Effect of prenatal exposure to an anti-inflammatory drug on neuron number in cornu ammonis and dentate gyrus of the rat hippocampus: A stereological study

Prenatal exposure to oxcarbazepine increases hippocampal apoptosis in rat offspring

This study assessed apoptosis in the offspring of rats exposed to oxcarbazepine (OXC) from day 7 to 15 of gestation. Three groups of pregnant Wistar rats were used: 1) Control, treated with saline solution; 2) treated with 100 mg/kg OXC; 3) treated with 100 mg/kg of carbamazepine (CBZ, as a positive control for apoptosis); the route of administration was intragastric. Apoptosis was detected at three postnatal ages using the TUNEL technique in the CA1, and CA3 regions of the hippocampus and in the dentate gyrus (DG); neurogenesis was assessed in the DG using an antibody against doublecortin. The litter characteristics were recorded. OXC increased apoptosis in all regions (p < 0.01) at the three ages evaluated. Lamination disruption occurred in CA1 and CA3 due to the neuron absence and to ectopic neurons; there were also malformations in the dorsal lamina of the DG in 38% and 25% of the pups born from rats treated with OXC and CBZ respectively. CBZ also increased apoptosis. No clear effect on neurogenesis in the DG was observed. The size of the litter was smaller (p < 0.01) in the experimental groups. Nineteen-day OXC fetuses had low weight (p < 0.01), but 21 and 30 postnatal days old CBZ and OXC pups were overweight (p < 0.01). The results demonstrate that OXC administered during gestation is pro-apoptotic, alters the cytoarchitecture of the hippocampus, reduces litter size, and probably influences postnatal weight. We provide evidence of the proapoptotic effect of CBZ when administered early in gestation.

The effect of maternal treatment with diclofenac sodium and thymoquinone on testicular parameters in rat offspring

INTRODUCTION AND OBJECTIVE

Diclofenac sodium (DS) can have toxic effects on various tissues and organs, as well as causing foetal and new-born malformations. Thymoquinone (TQ), the basic bioactive compound of black seed oil, is an antioxidant and antineoplastic substance. The aim of our study was to explore the effects of DS and TQ exposure during gestation on offspring rat testicular histology.

MATERIALS AND METHODS

Mother pregnant rats were divided into five groups: control, saline, DS, TQ and DS plus TQ (DS+TQ) four animals for each group. They were then treated as follows between day of 5 and 15 of gestation: the control group received no treatment. The saline group received physiological saline (1mg/kg/d) via the intraperitoneal (IP) route; the DS group received an intramuscular (IM) injection of DS (6.1mg/kg/d); the TQ group received TQ (5mg/kg/d) dissolved in drinking water; and the DS+TQ group received DS (6.1mg/kg/d) and TQ (5mg/kg/d) dissolved in water. After birth, the male rats were fed for four weeks, and at the end of this period offspring were sacrificed. Stereological methods, physical disector and Cavalieri principle were used for particle counting and volume estimation respectively.

RESULTS

The results revealed a significant decrease in the total number of Sertoli and Leydig cells in 4-week-old rats in the DS group (p<0.05), and TQ not have provide protection against this adverse effect of DS.

CONCLUSIONS

In this study, DS at a dose of 6.1mg/kg, equivalent to a dose of 1mg/kg in humans, decreased the number of Sertoli and Leydig cells, and TQ did not have a protective effect against the adverse effect of DS during the gestation period. These results show that new dose depend studies on TQ and DS interaction are requested to see protective effect of TQ.

Prenatal exposure of diclofenac sodium alters the behavioral development of young Wistar rats

Diclofenac sodium (DS), a potent inhibitor of cyclooxygenase, reduces the release of arachidonic acid and formation of prostaglandins. Being a nonsteroid drug that shows antiinflammatory action, the possible side effects of fetal DS administration gain importance in public and medical applications. Herein, the effects of DS administration (1 mg/kg) during gestational days 5–20 were investigated on the performance of Wistar rat pups in a variety of behavioral tasks. Four-week-old pups were subjected to sensory motor tests, a plus maze, an open field, the Morris water maze, and a radial arm maze. Fetal DS disrupted some sensory motor performances, such as visual placing and climbing in both females and males. In the open field, DS females had a higher level of anxiety and male DS pups habituated to the environment slowly compared to controls. The DS pups showed slower rates of learning, whereas no substantial between-group differences were found in the performance of spatial memory compared to both controls. Furthermore, working memory was negatively affected by fetal DS. In conclusion, it was indicated that DS administration during pregnancy had slight behavioral impacts with a delay in learning and a defect in the short-term memory in juvenile rats.

