 8 + 8), I/R (n = 8 + 8) and I/R+leptin group (n = 8 + 8). The rats in the I/R+leptin group were treated intraperitoneally with leptin (10 microg/kg) 60 min prior to ischemia induction. At the end of the reperfusion period, urinary bladders of the first eight rats from each group were removed for TUNEL staining processing while the others were removed for biochemical analyses for MDA and TNF-alpha levels. In the I/R group, the ratios of TUNEL-positive nuclei were higher than the control and the I/R+leptin groups. The MDA and TNF-alpha levels of the bladder tissue in the I/R group were higher than the control and leptin-treated groups. TUNEL-staining and biochemical studies revealed that leptin has a protective effect on urinary bladder I/R injury.     

Protective Effect of Zinc on Cyclophosphamide-Induced Hematoxicity and Urotoxicity

Cyclophosphamide (CP) is widely used for the treatment of neoplastic diseases; however, its toxicity causes dose-limiting side effects. Zinc (Zn) is an essential trace element and has important biological functions that control many cell processes including DNA synthesis, normal growth, reproduction, fetal development, bone formation, and wound healing. Therefore, the toxicity of CP and the possible protective effect of Zn on blood cells, bone marrow, and bladder of rat were investigated in this study. Intraperitoneal administration of 50, 100, or 150 mg/kg CP for 3 days caused, in a dose-dependent manner, reductions in the number of leukocytes, thrombocytes, and bone marrow nucleated cells and a serious urotoxicity. To explore whether CP-induced damages could be prevented by Zn, other groups of rats were pretreated with 4 or 8 mg/kg ZnCl2 intraperitoneally for 3 days then challenged with respective doses of CP plus ZnCl2 on day 4 for three more days. The results indicated that treatment of rats with Zn could dose-dependently alleviate CP-induced toxicities on blood cells, bone marrow cells, and urinary bladder. We suggest that Zn could be a potentially effective drug in the prevention of CP-related hematoxicity and urotoxicity.     

Evaluation of alkaline pretreatment temperature on a multi-product basis for the co-production of glucose and hemicellulose based films from lignocellulosic biomass

Cotton stalks were subjected to alkaline pretreatment for the co-production of glucose and hemicellulose based films with a multi-product approach. Three pretreatment temperatures (25, 60 and 90 °C) were evaluated for their effects both on the glucose yield and on the properties of hemicellulose based films. Compared to untreated cotton stalks, the glucose yields were enhanced 3.9, 4.1 and 4.2 times for pretreatments conducted at 25, 60 and 90 °C, respectively. The pretreatment temperature of 90 °C was detrimental in terms of film formation. Tensile energy to break values of the films obtained after pretreatments conducted at 25, 60 and 90 °C were 1.1, 0.8, and 0.4 MJ/m³, respectively. The hemicellulosic part of the process, which considers the production of hemicellulose based films, should govern the pretreatment temperature since it was more responsive to the changes in the pretreatment temperature compared to the cellulosic part that accounts for glucose production.     

Orthogonal High-Throughput Thermal Scanning Method for Rank Ordering Protein Formulations

A high-throughput thermal-scanning method to rank-order formulation conditions for therapeutic proteins is described. Apparent transition temperatures for unfolding and aggregation of four different proteins are determined using the dyes SYPRO Orange and thioflavin T (ThT) under a variety of buffer conditions. The results indicate that the ThT-based thermal scanning method offers several advantages over the previously described SYPRO Orange-based thermal scanning and allows rapid rank ordering of solution conditions relevant toward long-term storage of therapeutic molecules. The method is also amenable to high protein concentration and does not require sample dilution or extensive preparation. Additionally, this parallel use of SYPRO Orange and ThT can be readily applied to the screening of mutants for their unfolding and aggregation propensities.     

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 60 min prior to surgical operation single doses of physiological serum, carvacrol and silymarin, respectively. Group II, III and IV animal were subjected to 45 min long liver ischemia and 60 min 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.     

Stereospecific interactions between histidine and monoclonal antibodies

Histidine is a frequently used buffer in the final formulation of many commercialized monoclonal antibodies (mAbs), with histidine helping to stabilize the antibody during storage in addition to its buffering function. The objective of this study was to examine the stereospecificity of any histidine-antibody interactions using a combination of experimental studies and molecular dynamics simulations. Isothermal titration calorimetry provided evidence of weak stereospecific interactions, with the antibody showing approximately two to four additional interaction sites for d - versus l -histidine. The greater interactions with d -histidine were confirmed by measurements of the net protein charge using electrophoretic light scattering. The reduction in the net negative charge of the antibody in d -histidine led to significantly different behavior during diafiltration due to Donnan exclusion effects. Molecular dynamics simulations corroborated the presence of additional d -histidine interaction sites. These results provide the first demonstration of weak stereospecific interactions between l - and d -histidine and a mAb and the implications of these interactions for antibody formulation.     

Mast cell stabilizator and antioxidant effects of epidermal growth factor (EGF) on gastric mucosal injury induced by ethanol in rats

The role of epidermal growth factor (EGF), a polypeptide containing 53 amino acids, on protection and repair of ethanol-induced gastric mucosal injury was investigated in rats. In addition, the effects of EGF on the gastric damage were evaluated histopathologically. We used 48 Spraque-Dawley rats which were divided into [corrected] three groups as control rats, ethanol treated rats and ethanol+EGF treated rats. The ethanol group was given a gastric gavage containing 1 ml of 80% ethanol (v/v) prepared in distilled water. EGF (100 microg/kg) was given by intragastric gavage 30 min before the administration of ethanol. We studied histopathological evaluation and the histochemical heterogeneity of mast cells and its degree of degranulation. Besides, gastric tissue malondialdehyde (MDA), protein sulfhydryl groups (SH), and protein carbonyl levels were measured. EGF treatment stabilized mast cells degranulation and had lower polymorphonuclear leukocytes (PMNL) infiltration, ulcer index, histamine, and MDA; protein carbonyl levels were also lower, compared to the non-treated animals. EGF exerts a protective effect on gastric mucosa to ethanol-induced gastric injury probably through antioxidant and mast cell stabilizing mechanism.