فهرست مطالب

Basic Medical Sciences - Volume:20 Issue: 5, 2017
  • Volume:20 Issue: 5, 2017
  • تاریخ انتشار: 1396/02/27
  • تعداد عناوین: 16
|
  • Youstina Michael, Laura P. Weber, Morgan Riggan, Robert S. Hoffman Pages 457-457
    Dear editor
    We read with interest the recent article by Yousefi et al “Comparison of activated charcoal (AC) and sodium polystyrene sulfonate (SPS) resin efficiency on reduction of amitriptyline oral absorption in rat as treatments for overdose and toxicities” (1). While we commend the authors for studying the important issue of gastrointestinal decontamination, we have a few concerns with this study.
    First, it was unclear why the rats were euthanized at 60 minutes, allowing for only one amitriptyline concentration. If the study objective was to assess the efficacy of AC and SPS in reducing systemic absorption of AMT, the area under the concentration vs time curve (AUC) is needed to assess the total body burden of AMT. Further, Cmax cannot be determined using a single point in time. The information presented only allows evaluation of drug concentration after 55 min or 30 min of drug contact time. In fact it is possible that SPS delayed the peak and increased the total drug absorbed, which would be missed by their sampling method.
    Additionally, we question the use of SPS in actual patients without considering the possibility of inducing
    electrolyte imbalances. SPS is known to cause hypokalemia in eukalemic subjects (2). Given that sodium bicarbonate, the standard treatment for amitriptyline toxicity, shifts potassium intracellularly, combining the two modalities may further lower the potassium and place a patient at risk of QTc prolongation and Torsade de Pointes (TdP).
    Thus, we feel that it is premature to suggest that SPS is more efficient than AC for the treatment of overdosed humans. Extrapolation of their animal model is quite difficult with the limitations we have highlighted.
  • Sobhan Faezi, Ahmad Reza Bahrmand, Seyed Davar Siadat, Iraj Nikokar, Soroush Sardari, Mehdi Mahdavi * Pages 458-466
    Objective(s)
    Infection with Pseudomonas aeruginosa has been a long-standing obstacle for clinical therapy due to the complexity of the genetics and pathogenesis, as well for widespread resistance to antibiotics, thus attaching great importance to explore effective vaccines for prevention and treatment. This paper focuses on the introduction of novel Pseudomonas aeruginosa type IV pili (T4P)-based fusion protein containing the secretin domain of PilQ and tandem PilA-related peptides.
    Materials And Methods
    We surveyed the expression of the PilQ380-705-PilA fusion protein in-frame with pET26b vector in which a rigid linker was used between two polypeptides and flexible linkers were inserted between the three tandem repeats and each pilA domains. The transformants were expressed in Escherichia coli BL21. The reactivity of specific antisera to the fusion protein was assessed by ELISA. The biological activities of this candidate vaccine were evaluated by western blotting, opsonophagocytosis, and twitching inhibition assays.
    Results
    The fusion protein was purified in high yield by osmotic shock method using HisTrap affinity column. The protein was confirmed by immunoblot analysis. The checkerboard titration showed that the optimal dilution of the antibody to react with antigen is 1:128. Results of opsonophagocytosis assay revealed that the antibodies elevated to the fusion protein promoted phagocytosis of the PAO1 and 6266E strains, so that the twitching immobilization test confirmed these results.
    Conclusion
    Due to excellent killing activity mediated by opsonic antibodies and efficient immobilization of the strains, it seems that PilQ380-705-PilA fusion protein could be a reliable candidate vaccine against P. aeruginosa infection.
