Pioglitazone inhibits oxidative stress, MMP-mediated inflammation and vascular dysfunction in high glucose-induced human saphenous vein grafts

AIMS

The aim of this study was to investigate the effects of pioglitazone on reactive oxygen species (ROS), expressions/activities of MMPs and TIMP-2, and VSMC proliferation and vascular reactivity in high glucose (HG)-induced human saphenous vein (HSV) grafts.

METHODS

HSV grafts (n = 10) obtained from patients undergoing CABG were incubated with 30 mM glucose and/or 10 μM pioglitazone or 0.1 % DMSO for 24 h after endothelium removal. ROS levels were examined by chemiluminescence assay, MMP-2,-9,-14, TIMP-2, and α-SMA expression/activity was determined by gelatine zymography/immunohistochemistry. Vascular reactivity to potassium chloride, noradrenaline, serotonin, prostaglandin F_2α and papaverine was assessed in HSVs.

RESULTS

HG induced superoxide anion (SA) (123 %) and other ROS levels (159 %), up-regulated MMP-2 expression (180 %)/activity (79 %), MMP-14 expression (24 %) and MMP-9 activity while down-regulating TIMP-2 expression (27 %). HG elevated total MMP-2/TIMP-2 ratio (483 %) and MMP-14/TIMP-2 ratio (78 %). However, HG plus pioglitazone inhibited SA (30 %) and other ROS levels (29 %), down-regulated MMP-2 expression (76 %)/activity (83 %), MMP-14 expression (38 %) and MMP-9 activity, while reversing TIMP-2 expression (44 %). HG plus pioglitazone decreased total MMP-2/TIMP-2 ratio (91 %) and MMP-14/TIMP-2 ratio (59 %). HG impaired contractions to all agents but pioglitazone improved them.

CONCLUSIONS

Pioglitazone may contribute to the prevention of restenosis and maintaining vascular function in HSV grafts of DM patients undergoing CABG.

Vagus nerve bundle stimulation using 1505-nm laser irradiation in an in-vivo rat model

Laser nerve stimulation using near-infrared laser irradiation has recently been studied in the peripheral nervous system as an alternative method to conventional electrical nerve stimulation. Bringing this method to the vagus nerve model could leverage this emerging stimulation approach to be tested in broader preclinical applications. Here, we report the capability of the laser nerve stimulation method on the rat vagus nerve bundle with a 1505-nm diode laser operated in continuous-wave mode. Studies of the stimulation threshold and laser-induced acute thermal injury to the nerve bundle were also performed to determine a temperature window for safe, reliable and reproducible laser stimulation of the rat vagus nerve bundle. The results show that laser stimulation of the vagus nerve bundle provides reliable and reproducible nerve stimulation in a rat model. These results also confirm a threshold temperature of >42°C with acute nerve damage observed above 46°C. A strong correlation was obtained between the laser time required to raise the nerve temperature above the stimulation threshold and the mean arterial pressure response. Advantages of the method such as non-contact delivery of external stimulus signals at mm scaled distance in air, enhanced spatial selectivity and electrical artefact-free measurements may indicate its potential to counteract the side effects of conventional electrical vagus nerve stimulation.

Robust, Long-Term Culture of Endoderm-Derived Hepatic Organoids for Disease Modeling

Organoid technologies have become a powerful emerging tool to model liver diseases, for drug screening, and for personalized treatments. These applications are, however, limited in their capacity to generate functional hepatocytes in a reproducible and efficient manner. Here, we generated and characterized the hepatic organoid (eHEPO) culture system using human induced pluripotent stem cell (iPSC)-derived EpCAM-positive endodermal cells as an intermediate. eHEPOs can be produced within 2 weeks and expanded long term (>16 months) without any loss of differentiation capacity to mature hepatocytes. Starting from patient-specific iPSCs, we modeled citrullinemia type 1, a urea cycle disorder caused by mutations in the argininosuccinate synthetase (ASS1) enzyme. The disease-related ammonia accumulation phenotype in eHEPOs could be reversed by the overexpression of the wild-type ASS1 gene, which also indicated that this model is amenable to genetic manipulation. Thus, eHEPOs are excellent unlimited cell sources to generate functional hepatic organoids in a fast and efficient manner.

