The effects of soy and tamoxifen on apoptosis in the hippocampus and dentate gyrus in a pentylenetetrazole-induced seizure model of ovariectomized rats.

The effects of tamoxifen and soy on apoptosis of the hippocampus and dentate gyrus of ovariectomized rats after repeated seizures were investigated. Female rats were divided into: (1) Control, (2) Sham, (3) Sham-Tamoxifen (Sham-T), (4) Ovariectomized (OVX), (5) OVX-Tamoxifen (OVX-T), (6)OVX-Soy(OVX-S) and (7) OVX-S-T. The animals in the OVX-S, OVX-T and OVX-S-T groups received soy extract (60 mg/kg; i.p.), tamoxifen (10 mg/kg) or both for 2 weeks before induction of seizures. The animals in these groups additionally received the mentioned treatments before each injection of pentylenetetrazole (PTZ; 40 mg/kg) for 6 days. The animals in the Sham and OVX groups received a vehicle of tamoxifen and soy. A significant decrease in the seizure score and TUNEL-positive neurons was seen in the OVX group compared to the Sham (P < 0.001). The animals in both the OVX-T and OVX-S groups had a significantly higher seizure score as well as number of TUNEL-positive neurons compared to the OVX group (P < 0.01-P < 0.001). Co-treatment of the OVX rats by the extract and tamoxifen decreased the seizure score and number of TUNEL-positive neurons compared to OVX-S (P < 0.001). Treatment of the OVX rats by either soy or tamoxifen increased the seizure score as well as the number of TUNEL-positive neurons in the hippocampal formation. Co-administration of tamoxifen and soy extract inhibited the effects of the soy extract and tamoxifen when they were administered alone. It might be suggested that both soy and tamoxifen have agonistic effects on estrogen receptors by changing the seizure severity.

Protective effects of ascorbic acid and garlic extract against lead-induced apoptosis in developing rat hippocampus.

Lead exposure has negative effects on developing nervous system and induces apoptosis in newly generated neurons. Natural antioxidants (i.e. Ascorbic acid and Garlic) might protect against lead-induced neuronal cell damage. The aim of the present study was to investigate the protective effects of Ascorbic acid and Garlic administration during pregnancy and lactation on lead-induced apoptosis in rat developing hippocampus. Timed pregnant Wistar rats were administrated with Lead (1500 ppm) via drinking water (Pb group) or lead plus Ascorbic acid (Pb + AA Group, 500 mg/kg, IP), or lead plus Garlic Extract (Pb + G Group, 1 ml garlic juice/100 g BW, via Gavage) from early gestation (GD 0) until postnatal day 50 (PN 50). At the end of experiments, the pups' brains were carefully dissected. To identify neuronal death, the brain sections were stained with TUNEL assay. Mean of blood and brain lead levels increased significantly in Pb group comparing to other studied groups (P < 0.01). There was significant reduction in blood and brain lead level in Pb + AA and Pb + G groups when compared to those of Pb group (P < 0.01). The mean number of TUNEL positive cells in the CA1, CA3, and DG was significantly lower in the groups treated by either Ascorbic acid or Garlic (P < 0.05). Administration of Ascorbic acid and Garlic during pregnancy and lactation protect against lead-induced neuronal cell apoptosis in the hippocampus of rat pups partially via the reduction of Pb concentration in the blood and in the brain.

The effects of tamoxifen and soy on dark neuron production in hippocampal formation after pentylenetetrazole-induced repeated seizures in rats.

BACKGROUND: Regarding the similar modulatory effects of both soy and tamoxifen on the actions of estrogen which have previously reported, the aim of the present study was to investigate the effects of these two estrogen like compounds alone and in combination on dark neuron production in hippocampal formation of ovariectomized rats after pentylenetetrazole-induced repeated seizure. METHODS: The rats were randomly divided into six groups: control, sham, OVX, OVX-soy (OVX-S), OVX-tamoxifen (OVX-T) and OVX-soy-tamoxifen (OVX-S-T). The animals of OVX-S, OVX-T and OVX-S-T groups received the soy extract (60mg/kg; i.p.), tamoxifen (10mg/kg) or both for 2 weeks before induction of seizures. The animals of these groups were also treated by soy extract, tamoxifen or both before each injection of PTZ (40mg/kg) for 6 days. The animals of sham and OVX groups received saline plus tween instead of tamoxifen and soy extract. The animals of control group did not treat by PTZ, tamoxifen and soy. The rats were placed in Plexiglas cages separately and observed for 60min. The brain tissues were then removed and subjected for histological studies. RESULTS: A significant decrease in the seizure score was seen in OVX group comparing to sham. The animals of both OVX-T and OVX-S groups had a significant higher seizure score compared to OVX group. Co-treatment of the ovariectomized rats by both soy extract and tamoxifen decreased the seizure score compared to OVX-S and OVX-T groups. The results of histological study showed that the dark neuron number in CA1, CA2, CA3 and dentate gyrus (DG) of hippocampus area in OVX-T and OVX-S groups was higher than that of OVX group (P<0.05-P<0.01). In CA3, the produced dark neurons of OVX-S-T group were lower than that OVX-S group (P<0.01). CONCLUSION: The results of present study showed that treatment of the ovariectomized rats by either soy extract or tamoxifen increased the seizure score as well as dark neurons. Co-treatment with soy extract and tamoxifen did not potentiate the effects of each of them alone. Co-administration of the tamoxifen and soy extract inhibited the effects of the soy extract and tamoxifen when they administered alone.

