Differential effects of antiseizure medications on neurogenesis: Evidence from cells to animals.

Neurogenesis, the process of generating functionally integrated neurons from neural stem and progenitor cells, is involved in brain development during embryonic stages but continues throughout life. Adult neurogenesis plays essential roles in many brain functions such as cognition, brain plasticity, and repair. Abnormalities in neurogenesis have been described in many neuropsychiatric and neurological disorders, including epilepsy. While sharing a common property of suppressing seizures, accumulating evidence has shown that some antiseizure medications (ASM) exhibit neuroprotective potential in the non-epileptic models including Parkinson's disease, Alzheimer's disease, cerebral ischemia, or traumatic brain injury. ASM are a heterogeneous group of medications with different mechanisms of actions. Therefore, it remains to be revealed whether neurogenesis is a class effect or related to them all. In this comprehensive literature study, we reviewed the literature data on the influence of ASM on the neurogenesis process during brain development and also in the adult brain under physiological or pathological conditions. Meanwhile, we discussed the underlying mechanisms associated with the neurogenic effects of ASM by linking the reported in vivo and in vitro studies. PubMed, Web of Science, and Google Scholar databases were searched until the end of February 2023. A total of 83 studies were used finally. ASM can modulate neurogenesis through the increase or decrease of proliferation, survival, and differentiation of the quiescent NSC pool. The present article indicated that the neurogenic potential of ASM depends on the administered dose, treatment period, temporal administration of the drug, and normal or disease context.

The protective effects of curcumin against cigarette smoke-induced toxicity: A comprehensive review.

Cigarette smoking (CS) is a crucial modifiable risk of developing several human diseases and cancers. It causes lung, bladder, breast, and esophageal cancers, respiratory disorders, as well as cardiovascular and metabolic diseases. Because of these adverse health effects, continual efforts to decrease the prevalence and toxicity of CS are imperative. Until the past decades, the impacts of natural compounds have been under investigation on the harmful effects of CS. Turmeric (Curcuma longa), a rhizomatous herbaceous perennial plant that belongs to the Zingiberaceae family, is the main source of curcumin. This review is an attempt to find out the current knowledge on CS's harmful effects and protective potential of curcumin in the pulmonary, liver, brain, gastrointestinal, and testis organs. According to the present review, simultaneous consumption of curcumin and CS can attenuate CS toxicities including chronic obstructive pulmonary disease, gastrointestinal toxicity, metabolic diseases, testis injury, and neurotoxicity. Moreover, curcumin suppresses carcinogenesis in the skin, liver, lungs, breast, colon, and stomach. Curcumin mediates these protective effects through antioxidant, anti-inflammatory, anti-apoptotic, and anti-carcinogenicity properties.

Everolimus attenuates glutamate-induced PC12 cells death.

BACKGROUND: Glutamate-induced neuronal cell death plays a key role in neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Some recent studies reported the potential immunomodulatory and neuroprotective properties of inhibitors of serine-threonine kinase, mTOR (mammalian target of rapamycin). However, no study was conducted about the neuroprotective potential of everolimus (EVR), a selective and potent mTOR inhibitor. Therefore, this study was planned to investigate whether EVR has protective effects against glutamate-induced toxicity in PC12 cells, which are used as model for neurons injury, and to elucidate the underlying mechanism. METHODS: PC12 cells were concurrently treated with glutamate (8 mM) and EVR (0-40 nM) for 24 h. Then, the cells viability, apoptosis rate, and apoptosis-related proteins (caspase-3, bax and bcl-2) were measured using MTT, annexin V/PI and immunoblotting assays. RESULTS: Analyzing the protective effect of different concentrations of EVR (0-40 nM) against glutamate-induced cytotoxicity revealed a significant increase in cell viability in co-treatment regimen (p < 0.01). Also, EVR (40 nM) significantly (p < 0.01) inhibited glutamate-induced apoptosis through depressing the elevation of bax/bcl-2 ratio and expression of cleaved caspase-3, concentration depend. CONCLUSION: The results demonstrated, for the first time, that EVR could protect against glutamate-mediated PC12 cell death via inhibiting apoptosis.

