Pergin Atilla

In vitro and in vivo studies of ibuprofen-loaded biodegradable alginate beads

The irritation effects of ibuprofen, a widely used non-steroidal anti-inflammatory drug (NSAID), were evaluated on mouse gastric and duodenal mucosa when suspended in 0.5% (w/v) sodiumcarboxymethylcellulose (NaCMC) solution and loaded in alginate beads. The ionotropic gelation method was used to prepare controlled release alginate beads of ibuprofen. The influence of various formulation factors on the encapsulation efficiency, as in vitro drug release and micromeritic properties, was investigated. Other variables included the alginate concentration, percentage drug loading and stirring speed during the microencapsulation process. Scanning electron micrographs of alginate beads loaded with ibuprofen showed rough surface morphology and particle sizes in the range of 1.15 ± 0.4–3.15 ± 0.6 mm. The yield of microspheres, as collected after drying, was generally 80–90%. Formulation code H showing t50% value of 3.5 h was chosen for in vivo trials because of the appropriate drug release properties. For in vivo trials, free ibuprofen (100 mg kg−1), blank and ibuprofen (100 mg kg−1) loaded alginate beads (formulation code H) were suspended in 0.5% (w/v) NaCMC solution and each group was given to six mice orally by gavage. NaCMC solution was used as a control in experimental studies. In vivo data showed that the administration of ibuprofen in alginate beads prevented the gastric lesions.

In vitro growth stimulatory and in vivo wound healing studies on cycloartane-type saponins of Astragalus genus

AIM OF THE STUDY The present study was undertaken to evaluate the wound healing effects of the four chief saponins of Astragalus species [cycloastragenol (CA), astragaloside IV (AG), cyclocephaloside I (CCI) and cyclocanthoside E (CCE)]. MATERIAL AND METHODS Effects of cell viability and proliferation of the isolated compounds were evaluated by the MTT assay on human keratinocyte. The wound healing activity was studied by using in vitro wound healing, proliferation and migration scratch assay. In order to see in vivo effectiveness of the compounds, an animal study with Sprague-Dawley male rats at the age of 12 weeks was carried out, and then the main histological outcomes were investigated to observe reepithelization, neovascularization, and presence of inflammatory cells, granulation tissue amount and maturation. RESULTS All the compounds increased both fibroblast proliferation and migration, but the effects were much superior for CA at 1 ng/ml concentration. Among the compounds, based on the histological findings, 5% CA preparation was found to be the most remarkable in vivo wound healing agent showing greater cell density, more regularly organized dermis and more newly formed blood vessels. CONCLUSION Results of this study indicate that the cycloartane-type saponins are the principal constituents responsible for wound healing activities of the roots of Astragalus species substantiating its use in traditional medicine.

The effect of taurine on mesenteric blood flow and organ injury in sepsis

Summary.Endotoxin decreases mesenteric blood flow and inflicts organ injury via free radicals. We investigated whether taurine, an endogenous antioxidant and vasodilator, could attenuate the deleterious effects of endotoxin in a mouse model of sepsis. Swiss albino mice were allocated into four groups and treated either with taurine (150 mg/kg, i.p. at 0th, 8th, 16th h) or its solvent sterile saline (NaCl 0.9%, w/v) while E. coli endotoxin (20 mg/kg, i.p.) or its solvent saline were also given at 8th h. At 24th h the animals were anaesthetized and the mesenteric blood flow was measured by using perivascular ultrasonic Doppler-flowmeter. The animals were then exsanguinated, the spleen, liver, and kidneys were isolated for histopathological examination. Thiobarbituric acid-reacting substances (TBARS), glutathione, and myeloperoxidase activity were determined in the liver samples. Endotoxin significantly decreased the mesenteric blood flow and glutathione levels in liver while TBARS and myeloperoxidase activity were increased. However, taurine did not block the deleterious effects of endotoxin nor it did attenuate the histopathological injury. Therefore, we concluded that endotoxin-induced organ injury via free radicals is resistant to blockade by taurine.

Angiotensin-converting enzyme inhibitor enalapril reduces formation of hypertrophic scars in a rabbit ear wounding model.

Background: Angiotensin-converting enzyme inhibitors are widely used in medicine because of their antihypertensive and antifibrogenic effects. Angiotensin-converting enzyme activates angiotensin I to angiotensin II, which plays an important regulatory role in wound healing and collagen production. The authors investigated whether systemic administration of angiotensin-converting enzyme inhibitors has any effect on formation of hypertrophic scars using the rabbit ear wound model. Methods: Sixteen New Zealand albino rabbits were divided into four groups, and four punch defects were created on each ear. The first group received oral enalapril immediately after the creation of punch defects. The second group received oral enalapril on day 28 after the formation of scars. The third group received intralesional steroid injections on days 28 and 35. The fourth group was the control group. The rabbits were killed on day 40. The harvested specimens were analyzed histomorphometrically and immunohistochemically. Results: Early enalapril application decreased the scar elevation index and fibroblast and capillary counts significantly, compared with the values in the control group. Late enalapril application decreased fibroblast counts significantly; however, there was no difference in scar elevation index compared with the control group. There was no difference between early enalapril application and steroid therapy in terms of scar elevation index and capillary and fibroblast counts. However, early and late enalapril groups displayed lower collagen type III immunoreactivity compared with the steroid and control groups. Conclusion: Early application of enalapril following dermal injury reduces formation of hypertrophic scars, probably because of its down-regulatory effects on type III collagen production.

