Modulation of lipopolysaccharide stimulated nuclear factor kappa b mediated inos/no production by bromelain in rat primary microglial cells

Background: Microglial cells act as the sentinel of the central nervous system. They are involved in neuroprotection but are highly implicated in neurodegeneration of the aging brain. When over-activated, microglia release pro-inflammatory factors, such as nitric oxide [NO] and cytokines, which are critical in eliciting neuroinflammatory responses associated with neurodegenerative diseases. This study examined whether bromelain, the pineapple-derived extract, may exert an anti-inflammatory effect in primary microglia and may be neuroprotective by regulating microglial activation.

Methods: Following the isolation of neonatal rat primary microglial cells, the activation profile of microglia was investigated by studying the effects of bromelain [5, 10, 20, and 30 ng/ml] on the levels of NO, inducible nitric oxide synthase [iNOS], and nuclear factor kappa B [NF-KB] in microglia treated with lipopolysaccharide [LPS] [1 ng/ml]. Data were analyzed using Student's t-test. P values less than 0.05 were considered to be statistically significant, compared with the LPS-treated group without bromelain

Results: Results showed that pretreatment of rat primary microglia with bromelain, decreased the production of NO induced by LPS [1 u,g/ml] treatment in a dose-dependent manner. Bromelain [30 micro.g/ml] also significantly reduced the expression of iNOS at mRNA level and NF-KB at protein level. Moreover, the study of mitochondrial activity in microglia indicated that bromelain had no cytotoxicity at any of the applied doses, suggesting that the anti-inflammatory effects of bromelain are not due to cell death

Conclusion: Bromelain can be of potential use as an agent for alleviation of symptoms in neurodegenerative diseases

[ effect of intrathecal administration of cocaine and serotonergic antagonist [cyproheptadine] on nociception in rat]

Cocaine by effect on central nervous system inhibits reuptake of monoamines [serotonin, norepinephrine and dopamine] to presynaptic terminal and increases their concentration. Monoamines such as serotonin cause analgesia at the spinal level. This study investigates the effects of systemic and spinal administration of cocaine on pain sensation and the relation between these effects and serotonin. Male Wistar rats [200-250g] were set in groups: saline [i.p], saline/DMSO [i.p], cocaine 25mg/kg [i.p], saline [i.t], saline/DMSO [i.t], cocaine 100micro g/10 micro l [i.t], cyproheptadine 33 micro g/10 micro l [i.t.] and cyproheptadine 33 micro g/10 micro l/cocaine 100 micro g/10 micro l [i.t]. Tail flick latency was measured before and after administration. Intraplantar formalin was used for induction of chemical pain. The data was analyzed by T-Test and ANOVA. Pain in both phases of formalin test was reduced in both cocaine 25mg/kg [i.p] [P<0.01] and cocaine 100 micro g/10 micro l [i.t.] [P<0.01]. However, in cyproheptadine 33 micro g/10 micro l [i.t], was increased in the first phase [P<0.01]. In cyproheptadine 33 micro g/10 micro l/cocaine 100 micro g/10 micro l [i.t.], the part of pain reduction induced by cocaine was reversed, in both phases [P<0.01]. In tail flick test the results of cyproheptadine 33 micro g/10 micro l [i.t.] showed reduced tail flick latency [P<0.001]. Inhibition of serotonin reuptake at the spinal level plays role in analgesic effects of cocaine probably, because release of serotonin from the spinal serotonergic terminals causes inhibition of pain neurons and reduction of pain. In addition, inhibition of spinal serotonin receptors by cyproheptadine reduced part of analgesic effects of cocaine probably

Effect of Oseltamivir on hyperalgesia induced by low concentrations of morphine and morphine tolerance in Drosophila melanogaster

Introduction: Morphine has been known as a drug with different paradoxical effects, analgesic and hyperalgesic. On the other hand, repeated morphine administration, induces morphine tolerance in mammals. The aim of recent study is investigating tolerance to morphine in Drosophila melanogaster and the effect of Oseltamivir [an inhibitor of G2 receptors] on hyperalgesia induced by low concentrations of morphine and morphine tolerance

Materials and methods: In this study, stage 3 of larvae and adult state of wild Drosophila melanogaster were used. For evaluating the effect of Oseltamivir on hyperalgesic effect of low concentration Morphine, Oseltamivir [0.2 mg/l] and low concentrations of morphine were added to media culture. Then behavior of larvae and adults to thermal [using Hot plate, 47°C] and chemical [capsaicin and acetic acid] pain stimulations were recorded. For morphine tolerance experiments in larvae, repeated morphine administration [0.1 and 0.01 mg/l] was done and their response to thermal pain was evaluated. The same method was used in adults but with other doses of morphine [200 and 300 mg/l]. Finally to investigate the mechanism of morphine tolerance, Oseltamivir was administered too