Beneficial effects of levetiracetam in streptozotocin-induced rat model of Alzheimer's disease.

Alzheimer's disease (AD) is the most common neurodegenerative disorder among the elderly. In the light of increasing AD prevalence and lack of effective treatment, new strategies to prevent or reverse this condition are needed. Levetiracetam (LEV) is a newer antiepileptic drug that is commonly used to treat certain types of seizures. Researches indicated that LEV has several other pharmacological activities, including improvement of cognitive function. In this study, the recovery effects of chronic (28 days) administration of LEV (50, 100, and 150 mg/kg, ip) on cognitive deficits caused by the intracerebroventricular (icv) injection of streptozotocin (STZ), as a model for sporadic AD, were evaluated in rats. We also considered the protective effects of LEV against hippocampal cell loss, oxidative damage, acetylcholinesterase (AChE) activity, neuroinflammation, and tauopathy caused by STZ. LEV (100 and 150 mg/kg) significantly attenuated the STZ-induced learning and memory impairments in the passive avoidance and Morris water maze (MWM) tasks. In addition, LEV suppressed STZ-induced hippocampal neuronal loss, while restored alterations in the redox status (lipid peroxides and glutathione), AChE activity, proinflammatory cytokines (IL-1ß, IL-6, TNF-α), and hyperphosphorylation of tau linked to STZ administration. In conclusion, our study demonstrated that LEV alleviated hippocampal cell death and memory deficits in STZ-AD rats, through mitigating oxidative damage, suppression of proinflammatory cytokines expression, and inhibition of abnormal tau hyperphosphorylation.

Intrahippocampal co-administration of nicotine and O-acetyl-L-carnitine prevents the H-89-induced spatial learning deficits in Morris water maze.

OBJECTIVES: H-89 (a protein kinase AII [PKA II] inhibitor) impairs the spatial memory in the Morris water maze task in rats. In the present study, we aimed to study the protective effects of nicotine and O-acetyl-L-carnitine against H-89-induced spatial memory deficits. METHODS: Spatial memory impairment was induced by the bilateral intrahippocampal administration of 10 µM H-89 (dissolved in dimethyl sulfoxide, DMSO) to rats. The rats then received bilateral administrations of either nicotine (1 µg/µL, dissolved in saline) or O-acetyl-L-carnitine (100 µM/side, dissolved in deionized water) alone and in combination. Control groups received either saline, deionized water, or DMSO. RESULTS: The H-89-treated animals showed significant increases in the time and distance travelled to find hidden platforms, and there was also a significant decrease in the time spent in the target quadrant compared to DMSO-treated animals. Nicotine and O-acetyl-L-carnitine had no significant effects on H-89-induced spatial learning impairments alone, but the bilateral intrahippocampal co-administration of nicotine and O-acetyl-L-carnitine prevented H-89-induced spatial learning deficits and increased the time spent in the target quadrant in comparison with H-89-treated animals. CONCLUSIONS: Our results indicated the potential synergistic effects of nicotine and O-acetyl-L-carnitine in preventing protein kinase AII inhibitor (H-89)-induced spatial learning impairments.

Effects of Quercetin and Resveratrol on Zinc Chloride- and Sodium Metavanadate-Induced Passive Avoidance Memory Retention Deficits in Male Mice.

Quercetin and resveratrol are found in a variety of fruits and vegetables and have several biological and pharmacological properties. In this study, the effects of quercetin [50 mg/kg, intraperitoneal (i.p.)] and resveratrol (50 mg/kg, i.p.) on zinc chloride (ZnCl2; 75 mg/kg/d, 2 weeks oral gavage) and sodium metavanadate (SMV; 22.5 mg/kg/d, 2 weeks oral gavage) induced passive avoidance memory retention were investigated in step-through passive avoidance tasks. ZnCl2 was dissolved in saline and SMV was dissolved in drinking water. Mice received ZnCl2 or SMV orally for two weeks and were administered quercetin or resveratrol by i.p. injection on day 14, days 12 and 14, or days 10, 12, and 14. At the end of treatment, animals were trained for one day in a step-through passive avoidance task, then alterations in avoidance memory retention were evaluated after 24, 48, 96, and 168 h. Oral consumption of ZnCl2 and SMV decreased latency time compared with control groups. Both quercetin and resveratrol (50 mg/kg, i.p.) prevented ZnCl2- and SMV-induced avoidance memory retention impairments and did not significantly alter muscle strength, as demonstrated in rotarod tasks. No significant differences were observed between mice who received single, double, or triple doses of quercetin or resveratrol. The results suggest that quercetin and resveratrol may have preventive effects on ZnCl2- and SMV-induced memory impairment in male mice.