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iPSC-derived EpCAM⁺ endodermal cells generate functional hepatic organoids (eHEPOs)

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eHEPOs can be stably maintained in long-term culture

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An organoid-based model for a urea cycle disorder (citrullinemia) is generated

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Genetic manipulation of disease-specific eHEPOs rescues disease phenotype

Melatonin Attenuates LPS-Induced Acute Depressive-Like Behaviors and Microglial NLRP3 Inflammasome Activation Through the SIRT1/Nrf2 Pathway

Inflammation is a crucial component of various stress-induced responses that contributes to the pathogenesis of major depressive disorder (MDD). Depressive-like behavior (DLB) is characterized by decreased mobility and depressive behavior that occurs in systemic infection induced by Lipopolysaccharide (LPS) in experimental animals and is considered as a model of exacerbation of MDD. We assessed the effects of melatonin on behavioral changes and inflammatory cytokine expression in hippocampus of mice in LPS-induced DLB, as well as its effects on NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome activation, oxidative stress and pyroptotic cell death in murine microglia in vitro. Intraperitoneal 5 mg/kg dose of LPS was used to mimic depressive-like behaviors and melatonin was given at a dose of 500 mg/kg for 4 times with 6 h intervals, starting at 2 h before LPS administration. Behavioral assessment was carried out at 24 h post-LPS injection by tail suspension and forced swimming tests. Additionally, hippocampal cytokine and NLRP3 protein levels were estimated. Melatonin increased mobility time of LPS-induced DLB mice and suppressed NLRP3 expression and interleukin-1β (IL-1β) cleavage in the hippocampus. Immunofluorescence staining of hippocampal tissue showed that NLRP3 is mainly expressed in ionized calcium-binding adapter molecule 1 (Iba1) -positive microglia. Our results show that melatonin prevents LPS and Adenosine triphosphate (ATP) induced NLRP3 inflammasome activation in murine microglia in vitro, evidenced by inhibition of NLRP3 expression, Apoptosis-associated speck-like protein containing a CARD (ASC) speck formation, caspase-1 cleavage and interleukin-1β (IL-1β) maturation and secretion. Additionally, melatonin inhibits pyroptosis, production of mitochondrial and cytosolic reactive oxygen species (ROS) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling. The beneficial effects of melatonin on NLRP3 inflammasome activation were associated with nuclear factor erythroid 2–related factor 2 (Nrf2) and Silent information regulator 2 homolog 1 (SIRT1) activation, which were reversed by Nrf2 siRNA and SIRT1 inhibitor treatment.

Protective Effect of Acetyl-L-Carnitine Against Doxorubicin-induced Cardiotoxicity in Wistar Albino Rats

BACKGROUND AND AIMS

Anthracyclines are one of the most preferred agents in practical pediatric oncology despite their dose-dependent cardiotoxic effects. The aim of this study was to investigate whether or not acetyl-L-carnitine (ALCAR) has protective effects on doxorubicin (DOX)-induced cardiotoxicity.

METHODS

Wistar rats were divided into four groups; control, DOX, ALCAR and ALCAR+DOX. Rats in the first group were given saline on study days, whereas those in the second group were given a single dose of DOX on the 5^th day and saline on the other days. Rats in the third group were given ALCAR and those in the fourth group were given ALCAR on study days but also given only a single dose of DOX on the fifth day of the study. Ejection fractions (EF) were measured by echocardiography before and after drug administration. Heart tissues were evaluated by light and electron microscopy. Apoptotic cells were determined with TUNEL and caspase-3 staining.

RESULTS

DOX significantly decreased the EF values, whereas ALCAR did not. Cardiac functions were higher in the ALCAR+DOX group when compared to the DOX group. DOX administration caused a cardiac injury not only functionally, but also structurally, whereas ALCAR prevented it.

CONCLUSIONS

ALCAR has a capacity of preventing DOX-induced cardiac injury at both functional and structural levels.

Effects of Quercetin Treatment on Epithelium-derived Cytokines and Epithelial Cell Apoptosis in Allergic Airway Inflammation Mice Model

Quercetin is a dietary flavonoid which has anti-inflammatory effects. This study aimed to evaluate the influence of quercetin on histopathological aspects and airway epithelium in  allergic airway  inflammation mice model. Twenty-eight BALB/c mice were randomly divided into four groups: Group I (control), Group II (untreated mice with allergic airway inflammation), Group III (allergic airway inflammation quercetin-treated [16mg/kg/day]), Group IV (allergic airway inflammation dexamethasone-treated [1mg/kg/day]). Ovalbumin was administered intraperitoneally and via inhalation to achieve allergic airway inflammation mice model and treatments were also given intraperitoneally. Epithelium thickness, subepithelial smooth muscle thickness, number of mast and goblet cells, and basement membrane thickness were examined on samples isolated from lung. Immunohistochemical evaluationof lung tissues was performed using  IL-25, IL-33, thymic stromal lymphopoietin (TSLP), terminal deoxynucleotidyl transferase-mediated dUTP nick endlabeling (TUNEL) and cysteine-dependent aspartate-specific proteases(caspase)-3 antibodies. IL-4, IL-25, IL-33, TSLP were quantified in bronchoalveolar lavage (BAL) and OVAspecific IgE levels was measured in serum by standard ELISA protocols. IL-25, IL-33, thymic stromal lymphopoietin (TSLP) and cysteine-dependent aspartate-specific proteases (caspase)-3. Quercetin treatment led to lower epithelial thickness, subepithelial smooth muscle thickness, goblet and mast cell numbers compared to untreated  mice with allergic airway inflammation (p<0.05). However, quercetin treatment was not effective on improving basal membane thickness. Immunohistochemical scores of IL-25, IL-33, TSLP, caspase-3 and TUNEL were lower in quercetin-treated mice  t compared to untreated mice with allergic airway inflammation (p<0.05). IL-4, IL-25, IL-33, TSLP levels in BAL and OVA-specific IgE in serum were lower in quercetin treated mice compared to untreated mice (p<0.05). These findings suggest that quercetin improves chronic histopathological changes except basal membrane thickness in lung tissue and its beneficial effects on inflammation might be related to modulating epithelium derived cytokines and epithelial apoptosis.