    Keywords: Fusion protein, pET26b, PilA, PilQ, Pseudomonas aeruginosa, Type IV pili
  • Parinaz Ghadam*, Fatemeh Akhlaghi, Ahya Abdi Ali Pages 467-473
    Objective(s)
    Pseudomonas aeruginosais a Gram-negative and aerobic rod bacterium that displays mucoid and non-mucoid phenotype. Mucoid strains secrete alginate, which is the main agent of biofilms in chronic P. aeruginosa infections, show high resistance to antibiotics; consequently, the biological disruption of mucoid P. aeruginosa biofilms is an attractive area of study for researchers. Alginate lyase gene (algl) is a member of alginate producing operon which by glycosidase activity produces primer for other enzymes in this cluster. Also this activity can destroy the extracellular alginate; therefore this enzyme participates in alginate production and destruction pathway. Alginate lyase causes detachment of a biofilm by reducing its adhesion to the surfaces, and increases phagocytosis and antibiotic susceptibility. In this study, alginate lyase was purified in just one step and its properties were investigated.
    Materials And Methods
    The purification was done by affinity chromatography, analysed by SDS-PAGE, and its effect on P. aeruginosa biofilms was surveyed by micro titer plate assay and SEM. The substrate specificity of the enzyme was determined by PCR.
    Results
    Alginate lyase from isolate 48 was purified in one step. It is more thermally resistant than alginate lyase from Pseudomonas aeruginosa PAO1 and poly M, poly G and poly MG alginate were the substrate of this enzyme. Moreover, it has an eradication effect on biofilms from P. aeruginosa 48 and PAO1.
    Conclusion
    In this study an alginate lyase with many characteristics suitable in medicine such as thermal stability, effective on poly M alginate, and bacterial biofilm destructive was introduced and purified.
    Keywords: Alginate lyase, Pseudomonas aeruginosa, Affinity chromatography, Biofilm destruction
  • Li Wang, Wei Liu, Ying Fan, Tingting Liu, Chunjiang Yu * Pages 474-480
    Objective(s)
    Increasing evidence suggests that Alzheimer’s disease (AD) is associated with diabetes. Rosiglitazone, a peroxisome proliferator-activated receptor γ (PPAR-γ) agonist and anti-diabetic agent, may improve symptoms of AD. However, the underlying therapeutic potential of it has not been fully elucidated.
    Materials And Methods
    Rats were divided into four groups: control group, sham operated group, Streptozotocin (STZ) group, rosiglitazone (RGZ) group. Particularly, the STZ-induced rat model was established by intracerebroventricular injection (3 mg/kg) on the first and third day. The water maze behavioral test was performed to evaluate spatial reference learning and memory of the rats. Aβ1-40 and Aβ1-42 levels were measured by ELISA method. To determine APP-derived fragment, BACE1 and Aβ degrading enzymes levels, such as NEP and IDE, as well as Aβ transportation protein level, such as LRP1, RAGE, Abca1 and APOE , which were analyzed by Western blot. Immunohistochemistry was used to observe the change of Aβ1-40 and Aβ1-42 in hippocampus.
    Results
    Chronic treatment with RGZ could reduce the Aβ level and improved spatial memory performance in STZ-induced rat model. However, RGZ modified the expression of specific transport proteins monitoring Aβ clearance, such as ATP-binding cassette transporter 1 (ABCA1), lipoprotein receptor-related protein 1 (LRP1), and the advanced glycation end product-specific receptor (RAGE) rather than change levels of Aβ degrading enzymes, such as IDE and NEP, nor affect APP processing.
    Conclusion
    As a potential therapeutic strategy, rosiglitazone might exert anti-AD effect not by alteration of APP processing pathway and Aβ degradation directly, but through promotion of Aβ clearance indeed.
    Keywords: Alzheimer's disease, Amyloid precursor protein processing, ?-amyloid peptide clearance, Peroxisome proliferator activated receptor ?
  • Hong Zhao, Fei Liu, Ruichun Jia, Huiying Chang, Haixia Li, Meijuan Miao, Hui Wang, Zhiping Yang* Pages 481-488
    Objective(s)
    Chronic myelogenous leukemia (CML) is a chronic myeloproliferative disorder characterized by the accumulation of myeloid cells with a chromosomal translocation known as the Philadelphia chromosome. In this study, we investigated the roles of miR-570 in CML development.