Tadalafil Reversed H-89 - and Scopolamine - Induced Spatial Learning Impairments in Male Rats.

Accumulated evidence shows that the cAMP and cGMP signaling pathway plays an important role in memory function and neuronal plasticity. Phosphodiesterase 5 (PDE5) is a hopeful therapeutic target in AD (Alzheimer disease), and PDE5 inhibition may be a good therapeutic strategy for the treatment of AD. In the present study, the four-day bilateral intra-hippocampal infusion of H-89 as a protein kinase AII inhibitor (10 µM/side) and intra-peritoneal injections of tadalafil (20 mg/kg) and scopolamine (0.5 mg/kg) alone and also on combination on spatial learning in Morris water maze (MWM) were investigated. DMSO and saline were used as controls for H-89 and other mentioned drugs, respectively. Rats were trained for 4 days; each day included one block of four trials. Post- training probe trial tests were performed on day 5. Administration of H-89 and scopolamine led to a significant impairment in spatial learning compared to their related controls. But, combination of tadalafil/H-89 or tadalafil/scopolamine reversed H-89 or scopolamine- induced spatial learning deficits in MWM. Taken together, these results showed the probable regulatory effects of cGMP on cholinergic and cAMP/PKA signaling pathways in co-administrations of these mentioned drugs on spatial learning in MWM.

An updated review of protective effects of rosemary and its active constituents against natural and chemical toxicities.

Natural and chemical toxic agents cause severe adverse effects on people's health in a variety of exposing ways. Herbal medications have taken into consideration as alternative safe treatments for toxicities. Rosmarinus officinalis also known as rosemary belongs to the Lamiaceae family. Rosemary and its constituents including carnosic acid, rosmarinic acid, and carnosol have a lot of benefits such as anti-inflammatory, antioxidant, anti-mutagenic, anti-bacterial, antiviral, antinociceptive, and neuroprotective activities. In this literate review, we focused on the protective effects of rosemary and its main compounds against natural and chemical toxicities in both in vitro and in vivo studies. The protective effects of rosemary and its components are mostly mediated through different mechanisms such as the inhibition of oxidative stress, reduction of inflammatory mediators including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-17 (IL-17), cyclooxygenase-2 (COX-2) and nuclear factor ĸB (NF-ĸB) as well as the modulation of apoptosis and mitogen-activated protein kinase (MAPK) signaling pathways.

Potential protective roles of phytochemicals on glutamate-induced neurotoxicity: A review.

Glutamate, as an essential neurotransmitter, has been thought to have different roles in the central nervous system (CNS), including nerve regeneration, synaptogenesis, and neurogenesis. Excessive glutamate causes an up-regulation of the multiple signaling pathways, including phosphoinositide-3 kinase/protein kinase B (PI3K/Akt), Akt/mammalian target of rapamycin (mTOR) protein, mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK)1/2, and autophagy that are involved in neurodegenerative diseases pathophysiology. There are numerous findings on curcumin, astaxanthin, thymoquinone, and berberine, as natural products, which have outstanding effects in cell signaling far beyond their anti-oxidant activity, considering as a potential therapeutic target for glutamate excitotoxicity. Herein, we address the role of glutamate as a potential target in neurodegenerative diseases and discuss the protective effects of certain phytochemicals on glutamate-induced neurotoxicity.

Genus Boswellia as a new candidate for neurodegenerative disorders.