The effects of nano-silver and garlic administration during pregnancy on neuron apoptosis in rat offspring hippocampus.

OBJECTIVES: The aim of this study was to investigate the effects of nano-silver and garlic administration during pregnancy on neuron apoptosis in rat offspring hippocampus. MATERIALS AND METHODS: FIFTY PREGNANT WISTAR RATS WERE RANDOMLY DIVIDED INTO FIVE GROUPS: 1- nano-silver (N.S) group; 30 mg/kg of N.S treated via gavage. 2- Control (C) group, administrated with distilled water via gavage. 3- N.S and garlic (N.S+G) group; N.S (30 mg/kg) and garlic juice (1 ml/100 g) treated via gavage simultaneously. 4- Garlic group (G); garlic juice (1 ml/100 g) administrated via gavage, 5- normal (N) without any intervention. All the interventions were done during pregnancy (21 days). Finally, the brains of rat offspring were removed to use for nano-silver level measurement and TUNEL staining. The mean of TUNEL positive cell numbers per unit area (NA) in different regions of hippocampus were compared in all animal groups. RESULTS: The results revealed a significant increase of hippocampus nano-silver level in N.S and N.S+G groups comparing to N group (P<0.05) and a significant decrease in nano-silver level in N.S+G group comparing to N.S group (P<0.01). The number of TUNEL positive cells in the CA1, CA3, and DG fields of rat offspring hippocampus increased in N.S and N.S+G groups comparing to other ones, and also reduced significantly in N.S+G group comparing to N.S group ((¥) P< 0.01). CONCLUSION: Our results showed that co-administration of nano-silver and garlic during pregnancy may lead to reduce nano-silver induced apoptotic cells in their offspring hippocampus.

Immunohistochemical study of type III collagen expression during pre and post-natal rat skin morphogenesis.

OBJECTIVE(S): Skin extracellular matrix, which contains type I and type III collagens, is involved in skin development. The aim of this study was to investigate type III collagen distribution pattern as well as its changes during pre and post-natal skin morphogenesis in rats. MATERIALS AND METHODS: Ventral skins of Wistar rat embryos at different stages from 10 to 20 gestational day (E10-E20) and also one month and one year post natal rat pups were fixed in normalin, embedded in paraffin and 5 µm thick sections were incubated with Anti type III collagen antibody. In order to detect staining intensity, the reactions were observed and graded by three examiners separately. Kruskal-Wallis non-parametric statistical test and SPSS software version 11.5 were used to compare differences between samples. RESULTS: Immunoreactivity of type III collagen was distributed weakly in the mesenchymal connective tissue on day 10 (E10). The observed reaction was increased onE12 and E14. This reaction was clear in basement membrane, relatively intensive in dermal papillae and moderate in dermal reticularis on E14. This immunoreactivity pattern was increased afterward on E16, not changed on E18 and decreased in dermal reticularis on E20. The density of collagen type III in dermal papillae and dermal reticularis in skin of one year old rats were decreased comparing to one month old rats. CONCLUSION: Our results showed that type III collagen is expressed and timely regulated during pre and post natal rat skin morphogenesis.

Estrogen-dependent effect of soy extract on pentylenetetrazole-induced seizures in rats.