    Materials And Methods
    Expression of miR-570 in CML samples and cell lines was determined by qRT-PCR. Glucose uptake and ATP concentration detection assays were used to analyze cell glucose metabolism. MTT and western blot assays were performed for cell proliferation and apoptosis, respectively. The targets of miR-570 were predicted by bioinformatics and confirmed using luciferase activity, qRT-PCR and western blot assays.
    Results
    The expression levels of miR-570 were significantly reduced in CML clinical samples and cells. Overexpression of miR-570 inhibited cell proliferation, promoted apoptosis, and suppressed glucose metabolism in CML cells. Insulin receptor substrates (IRS) 1 and IRS2 were identified as direct targets of miR-570. IRS1 or IRS2 were knocked down in K562 cells.Loss of IRS1/2 expression led to suppressed cell proliferation, elevated apoptosis, and decreased glucose metabolism in CML cells, which is consistent with their roles as miR-570 targets.
    Conclusion
    MiR-570 directly targeted IRS1 and IRS2 in CML, suppressing cell proliferation and glucose metabolism. MiR-570 may provide a strategy for CML therapy.
    Keywords: Chronic myelogenous leukemia, IRS1, IRS2, miR-570
  • Fatemeh Kazemi Lomedasht V., Kamran Pooshang Bagheri, Mahdi Habibi Anbouhi, Ensiyeh Hajizadeh Safar, Delavar Shahbazzadeh, Hasan Mirzahosseini, Mahdi Behdani * Pages 489-496
    Objective(s)
    Lung cancer is the main leading cause of cancer death worldwide. Angiogenesis is the main step in proliferation and spreading of tumor cells. Targeting vascular endothelial growth factor (VEGF) is an effective approach for inhibition of cancer angiogenesis. Nanobodies (NBs) are a novel class of antibodies derived from the camel. Unique characteristics of Nbs like their small size and good penetration to tumor tissues makes them promising tools in drug development. Development of NBs targeting both human and mouse VEGF is required for understanding their in vivo functions. Therefore, development of cross-species reactive anti-VEGF Nbs for immunotherapy of lung cancer was the main aim of the current study.
    Materials And Methods
    Here we developed NBs from Camelus dromedarius library with high specificity and binding affinity to both human and mouse VEGF. In vitro and In vivo function of developed NB was evaluated on human endothelial cells and lung epithelial tumor cells (TC-1).
    Results
    A nanobody showed the highest affinity to human and mouse VEGF and potently inhibited VEGF in the ELISA experiment. Anti-VEGF NBs significantly inhibited in vitro human endothelial cell migration through blockade of VEGF (P=0.045). Anti-VEGF NBs also significantly inhibited in vivo TC-1 growth in a dose-dependent manner (P=0.001) and resulted in higher survival rate in the nanobody treated group
    Conclusion
    These findings demonstrate the potential of anti-VEGF NBsin tumor growth inhibition and are promising as novel cancer therapeutic candidate.
    Keywords: Angiogenesis Immunotherapy, Lung Cancer, Nanobody, Vascular endothelial growth factor
  • Mohammad Shokrzadeh, Sara Sadat Hosseini, Marjan Fallah, Fatemeh Shaki * Pages 497-502
    Objective(s)
    Hyperglycemia promotes oxidative stress that plays a crucial role in the pathogenesis of Diabetic nephropathy (DN). In this study, we investigated the synergism effects of hydroalcoholic extract of Urtica dioica and pioglitazone (PIO) on the prevention of DN in streptozotocin induced-diabetic mice.
    Materials And Methods
    Forty-two mice were divided into six groups as follows: non-diabetic control group, DMSO group (as solvent), diabetic group and four treatment groups which received U. dioica, pioglitazone, U. dioica plus pioglitazone and vitE. Diabetes was induced by a single dose of streptozotocin (STZ) (200 mg/kg body wt, IP) diluted in citrate buffer (pH= 4.6). After 4 weeks treatment, all animals were anaesthetized and blood was collected for serum urea and creatinine levels assessment in plasma and kidney tissue were excised for evaluation of oxidative stress markers.