Results: morphine tolerance was occurred in Drosophila melanogaster similar to mammals. Repeated morphine administration diminished anti nociceptive effects of morphine [p<0.001]. Oseltamivir reduced morphine tolerance and hyperalgesic effects of low concentration morphine in both pain models [thermal and chemical nociception], [p<0.01]

Conclusion: opioid systems can involve pain modulation [hyperalgesia and analgesia] in Drosophila like vertebrates. Our results showed inhibition of excitatory G-protein [Gs] by Oseltamivir, inhibit morphine induced hyperalgesia and this is another confirmation for involvement of excitatory G-proteins in morphine induced tolerance

[Effects of repeated anesthesia by thiopental in neonatal period on PTZ-induced convulsions and pain responses during maturation in rats]

General anesthetics during critical periods of brain development may cause some serious malformations or side effects. Anesthetic drugs can involve in the brain development and synaptogenesis at the critical period of development. There are some controversy with regards the effects of [neurodegenerative or neuroprotective] barbiturates on brain. The aim of the present study was to investigate the possible relation between repeated induced thiopental [a GABAA agonist] anesthesia at the postnatal period and pentylentetrazol-induced convulsions and pain responses in adult in the Wistar rats. 40 male neonate rats were divided into experimental and sham groups. The experimental group [n=20] was deeply anesthetized with thiopental [30 mg/kg daily] during 10 to 20-days of post- natal period and physiologic serum was used for sham animals. After maturation of male rats, the PTZ-induced seizures were induced by daily interapritoneally injection of PTZ [45 mg/kg], and the latency of the appearance of generalized epileptiform behaviors was recorded. Pain responses were also evaluated using tail-flick and formalin tests. No significant differences were found in the lantency of the appearance of behavioural convulsions and pain sensitivity between experimental and sham groups. Our findings indicate that prior exposure to thiopental during nenonatal stage has no effects on PTZ-induced seizures and also pain responses after maturation. Developmental compensatory mechanisms may protect the brian against the possible damage that induced by repeated thipopental during neonatal period.

Effects of infantile repeated hyperglycemia on behavioral alterations in adult male and female rats

Anxiety symptoms have been reported to be present in many patients with diabetes mellitus. However, little is known about the effects of hyperglycemia in critical periods of the central nervous system development. We assessed locomotive, exploratory, and anxiety behaviors in adult rats that remained from infantile repeated hyperglycemia by the open field and elevated plus maze tests. Our findings showed significant hypo activity, reduced locomotive/exploratory activities, increased fear related behaviors, and anxiety state between hyperglycemic and control adult males and the same differences were observed among females. In addition, no significant behavioral alterations between male and female animals were observed. This study determined that repeated increments in daily blood sugar levels in newborns may affect neuronal functions and provide behavioral abnormalities in adults

Role of the Lewis and ABO Blood Group Antigens in Helicobacter pylori Infection

Background: Helicobacter pylori infection is a major risk factor for chronic gastritis and gastric cancer. Some findings show increased frequencies of these diseases in individuals with type O blood and in secretors (expressing Leb antigen), but other studies have not found any relationship between blood groups and this infection. Given that H. pylori infection and gastric cancer are common in Iran, the assessment of the pathogenesis of this infection in relation to these blood groups could be valuable. Methods: In a cross-sectional study, we determined the ABO and Lewis blood groups of participants using the tube method and evaluated the level of anti-H. pylori immunoglobulin G using an enzyme-linked immunosorbent assay. This study included 171 Iranian blood donors from Mashhad, Iran, during 2010. The significance of the differences in the frequencies of the Lewis and ABO phenotypes between individuals infected with and without H. Pylori infection were tested using the chi-square test. A P-value < 0.05 was considered significant. Results: H. pylori infection was found in 76.6% of the study subjects (n = 131). The most common ABO blood group was O (33.9%), and the most common Lewis blood group was Le(a-b+) (54.7%). The frequencies of the ABO, Lewis, and secretion phenotypes were not significantly different between the infected and uninfected subjects. Conclusion: We did not find any significant relationship between the Lewis, ABO, and secretion phenotypes and H. pylori infection.

effect of scopolamine on avoidance memory and hippocampal neurons in male wistar rats

