Birsen Ozyurt

The protective effects of omega − 3 fatty acids against MK-801-induced neurotoxicity in prefrontal cortex of rat

The aims of this study are to investigate the contribution effect of oxidative stress in MK-801-induced experimental psychosis model, and to show that prevention of oxidative stress may improve prognosis. Because oxidative damage has been suggested in the neuropathophysiology of schizophrenia, the possible protecting agents against lipid peroxidation are potential target for the studies in this field. For this purpose, Wistar Albino rats were divided into three groups: the first group was used as control, MK-801 was given to the rats in the second group and MK-801+omega-3 essential fatty acids (EFA) was given to the third group. MK-801 was given intraperitoneally at the dose of 0.5mg/(kgday) once a day for 5 days in experimental psychosis group. In the second group, 0.8g/(kgday), omega-3 FA (eicosapentaenoic acid, 18%, docosahexaenoic acid, 12%) was given to the rats while exposed MK-801. In control group, saline was given intraperitoneally at the same time. After 7 days, rats were killed by decapitation. Prefrontal brain area was removed for histological and biochemical analyses. As a result, malondialdehyde (MDA), as an indicator of lipid peroxidation, protein carbonyl (PC), as an indicator of protein oxidation, nitric oxide (NO) levels and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities as antioxidant enzymes, and xanthine oxidase (XO) and adenosine deaminase (AD) activities as an indicator of DNA oxidation was found to be increased significantly in prefrontal cortex (PFC) of MK-801 group (P<0.0001) compared to control group. In omega-3 FA treated rats, prefrontal tissue MDA, PC and NO levels as well as SOD, GSH-Px, XO, and AD enzyme activities were significantly decreased when compared to MK-801 groups (P<0.0001) whereas catalase (CAT) enzyme activity was not changed. Moreover, in the light of microscopic examination of MK-801 groups, a great number of apoptotic cells were observed. omega-3 FA supplementation decreased the apoptotic cell count in PFC. The results of this study revealed that oxidative stress and apoptotic changes in PFC may play an important role in the pathogenesis of MK-801-induced neuronal toxicity. This experimental study also provides some evidences for the protective effects of omega-3 FA on MK-801-induced changes in PFC of rats.

The activities of liver adenosine deaminase, xanthine oxidase, catalase, superoxide dismutase enzymes and the levels of malondialdehyde and nitric oxide after cisplatin toxicity in rats: protective effect of caffeic acid phenethyl ester.

The aim of this experimental study was to investigate the effects of caffeic acid phenethyl ester (CAPE), an antioxidant agent, on cisplatin-induced hepatotoxicity through adenosine deaminase (AD), xanthine oxidase (XO), catalase (CAT), superoxide dismutase (SOD) activities and malondialdehyde (MDA) and nitric oxide (NO) levels in liver tissue of rats. Wistar albino rats were divided into three groups: control group (n-6), cisplatin group (n-9) and CAPE+cisplatin group (n-8). All the chemicals used were applied intraperitoneally. Spectrophotometric methods were used to determine the activities of the above-mentioned enzymes in the liver tissue. NO level and XO activity were found to be increased in the cisplatin group compared to the control group. NO level was found to be decreased in the cisplatin+CAPE group in comparison with the cisplatin group. There was no significant change in the activity of XO between the cisplatin and cisplatin+CAPE groups. The activity of SOD was lower in the cisplatin group than both the control and cisplatin+CAPE groups. There was no significant change in the activity of CAT between the control and cisplatin groups. CAT activity was increased in the cisplatin+CAPE group compared to the cisplatin group. The AD activity and MDA level remained unchanged in all groups. The results obtained suggested that CAPE significantly attenuated the hepatotoxicity as an indirect target of cisplatin in an animal model of cisplatin-induced nephrotoxicity.

