Altug Yavasoglu

Evaluation of skin permeation and anti-inflammatory and analgesic effects of new naproxen microemulsion formulations

The aim of this study was to evaluate the potential application of microemulsions as a transdermal drug delivery for naproxen (Np). The pseudo-ternary phase diagrams were developed for microemulsions composed of isopropyl myristate, Span 80, Labrafil M, Labrasol, and Cremophor EL, ethanol and isopropyl alcohol and 0.5N sodium hydroxide. The final concentration of Np in microemulsion systems was 10% (w/w). The microemulsions were characterised by conductivity, droplet size, viscosity and pH. Moreover, in vitro permeability studies were performed using diffusion cells from rat skin. The permeation rates of Np from microemulsions (M1(Np) and M2(Np)) were higher than the commercial (C) gel formulation. The paw oedema test was performed in rats to evaluate the anti-inflammatory activity of Np. The volume increase in paw oedema after 6hr was 0.71±0.46% with M2(Np), whereas M1(Np) and C exhibited 6.48±2.71% and 14.97±3.15% increases in oedema, respectively. Additionally, a significant analgesic effect was detected in the hot plate and tail-flick tests for all test microemulsion and C formulations when compared with the control. Histopathological examination of the treated skin was performed to investigate changes in skin morphology. In conclusion, the microemulsion formulations, especially the M2(Np) formulation, may be used as an effective alternative for the transdermal delivery of Np.

Pinealectomy exaggerates and melatonin treatment suppresses neuroma formation of transected sciatic nerve in rats: gross morphological, histological and stereological analysis

Abstract:  At present, an intensive effort for prevention of neuroma formation following peripheral nerve section continues. It has been recently suggested that surgical pinealectomy (Px) induces elevation of the collagen content in the granulation tissue of a wound, while melatonin application after Px suppresses elevation of the collagen accumulation in the tissue. The aim of the present study was to assess whether melatonin had the ability to suppress collagen production and neuroma formation following peripheral nerve transection. A total of 40 male rats (four groups of 10) were left intact (intact controls) or sham operated (sham group), were Px, or were Px and given melatonin (Px + melatonin group). All animals underwent a surgical intervention consisting of right sciatic nerve neurectomy. After 4 wk, the animals were killed following intracardiac perfusion. Gross morphology of neuroma formation in the proximal nerve segment was examined and proximal neuroma evaluated. Macroscopic and microscopic findings revealed that Px caused a proliferation of connective tissue and large neuroma formation at the proximal ends of transected nerves. Stereological analysis showed that there was a statistically significant reduction in connective tissue content of the same region in Px animals treated with melatonin (P < 0.005). The results achieved in a rodent model of sciatic nerve neuroma formation showed that there was a positive correlation between macroscopic and microscopic observations, and that melatonin enhanced axonal regeneration presumably due to its inhibitory effect on neuroma formation.

Toxic effects of anatoxin-a on testes and sperm counts of male mice.

Anatoxin-a, a potent neurotoxin, is one of a number of toxins produced by cyanobacteria especially some strains of Anabaena. Toxic cyanobacteria are found worldwide in inland and coastal water environments. The present study was performed to evaluate the toxicity of anatoxin-a on testes and sperm counts of male mice. The animals of the treatment groups were administered with 50, 100 and 150microg/kg/day anatoxin-a for seven consecutive days by intraperitoneal (i.p.) route. Although there were no significant changes in body weight gain, and absolute and relative testes weights, absolute and relative weights of cauda epididymis reduced significantly in the 100 and 150microg/kg groups when compared with control group. The number of sperm count in cauda epididymis was reduced dose dependently in all treatment groups compared with control animals. Anatoxin-a caused dose-dependent histopathological changes in the testes of mice such as degenerations in seminiferous tubules, intercellular disassociation of spermatogenetic cell lines, sloughing of germ cells into tubular lumen, vacuolisation in Sertoli cells and loss of germ cells. The epithelial thickness of seminiferous tubules decreased significantly in all treatment groups in a dose-dependent manner.