Resveratrol ameliorates 2,4-dinitrofluorobenzene-induced atopic dermatitis-like lesions through effects on the epithelium

Background. Resveratrol is a natural polyphenol that exhibits anti-inflammatory effects. The aim of this study was to investigate the effects of resveratrol treatment on epithelium-derived cytokines and epithelial apoptosis in a murine model of atopic dermatitis-like lesions.

Material and Methods. Atopic dermatitis-like lesions were induced in BALB/c mice by repeated application of 2,4-dinitrofluorobenzene to shaved dorsal skin. Twenty-one BALB/c mice were divided into three groups: group I (control), group II (vehicle control), and group III (resveratrol). Systemic resveratrol (30 mg/kg/day) was administered repeatedly during the 6th week of the experiment. After the mice had been sacrificed, skin tissues were examined histologically for epithelial thickness. Epithelial apoptosis (caspase-3) and epithelium-derived cytokines [interleukin (IL)-25, IL-33, and thymic stromal lymphopoietin (TSLP)] were evaluated immunohistochemically.

Results. Epithelial thickness and the numbers of IL-25, IL-33, TSLP and caspase-3-positive cells were significantly higher in group II compared to group I mice. There was significant improvement in epithelial thickness in group III compared with group II mice (p < 0.05). The numbers of IL-25, IL-33, and TSLP-positive cells in the epithelium were lower in group III than in group II mice (p < 0.05). The number of caspase-3-positive cells, as an indicator of apoptosis, in the epithelium was significantly lower in group III than in group II mice (p < 0.05).

Conclusion. Treatment with resveratrol was effective at ameliorating histological changes and inflammation by acting on epithelium-derived cytokines and epithelial apoptosis.

Effects of inhaled L-arginine administration in a murine model of acute asthma

Increased arginase activity in the airways decreases L-arginine and causes deficiency of bronchodilating and anti-inflammatory nitric oxide (NO) in asthma. As, it is suggested that L-arginine may have therapeutic potential in asthma treatment, we aimed to investigate the effects of inhaled L-arginine on oxygen saturation (SaO₂) and airway histology in a murine model of acute asthma. Twenty eight BALB/c mice were divided into four groups; I, II, III and IV (control). All groups except the control were sensitized and challenged with ovalbumin. After establishement of acute asthma attack by metacholine administration, the mice were treated with inhaled L-arginine (Group I), saline (Group II) and budesonide (Group III), respectively. SaO₂was measured by pulse oximeter just before and 5 min after methacholine. A third measurement of SaO₂was also obtained 15 min after drug administration in these study groups. Inflammation in the lung tissues of the sacrificed animals were scored to determine the effects of the study drugs. The number of eosinophils in bronchoalveolar lavage (BAL) was determined. The results indicated that inflammatory scores significantly improved in groups receiving study drugs when compared with placebo and L-arginine was similar in decreasing scores when compared with budesonide. SaO₂had a tendency to increase after L-arginine administration after acute asthma attack and this increase was statistically significant (p=0.043). Eosinophilia in BAL significantly reduced in group receiving L-arginine when compared with placebo (p<0.05). Thus in this study we demonstrated that L-arginine improved SaO₂and inflammatory scores in an acute model of asthma.

Effectiveness of thymoquinone in the treatment of experimental asthma

BACKGROUND

Thymoquinone (TQ), the main active constituent of the volatile oil extracted from Nigella sativa's seeds, is used for the treatment of inflammatory diseases and exhibits a variety of pharmacological effects.

METHODS

Twenty-eight BALB/c female mice were divided into four groups: I (sham-operated control group), II, III, and IV. All groups except for the sham-operated group were sensitized and challenged with ovalbumin. The sham-operated group received nebulized saline in challenge period. Mice in groups III and IV were administered TQ at a dose of 3 mg/kg and dexamethasone 1 mg/kg, respectively, intraperitoneally once a day for the final 5 days of the challenge period. Animals were sacrificed 24 h after the last drug administration and the airway samples were evaluated histologically by light microscopy.