Neurodegenerative diseases, characterized by progressive loss of neurons, share common mechanisms such as apoptotic cell death, mitochondrial dysfunction, inflammation, and oxidative stress. Genus Boswellia is a genus in the Burseraceae family. It comprises several species traditionally used for treatment of chronic inflammatory diseases, cerebral edema, chronic pain syndrome, gastrointestinal diseases, tumors, as well as enhancing intelligence. Many studies have been carried out to discover therapeutic approaches for neurodegenerative diseases such as Alzheimer's diseases, Parkinson's disease, Huntington's disease, multiple sclerosis and amyotrophic lateral sclerosis, stroke, and concomitant cognitive deficits. However, no curative treatment has been developed. This paper provides an overview of evidence about the potential of the Boswellia species and their main constituents, boswellic acids, as modulators of several mechanisms involved in the pathology of the neurodegenerative diseases. In vitro, animal, and clinical studies have confirmed that Boswellia species contain bioactive components that may enhance cognitive activity and protect against neurodegeneration. They exert the beneficial effects via targeting multiple pathological causes by antioxidative, anti-inflammatory, antiamyloidogenic, and anti-apoptotic properties. The Boswellia species, having neuroprotective potential, makes them a promising candidate to cure or prevent the neurodegenerative disorders.

Milk thistle (Silybum Marianum) as an antidote or a protective agent against natural or chemical toxicities: a review.

Biological and chemical agents cause dangerous effects on human health via different exposing ways. Recently, herbal medicine is considered as a biological and safe treatment for toxicities. Silybum marianum (milk thistle), belongs to the Asteraceae family, possesses different effects such as hepatoprotective, cardioprotective, neuroprotective, anti-inflammatory and anti-carcinogenic activities. Several studies have demonstrated that this plant has protective properties against toxic agents. Herein, the protective effects of S. marianum and its main component, silymarin, which is the mixture of flavonolignans including silibinin, silydianin and silychristin acts against different biological (mycotoxins, snake venoms, and bacterial toxins) and chemical (metals, fluoride, pesticides, cardiotoxic, neurotoxic, hepatotoxic, and nephrotoxic agents) poisons have been summarized. This review reveals that main protective effects of milk thistle and its components are attributed to radical scavenging, anti-oxidative, chelating, anti-apoptotic properties, and regulating the inflammatory responses.

Reno-protective effect of Rheum turkestanicum against gentamicin-induced nephrotoxicity.

OBJECTIVES: Gentamicin belongs to the family of aminoglycoside antibiotics and is a preferred drug in developing countries because of its low cost, availability, and potent effects against bacterial. However, gentamicin can induce nephrotoxicity. In this research, hydroalcoholic extract of Rheum turkestanicum was used against gentamicin- induced nephrotoxicity and its effect against gentamicin-induced nephrotoxicity in rats has been investigated. MATERIALS AND METHODS: The rats were placed into one of these groups: saline group, gentamicin group that received gentamicin 80 mg/kg/day for six days, and two treatment groups that received R. turkestanicum intraperitoneally at doses of 100 and 200 mg/kg body weight, respectively, 1 hr before gentamicin injections. Urine samples were collected at 24 hr to measure glucose and protein concentration. Blood samples were collected to determine serum urea and creatinine. One kidney was homogenized to measure malondialdehyde and thiol, and the other kidney was kept for pathological studies. RESULTS: Gentamicin increased the level of urinary glucose and protein, and increased malondialdehyde while it decreased thiol in kidney tissue, and increased the concentration of urea and creatinine in the serum. Histopathological pathology revealed renal damage following gentamicin usage; however, the extract was able to improve gentamicin toxicity. CONCLUSION: R. turkestanicum has positive effects in the attenuation of gentamicin-induced nephrotoxicity.

The role of fibromodulin in cancer pathogenesis: implications for diagnosis and therapy.