Biotoxicity of diclofenac on two larval amphibians: Assessment of development, growth, cardiac function and rhythm, behavior and antioxidant system

The non-steroidal anti-inflammatory drug diclofenac (DCF) threatens the health of aquatic animals and ecosystems. In the present study, different biological endpoints (mortality, development and growth, abnormalities, cardiotoxicity, neurotoxicity and antioxidant system) were used to characterize the acute and chronic effects of DCF (at concentrations ranging between 125 and 4000 μg L^-1) on two amphibian species from Argentina (Trachycephalus typhonius and Physalaemus albonotatus). Results showed that the larval developmental, growth rates, and body condition of DCF-exposed individuals of both species were significantly reduced. DCF-exposed individuals also showed several morphological abnormalities, including significantly altered body axis, chondrocranium and hyobranchial skeleton, and organ and visceral abnormalities including cardiac hypoplasia, malrotated guts, asymmetrically inverted guts, and cholecystitis. DCF also had a significant effect on the swimming performance of both species: at low concentrations (125 and 250 μg L^-1), swimming distance, velocity and global activity decreased, whereas, at high concentrations (1000 and 2000 μg L^-1), these behavioral responses increased. Regarding cardiac function and rhythm, at DCF concentrations higher than 1000 μg L^-1, the heart frequency and ventricular systole interval of both species were significantly reduced. Regarding the antioxidant system, the activity of acetylcholinesterase indicated that DCF is neurotoxic and thus related to the changes in behavioral performance. The DCF concentrations studied produced a biochemical imbalance between radical oxygen species production and antioxidant systems. The sensitivities to sublethal and chronic DCF exposure in both anuran species were similar, thus indicating the inherent complexity involved in understanding the biotoxic effects of DCF.

Peripheral nerve and diclofenac sodium: Molecular and clinical approaches

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most frequently prescribed medications worldwide. Diclofenac sodium (DS), one of these NSAIDs, has a high specificity for arachidonic acid-degrading cyclooxygenase (COX)-2 enzymes. This drug can be used to relieve neuropathic pain. In this review, we examine the relevant researches, including in vivo, animal, and clinical human studies, with the aim of understanding the effect of DS on the peripheral nerves. In injured nerves, COX-2 is potently upregulated around the injury site. When a nerve is damaged, both COX-1 and COX-2 expression is increased in macrophages and Schwann cells. In addition, COX inhibitors can promote axonal outgrowth in cultured neurons. Neuropathic pain occurs after injury and leads to dysfunction of the peripheral nervous system. NSAIDs can modulate the nociceptive and inflammatory pain pathways and control neuropathic pain. DS may accelerate nerve regeneration and its effects on healing, as well as causing deleterious effects in the developing nerves. DS teratogenicity disrupts myelin sheath thickness and axon structure. Understanding the possible benefits and limitations of DS and specific conditions such as prenatal use will be of benefit in clinical practice.

The neuroprotective effect of melatonin on the hippocampus exposed to diclofenac sodium during the prenatal period

Melatonin (Mel) has strong antioxidant properties since it is a direct scavenger of oxygen-based free radicals and related species. The main aim of this study is to show whether the effects of Mel can prevent the potential adverse effects of diclofenac sodium (DS), used as a non-steroidal anti-inflammatory drug (NSAID) during the prenatal period, on the newborn experimental rat brain tissues using stereological methods Twenty-four male 12-week old Wistar albino rats were used. The study involved four groups (each containing six rats), those exposed, during the prenatal period, to saline 1ml/kg (Saline group), to diclofenac sodium 3.6mg/kg (DS group), or to diclofenac sodium+melatonin 50mg/kg (DS+Mel group), and a control group (Cont group). At the end of the experiment, the brains were removed from the cranium for histological and stereological analyses. Cell loss in the hippocampus exposed to DS was observed compared to the Cont group (p<0.01), and a similar side-effect was also seen in the Saline group (p<0.01). However, there was no significant difference in cell numbers between the Cont and DS+Mel groups (p>0.05). These results suggest that exposure to DS during pregnancy causes a decrease in the number of cells in the hippocampus and dentate gyrus in the postnatal period. Using Mel, a neuroprotective agent, reduced the toxic effects of DS.