RESULTS

All histological parameters in Group III, similar to Group IV, were improved when compared to Group II. All variables except numbers of goblet cells were found to be significantly better in Group III and Group IV compared to Group II.

CONCLUSIONS

In our study, we demonstrated that TQ administration alleviates the pathological changes of chronic asthma. TQ might be a promising therapy for asthma in the.

Glycyrrhizin and long-term histopathologic changes in a murine model of asthma

BACKGROUND

Licorice root has been widely used to treat bronchial asthma for many years. However, the effect of this herb on lung histopathologic features is not fully understood.

OBJECTIVE

In this study, we aimed to determine the effects of oral administration of glycyrrhizin, an active constituent of licorice root, on lung histopathologic features in BALB/c mice, in which the model of chronic asthma was established.

METHODS

Twenty-eight BALB/c mice were divided into 4 groups: control, placebo, dexamethasone, and glycyrrhizin. Mice in the treatment and placebo groups were sensitized with 2 intraperitoneal injections of ovalbumin and then were exposed to aerosolized ovalbumin for 30 minutes per day on 3 days each week for 8 weeks beginning on the 21st study day. In the last week of inhalational exposure, mice in the placebo group received saline and those in the treatment groups received either dexamethasone, 1 mg/kg, or glycyrrhizin, 10 mg/kg, via orogastric gavage for 7 consecutive days. Animals were humanely killed 24 hours after the last ovalbumin and drug exposure. Lung histopathologic findings were evaluated using light and electron microscopy.

RESULTS

As evaluated in the control, placebo, dexamethasone, and glycyrrhizin groups, respectively, the mean (SD) basement membrane thickness was 306.34 (36.91), 657.52 (98.99), 405.13 (96.1), and 465.01 (121.48) nm; subepithelial smooth muscle thickness was 7.22 (1.37), 11.24 (1.85), 5.62 (1.15), and 7.76 (1.11) μm; epithelium thickness was 19.48 (1.22), 41.62 (5.49), 22.59 (3.18), and 25.54 (4.68) μm; number of mast cells was 1.34 (0.19), 3.62 (0.5), 2.06 (0.77), and 2.77 (0.23)/16,400 μm(2); and number of goblet cells was 0.32 (0.1), 4.92 (0.82), 0.66 (0.06), and 0.98 (0.15)/100 μm. Evaluation of lung histopathologic features demonstrated that the chronic asthma model of mice was successfully established, with significantly higher numbers of goblet and mast cells and increased thickness of epithelium, basement membrane, and subepithelial smooth muscle layers (P < 0.001 for all) in the asthma group compared with in the control group. The number of goblet (P < 0.001) and mast (P < 0.02) cells and the thickness of basement membrane (P < 0.001), subepithelial smooth muscle layers (P ≤ 0.001), and epithelium of the lung (P < 0.001) were found to be significantly lower in the glycyrrhizin group compared with in the placebo group. When the glycyrrhizin and dexamethasone groups were compared, there was no statistically significant difference between the 2 groups in the histopathologic parameters, including thickness of basement membrane (P = 0.514), subepithelial smooth muscle (P = 0.054), and epithelium (P = 1.0) and number of mast (P = 0.075) and goblet (P = 0.988) cells.

CONCLUSIONS

The results of this study suggest that the group receiving glycyrrhizin had amelioration of all established chronic histopathologic changes of lung in the mouse model of asthma. Further studies are needed to evaluate the efficacy of glycyrrhizin in the management of asthma.

Neuronal apoptosis in the neonates born to preeclamptic mothers

OBJECTIVE

Preeclampsia may result in uteroplacental insufficiency and chronic intrauterine fetal distress. The aim of this study is to address this issue investigating neuronal apoptosis in an experimental model of preeclampsia and to evaluate the neurological outcome of the perinatal asphyxia in the neonates born to preeclamptic mother.

MATERIALS AND METHODS

Two out of four pregnant Sprague-Dawley rats (preeclamptic group) were given water containing 1.8% NaCl on gestation day 15 and 22 in order to establish the model of preeclampsia whereas other two (non-preeclamptic group) received normal diet. A model of perinatal asphyxia was established on the postnatal 7th day to one preeclamptic and one non-preeclamptic dam. Overall 23 pups born to overall four dams were decapitated to assess neuronal apoptosis by the TUNEL assay.

RESULTS

The number of apoptotic neuronal cells was significantly higher in the preeclampsia groups in comparison with the control group (p = 0.006 and p = 0.006, respectively). It was also significantly higher in the asphyctic/non-preeclamptic group than the count in the control group (p = 0.01). There was also significant difference between both asphyctic groups (p = 0.003).