OBJECTIVE: To study the different effects of soy extract on pentylenetetrazole (PTZ)-induced seizures in the presence and absence of ovarian hormones in rats, and the gender-dependent differences in the effects of phytoestrogens on behavior. METHODS: Male and female Wistar rats were randomly divided into nine groups with eight in each, namely, male-saline (M-saline), male-low-dose soy (M-LDS), male-high-dose soy (M-HDS), sham-saline (Sh-saline), sham-low-dose soy (Sh-LDS), sham-high-dose soy (Sh-HDS), ovariectomized-saline (OVX-saline), ovariectomized-low-dose soy (OVX-LDS) and ovariectomized-high-dose soy (OVX-HDS). The rats of groups 7 to 9 were ovariectomized under ketamine anesthesia. The rats of groups 2, 5 and 8 were treated by 20 mg/kg of soy extract while the animals of groups 3, 6 and 9 received 60 mg/kg of soy extract for two weeks. In groups 1, 4 and 7, saline was injected instead of soy extract. The animals were then injected by a single dose of PTZ (90 mg/kg body weight, intraperitoneally) and placed in a plexiglas cage and the latency to minimal clonic seizure (MCS) and generalized tonic-clonic seizure (GTCS) was recorded. RESULTS: Both MCS and GTCS latency in M-LDS and M-HDS groups was significantly lower than that in M-saline group (P<0.05 or P<0.01). Treatment for female sham rats by soy extract did not affect MCS and GTCS latency. The animals of OVX-LDS and OVX-HDS groups had lower MCS and GTCS latency in comparison with OVX-saline group (P<0.05 or P<0.01). CONCLUSION: It is concluded that the phytoestrogens of soy affect seizure severity induced by PTZ, but their effects are different in the presence or absence of ovarian hormones. However, further studies are necessary to be done.

The role of adenosine receptor agonist and antagonist on Hippocampal MDMA detrimental effects; a structural and behavioral study.

There is abundant evidence showing that repeated use of MDMA (3, 4-Methylenedioxymethamphetamine, ecstasy) has been associated with depression, anxiety and deficits in learning and memory, suggesting detrimental effects on hippocampus. Adenosine is an endogenous purine nucleoside that has a neuromodulatory role in the central nervous system. In the present study, we investigated the role of A2a adenosine receptors agonist (CGS) and antagonist (SCH) on the body temperature, learning deficits, and hippocampal cell death induced by MDMA administration. In this study, 63 adult, male, Sprague - Dawley rats were subjected to MDMA (10 and 20 mg/kg) followed by intraperitoneal CGS (0.03 mg/kg) or SCH (0.03 mg/kg) injection. The animals were tested for spatial learning in the Morris water maze (MWM) task performance, accompanied by a recording of body temperature, electron microscopy and stereological study. Our results showed that MDMA treatment increased body temperature significantly, and impaired the ability of rats to locate the hidden platform(P < 0.05). The number of hippocampal dark neurons also increased especially in CA1. These impairments were aggravated by co-administration of A2a antagonist (SCH) with MDMA. Furthermore, the administration of the A2a receptor agonist (CGS) provided partial protection against MWM deficits and hippocampal cell death(P < 0.05). This study provides for the first time evidence that, in contrast to A2a antagonist (SCH) effects, co-administration of A2a agonist (CGS) with MDMA can protect against MDMA hippocampal neurotoxic effects; providing a potential value in the prevention of learning deficits observed in MDMA users. However, the exact mechanism of these interactions requires further studies.

Regulatory changes of N-acetylgalactosamine terminal sugar in early mouse embryonic paraxial mesenchyme.

OBJECTIVE: The development of vertebrae is a complex phenomenon that is correlated with distinct morphological and biochemical alterations in the paraxial mesenchyme and glycoconjugates. The purpose of this study is to investigate the glycosylation pattern in paraxial mesenchyme-forming vertebrae by using the lectin histochemical technique. MATERIALS AND METHODS: In this descriptive-analytic study, B4G fixed paraffin sections of 9 to 15 day Balb/c mouse embryos were processed for histochemical studies using seven different HRP-labelled lectins: Glycin max (SBA), Maclura pomifera (MPA), Wistaria floribunda (WFA), Vicia villosa (VVA) which all of them are specific for N-acetylgalactosamine (GalNAc), Ulex europius (UEA1, binds to α-L-fucose), wheat germ agglutinin (WGA, binds to sialic acid), and Griffonia simplicifolia (GSA1-B4, binds to galactose terminal sugars). The sections were observed separately by three examiners who were blinded to the lectins. Grading was done according to the intensity of the tested lectins' reactions with the specimen, from negative (-) to severe (+++). Data was analysed with SPSS software (version 11.5) and the non-parametric Kruskal Wallis test; p<0.05 was considered significant. RESULTS: Our findings showed that among the tested lectins, only GalNAc residue sensitive lectins showed regulated changes in paraxial mesenchyme. Reactions of WFA and MPA lectins with paraxial mesenchyme were severe on GD9. Reactions of WFA continued to GD15 constantly, while MPA reactions continued strongly to GD12, significantly decreased thereafter (p<0.001), and then disappeared. VVA and SBA bindings initiated weakly on GD10 and continued to GD12 without changing. These reactions increased significantly (p<0.001) thereafter, became severe to GD14, and later disappeared. The other tested lectins did not reveal regulated changes. CONCLUSION: According to these findings it can be concluded that only the GalNAc terminal sugar showed temporally regulated changes during the early embryonic development of vertebrae in mice. Therefore it most likely plays a key role (s) in the development of vertebrae, especially in the conversion of mesenchymal cells into chondroblasts. The other tested terminal sugars may have no role in this phenomenon.