Fibromodulin (FMOD) is known as one of very important extracellular matrix small leucine-rich proteoglycans. This small leucine-rich proteoglycan has critical roles in the extracellular matrix organization and necessary for repairing of tissue in many organs. Given that the major task of FMOD is the modulation of collagen fibrillogenesis. However, recently observed that FMOD plays very important roles in the modulation of a variety of pivotal biological processes including angiogenesis, regulation of TGF-ß activity, and differentiation of human fibroblasts into pluripotent cells, inflammatory mechanisms, apoptosis and metastatic related phenotypes. Besides these roles, FMOD has been considered as a new tumor-related antigen in some malignancies such as lymphoma, leukemia, and leiomyoma. Taken together, these findings proposed that FMOD could be introduced as diagnostic and therapeutic biomarkers in treatment of various cancers. Herein, for first time, we highlighted the various roles of FMOD in the cancerous conditions. Moreover, we summarized the diagnostic and therapeutic applications of FMOD in cancer therapy.

Nigella sativa and thymoquinone attenuate oxidative stress and cognitive impairment following cerebral hypoperfusion in rats.

Nigella sativa, a plant widely used in traditional medicine, possesses anti-inflammatory, antioxidant and neuroprotective properties. In the present study, we investigated the effect of hydroalcoholic extract of N. sativa seeds (NSE) and its active constituent, thymoquinone (TQ), on learning and memory deficits, hippocampal acetylcholine esterase (AChE) activity, and markers of redox status, mainly lipid peroxidation and superoxide dismutase (SOD) activity following cerebral hypoperfusion in rats. Cerebral hypoperfusion was induced by permanent occlusion of bilateral common carotid arteries (2VO). Male Wistar rats were administered either a vehicle (sham group: 10 ml/kg/day, ip), NSE (100, 200, and 400 mg/kg/day, ip), TQ (10, 20, and 40 mg/kg/day, ip), or donepezil (5 mg/kg/day, ip) for 10 days (three days before and seven days after ligation). Spatial learning and memory deficits were investigated using the Morris water maze (MWM) task. 2VO produced significant learning and memory deficits as evidenced by increased latency time to reach the hidden platform, increased swimming time, and decreased time spent in the target quadrant in the probe trial in the MWM task. There was also a significant increase in the lipid peroxidation level and AChE activity, and a significant decrease in SOD activity in the hippocampal portion of hypoperfused rats, as compared with the sham group. Treatment with NSE (400 mg/kg/day; p < 0.001) and TQ (40 mg/kg/day; p < 0.001), as well as donepezil significantly prevented learning and memory impairments and alleviated changes in the hippocampal lipid peroxide level and SOD and AChE activities in this model. In conclusion, our data suggest that N. sativa and thymoquinone have a beneficial role in cerebrovascular insufficiency states and dementia.

Evaluation of Rheum Turkestanicum in Hexachlorobutadien-Induced Renal Toxicity.

Hexachlorobutadien is nephrotoxic agent in rodents. The mechanism of toxicity includes generation of free radicals, depletion of thiol groups and production of toxic metabolites. Antioxidant compounds may reduce HCBD-nephrotoxicity. In this research we investigated the effect of Rheum turkeatanicum extract against HCBD-toxicity. The animals were divided to 4 groups which were including control (saline, 1 mL/kg), HCBD (100 mg/kg) and treatment groups which received extract at doses 100 and 200 mg/kg. The extract were administered as intraperitoneally (i.p.) 1 h before HCBD injection (i.p.). The animals were anesthetized by ether, 24 h after HCBD administration. The results showed elevation of serum creatinine, serum urea, urinary protein, urinary glucose, malondialdehyde levels in kidney and reduction of thiol in kidney by HCBD. The histopathological studies showed that there was apoptosis and necrosis in HCBD treated groups. Administration of R.turkestanicum reduced HCBD toxicity. The extract reduced hitopathological changes in kidney. It may be concluded that the nephroprotective effect of extract may be due to different mechanisms such as antioxidant activity or by decreasing the toxic metabolites of HCBD or inhibition of enzymes which are involved in the bioactivation of HCBD such as glutathione-S-transferase (GST) or cysteine-S-conjugate ß-lyase.

Safranal Attenuates Excitotoxin-Induced Oxidative OLN-93 Cells Injury.