CONCLUSION

We conclude that preeclampsia causes small babies for the gestational age and cerebral hypoplasia. Both preeclampsia and perinatal asphyxia can cause increased neuronal apoptosis in the neonatal brains. However, the prognosis for neurological outcome is much worse when the perinatal asphyxia occurs in newborns born to preeclamptic mothers.

Assessment of Protective Effects of Pheniramine Maleate on Reperfusion Injury in Lung After Distant Organ Ischemia

Objective:

The aim of this study is to investigate the protective effects of methylprednisolone (MP) and pheniramine maleate (PM) on reperfusion injury of lungs developing after ischemia of the left lower extremity of rats.

Materials and methods:

A total of 28 randomly selected male rats were divided into 4 groups, each consisting of 7 rats. Group 1 was the control group. Group 2 was the sham group (ischemia/reperfusion [I/R]). Rats in group 3 were subjected to I/R and given PM (Ph group) and rats in group 4 were subjected to I/R and given MP (Pn group).

Results:

Malondialdehyde levels were significantly lower in Ph group than in I/R group ( P < .05). Superoxide dismutase and glutathione peroxidase enzyme activities were found to be significantly higher in Ph group than in the I/R group ( P < .05). Histological examination demonstrated that PM had protective effects against I/R injury. Conclusions: The PM has a protective effect against I/R injury in rat lung.

The effects of PPAR-γ agonist pioglitazone on renal ischemia/reperfusion injury in rats

BACKGROUND

Acute renal failure due to renal ischemia/reperfusion (IR) injury is a significant clinical problem in cardiovascular surgery. Reactive oxygen species and inflammation play essential roles in the pathophysiology of IR injury. Matrix metalloproteinases (MMPs) are enzymes that play important roles in inflammation and mediate extracellular matrix degradation. It is known that peroxisome proliferator-activated receptor-γ agonists have antiinflammatory and antioxidant effects. In the present study, we aimed to investigate the effects of pioglitazone, a synthetic peroxisome proliferator-activated receptor-γ agonist, on MMPs and oxidative stress in a renal IR injury model in rats.

MATERIALS AND METHODS

Male Wistar albino rats were divided into three groups: control (n = 7), placebo (n = 7; saline/p.o.), and pioglitazone (n = 7; 5 mg/kg/day/p.o.). In the control group, a right nephrectomy was conducted without left renal IR injury. In the placebo and pioglitazone groups, pretreatments were started 3 d before operation. In both groups, left renal pedicles were clamped for 60 min and then reperfused for 60 min. Paraffinized renal sections were evaluated histopathologically. Furthermore, expressions of MMP-2, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-2, superoxide dismutase 1 (SOD1), and p47-phox/p67-phox subunits of NADPH oxidase were determined by immunostaining and scoring.

RESULTS

In the placebo group, renal IR injury induced diffuse tubular necrosis and intense acute inflammation, but pioglitazone inhibited these effects. MMP-2, MMP-9, and TIMP-2 expression increased in the placebo group. However, while MMP-2 and -9 expression decreased, TIMP-2 expression did not change in the pioglitazone group. p47-phox/p67-phox expression increased in the placebo group, but SOD1 expression did not change. Pioglitazone diminished p47-phox/p67-phox expression, whereas it enhanced SOD1 expression.

CONCLUSION

Our results suggest that pioglitazone might be helpful to reduce renal IR injury because of its antiinflammatory and antioxidant effects.

Beneficial effects of erythropoietin on airway histology in a murine model of chronic asthma

BACKGROUND

Erythropoietin (EPO) is originally defined as a haematopoietic growth factor, but also has anti-inflammatory effects through cytokine modulation. This anti-inflammatory and cytokine modulating effect has not been investigated for the treatment of asthma. We aimed to determine the beneficial effects of erythropoietin on lung histology of murine model of chronic asthma.

METHODS

Thirty-five BALB/c mice were divided into five groups: I; II; III; IV; and control group. All groups except control group were sensitised and challenged with ovalbumin. Mice with experimentally induced asthma in Group I received saline; Group II EPO 500IU/kg; Group III EPO 1000IU/kg; and Group IV dexamethasone 1mg/kg intraperitoneally once a day in the last five days of the challenge period. Animals were sacrificed 24h after the last administration of study drugs. Histological findings of airways were evaluated by light and electron microscopic examination.

RESULTS

All histological parameters of asthma in the group treated with a high dose of EPO (Group III) were significantly ameliorated when compared with the group treated with saline (Group I). In comparison to the group treated with low dose of EPO (Group II) and the group treated with saline (Group I), basement membrane thicknesses and number of mast cells were significantly lower in the group treated with low dose of EPO (Group II). All histological parameters were similar between the group treated with high dose of EPO (Group III) and the group treated with dexamethasone (Group IV) except higher number of mast cells in the group treated with high dose of EPO (Group III). Additionally, the results of all histological parameters in the group treated with high dose of EPO (Group III) were significantly better when compared with the group treated with low dose of EPO (Group II).