    Results
    Treatment with U. dioica significantly inhibited increase in serum urea and creatinine in plasma that were observed in diabetic mice. Furthermore, the elevated level of oxidative stress markers (glutathione oxidation, lipid peroxidation (LPO), protein carbonyl) in renal supernatant of diabetic mice was inhibited by U. dioica treatment. Interestingly, U. dioica promoted beneficial effects of PIO in reducing STZ-induced hyperglycemia, renal damage and oxidative stress markers.
    Conclusion
    Our findings showed that PIO plus U. dioica have synergism protective effects against STZ-induced nephropathy that can be a candidate as a therapeutic approach in order to treatment of DN.
    Keywords: Diabetes, Nephropathy, Oxidative Stress, Urtica dioica, Pioglitazone, Stereptozocin
  • Abdelrahman Abushouk, Amr Muhammad Abdo Salem, Mohamed M. Abdel Daim* Pages 503-510
    Cardiovascular disorders are the leading cause of mortality worldwide. Berberis vulgaris (B. vulgaris) is a commonly used plant in traditional medicine. In recent studies, B. vulgaris showed antiarrhythmic, antihypertensive, anticholinergic, and cardioprotective effects. We reviewed the literature to explore the possible prophylactic and therapeutic roles of B. vulgaris in cardiovascular medicine. A computer literature search was conducted to identify all relevant studies that have investigated the role of B. vulgaris in prevention or treatment of cardiovascular diseases.We also searched the citations of the retrieved articles. Using a systematic approach, we conducted a scoping review that included a total of 37 articles. Twelve studies examined the antihypertensive effects of B. vulgaris, seven studies investigated its antiarrhythmic effects, while its inotropic and cardioprotective effects were evaluated in four and eight studies, respectively. B. vulgaris showed a beneficial effect in reducing blood pressure, enhancing cardiac contractility, and protection from reperfusion injury. However, the mechanisms of these effects are still under investigation. Moreover, it could modify major risk factors for cardiovascular disorders, such as oxidative stress, hyperglycemia, and hyperlipidemia. Further studies are needed to translate these findings into effective cardiovascular medications.
    Keywords: Antiarrhythmic, Antihypertensive, Berberis vulgaris, Cardioprotective Cardiovascular
  • Suhail Ahmed Almani, Iqbal Ahmed Memon, Tariq Zaffar Shaikh, Haji Khan Khoharo*, Ikramuddin Ujjan Pages 511-515
    Objective(s)
    Causality of occurrence of metformin-associated lactic acidosis (MALA) is a clinical problem. Currently, there is no drug available to prevent MALA. The present study was conducted to evaluate the protective effect of Berberine (BBR) against MALA in induced diabetic rat model.
    Materials And Methods
    A sample of 75 healthy male Wistar rats was randomly selected according to inclusion and exclusion criteria. 75 male Wistar rats were randomly divided into a control and 4 experimental groups. Streptozotocin (STZ) in citrate buffer (pH 4.5) at a dose of 45 mg/kg was injected for induction of diabetes mellitus and rats achieving fasting blood glucose >250 mg/dl were included. Blood samples were collected 18 hr after the last dose of metformin and berberine. Ethical approval was taken before the study was conducted. Staistix 10.0 (USA) software was used for data analysis.
    Results
    Berberine decreased MALA. Metformin, metformin BBR 50 mg/kg bwt, and metformin BBR 100 mg/kg bwt showed serum lactate as 1.87±0.4 mmol/lL, 1.62 ± 0.44 mmol/l and 1.47± 0.45 mmol/l, respectively (P=0.0001). Insulin resistance and liver enzymes were improved in BBR treated rats.