Estrogen-dependent effect of soy extract on pentylenetetrazole-induced seizures in rats / 中西医结合学报

To study the different effects of soy extract on pentylenetetrazole (PTZ)-induced seizures in the presence and absence of ovarian hormones in rats, and the gender-dependent differences in the effects of phytoestrogens on behavior.

Effects of soy extract on pentylenetetrazol-induced seizures in ovariectomized rats.

OBJECTIVE: To investigate the effects of soy extract on pentylenetetrazol (PTZ)-induced seizures in ovariectomized (OVX) rats. METHODS: Female Wistar rats were randomly divided into 4 groups (n=15 in each group) as follows: sham-operated, OVX, low-dose soy (LDS) and high-dose soy (HDS). The rats in each group were divided into two subgroups and received daily injection of a low dose of PTZ (40 mg/kg body weight, intraperitoneally, n=7 in each subgroup) for 14 d or a single injection of a high dose of PTZ (90 mg/kg body weight, intraperitoneally, n=8 in each subgroup). The rats of LDS and HDS groups were injected with 20 and 60 mg/kg body weight of soy extract intraperitoneally, respectively, just 30 min before each PTZ injection. The rats of the sham-operated and the OVX groups received saline instead of soy extract. After treatment, the rats were placed in a plexiglas cage and their behaviors were observed for 60 min. RESULTS: The results of repeated injection of low dose of PTZ during 14 d showed that the seizure score of the rats of OVX group on days 3, 5, 8, 10, 11, 12, and 13 was lower than that of the sham-operated group (P<0.05 or P<0.01). However, the rats of both LDS and HDS groups had higher score compared with the OVX group on the mentioned days (P<0.05 or P<0.01). The results of a single injection of a high dose of PTZ showed a significant increase (P<0.01) in the generalized tonic-clonic seizure (GTCS), but not the minimal clonic seizure (MCS) in the OVX rats compared with the sham-operated rats. Treatment with both low and high doses of soy extract significantly decreased the GTCS and MCS latencies compared with the OVX group (P<0.01). CONCLUSION: Female hormones affect seizure severity induced by PTZ, and phytoestrogens of soy mimic this effects. However, more investigations need to be done in the future.

Effects of soy extract on pentylenetetrazol-induced seizures in ovariectomized rats / 中西医结合学报

Objective: To investigate the effects of soy extract on pentylenetetrazol (PTZ)-induced seizures in ovariectomized (OVX) rats. Methods: Female Wistar rats were randomly divided into 4 groups (n=15 in each group) as follows: sham-operated, OVX, low-dose soy (LDS) and high-dose soy (HDS). The rats in each group were divided into two subgroups and received daily injection of a low dose of PTZ (40 mg/kg body weight, intraperitoneally, n=7 in each subgroup) for 14 d or a single injection of a high dose of PTZ (90 mg/kg body weight, intraperitoneally, n=8 in each subgroup). The rats of LDS and HDS groups were injected with 20 and 60 mg/kg body weight of soy extract intraperitoneally, respectively, just 30 min before each PTZ injection. The rats of the sham-operated and the OVX groups received saline instead of soy extract. After treatment, the rats were placed in a plexiglas cage and their behaviors were observed for 60 min. Results: The results of repeated injection of low dose of PTZ during 14 d showed that the seizure score of the rats of OVX group on days 3, 5, 8, 10, 11, 12, and 13 was lower than that of the sham-operated group (P<0.05 or P<0.01). However, the rats of both LDS and HDS groups had higher score compared with the OVX group on the mentioned days (P<0.05 or P<0.01). The results of a single injection of a high dose of PTZ showed a significant increase (P<0.01) in the generalized tonic-clonic seizure (GTCS), but not the minimal clonic seizure (MCS) in the OVX rats compared with the sham-operated rats. Treatment with both low and high doses of soy extract significantly decreased the GTCS and MCS latencies compared with the OVX group (P<0.01). Conclusion: Female hormones affect seizure severity induced by PTZ, and phytoestrogens of soy mimic this effects. However, more investigations need to be done in the future.