Prenatal exposure to low-dose diclofenac sodium does not affect total neuron numbers in spinal segment T13 in rats

The main purpose of the present study was to investigate the effects of diclofenac sodium (DS) on the total number of neurons in segment T13 of the spinal cord of offspring of pregnant rats using stereological methods. Eighteen adult female Wistar albino rats weighing 150-200g were used. Pregnant female rats were divided into three groups; a control group, a sham group and a DS (1mg/kg, intramuscular) exposed group. The DS and sham groups received injection from the 5th day of gestation to the 19th. Twenty eight days after birth, the offspring rats were perfused with 4% buffered formalin. T13, which is one of transverse spinal cord segments, were isolated and processed for routine paraffin histology. 5μm sections were obtained using a rotary microtome according to systematic random sampling strategies. Every 40th section was taken and sections were stained with modified Giemsa. All types of motor neuron cell were identified according to their morphology. In this study, the "disector-Cavalieri combination" method was used in the stereological examination of neurons. The motor neurons were counted in the right gray matter of the ventral horn in the spinal cord segment. The Kruskal-Wallis test was used for comparison the groups. In terms of motoneuron number, no significant difference among the groups was found (p>0.05). In conclusion, our results indicated that prenatal exposure to DS has no effect on the total number of motor neuron of the offspring rats.

Evaluation of developmental toxicity and teratogenicity of diclofenac using Xenopus embryos

Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) with analgesic and anti-pyretic properties. This compound is therefore used to treat pain, inflammatory disorders, and dysmenorrhea. Due to its multimodal mechanism of action and ability to penetrate placenta, diclofenac is known to have undesirable side effects including teratogenicity. However, limited data exist on its teratogenicity, and a detailed investigation regarding harmful effects of this drug during embryogenesis is warranted. Here, we analyzed the developmental toxic effects of diclofenac using Xenopus embryos according to the Frog Embryo Teratogenesis Assay-Xenopus (FETAX) protocol. Diclofenac treatment exerted a teratogenic effect on Xenopus embryos with a teratogenic index (TI) value of 2.64 TI; if this value is higher than 1.2, the cut-off value indicative of toxicity. In particular, mortality of embryos treated with diclofenac increased in a concentration-dependent manner and a broad spectrum of malformations such as shortening and kinking of the axis, abdominal bulging, and prominent blister formation, was observed. The shape and length of internal organs also differed compared to the control group embryos and show developmental retardation on histological label. However, the expression of major tissue-specific markers did not change when analyzed by reverse transcription-polymerase chain reaction (RT-PCR). In conclusion, diclofenac treatment can promote teratogenicity that results in morphological anomalies, but not disrupt the developmental tissue arrangement during Xenopus embryogenesis.

Evaluation of neuroprotection by melatonin against adverse effects of prenatal exposure to a nonsteroidal anti-inflammatory drug during peripheral nerve development

The potential ability of melatonin to protect against impairment of the fetal peripheral nerve system due to maternal consumption of diclofenac sodium (DS) was investigated. Eighty-four pregnant rats were divided into seven groups: control (CONT), saline administered (PS), DS administered (DS), DS with low-dose melatonin administered (DS+MLT10), DS with high-dose melatonin administered (DS+MLT50), low-dose melatonin administered (MLT10), and high-dose melatonin administered (MLT50). After the pregnancy, six male newborn rats from each group were sacrificed at 4 and 20 weeks of age. Their right sciatic nerves were harvested, and nerve fibers were evaluated using stereological techniques. Mean numbers of myelinated axons, axon cross-section areas and the mean thickness of the myelin sheet were estimated. Four-week-old prenatally DS-exposed rats had significantly fewer axons, a smaller myelinated axonal area, and a thinner myelin sheath compared to CONT group (p<0.05). Although melatonin at both doses significantly increased axon numbers, only a high dose of melatonin increased the diameter of those axons (p<0.05). At 20-weeks of age, myelinated axon number in the DS group was not only significantly lower than all other groups (p<0.05) but also the cross-sectional area of these axons was smaller than all other groups (p<0.05). There were no differences between the groups regarding the mean thickness of the myelin sheet. The current study indicates that prenatal exposure to DS decreases the number and the diameter of sciatic nerve axons and that melatonin prophylaxis can prevent these effects.