OBJECTIVES: Researches have been shown that glutamic acid (GA) or quinolinic acid (QA) can play role in neuroinflammatory and demyelinating diseases including multiple sclerosis (MS), mainly via oligodendrocytes activation and extreme free radicals generation. Recent studies have demonstrated that safranal, an active constituent of Crocus sativus, has several pharmacological effects such as antioxidant, anti-inflammatory and neuroprotective properties. Since there is no data about the impact of safranal on MS, this study was designed to investigate the protective effect of safranal on OLN-93 oligodendrocytes injury induced by GA or QA. MATERIALS AND METHODS: At first, the potential toxic effect of safranal on OLN-93 viability was evaluated. Also, the cells were pretreated with safranal (0.1, 1, 10, 50, 100 and 200 µM) for 2 h and then subjected to GA (16 mM) or QA (8 mM) toxicity for 24 h, in which the same treatments were applied. The cell viability and parameters of redox status such as the levels of intracellular reactive oxygen species (ROS) and lipid peroxidation were measured. RESULTS: Safranal at concentration ranges of 1-800 µM had no toxic effect on cell viability (p>0.05). Treatment with safranal significantly increased cell viability following GA or QA insults at concentrations higher than 1 µM (p<0.01). The cytoprotective potential of safranal was also accompanied by decreased ROS accumulation (p<0.001) and malondialdehyde level (p<0.001) following GA or QA insults. CONCLUSION: The data suggests that safranal exhibits oligoprotection potential by means of inhibiting oxidative stress parameters.

Everolimus, a mammalian target of rapamycin inhibitor, ameliorated streptozotocin-induced learning and memory deficits via neurochemical alterations in male rats.

Everolimus (EVR), as a rapamycin analog, is a selective inhibitor of the mammalian target of rapamycin (mTOR) kinase and its associated signaling pathway. mTOR is a serine/threonine protein kinase and its hyperactivity is involved in the pathophysiology of Alzheimer's disease (AD) and associated cognitive deficits. The present study evaluated the impact of EVR, on cognitive functions, hippocampal cell loss, and neurochemical parameters in the intracerebroventricular streptozotocin (icv-STZ) model of AD rats. EVR (1 and 5 mg/kg) was administered for 21 days following the single administration of STZ (3 mg/kg, icv) or for 7 days on days 21-28 post-STZ injection after establishment of cognitive dysfunction. Cognitive deficits (passive avoidance and spatial memory), oxidative stress parameters, acetylcholinesterase (AChE) activity, and percentage of cell loss were evaluated in the hippocampus. Chronic administration (1 and 5 mg/kg for 21 days from the day of surgery and icv-STZ infusion) or acute injection (5 mg/kg for 7 days after establishment of cognitive impairment) of EVR significantly attenuated cognitive dysfunction, neuronal loss, oxidative stress and AChE activity in the hippocampus of STZ-AD rats. In conclusion, our study showed that EVR could prevent or improve deteriorations in behavioral, biochemical and histopathological features of the icv-STZ rat model of AD. Therefore, inhibition of the hyperactivated mTOR may be an important therapeutic target for AD.

Protective effect of Rheum turkestanicum root against mercuric chloride-induced hepatorenal toxicity in rats.

OBJECTIVE: The present study was designed to investigate the protective effects of hydroalcoholic extract of Rheum turkestanicum against HgCl2 hepatorenal toxicity in rats. MATERIALS AND METHODS: Animals were randomly divided into five groups (n= 6 in each group) and received HgCl2 and plant's extract, intraperitoneally. Group1 received saline (1 mL/kg/day), group 2 received extract (200 mg/kg/day), group 3 was treated with HgCl2 (5 mg/kg/day,) and groups 4 and 5 received the extract (100 and 200 mg/kg/day, respectively), 1 hr before HgCl2 administration. All injections last for 3 days. Blood samples and specimens of the liver and kidney were collected 24 hr after the last injection. RESULTS: Data showed that HgCl2 significantly increases liver malondialdehyde (MDA) level, reduces total sulfhydryl content and increases serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity, compared to control group. The histopathological changes such as inflammatory cells infiltration was observed in HgCl2-treated group while plant's extract partially improved histological changes. The extract (100 and 200 mg/kg/day) improved the liver functions as reflected by significant reductions in AST and ALT levels in serum, MDA decreased and the content of total sulfhydryl elevated. Also, the extract improved necrosis and atrophy of the kidney induced byHgCl2. Pretreatment with the extract reduced creatinine and urea in serum, and glucose and protein concentrations in urine, compared to HgCl2- treated group (group III). The extract significantly reversed HgCl2-induced depletion in thiol content and elevation in MDA content. CONCLUSION: Therefore, oxidative stress may play an important role in HgCl2-induced hepatorenal injury and R. turkestanicum extract may be regarded as a useful to protect the kidney and liver against HgCl2-induced oxidative damage.