CONCLUSIONS

We found that EPO ameliorated histological changes of chronic murine model of asthma. Further studies are needed to evaluate the efficacy of EPO in the treatment of asthma.

Glycyrrhizin and long-term histopathologic changes in a murine model of asthma

BACKGROUND

Licorice root has been widely used to treat bronchial asthma for many years. However, the effect of this herb on lung histopathologic features is not fully understood.

OBJECTIVE

In this study, we aimed to determine the effects of oral administration of glycyrrhizin, an active constituent of licorice root, on lung histopathologic features in BALB/c mice, in which the model of chronic asthma was established.

METHODS

Twenty-eight BALB/c mice were divided into 4 groups: control, placebo, dexamethasone, and glycyrrhizin. Mice in the treatment and placebo groups were sensitized with 2 intraperitoneal injections of ovalbumin and then were exposed to aerosolized ovalbumin for 30 minutes per day on 3 days each week for 8 weeks beginning on the 21st study day. In the last week of inhalational exposure, mice in the placebo group received saline and those in the treatment groups received either dexamethasone, 1 mg/kg, or glycyrrhizin, 10 mg/kg, via orogastric gavage for 7 consecutive days. Animals were humanely killed 24 hours after the last ovalbumin and drug exposure. Lung histopathologic findings were evaluated using light and electron microscopy.

RESULTS

As evaluated in the control, placebo, dexamethasone, and glycyrrhizin groups, respectively, the mean (SD) basement membrane thickness was 306.34 (36.91), 657.52 (98.99), 405.13 (96.1), and 465.01 (121.48) nm; subepithelial smooth muscle thickness was 7.22 (1.37), 11.24 (1.85), 5.62 (1.15), and 7.76 (1.11) μm; epithelium thickness was 19.48 (1.22), 41.62 (5.49), 22.59 (3.18), and 25.54 (4.68) μm; number of mast cells was 1.34 (0.19), 3.62 (0.5), 2.06 (0.77), and 2.77 (0.23)/16,400 μm(2); and number of goblet cells was 0.32 (0.1), 4.92 (0.82), 0.66 (0.06), and 0.98 (0.15)/100 μm. Evaluation of lung histopathologic features demonstrated that the chronic asthma model of mice was successfully established, with significantly higher numbers of goblet and mast cells and increased thickness of epithelium, basement membrane, and subepithelial smooth muscle layers (P < 0.001 for all) in the asthma group compared with in the control group. The number of goblet (P < 0.001) and mast (P < 0.02) cells and the thickness of basement membrane (P < 0.001), subepithelial smooth muscle layers (P ≤ 0.001), and epithelium of the lung (P < 0.001) were found to be significantly lower in the glycyrrhizin group compared with in the placebo group. When the glycyrrhizin and dexamethasone groups were compared, there was no statistically significant difference between the 2 groups in the histopathologic parameters, including thickness of basement membrane (P = 0.514), subepithelial smooth muscle (P = 0.054), and epithelium (P = 1.0) and number of mast (P = 0.075) and goblet (P = 0.988) cells.

CONCLUSIONS

The results of this study suggest that the group receiving glycyrrhizin had amelioration of all established chronic histopathologic changes of lung in the mouse model of asthma. Further studies are needed to evaluate the efficacy of glycyrrhizin in the management of asthma.

Does carbon dioxide therapy really diminish localized adiposities? Experimental study with rats

BACKGROUND

The probability of a positive effect of carbon dioxide (CO(2)) gas on the physiologic oxidative lipolytic process led to its use for localized adiposities. The authors considered that existing studies on CO(2) therapy were not sufficient to exhibit the efficiency of CO(2) therapy. The scientific basis for evaluating CO(2) therapy including standard dietary regimen, standard daily physical effort, and standard psychosocial stimuli was not clear. Despite this unclear situation, CO(2) therapy is extremely popular worldwide. The authors designed an experimental study using histomorphologic examination and the laser-Doppler flow meter to monitor treated tissue in rats. They devised a controlled applicator device appropriate for gas injection of rats and compared biochemical effects between CO(2) and breathable air.

METHODS

In this study, 28 female Wistar rats weighing 300 g were divided into five groups: sham group, acute effect of CO(2) group, acute effect of breathable air group, chronic effect of CO(2) group, and chronic effect of breathable air group. Gas was injected into the right groin of the rats via a specially designed device.