Examination of age-dependent effects of fetal ethanol exposure on behavior, hippocampal cell counts, and doublecortin immunoreactivity in rats

Ethanol is known as a potent teratogen having adverse effects on brain and behavior. However, some of the behavioral deficits caused by fetal alcohol exposure and well expressed in juveniles ameliorate with maturation may suggest some kind of functional recovery occurring during postnatal development. The aim of this study was to reexamine age-dependent behavioral impairments in fetal-alcohol rats and to investigate the changes in neurogenesis and gross morphology of the hippocampus during a protracted postnatal period searching for developmental deficits and/or delays that would correlate with behavioral impairments in juveniles and for potential compensatory processes responsible for their amelioration in adults. Ethanol was delivered to the pregnant dams by intragastric intubation throughout 7-21 gestation days at daily dose of 6 g/kg. Isocaloric intubation and intact control groups were included. Locomotor activity, anxiety, and spatial learning tasks were applied to juvenile and young-adult rats from all groups. Unbiased stereological estimates of hippocampal volumes, the total number of pyramidal and granular cells, and double cortin expressing neurons were carried out for postnatal days (PDs) PD1, PD10, PD30, and PD60. Alcohol insult during second trimester equivalent caused significant deficits in the spatial learning in juvenile rats; however, its effect on hippocampal morphology was limited to a marginally lower number of granular cells in dentate gyrus (DG) on PD30. Thus, initial behavioral deficits and the following functional recovery in fetal-alcohol subjects may be due to more subtle plastic changes within the hippocampal formation but also in other structures of the extended hippocampal circuit. Further investigation is required.

Effects of postnatal hyperoxia exposure on the rat dentate gyrus and subventricular zone

Premature newborns may be exposed to hyperoxia in the first postnatal period, but clinical and experimental works have raised the question of oxygen toxicity for the developing brain. However, specific analysis of hyperoxia exposure on neurogenesis is still lacking. Thus, the aim of the present study was to evaluate possible changes in the morphometric parameters of the main neurogenic sites in newborn rats exposed to 60 or 95 % oxygen for the first 14 postnatal days. The optical disector, a morphometric method based upon unbiased sampling principles of stereology, was applied to analyse cell densities, total volumes, and total cell numbers of the dentate gyrus (DG) and subventricular zone (SVZ). Apoptosis and proliferation were also studied by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling method and anti-ki67 immunohistochemistry, respectively. Severe hyperoxia increased the percentage of apoptotic cells in the DG. Moderate and severe hyperoxia induced a proliferative response both in the DG and SVZ, but the two neurogenic sites showed different changes in their morphometric parameters. The DG of both the hyperoxic groups showed lower volume and total cell number than that of the normoxic one. Conversely, the SVZ of newborn rats exposed to 95 % hyperoxia showed statistically significant higher volume and total cell number than SVZ of rats raised in normoxia. Our findings indicate that hyperoxia exposure in the first postnatal period affects both the neurogenic areas, although in different ways, i.e. reduction of DG and expansion of SVZ.

Acute effects of triclosan, diclofenac and carbamazepine on feeding performance of Japanese medaka fish (Oryzias latipes)

The toxicity of three pharmaceutical and personal care products (PPCPs)--carbamazepine (CBMZ), diclofenac (DCF), and triclosan (TCS)--was examined by measuring their effects on feeding behavior and swimming speed of adult Japanese medaka fish (Oryzias latipes). Medaka were exposed to 6.15 mg L(-1) CBMZ, 1.0 mg L(-1) DCF, 0.17 mg L(-1) TCS, or no PPCP (control) for 9 d. Fish behaviors were monitored during days 5-9 of the exposure period. Feeding behavior (time to eat midge larvae, TE) and swimming speed (SS) of individual exposed and control fish were tracked in two dimensions, using an automated system with a digital charge-coupled device camera. As a result, feeding behavior was affected by exposure to CBMZ and DCF, while SS was altered by exposure to CBMZ and TCS. Thus, TCS, DCF and CBMZ appear to affect fish behaviors through different mechanisms. Overall, the results suggest that behavioral changes may provide a sensitive indicator for assessing the toxicity of PPCPs to aquatic organisms.