Hypothalamic superoxide dismutase, xanthine oxidase, nitric oxide, and malondialdehyde in rats fed with fish ω-3 fatty acids

Phospholipids located in the cellular membrane play a critical role in the fluid-mosaic model of membrane structure and membrane function. Evidence is mounting for the role of abnormal phospholipid metabolism in some neuropsychiatric disorders including schizophrenia. As an important essential fatty acid (EFA), omega-3 (omega-3) fatty acid series are found in large amounts in fish oil. The aim of this experimental study was to assess the changes of some of the oxidant and antioxidant parameters in the hypothalamus of rats fed with omega-3 EFA diet (0.4 g/kg/day) for 30 days. Eight control rats and nine rats fed with omega-3 were decapitated under ether anesthesia, and hypothalamus was removed immediately. Malondialdehyde (MDA) and nitric oxide (NO) levels as well as superoxide dismutase (SOD) and xanthine oxidase (XO) enzyme activities in the hypothalamus were measured. SOD activity was significantly decreased in omega-3 EFA treated group compared to control group (p < 0.014). Tissue MDA and NO levels were also decreased in omega-3 EFA treated group compared to control rats (p < 0.0001). Xanthine oxidase activity was found to be increased in omega-3 EFA treated rats when compared to the control group (p < 0.0001). Taken together, this preliminary animal study provides strong support for a therapeutic effect of omega-3 EFA in some neuropsychiatric disorders in which reactive oxygen species (ROS) are recently accused to be an important physiopathogenetic factor.

Effect of prenatal exposure to diclofenac sodium on Purkinje cell numbers in rat cerebellum: a stereological study.

Diclofenac sodium (DS) is commonly used as a non-steroidal anti-inflammatory drug. Although several adverse effects are clearly established, it is still unknown whether prenatal exposure to DS has an effect on the development of the cerebellum. In this study, we investigated the total number of Purkinje cells of the cerebellum in a control group and in a DS-treated group of male rats using a stereological method. The DS in a dose of 1 mg/kg daily was intraperitoneally injected to the drug-treated group of pregnant rats beginning from the 5th day after mating for a period of 15 days during pregnancy. Physiological serum at 1 ml dose was intraperitoneally injected to the control group of pregnant rats at the same period. After delivery, male offspring were obtained and each main group was divided into two subgroups that were 4-week-old (4W-old) and 20-week-old (20W-old). Our results showed that the total number of Purkinje cells in offspring of drug-treated rats was significantly lower than in the offspring of control animals. These results suggest that the Purkinje cells of a developing cerebellum may be affected by administration of DS during the prenatal period.

Protective effects of caffeic acid phenethyl ester on skeletal muscle ischemia-reperfusion injury in rats

There is a great evidence that reactive oxygen species (ROS) play an important role in the pathophysiology of ischemia −reperfusion(I/R)injury in skeletal muscle.Caffeic acid phenethyl ester(CAPE)is a component of honeybeep ropolis.It has antioxidant, anti−inflammatory and free radical scavenger properties.The aim of this study is to determine the protective effects of CAPE against I/R injury in respect of protein oxidation, neutrophil in filtration, and the activities of xanthine oxidase(XO)and adenosine deaminase(AD)onan<invivomodel of skeletal muscle I/R injury.Rats were divided into three equal groups each consisting of sixrats:Sham operation, I/R, and I/R plus CAPE(I/R+CAPE)groups.CAPE was administered intraperitoneally 60 min before the beginning of the reperfusion.At the end of experimental procedure, blood and gastrocnemius muscle tissues were used for biochemical analyses.Tissue protein carbonyl(PC)levels and the activities of XO, myeloperoxidase(MPO) and AD in I/R group were significantly higher than that of control(p0.01, p0.05, p0.01, p0.005, respectively).Administration of CAPE significantly decreased tissue PC levels, MPO and XO activities in skeletal muscle compared to I/R group(p0.01, p0.05, p0.05, respectively).In addition, plasma creatine phosphokinase(CPK), XO and ADactivities were decreased in I/R+CAPE group compared to I/R group(p0.05, p0.05, p0.001). The results of this study revealed that free radical attacks may play an important role in the pathogenesis of skeletal muscle I/R injury. Also, the potent free radical scavenger compound, CAPE, may have protective potential in this process. Therefore, it can be speculated that CAPE or other antioxidant agents may be useful in the treatment of I/R injury as well as diffused traumatic injury of skeletal muscle.