    Conclusion
    The present study reports berberine protects against MALA in streptozocin-induced diabetes mellitus.
    Keywords: Berberine, Insulin resistance, Lactic acidosis, Metformin
  • Seyede Zohre Kamrani Rad, Maryam Rameshrad, Hossein Hosseinzadeh* Pages 516-529
    Berberis vulgaris and berberine, its main component, traditionally have been used for treatment of various disorders. The pharmacological properties of them have been investigated using different in vivo and in vitro models. In spite of beneficial effects of B. vulgaris on different cell lines, there are documents have revealed negative impacts of it on animal and human. In this regards, the determination of its toxicity in a scientific view is necessary. In current report, we provide classified information about the toxicity of B. vulgaris and berberine in different conditions consist of acute, sub-acute, sub-chronic and chronic state. Besides, it discusses the cytotoxicity, genotoxicity, mutagenicity, and carcinogenicity of B. vulgaris and berberine as well as developmental toxicity and clinical studies. Data from the present study indicate that their toxicity is depending on the route and duration of administration. According to present study, they could induce GI upset and ulceration, immunotoxicity, phototoxicity, neurotoxicity, cardiotoxicity and jaundice in a dose dependent manner. They should be used with caution in pregnancy, neonatal and G6PD deficiency. Besides, consideration should be taken in co-administration of berberine with drugs that are metabolized with CYP enzymes due their inhibitory effects on these enzymes. Furthermore, they evoke cytotoxicity on both normal and cancer cell line which is time and concentration dependent.
    Keywords: Acute toxicity, Berberine, Berberis vulgaris, Cancer cell, chronic toxicity, CYP enzyme, Developmental toxicity, Pregnancy
  • Saeed Mohammadi, Fakhri Sadat Seyedhoseini, Jahanbakhsh Asadi, Yaghoub Yazdani * Pages 530-537
    Objective(s)
    Current acute myeloid leukemia (AML) therapeutic strategies have irreversible side-effects. Berberine (BBR) is an isoquinoline alkaloid, which has been known as an aryl hydrocarbon receptor (AhR) ligand. AhR is a cytoplasmic receptor, which is involved in the regulation of cellular and immune responses. Here, we investigated the expression profile of genes involved in the cell cycle and different cytokines upon BBR-mediated AhR activation on AML THP-1 cell line.
    Materials And Methods
    THP-1 cells and normal monocytes were treated with different concentrations of BBR (10 μM, 25 μM, 50 μM, and 100 μM) for 24 and 48 hr. The cell viability was measured by MTT assay. Real-time RT-PCR was conducted to evaluate the expression of AhR, cytochrome P450 1A1 (CYP1A1), interleukin 1 beta (IL1β), p21, p27, cyclin-dependent kinase 2 (CDK2) and p53. Cellular expression of AhR was also assessed using immunofluorescence method. ELISA was used to determine the level of IL-10 and IL-12 cytokines.
    Results
    BBR inhibits the proliferation of THP-1 cells in a dose- and time-dependent manner with minimal toxicity on normal monocytes. Phorbol 12-myristate 13-acetate (PMA) treatment increased the cellular expression of AhR. The AhR target genes (CYP1A1, IL1β) were overexpressed upon BBR treatment. BBR downregulated Cdk2 and upregulated p21, p27 and p53 genes in THP-1 cells. IL-10 was significantly increased upon BBR treatment, while IL-12 was not significantly changed in all combinations.
    Conclusion
    BBR could be introduced as an effective chemotherapeutic agent against AML by giving rise to the expression of CDK inhibitors and anti-inflammatory cytokines and downregulation of CDK2.