Chronic prenatal exposure to the 900 megahertz electromagnetic field induces pyramidal cell loss in the hippocampus of newborn rats

Widespread use of mobile phones which are a major source of electromagnetic fields might affect living organisms. However, there has been no investigation concerning prenatal exposure to electromagnetic fields or their roles in the development of the pyramidal cells of the cornu ammonis in postnatal life. Two groups of pregnant rats, a control group and an experimental group, that were exposed to an electromagnetic field were used. For obtaining electromagnetic field offspring, the pregnant rats were exposed to 900 megahertz electromagnetic fields during the 1–19th gestation days. There were no actions performed on the control group during the same period. The offspring rats were spontaneously delivered—control group ( n = 6) and electromagnetic field group ( n = 6). Offspring were sacrificed for stereological analyses at the end of the 4th week. Pyramidal cell number in rat cornu ammonis was estimated using the optical fractionator technique. It was found that 900 megahertz of electromagnetic field significantly reduced the total pyramidal cell number in the cornu ammonis of the electromagnetic field group ( P < 0.001). Therefore, although its exact mechanism is not clear, it is suggested that pyramidal cell loss in the cornu ammonis could be due to the 900 megahertz electromagnetic field exposure in the prenatal period.

Effects of prenatal exposure to a 900 MHz electromagnetic field on the dentate gyrus of rats: a stereological and histopathological study

Electromagnetic fields (EMFs) inhibit the formation and differentiation of neural stem cells during embryonic development. In this study, the effects of prenatal exposure to EMF on the number of granule cells in the dentate gyrus of 4-week-old rats were investigated. This experiment used a control (Cont) group and an EMF exposed (EMF) group (three pregnant rats each group). The EMF group consisted of six offspring (n=6) of pregnant rats that were exposed to an EMF of up to 900 megahertz (MHz) for 60 min/day between the first and last days of gestation. The control group consisted of five offspring (n=5) of pregnant rats that were not treated at all. The offspring were sacrificed when they were 4 weeks old. The numbers of granule cells in the dentate gyrus were analyzed using the optical fractionator technique. The results showed that prenatal EMF exposure caused a decrease in the number of granule cells in the dentate gyrus of the rats (P<0.01). This suggests that prenatal exposure to a 900 MHz EMF affects the development of the dentate gyrus granule cells in the rat hippocampus. Cell loss might be caused by an inhibition of granule cell neurogenesis in the dentate gyrus.

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.

Effects of postnatal formaldehyde exposure on pyramidal cell number, volume of cell layer in hippocampus and hemisphere in the rat: a stereological study

The purpose of the present study was to determine whether exposure of neonatal rats to formaldehyde (FA) had either early or delayed effects on the numbers of pyramidal cells in the cornu ammonis (CA) of the hippocampus. Neonatal Wistar rats were exposed to 0 ppm (control group), 6 ppm and 12 ppm (high concentration group) of FA concentrations throughout the 30-day period following the birth by placing them for 6 h/day in a glass chamber containing FA vapor. Then, some of the animals from each FA-treated group were anesthetized and decapitated at the day 30, and the remaining ones were killed at the day 90. The brains were removed immediately and fixed in 10% neutral-buffered FA solution. The Cavalieri principle was used to determine the volumes of the CA and the entire cerebral hemisphere. The optical fractionator counting method was used to estimate the total number of pyramidal cells in the CA. The appearance of pyramidal cells was normal under light microscopy at both postnatal day (PND) 30 and PND 90 in all groups. There were concentration-related volume changes of CA at PND 30 and PND 90; low concentration of FA significantly increased, whereas high concentration decreased the volume of CA in comparison of the control at PND 30. Importantly, high concentration of FA at PND 90 increased the volume of CA in comparison of the low concentration but not with the control. Furthermore, low and high concentrations of FA decreased the volume of hemisphere at PND 30, whereas a reverse effect of these concentrations was observed at the hemisphere of PND 90 in comparison of the control. In both CA and cerebral hemisphere, an age-related volume decrease in both control and low/high concentration groups were found. On the other hand, there were significant age-related reductions in the total number of pyramidal cells at 90 days of age irrespective of the groups examined. Rats treated with high concentration FA were seen to have significantly fewer pyramidal cell neurons than either the animals treated with low concentration FA or control groups (p<0.01). These observations indicate that pyramidal cells in the hippocampus may be vulnerable to FA exposure during the early period of life.