Long-term simvastatin attenuates lung injury and oxidative stress in murine acute lung injury models induced by oleic Acid and endotoxin.

BACKGROUND: 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitors have several pleiotropic effects, including anti-inflammatory properties, and are reported to improve endothelial functions. Pathophysiologically, acute lung injury (ALI) is caused by a severe inflammatory response and endothelial dysfunction. OBJECTIVE: To investigate the effects of simvastatin (an HMG-CoA reductase inhibitor) on oxidative stress and lung histopathology in 2 murine models of ALI, induced by oleic acid and endotoxin. METHODS: The mice were randomly divided into 2 groups: one received 2 mg/kg/d intraperitoneal simvastatin for 15 days. Then the groups were further divided into 3, which received saline, oleic acid, or endotoxin. Four hours after inducing ALI we obtained lung samples for histopathology analysis, myeloperoxidase, glutathione, and malondialdehyde measurement, and blood samples for malondialdehyde measurement. RESULTS: Endotoxin and oleic acid lung injury increased tissue myeloperoxidase (P = .009 for both), decreased tissue glutathione (P = .02 and P = .009, respectively), and increased tissue malondialdehyde (P = .009 for both), compared to the control group. Simvastatin decreased myeloperoxidase only in the oleic acid group (P = .01). Simvastatin increased glutathione (P = .005 and P = .003, respectively) and lowered malondialdehyde in both the endotoxin and oleic acid groups (P = .003 for both). Histopathology revealed that simvastatin protected the lung tissue in both ALI models, but the protection was greater in the endotoxin group. CONCLUSIONS: Pretreatment with simvastatin decreased the severity of ALI in oleic acid and endotoxin ALI models, by decreasing inflammation and oxidative stress.

Systemic administration of interleukin-10 attenuates early ischemic response following spinal cord ischemia reperfusion injury in rats.

BACKGROUND The aim of this experimental study was to investigate the early effects of interleukin-10 (IL-10) and interleukin-1beta antagonist (anti-IL-1beta) against cellular damage, inflammatory reactivity, lipid peroxidation (LPO), and myeloperoxidase (MPO) activity induced by spinal cord ischemia reperfusion injury (IRI). METHODS Thirty-two single strain female Albino rats were divided into four groups: control (sham-operated), IRI-alone, IL-10-treated (100 mug/kg), and anti-IL-1beta-treated (1 mg/kg) groups after IRI. IRI was induced by balloon occlusion of the aorta and simultaneous hypovolemia during occlusion. The animals were sacrificed at 24 h. Histopathological and ultrastructural analyses, biochemical studies for determination of LPO and MPO activity and Comet assays (single cell electrophoresis for detecting DNA single strand breaks) were performed in all study groups. RESULTS Compared with the levels of control (sham-operated) animals, IRI produced a significant increase in the levels of LPO and MPO activity, and prominent tissue damage characterized by leukocyte infiltration, edema and neuronal and glial damage in the affected spinal cord in 24 h. The administration of IL-10 decreased LPO and MPO activity, and suppressed initial inflammatory response in the first 24 h. The effects of anti-IL-1beta were limited to decrease in LPO activity without considerable evidence of cellular preservation. CONCLUSIONS These data suggest that systemic administration of IL-10 attenuates the early ischemic response, and may restrict the tissue damage in the first 24 h after spinal cord ischemia reperfusion injury. Anti-IL-1beta has no considerable effect in this time window. The results of this preliminary study promote further studies with longer time windows on the effects of anti-inflammatory cytokines in spinal cord IRI.

Ureteropelvic junction obstruction causes histologic alterations in contralateral kidney.

BACKGROUND/PURPOSE Ureteropelvic junction (UPJ) obstruction causes histologic alterations both in ipsilateral and contralateral kidney. Because these alterations directly affect the fate of renal damage, definition of these alterations is of utmost importance from the clinical point of view. Thus, an experimental study is designed to determine the alterations of renal histology in response to partial and complete UPJ obstruction. METHODS Fifteen adult female New Zealand rabbits were assigned randomly into 3 groups (each containing 5 rabbits) according to the degree of unilateral UPJ obstruction as group I, sham operation was performed and served as the control group; group II, partial UPJ obstruction was made; group III, complete UPJ obstruction was made. The animals in group I and II were killed after 3 weeks, and animals in group III were killed after 2 weeks. Tissue samples were prepared and processed according to routine light microscopic tissue processing. RESULTS UPJ obstruction led to glomerulosclerosis, dilatation of proximal and distal tubules of loops of Henle, and dilatation of collecting tubes consistent with necrotic and apoptotic changes in ipsilateral kidneys. Severity of these degenerative changes depended on degree of obstruction. UPJ obstruction also led to histologic alterations on the contralateral kidneys such as glomerular edema, congested blood vessels, dilated tubuli, and necrotic and apoptotic changes in epithelia, which were more prominent in group III than group II. CONCLUSIONS It is well known that compensating changes including increased blood flow and parenchymal hypertrophy occurs in contralateral kidney as a response to unilateral UPJ obstruction. However histologic findings of this study confirmed progression of parenchymal damage and presence of apoptosis in contralateral kidney for the first time.