Oxidative stress in prefrontal cortex of rat exposed to MK-801 and protective effects of CAPE

MK-801 was shown to be one of the most neurotoxic non-competitive NMDA receptor antagonists. It is known that repeated injection of MK-801 was proposed in an animal model in psychosis. The aims of this study are to investigate the contributing effect of oxidative stress in MK-801-induced experimental psychosis model, and to show that prevention of oxidative stress may improve prognosis. Furthermore, there is evidence that oxygen free radicals play an important role in the pathophysiology of schizophrenia. In this study, Wistar Albino rats were divided into three groups: 1st group: Control, 2nd group: MK-801, 3rd group: MK-801+CAPE (Caffeic acid phenethyl ester) group. MK-801 was given intraperitoneally at the dose of 0.5 mg/kg/day for 5 days. CAPE was given to the treatment group while exposed to MK-801. In control group, saline was given intraperitoneally at the same time. After 7 days, rats were killed by decapitation. Prefrontal cortex (PFC) of rats was removed for biochemical and histological analyses. As a result, malondialdehyde (MDA), protein carbonyl (PC), nitric oxide (NO) levels and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and xanthine oxidase (XO) and adenosine deaminase (AD) enzyme activities were found to be increased significantly in prefrontal cortex (PFC) of MK-801 group (p<0.0001) compared to control group. In CAPE treated rats, prefrontal tissue MDA, PC, NO levels and, GSH-Px, XO, AD enzyme activities were significantly decreased when compared to MK-801 groups (p<0.0001) whereas catalase (CAT) enzyme activity was not changed. Moreover, in the light of microscopic examination of MK-801 groups, a great number of apoptotic cells were observed. CAPE treatment decreased the apoptotic cell count in PFC. The results of this study showed that MK-801-induced neurotoxicity caused oxidative stress in PFC of rats. This experimental study may also provide some evidences for the new treatment strategies with antioxidants in schizophrenia.

Prenatal exposure to diclofenac sodium changes the morphology of the male rat cervical spinal cord: a stereological and histopathological study.

Diclofenac sodium is one of the most commonly used non-steroidal anti-inflammatory drugs. It may cause alteration in the nervous system during neuronal development. However, there is no investigation concerning its role in the cervical spinal cord. Pregnant rats were divided into two groups, namely drug-treated and control (saline-injected) groups. To obtain the offspring of the drug-treated group, a dose of 1mg/kg daily diclofenac sodium (Voltaren, 75 mg/3 ml ampoule, Novartis) was injected into the pregnant rats beginning from the 5th day after mating to the 20th day of the pregnancy. To obtain the control group of offspring, serum physiological at a 1 ml/kg daily dose was injected into the pregnant control rats during the same period. Male offspring were obtained after delivery and each group was divided into two subgroups: 4-week-old and 20-week-old. The total neuron number in diclofenac sodium-treated rats was significantly lower than in the control group animals. The total volume of the cervical spinal cord segments (C1-C4) was also estimated. There was a significant difference between the volumes of the two groups, especially in the 20-week-old subgroup. This may suggest that development of neurons and volume of cervical spinal cord are affected in prenatal animals after administration of diclofenac sodium.