RESULTS

The bulging disappeared after approximately 30 min in the CO(2) injection groups but continued for more than 48 h in breathable air injection groups. The blood flow and velocity in terms of changes in the signals observed using the laser-Doppler technique did not demonstrate a significant increase in the values of the gas injection groups compared with the sham group 1. A statistical difference in the number of adipocytes was found between the groups.

CONCLUSION

The study findings demonstrated a statistically significant decrease in adipocyte diameters during both the early and late phases of the subjects injected with CO(2). With adipocyte volume defined as an achievement, CO(2) therapy was found to be more successful than air injection. Furthermore, compared with the control group, the decrease in adipocyte volume also was statistically significant in breathable air injected groups (groups 3 and 5). This result suggests that the mechanical effects of gas injection are more important than the metabolic effects.

Mesenchymal stem cells ameliorate the histopathological changes in a murine model of chronic asthma

Asthma therapies are effective in reducing inflammation but airway remodeling is poorly responsive to these agents. New therapeutic options that have fewer side effects and reverse chronic changes in the lungs are essential. Mesenchymal stem cells (MSCs) are promising for the development of novel therapies in regenerative medicine. This study aimed to examine the efficacy of MSCs on lung histopathology in a murine model of chronic asthma. BALB/c mice were divided into four groups: Group 1 (control group, n=6), Group 2 (ovalbumin induced asthma only, n=10), Group 3 (ovalbumin induced asthma + MSCs, n=10), and Group 4 (MSCs only, n=10). Histological findings (basement membrane, epithelium, subepithelial smooth muscle thickness, numbers of goblet and mast cells) of the airways and MSC migration were evaluated by light, electron, and confocal microscopes. In Group 3, all early histopathological changes except epithelial thickness and all of the chronic changes were significantly ameliorated when compared with Group 2. Evaluation with confocal microscopy showed that no noteworthy amount of MSCs were present in the lung tissues of Group 4 while significant amount of MSCs was detected in Group 3. Serum NO levels in Group 3, were significantly lower than Group 2. The results of this study revealed that MSCs migrated to lung tissue and ameliorated bronchial asthma in murine model. Further studies are needed to evaluate the efficacy of MSCs for the treatment of asthma.

The beneficial effects of tadalafil on renal ischemia-reperfusion injury in rats

Acute renal failure due to ischemia-reperfusion (I/R) injury is a common complication in cardiovascular surgery. We determined the influence of tadalafil on renal injury in a renal I/R model in rats. For this purpose, 21 male Wistar albino rats were separated into 3 groups: sham, placebo and tadalafil. A right nephrectomy was performed, and the left renal pedicles were occluded for 60 min and reperfused for 60 min in the placebo and tadalafil groups. A single dose of tadalafil (10 mg/kg) through an orogastric tube was administered to the tadalafil group. Tubular atrophy with acute inflammation in renal histology, total oxidant status (TOS) and total antioxidant status (TAS) were determined in tissue homogenates. Compared to the tadalafil group, tubular atrophy and acute inflammation was significant in the placebo group. TAS levels were significantly higher in the tadalafil group compared to the placebo (p = 0.01) and sham groups (p = 0.04). While TOS levels were significantly higher in the placebo group (p = 0.03), tadalafil did not significantly alter the TOS levels. The beneficial effects of tadalafil can be attributed to its protective effects on renal tubular cells and inhibition of leukocyte infiltration in renal tissue. We think that tadalafil treatment has an important role in reducing renal injury resulting from renal I/R.

Histopathologic changes in two mouse models of asthma

BACKGROUND

No studies to date have compared mouse models of asthma by evaluating airway histopathology.

OBJECTIVE

To compare 2 such models by studying chronic histopathologic changes of the airways using light and electron microscopy.

METHODS

Twenty-one male BALB/c mice were divided into 3 groups: a nebulization group sensitized via an intraperitoneal injection of 10 microg ovalbumin on days 0 and 14 and exposed to 2.5% aerosolized ovalbumin 3 days a week over the subsequent 8 weeks; an intranasal group sensitized via 2 intraperitoneal injections of 100 microg ovalbumin on days 0 and 14 and administered an intranasal dose of 500 microg ovalbumin on days 14, 27, 28, 29, 47, 61, 73, 74, and 75; and a control group that received nothing. Airway histopathologies were evaluated.

RESULTS

Basement membrane, epithelium, and subepithelial smooth muscle layer thicknesses and mast and goblet cell numbers were significantly higher in the nebulization group than in the control group. With the exception of mast cell numbers, these parameters were also significantly higher in the intranasal group than in the control group. On comparing the intranasal and the nebulization group, goblet cell numbers were significantly higher in the former and mast cells in the latter.

CONCLUSION

Both models replicated all the structural parameters of asthma except for mast cell numbers in the intranasal group (no significant difference with respect to the control group). Our findings do not provide sufficient evidence that one protocol is superior to the other. Larger studies are needed to compare different asthma protocols.