Effects of Preservatives in Nasal Formulations on the Mucosal Integrity: An Electron Microscopic Study

The preservatives benzalkonium chloride (BZC) and potassium sorbate (PS) are widely used in the formulation of nasal drops and cosmetics. Recently, a number of side effects that resulted from mucosal irritation caused by BZC and PS have been reported. Therefore, this study was performed to investigate the possible clinical and histological alterations induced by in vivo administration of these preservatives to the nasal mucosa of rats. 0.01% BZC and 0.12% PS were administered to the nostrils of male rats for 1 or 4 weeks. Clinical symptoms were recorded during the treatment, and light and electron microscopic examinations were carried out on samples taken from one third central and lower regions of the noses at the end of the treatment periods. Symptomatic changes such as sneezing and nasal rubbing were observed in almost all groups, starting from the 6th day of administration. Light and electron microscopy showed histological changes and nasal lesions induced by the preservatives. The symptomatic and histological changes were more pronounced with prolonged duration of administration. Therefore, it has been concluded that in vivo administration of the preservatives BZC and PS may be irritant to the respiratory epithelium of rats.

Protective effect of oxytocin on ovarian ischemia-reperfusion injury in rats

Oxytocin (OT), a neurohypophysial nonapeptide, plays dual role as a neurotransmitter/neuromodulator and a hormone. It has also well known protective properties against ischemia/reperfusion organ damage. This study investigated the effect of OT on experimentally induced ovarian torsion/de-torsion ischemia/reperfusion (I/R) injury in rats. Sprague-Dawley rats were assigned to five treatment groups (n=7/group): Group 1, sham-operated; Group 2, torsion; Group 3, 80 IU/kg of OT administration 30 min prior to torsion; Group 4, torsion/de-torsion; and Group 5, torsion followed by 80 IU/kg of OT administration 30 min prior to de-torsion. OT administration significantly decreased the tissue malondialdehyde (MDA) levels in both the torsion and OT group (Group 3), and torsion/de-torsion OT group (Group 5) in comparison with the torsion-only group (Group 2) and torsion/de-torsion group (Group 4). Histopathological finding scores including follicular degeneration, edema, hemorrhage, vascular congestion, and infiltration by inflammatory cells were found to be significantly decreased in the torsion and OT group (Group 3), and torsion/de-torsion OT group (Group 5) when compared with the torsion-only group (Group 2) and torsion/de-torsion group (Group 4). In conclusion, these results, verified with histopathologic evaluation and biochemical assays, suggest a probable protective role for OT in ischemia and I/R injury in rat ovaries.

Cholecalciferol (vitamin D 3) improves cognitive dysfunction and reduces inflammation in a rat fatty liver model of metabolic syndrome

AIM The aim of this study was to examine the effects of cholecalciferol on systemic inflammation and memory in the setting of fatty liver disease in rats. MATERIALS AND METHODS To induce the development of fatty liver disease, the rats were fed a 35% fructose solution over 8 weeks. Group I (n=6) was designated as the control group and fed with standard rat chow. Group II (n=6) was provided with, standard rat chow, and 0.3 μg/kg/day of oral cholecalciferol over a duration of 2 weeks. In addition to standard rat chow, group III (n=6) and group IV (n=6) were given 4 mL of the 35% fructose solution per day via oral gavage for 8 weeks. However, group IV was also given 0.3 μg/kg/day of oral cholecalciferol over 2 weeks. After the treatment period, passive avoidance tasks were performed by all groups. The liver and brain were harvested for subsequent biochemical and histopathologic analyses. KEY FINDINGS The development of fatty liver extends the memory latency period of passively avoiding tasks after 1 trial. Moreover, there were increases in brain TNF-α and plasma MDA levels according to two-way analysis of variance. Cholecalciferol supplementation decreased the latency period of passively avoiding tasks in rats with hepatosteatosis, and also significantly reduced brain TNF-α and plasma MDA levels. SIGNIFICANCE Fatty liver may contribute to the development of systemic inflammation, which affects cognition and causes deficits in memory; however, the anti-inflammatory and antioxidant properties of vitamin D may improve the cognitive function of rats with hepatosteatosis.

The effects of sunitinib on endometriosis

Abstract The aim of the present study was to evaluate the effect of sunitinib on endometriotic implants and adhesions in a rat endometriosis model. An experimental endometriosis model was created in 21 rats. These rats were randomly divided into three groups: Group 1 (control group, 7 rats) was given no medication; Group 2 (sunitinib group, 7 rats) was given 3 mg/kg per day of oral sunitinib; and Group 3 (danazol group, 7 rats) was given 7.2 mg/kg per day of oral danazol. The volume of endometriotic implants was calculated. The extent and severity of adhesions were evaluated. The groups were compared by the Students t-test, analysis of variance (ANOVA) and the Mann–Whitney U test. There was no statistically significant difference in the mean volume of endometriotic implants before medication between three groups. The volume of implants and extent, severity, total score of adhesions were significantly decreased after medication in Group 2 and Group 3. We noted that the volume of the endometriotic implants and adhesion formation were decreased both after sunitinib and danazol treatment. As a result, sunitinib seems to be effective for endometriotic peritoneal lesions. The effects of sunitinib in rat models give hope for improving the treatment of human endometriosis and prevention of pain symptoms.