An immunohistochemical evaluation of cell adhesion molecules in human dental pulp after tooth preparation and application of temporary luting cements

OBJECTIVE The aim of this study was to determine if temporary luting cements used with provisional restorations alter the expression of cell adhesion molecules (CAMs) in human dental pulp. STUDY DESIGN Twenty-five healthy human premolars and third molars scheduled to be extracted for orthodontic reasons were randomly assigned to 5 experimental groups. Group 1 included untreated teeth as negative control. In groups 2-5, provisional crowns were cemented to the prepared teeth with either eugenol-containing or eugenol-free temporary cement and extracted 24 or 48 h after the treatment. Expression ratio and staining intensity of CAMs, including E-selectin, P-selectin, intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and platelet endothelial cell adhesion molecule 1 (PECAM-1), was investigated in the pulp samples. The assessment of immunohistochemical reactions was performed by 2 independent observers using a semiquantitative scale. RESULTS Significant reductions were recorded in the expression ratio and/or the staining intensity of E-selectin, ICAM-1, and VCAM-1 in samples removed 48 h after treatment with eugenol-containing cement compared with intact teeth. This reduction was significant only for ICAM-1 for 48-h eugenol-free samples. Moreover, the eugenol-free cement group indicated considerably higher E-selectin, ICAM-1, and VCAM-1 expression compared with the eugenol-containing group (P < .005) 48 h after the application. The PECAM-1 reactivity was similar for all of the experimental groups. CONCLUSION Application of temporary luting cements after tooth preparation for full crown causes alterations in the expression of endothelial CAMs in the dental pulp.

Expression of adhesion and extracellular matrix molecules in the developing human brain

Cell adhesion molecules and extracellular matrix molecules have important roles in cell migration and connection. Their developmental expression has not been fully described in humans. In this report, these molecules were examined by immunohistochemistry in frontal tissue samples from 14- to 28-week-old fetuses aborted for obstetric reasons (n = 20) and four fetuses with nervous system abnormalities. Neural cell adhesion molecule (NCAM), tenascin, and laminin were expressed after 17 weeks. Neural cell adhesion molecule was observed in the neuropil, whereas tenascin and laminin also had cellular and vascular expression. Thrombospondin and fibronectin, apparent after 14 weeks, showed a redistribution from periventricular to outer cortical layers after midgestation. N-cadherin and integrin were observed in mid- and late gestation. Maternal or environmental conditions seemed to influence the pattern of expression. Fetuses with nervous system abnormalities had altered expression of several molecules. The descriptive data obtained in this study might constitute a basis for further studies investigating the role of these molecules in developmental abnormalities of the brain. (J Child Neurol 2002;17:707-713).

Cyclosporine A-induced acute hepatotoxicity in guinea pigs is associated with endothelin-mediated decrease in local hepatic blood flow

AIMS To bring further insight into the mechanism of cyclosporine A (CsA)-induced hepatotoxicity, the acute effect of CsA on local hepatic blood flow (LHBF) and its association with systemic hemodynamics, histopathological and biochemical indicators of liver toxicity were studied in guinea pigs in vivo. The association of endothelin (ET) and/or Cremophor-EL (C-EL, vehicle in parenteral CsA preparation) with CsA effects was also investigated. MAIN METHODS Animals were assigned into five groups; control, CsA, C-EL, Bosentan (non-selective ET receptor antagonist)+CsA, and BQ-123 (ET(A) receptor antagonist)+CsA. CsA was infused intravenously (i.v.) at 20 and 10mg/kg doses by 15 min interval. Antagonists were administered 15 min before CsA infusion. LHBF and mean arterial blood pressure (MAP) changes were simultaneously recorded. Blood and liver samples were collected for biochemical and histopathological examinations. KEY FINDINGS CsA, but not C-EL, decreased LHBF by 53.3% at the end of 30 min. Although being non-significant, CsA slightly increased MAP suggesting that, CsA-induced acute decrease in LHBF was likely independent of MAP changes. Bosentan (5mg/kg, i.v.) and BQ-123 (1mg/kg, i.v.) pre-treatments prevented the CsA-induced decrease in LHBF suggesting that CsA decreases LHBF through an ET-related mechanism. Additionally, CsA, but not its vehicle C-EL, caused marked acute pathological changes in the liver morphology. SIGNIFICANCE CsA-induced findings of acute hepatotoxicity were prevented by bosentan and BQ-123 pre-treatments. Thus, CsA seems to exert acute hepatotoxic effect through ET-related mechanisms.