Protective Effect of Rheum turkestanicum against Cisplatin by Reducing Oxidative Stress in Kidney Tissue.

BACKGROUND: Cisplatin is used as chemotherapeutic drug in the treatment of some solid tumors. It causes different side effects such as nephrotoxicity because of increasing oxidative stress and reactive oxygen species production. This study was designed to investigate the effect of Rheum turkestanicum on cisplatin-induced nephrotoxicity in rat. MATERIALS AND METHODS: Animals were randomly divided into four groups (six each). Group I received normal saline (1mL/day, intraperitoneally [i.p.]). Group II received a single dose of cisplatin (8mg/kg, i.p.). Groups III and IV received extract at doses of 100mg/kg and 200mg/kg, i.p., respectively, for 3 consecutive days, 1h before a single dose of cisplatin only at the first day. Blood samples were taken for measuring the level of urea and creatinine. Furthermore, 24-h urinary factors such as glucose and protein were measured. Histopathological observation was carried out on kidney sections. Statistical analysis was performed using one-way analysis of variance followed by Tukey-Kramer post hoc test for multiple comparisons. RESULTS: Cisplatin increased the lipid peroxidation, serum creatinine, serum urea, urinary glucose, and urinary protein, whereas decreased the content of thiol in kidney. The extract reduced serum creatinine, serum urea, urinary glucose, urinary protein, lipid peroxidation, and increased thiol following cisplatin administration. Histological studies revealed lower lesions in kidney in the extract-treated groups compared to cisplatin-treated one. CONCLUSION: This research showed the extract has protective effect against cisplatin-induced nephrotoxicity. This observation may be related to antioxidant properties of the extract.

Interactive involvement of hippocampal cAMP/PKA and cyclooxygenase-2 signaling pathways in spatial learning in the Morris water maze.

INTRODUCTION: Accumulated evidence shows that the cAMP-PKA signaling pathway plays a key role in memory functions. Cyclooxygenase-2, a critical player in neuroinflammation, has been confirmed in the pathogenesis of neurodegenerative diseases. This study is aimed to assess the effect of the interaction of cAMP-PKA and cyclooxygenase pathways on spatial memory acquisition in animal models. MATERIAL AND METHODS: In the present study, the effects of the four-day bilateral intra-hippocampal infusions of H-89 as a protein kinase AII inhibitor (10 µM/side), celecoxib (0.1 M/side) as a selective cyclooxygenase-2 inhibitor, cele-coxib/H-89 and bucladesine (10 µM/side)/celecoxib/H-89 on spatial memory acquisition in the Morris water maze were investigated. Control animals received bilateral intra-hippocampal infusions of dimethyl sulfoxide. Rats were trained for 4 days; each day included one block of four trials. Post-training probe trial tests were performed on day five. RESULTS: A bilateral intra-hippocampal infusion of H-89 and celecoxib led to a significant impairment in spatial learning compared to the controls through a notable decrease in escape latency and traveled distance. But, combination treatment of animals with celecoxib/H-89 and bucladesine/celecoxib/H-89 could considerably reverse celecoxib and H-89-induced spatial memory acquisition impairments in the Morris water maze. CONCLUSIONS: These results indicate the probable regulatory effects of cAMP/PKA and cyclooxygenase-2 signaling pathways on spatial memory acquisition in the Morris water maze.