Neuroprotective effects of selenium and ginkgo biloba extract (EGb761) against ischemia and reperfusion injury in rat brain

OBJECTIVES

To determine the neuroprotective effects of Ginkgo biloba extract (EGb761) and Selenium (Se), and the combination of these agents on ischemia/reperfusion (I/R) injury in a rat model of transient global cerebral I/R.

METHODS

This experimental study took place in the Animal Research Laboratory at Dokuz Eylul University, Izmir, Turkey in the year 2006. Fifty rats were subjected to cerebral I/R induced by right carotid artery occlusion technique for a duration of 45 minutes, and then were treated with EGb761 (50 mg/kg/day, ip) and Se (0.625 mg/kg, ip), alone or in combination for 14 days after surgery. Superoxide dismutase, and glutathione peroxidase activities were measured in the hippocampal tissues from 25 animals. Histopathological examinations were also carried out under light and electron microscopy from the rest of animals.

RESULTS

The results suggest that EGb761 has a potent neuroprotective effect against cerebral I/R induced injury in rat brain that is comparable with that of Se. However, the combined use of EGb761 and Se does not further protect from neuronal injury when compared with the use of both agents alone.

DISCUSSION

Our results suggest that administration of EGb761, Se and its combination with EGb761 have significant neuroprotective effects on I/R injury in rats via suppression of oxidative stress.

Suppression of apoptosis and oxidative stress by deprenyl and estradiol in aged rat liver

Aging is accompanied by significant structural and functional transformations of all organs and systems. Age-associated increase in apoptotic behavior may cause disease. Older cells are more susceptible to endogenous oxidative damage, and oxidative stress is a potent inducer of apoptosis. Deprenyl is an irreversible monoamine-oxidase B inhibitor which has anti-oxidant, anti-apoptotic and neuroprotective effects. Estrogen is also a neuroprotective and anti-oxidant hormone. The objectives of this study were to determine whether the anti-oxidative effects of deprenyl can suppress apoptotic activity, with or without estradiol, in aged female rat livers. In this study, ovariectomized female Wistar albino rats were divided into six groups as follows; young (3 months old) saline-treated control, aged (24 months old) saline-treated control, aged deprenyl treated, aged estradiol treated, aged deprenyl plus estradiol treated and aged sham controls. All rats except for the sham group were treated for 21 days. Determination of oxidative stress parameters was performed spectrophotometrically. To detect apoptotic cells, TUNEL staining was performed. The results were analyzed by one-way ANOVA post hoc Bonferroni test. Deprenyl and estradiol administration, alone or in combination, decreased significantly the levels of lipid peroxidation and increased superoxide dismutase activity in the liver relative to aged control and sham rats (P<0.05). The number of TUNEL positive cells decreased significantly in deprenyl and estradiol-treated rats compared with aged control and sham rats. The results indicate that deprenyl treatment alone, or in combination with estradiol, may modulate age-related apoptotic changes in rat liver by decreasing oxidative stress.

The protective effects of trimetazidine on testicular ischemia and reperfusion injury in rats

This study was designed to investigate the protective effect of trimetazidine [TMZ; 1-(2, 3, 4-trimethhoxibenzyl)-piperazine dihydrochloride], as an antioxidant agent, on torsion-detorsion-induced biochemical and histopathological changes in experimental testicular ischemia/reperfusion injury in rats. Twenty-seven male Wistar rats weighing 180-220 g were divided into five groups: control (C, n = 4), sham-operated (S, n = 4), ischemia (I, n = 6), ischemia-reperfusion (I/R, n = 6) and ischemia-reperfusion + trimetazidine (I/R + TMZ; n = 7). Control rats were used for basal normal values. In group I, 2 h torsion of the left testis was performed. In I/R and I/R + TMZ groups, following 2 h of torsion, 4 h detorsion of the testis was performed. In ischemia and I/R groups, physiologic saline was administered orally for 7 days, and the rats in I/R + TMZ group were pretreated orally with 5 mg/kg day TMZ for 7 days before inducing ischemia. At the end of each experiment, ipsilateral orchiectomies were performed for the tissue levels of malondialdehyde (MDA), glutathione peroxidase (GPx) enzyme activities and histopathological examinations in all groups. MDA levels were significantly reduced and GPx enzyme activities were significantly increased in testes in I/R+TMZ pretreated group compared to group I and I/R. The mean seminiferous tubular diameter (MSTD) and Johnsen's score were significantly better in I/R+TMZ group than groups I and I/R. Pretreatment with TMZ decreased germ cell apoptosis and caspase-3 expression in the ischemic testis. The present results show that TMZ has a protective activity in the testicular injury caused by I/R, and provide the first evidence of the role of TMZ for the prevention of I/R-induced testicular injury.