Aquaporin-1 and Aquaporin-3 Expressions in the Intervertebral Disc of Rats with Aging

OBJECTIVE The intervertebral disc (IVD) undergoes biochemical and morphologic degenerative changes during the process of aging. Aquaporins (AQPs) are a family of water channel proteins that facilitate water and small solute movement in tissues and may have a potential role in the aging degeneration of IVDs. One of the important problems in understanding disc degeneration is to find cellular molecules which contribute to the pathogenesis of IVDs. XThe aim of this study was to demonstrate the expression of aquaporin 1 and 3 in nucleus pulposus (NP), annulus fibrosus (AF) cells of rat lumbar intervertebral discs from both young and aged animals using immunohistochemistry. MATERIAL AND METHODS Twenty Wistar-albino rats were included in the study. The rats were separated into two groups: 2-month-old rats (n=10) as the young group, 18-month-old rats (n=10) as the old group. The intervertebral disc tissues obtained from the lumbar spine (L1-L4, 4 discs) were used for immunohistochemical staining of AQP-1 and 3. RESULTS This study demonstrated that AQP-1 and AQP-3 immunoreactivity significantly decreased in NP and AF of aged rats compared to the young rats. CONCLUSION We suggest that AQP-1 and 3 may contribute to the age related degeneration of the intervertebral disc.

Protective effects of thymoquinone and melatonin on intestinal ischemia-reperfusion injury.

Background/Aim: In the present study, we aimed to compare the potential protective effects of thymoquinone and melatonin by using equivalent dose, on oxidative stress-induced ischemia–reperfusion (IR) injury in the intestinal tissue of rats. Materials and Methods: The study was performed using 32 male Wistar–Albino rats (weighing 180–200 g) randomly divided into four groups: Group I, sham group; Group II, IR group; Group III, IR with melatonin group; and Group IV, IR with thymoquinone group. After laparotomy, ischemia and reperfusion were performed for 60 and 120 min, respectively, on all the groups. Intestinal tissue sections were stained using routine histological methods and examined under the light microscope. In addition, the sections were immunohistochemically stained using the TUNEL method for determination of apoptosis. Superoxide dismutase (SOD) activity, glutathione peroxidase (GSH-Px) activity, and malondialdehyde (MDA) levels in the intestinal tissue were also measured. Results: The IR group had significantly elevated tissue SOD activity, GSH-Px activity, and MDA levels compared with the sham group. Administration of thymoquinone and melatonin efficiently reduced these increases. Statistically significant number of apoptotic cells was observed in the intestinal tissue of IR group rats compared with the sham group. Treatment with thymoquinone and melatonin markedly reduced the number of apoptotic cells. Conclusion The effects of melatonin and thymoquinone on IR-induced oxidative stress in rat intestines were similar. Our findings suggest that melatonin and thymoquinone protect against IR-induced injury to intestinal tissues.

Stereologic analysis of bone produced by distraction osteogenesis or autogenous bone grafting in mandible.

To our knowledge, in the literature, any other investigation that numerically compared osteoblasts retrieved from transport distraction osteogenesis and bone grafting procedures using stereological methods is not reported. The purpose of this study was to compare the total number of osteoblast cells at 3 months in bone produced by distraction osteogenesis and that in autogenous bone graft. A total of 19 growing sheep (male aged 7 or 8 mo; weighing between 21 and 28 kg) were used in this study. Mandibular discontinuity defects created in mandibles of sheep were reconstructed by transport distraction osteogenesis and iliac crest bone graft and allowed to heal for 3 months. The animals were then killed, and the jaws were resected and prepared to be decalcified. Stereological and histologic examinations were performed. Intramembranous ossification and osteoid and trabecular formations were observed in both groups. In the distraction group, the mean ± standard deviation (SD) numerical density of the osteoblasts was found to be higher (0.0004866 ± [0.000044])when compared with those of both the graft (0.0003458 ± [0.000030]) and control groups (0.0002714 ± [0.000022]). Statistically significant differences were found among the groups (P < 0.05). Stereologic evaluation of bone in the sheep model demonstrated significantly greater osteoblast density in bone formed through transport distraction osteogenesis when compared with bone grafting and the control. Therefore, further studies should be conducted to evaluate the differences in both osteoblastic and osteoclastic cellular activities at different time points in distraction osteogenesis and autogenous bone grafting to assess the healing process of bone for clinical applications.