Effects of Resveratrol on Ovarian Morphology, Plasma Anti-Mullerian Hormone, IGF-1 Levels, and Oxidative Stress Parameters in a Rat Model of Polycystic Ovary Syndrome

Objective: To evaluate the effects of resveratrol in a rat model of polycystic ovarian syndrome (PCOS). Study Design: After PCOS model was formed by subcutaneous dihydrotestosterone pellets, rats were randomly divided into 2 groups. The first group (n = 7) was treated with 1 mL/kg/d isotonic saline and the second group (n = 7) was treated with 10 mg/kg/d resveratrol. Seven rats were taken as controls without any medication. Results: Our results showed (1) significant reduction in the number of antral follicle counts (P < .01); (2) significantly decreased plasma anti-Mullerian hormone and insulin-like growth factor 1 levels (P < .01 and P < .05, respectively); (3) significantly lower superoxide dismutase activity (P < .05); and (4) significantly increased glutathione peroxidase content (P < .01) following resveratrol treatment. Conclusion: Resveratrol appears to be effective in the treatment of PCOS due to its antioxidant properties. Future clinical studies with different dosages might provide useful implementations to our practice.

Determination of nitric oxide synthase activity and apoptosis of germ cells in different obstruction models.

We aimed to determine the changes of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) immunoreactivity and apoptosis after proximal and distal obstruction models on ipsilateral and contralateral testicular tissues. Male albino Wistar rats were randomly divided into three groups (n=30): a control group which underwent sham operations (n=10), a unilateral vasal ligation (n=10) and a unilateral epididymal ligation group (n=10). iNOS and eNOS distribution and apoptosis were studied in both ipsilateral and contralateral testes using quantitative immunohistochemistry. Nitric oxide synthase activity was significantly affected in ipsilateral and contralateral testes cells after vasal and epididymal ligation. eNOS immunoreactivity increased markedly after ipsilateral vasal ligation (ILVL). Degeneration-related changes were also associated with changes in apoptotic rate. Analysis using the terminal dUTP nick end-labeling TUNEL method revealed that apoptotic cell numbers significantly increased after ILVL. p53 and bcl-2 immunoreactivity increased in both experimental groups compared with the sham-operated group. Changes in iNOS and eNOS immunolocalisation were strongly associated with cell damage, because germ cell degeneration was more prominent in the ILVL group. Altered p53 immunolocalisation was also associated with cell degeneration, and a rise in bcl-2 immunoreactivity might be considered to reflect a protective mechanism in the testis. These cellular changes could enlighten understanding of the interaction between testicular functioning and damage.

Montelukast prevents ischaemia/reperfusion-induced ovarian damage in rats

OBJECTIVE To investigate the efficacy of montelukast for prevention of ischaemia/reperfusion (I/R) injury in rat ovary. STUDY DESIGN Twenty-four female adult rats were included in the study. I/R injury was induced by CO2 pneumoperitoneum in a laparoscopic rat model. The rats were divided at random into three groups: the sham group was subjected to catheter insertion but was not subjected to pneumoperitoneum; the saline group was subjected to 60 min of pneumoperitoneum and 30 min of reperfusion, with 1 mg/kg physiological saline administered 10 min before pneumoperitoneum; and the montelukast group was subjected to 60 min of pneumoperitoneum and 30 min of reperfusion, with 20mg/kg montelukast administered 10 min before pneumoperitoneum. Damage to ovarian tissue was scored by histopathological evaluation. Caspase-3 expression was determined immunohistochemically. Ovarian tissue levels of malondialdehyde and glutathione, and plasma total antioxidant capacity were measured biochemically. RESULTS In comparison with the sham group, ovarian sections in the montelukast group had higher scores for follicular degeneration and oedema (p<0.001). Montelukast treatment prevented tissue damage in ovaries, and this result was significant. Caspase-3 expression was only observed in ovarian surface epithelium in the saline and montelukast groups. However, the mean caspase-3 expression score was higher in the saline group than the montelukast group (p<0.001). Tissue levels of malondialdehyde were higher in the montelukast group than the sham group, but plasma total antioxidant capacity and tissue levels of glutathione were significantly lower. Pretreatment with montelukast reduced lipid peroxidation (p<0.005) and improved antioxidant status in rats (p<0.001). CONCLUSION Montelukast is effective for the prevention of I/R-induced damage in rat ovary.