    Keywords: Acute myeloid leukemia, Aryl hydrocarbon receptor, Berberine, Cell cycle regulation, THP-1
  • Nooshin Mohammadzadeh, Soghra Mehri, Hossein Hosseinzadeh* Pages 538-551
    Berberis vulgaris L (B. vulgaris) and its main constituent berberine have been used in traditional medicine for a long time. This medicinal plant and berberine have many properties that have attracted the attention of researchers over the time. According to several studies, B. vulgaris and berberine exhibited anti-inflammatory, antioxidant, anticonvulsant, antidepressant, anti-Alzheimer, anti-cancer, anti-arrhythmic, antiviral, antibacterial and anti-diabetic effects in both in vitro and in vivo experiments. In regard to many reports on protective effects of B. vulgaris and berberine on natural and chemical toxins, in the current review article, the inhibitory effects of these compounds against natural, industrial, environmental and chemical toxicities with focus on cellular mechanism have been categorized. It has been mentioned that berberine could ameliorate toxicity of chemical toxins in brain, heart, kidney, liver and lung in part through antioxidant, anti-inflammatory, anti-apoptotic, modulation of mitogen-activated protein kinase (MAPK) and nuclear factor-ĸB (NF-ĸB) signaling pathways.
    Keywords: Antidote, Anti-inflammation, Antioxidant, Barberry, Berberine, Berberis vulgaris, Chemical toxin, Natural toxin
  • Mohammad Rahimi-Madiseh, Paridokht Karimian, Marzieh Kafeshani, Mahmoud Rafieian Kopaei * Pages 552-556
    Objective(s)
    Various studies have shown that the diabetes is associated with liver failure. The objective of this study was determining the effects of Berberis vulgaris fruit on histopathological and biochemical markers of liver in diabetic rats.
    Materials And Methods
    In this experimental study, 60 male Wistar rats weighing 200-250 g with free access to water and ad libitum were randomly divided to five twelve-membered groups including healthy control (group 1), diabetic control (group 2, this two groups received distilled water), treated diabetic positive control (group 3) using dose 150 mg/kg/day metformin, and two groups treated with doses 200 (group 4) and 600 (group 5) mg/kg/BW of B. vulgaris extracts via gavage feeding for 8 weeks. Diabetes mellitus was experimentally induced by one dose injection of alloxan 120 mg/kg. This pre-clinical study was performed on 120 mg/kg alloxan induced diabetic rats.
    Results
    The hepatic steatosis status, liver cholestasis and fibrosis were not changed in group 4 and 5. Glycogen deposition changed mildly and polymorphonuclear neutrophils infiltration changed moderately at group 5. Liver hepatitis changed mildly and severely at group 3 as well as group 5, respectively. Glucose, serum glutamic-oxaloacetic transaminase, serum glutamic pyruvic transaminase, and alkaline phosphatase were lower in high dose group compared to other groups.
    Conclusion
    Results suggested that B. vulgaris extract can decrease liver damage by influencing hepatic histopathological and biochemical markers in diabetic rats.
    Keywords: Berberine, Biochemical markers, Diabetes, Histopathology, Herbal medicine, Liver diseases
  • Jamshid Tabeshpour, Mohsen Imenshahidi, Hossein Hosseinzadeh* Pages 557-568
    Metabolic syndrome (MetS), characterized by a cluster of metabolic abnormalities including hypertension, obesity, type 2 diabetes mellitus (T2DM) and dyslipidemia, is a well-known cardiovascular risk factor (CVRF). Cardiovascular disease (CVD) represents a massive healthcare burden worldwide. In recent years, with regard to the adverse effects of synthetic drugs, increasing attention has been paid by researchers to herbal medicines for a variety of disorders such as CVD. A large body of literature supports different pharmacological actions of Berberis vulgaris (B. vulgaris) and its active component, berberine (BBR), such as antidiabetic, antiobesity, hypotensive and hypolipidemic properties that could be interesting in the management of MetS associated with high CVD risk. Numerous preclinical in vitro and in vivo studies support all these effects. In this review, we evaluated the most related original articles to discover the role of B. vulgaris on various constituents of MetS and CVRF comprising dyslipidemia, obesity, high blood pressure and high blood glucose.