Cholinergic systems are involved in learning and memory. Scopolamine, a muscarinic acetylcholine receptor antagonist, is used as a standard/ reference drug for inducing cognitive deficits in healthy humans and animals. The purpose of this study was to evaluate the effects of scopolamine on avoidance memory and number of neurons in rat's hippocampus. Thirty five male albino Wistar rats [200 +/- 20 g] were used in this study. The rats were divided randomly into five groups: control group [healthy samples], sham [saline] and 3 experimental groups 0.2, 0.5 and 1 mg/kg [intraperitoneally - single dose of Scopolamine]. Animals were tested by passive avoidance method [shuttle box]. After one week, a memory test was taken from rats. Finally, with dissection of the rats' brains and tissue operations, neurons were stained with cresyl violet. Photographs of the samples in hippocampal areas were prepared, and neurons were counted. Our results showed that the number of neurons in all experimental groups was lower than that in the control group. The highest decrease in number of neurons was shown in response to 1 mg/kg scopolamine compared to the control group in all regions of hippocampus. Also, we found that in comparison to the saline-treated animals, the injection of scopolamine to rats after training, caused memory destruction. We concluded that memory impairment-induced by scopolamine is probably associated with neuronal loss and this decrease was dose dependent

effect of Iranian shallot or garlic aqueous extracts on learning, memory and serum biochemical variables in fructose-fed wistar rats

We determined the effect of a high fructose diet either alone or in combination with Iranian shallot or garlic extract on cognitive functions, plasma lipid profile, and the intraperitoneal glucose tolerance test [IPGTT]. Following induction of insulin resistance in fructose-fed rats [Fru-fed], they were randomly assigned to three subgroups. The first subgroup was kept as Fru-fed while the two other subgroups were daily treated by aqueous garlic or shallot extract. Twelve weeks treatment with shallot or garlic significantly prevented the learning and memory deficits induced by fructose-feeding. Administration of garlic, but not shallot extract could significantly diminish the levels of cholesterol and low-density lipoprotein. Treatment with garlic or shallot extract can significantly improve the IPGTT in the Fru-fed rats. The high fructose diet may contribute to spatial memory deficits. Iranian shallot or garlic extracts appear to improve learning and memory impairments in fructose-fed r

Effect of mobile phone microwaves on fetal period of BALB/ c mice in histological characteristics of hippocampus and learning behaviors

The possible risks of radio-frequency electromagnetic fields [EMF] for the living organisms and human body are a growing concern for our society. In this study, we examined the possibility of changes in working memory and hippocampal histological characteristics effects in mice brain following whole body exposure to microwave radiation. During gestation period, we exposed mice for 4 hr to Global system for mobile communications [GSM], Specific Absorption Rate [SAR] of 200 mW/kg. Pregnant control mice were sham-exposed or free in a cage without further restraining. Three month after exposure, animals were prepared for behavioral [Radial Arm Maze [RAM] and Morris Water Maze [MWM]] and histological studies. The showed that microwave exposed mice were slower than sham, and control in finding the platform. Analyses of error rates in RAM and MWM performance revealed significant differences which emphasize the effect of acute exposure to pulsed microwaves in deficit of spatial reference memory in the mice. However in this study exposed group didn't show any statistically significant loss of hippocampal CA1, CA3 neurons versus controls or sham. We conclude that there is evidence from the current study that exposure to MW radiation under parameters examined caused decrements in the ability of mice to learn the spatial memory task

Evaluation of the effect of Islamic fasting on lung volumes and capacities in the healthy persons

To evaluate the changes in pulmonary volumes during and after Islamic fasting. It is a cohort study conducted on 117 healthy subjects selected on a random basis from employees, professors and students of Iran University of Medical Sciences, Tehran, Iran, between December 1999 and January 2000. All of them underwent spirometry 10 days prior to Ramadan, 2 times during Ramadan, and one time 10 days post-Ramadan. In first visit, in addition to spirometry they underwent medical examination to make sure they are healthy. All of their spirometries and background information were collected. Repeated measurements analysis of varience method was used to compare the measurements. Approximately 69% of subjects were male and the mean age was 23.9 years. Mean fasting time was 27.8 days. The mean difference in forced expiratory volume in 1 second [FEV1%] was significant between the 4 visits [P=0.01]. The mean FEV1% increased both during fasting and after Ramadan [P=0.017]. The mean vital capacity and peak expiratory flow rate values increased during Ramadan significantly [p=0.043, P<0.001]. Although the mean maximum mid-expiratory flow decreased in the beginning of Ramadan and significantly increased subsequently [P=0.02], MEF50% [P=0.004] and MEF75% [P=0.047] increased in the beginning of Ramadan and decreased subsequently. As a whole, fasting increases lung volumes and might improve pulmonary function. This finding seems to be relevant to the changes in weight during Ramadan