    This review suggests a potential role of B. vulgaris and BBR in the managing of MetS; nevertheless more investigations, especially reliable clinical trials, need to be accomplished to evaluate their effectiveness.
    Keywords: Berberis vulgaris, Berberine, Cardiovascular disease, Diabetes, Dyslipidemia, Hypertension, metabolic syndrome
  • Mohammad Rahimi-Madiseh, Zahra Lorigoini, Hajar Zamani-Gharaghoshi, Mahmoud Rafieian Kopaei * Pages 569-587
    The medicinal plants from genus Berberis are particularly important in traditional medicine and the food basket of Iranians. Given various plants from genus Berberis and their economic, nutritional, and medicinal status in Iran, this study seeks to investigate the findings of recent studies on the phytochemical characteristics, specifications, and uses of Berberis vulgaris. In this review article, 350 articles were initially retrieved from reliable scientific databases using relevant search terms. Then, 230 articles were selected and 120 were excluded after a primary analysis. Finally, 98 articles related to the subject under study were meticulously examined and the required data were extracted and classified according to the research purposes. The findings were divided into eight separate sections: Introducing Berberidaceae family, different species of Berberis, pharmaceutical organs, B. vulgaris nutrition facts and minerals, the antioxidants and alkaloids compounds in fruit and other organs, action mechanisms of preventing and treating diseases, traditional uses of B. vulgaris, and its properties reported by recent studies. The results briefly indicate that B. vulgaris contains a large number of phytochemical materials including ascorbic acid, vitamin K, several triterpenoids, more than 10 phenolic compounds and more than 30 alkaloids. Therefore B. vulgaris may have anti-cancer, anti-inflammatory, antioxidant, antidiabetic, antibacterial, analgesic and anti-nociceptive and hepato-protective effects. Regarding the use of different organs of B. vulgaris in traditional medicine and their confirmed effects in the recent studies, it is possible to use different organs of B. vulgaris, especially fruit, to develop new drugs.
    Keywords: Berberis, Iran, Plants Medicinal, Secondary Metabolism, Traditional
  • Berberine attenuates convulsing behavior and extracellular glutamate and aspartate changes in 4-aminopyridine treated rats
    Hamid Reza Sadeghnia, Ali Reza Taji, Fatemeh Forouzanfar, Hossein Hosseinzadeh * Pages 588-593
    Objective(s)
    K channel blocker 4-aminopyridine (4-AP) stimulates the release of glutamate from nerve terminals and induces seizures. Berberine as a potential herbal drug exerts several pharmacological actions on the central nervous system including anxiolytic, anticonvulsant, and neuroprotective properties. The present study aimed to investigate the effect of berberine on seizure onset and time course of the extracellular levels of excitatory amino acids (EAA), glutamate and aspartate, changes produced by 4-AP in rat hippocampus.
    Materials And Methods
    The rats were given either saline or berberine (50, 100 and 200 mg/kg, IP) 40 min before administration of 4-AP (15 mg/kg, IP) and the onset of seizure was recorded. A group of rats also received diazepam (DZP, 15 mg/kg, IP) 20 min prior to 4-AP administration. Hippocampal extracellular levels of EAA were also measured using microdialysis assay. Analysis of the dialysate samples was performed by reversed-phase high performance liquid chromatography (HPLC) with precolumn derivatization with o-phthaldialdehyde and fluorescence detection.
    Results
    Our findings suggest that berberine significantly delayed the seizure onset following 4-AP injection. There was a considerable increase in the extracellular glutamate and aspartate levels in 4-AP treated rats and 4-AP-evoked release of EAA was sharply reduced (about 4-5 fold especially at 20 min after 4-AP administration) in berberine treatment groups.
    Conclusion
    The results of present study show that berberine attenuates 4-AP induced seizures by decreasing hippocampal aspartate and glutamate release in rats.
    Keywords: Barberry, Berberis vulgaris, Berberine, Excitatory amino acids, 4-Aminopyridine (4-AP), Seizure