scholarly journals Synedrella nodiflora Extract Depresses Excitatory Synaptic Transmission and Chemically-Induced In Vitro Seizures in the Rat Hippocampus

2021 ◽  
Vol 12 ◽  
Author(s):  
Patrick Amoateng ◽  
Thomas A. Tagoe ◽  
Thomas K. Karikari ◽  
Kennedy K. E Kukuia ◽  
Dorcas Osei-Safo ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Hippocampal Neurons ◽  
Seizure Activity ◽  
Ethanolic Extract ◽  
Excitatory Synaptic Transmission ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Ca1 Region ◽  
Synedrella Nodiflora

Extracts of the tropical Cinderella plant Synedrella nodiflora are used traditionally to manage convulsive conditions in the West African sub-region. This study sought to determine the neuronal basis of the effectiveness of these plant extracts to suppress seizure activity. Using the hippocampal slice preparation from rats, the ability of the extract to depress excitatory synaptic transmission and in vitro seizure activity were investigated. Bath perfusion of the hydro-ethanolic extract of Synedrella nodiflora (SNE) caused a concentration-dependent depression of evoked field excitatory postsynaptic potentials (fEPSPs) recorded extracellularly in the CA1 region of the hippocampus with maximal depression of about 80% and an estimated IC50 of 0.06 mg/ml. The SNE-induced fEPSP depression was accompanied by an increase in paired pulse facilitation. The fEPSP depression only recovered partially after 20 min washing out. The effect of SNE was not stimulus dependent as it was present even in the absence of synaptic stimulation. Furthermore, it did not show desensitization as repeat application after 10 min washout produced the same level of fEPSP depression as the first application. The SNE effect on fEPSPs was not via adenosine release as it was neither blocked nor reversed by 8-CPT, an adenosine A1 receptor antagonist. In addition, SNE depressed in vitro seizures induced by zero Mg2+ and high K+ -containing artificial cerebrospinal fluid (aCSF) in a concentration-dependent manner. The results show that SNE depresses fEPSPs and spontaneous bursting activity in hippocampal neurons that may underlie its ability to abort convulsive activity in persons with epilepsy.

scholarly journals In vitro inhibitory potentials of ethanolic extract of Moringa oleifera flower against enzymes activities linked to diabetes

2021 ◽  
Vol 10 (4) ◽  
pp. 408-414
Author(s):  
Oluwaseun Ruth Olasehinde ◽  
Olakunle Bamikole Afolabi ◽  
Benjamin Olusola Omiyale ◽  
Oyindamola Adeniyi Olaoye
Keyword(s):  
Free Radical ◽  
Moringa Oleifera ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Ethanolic Extract ◽  
Antidiabetic Activity ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Antioxidant Power

Introduction: Diabetes mellitus (DM) has been recognized as the seventh leading cause of global mortality; however, researchers seek alternative means to manage the menace. The current study sought to investigate antioxidant potentials, α-amylase, and α-glucosidase inhibitory activities of ethanolic extract of Moringa oleifera flower in vitro. Methods: Antioxidant properties of the extract were appraised by assessing its inhibition against 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl (OH•), and hydrogen peroxide (H2O2) free radicals, as well as ferric reducing antioxidant power (FRAP), the antidiabetic activity was evaluated by α-amylase and α-glucosidase inhibition.Results: In this study, ethanolic extract of M. oleifera flower demonstrated a significant (P < 0.05) inhibition against DPPH free radical (43.57–83.56%) in a concentration-dependent manner, while FRAP (101.76 ± 1.63 mg/100 g), OH• scavenging ability (71.62 ± 0.95 mg/100 g), and H2O2 free radical scavenging capacity (15.33 ± 1.20 mg/100 g) were also observed. In the same manner, ethanolic extract of M. oleifera flower revealed a significant (P < 0.05) inhibition against α-amylase (IC50= 37.63 mg/mL) and α-glucosidase activities (IC50= 38.30 mg/mL) in the presence of their respective substrates in a concentration-dependent manner in comparison with acarbose. Conclusion: Ethanoic extract of M. oleifera flower could be useful as an alternative phytotherapy in the management of DM, having shown a strong antioxidative capacity and substantial inhibition against the activities of key enzymes involved in carbohydrate hydrolysis in vitro.

Characterization of dopamine receptors mediating inhibition of excitatory synaptic transmission in the rat hippocampal slice

1996 ◽  
Vol 76 (3) ◽  
pp. 1887-1895 ◽  
Author(s):  
K. S. Hsu
Keyword(s):  
Synaptic Transmission ◽  
Receptor Antagonist ◽  
Receptor Agonist ◽  
Hippocampal Slices ◽  
D2 Receptor ◽  
D1 Receptor ◽  
Excitatory Synaptic Transmission ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Ca1 Neurons

1. The effect of dopamine (DA) on the excitatory synaptic transmission was studied in the CA1 neurons of rat hippocampal slices using intracellular recording technique. 2. Depolarizing excitatory postsynaptic potentials (EPSPs) were evoked by stimulation of the Schaffer collateral-commissural pathway. Superfusion of DA (0.03-1 microM) reversibly decreased the EPSP in a concentration-dependent manner and with an estimated IC50 of 0.3 microM. The sensitivity of postsynaptic neurons to the glutamate-receptor agonists, alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid or N-methyl-D-aspartate was unchanged by DA (0.3 microM) pretreatment. In addition, DA (0.3 microM) increased the magnitude of paired-pulse facilitation, a phenomenon attributed to an increase in the amount of transmitter released in response to the second stimulus. 3. The reduction of DA (0.3 microM) on the EPSP was antagonized by sulpiride (1-10 nM), a selective D2-receptor antagonist. However, D1-receptor antagonist, SKF-83566 (1-10 microM), did not significantly affect the reduction of DA (0.3 microM) on the EPSP. 4. (+/-)-2-(N-Phenylethyl-N-propyl)amino-5-hydroxytetralin (1 microM), an agonist of D2 receptor, mimicked the inhibitory effect of DA on the EPSP. However, neither the D1-receptor agonist SKF-38393 (1 microM) nor the D3-receptor agonist (PD-128,907 (1 microM) affected the EPSP. 5. Incubation of hippocampal slices with pertussis toxin (PTX, 5 micrograms/ml) for 12 h prevented the reduction of EPSP induced by DA (0.3 microM). 6. Rp-adenosine-3',5'-cyclic monophosphothioate (25 microM), a potent inhibitor of protein kinase A (PKA), alone decreased the amplitude of EPSP below baseline values and prevented the subsequent reduction by DA (0.3 microM). 7. These results indicate that DA at a low concentration (< or = 0.3 microM) reduces the excitatory response of hippocampal CA1 neurons after synaptic stimulation via the activation of presynaptic D2 receptors. The presynaptic action of DA is mediated by a PTX-sensitive Gi-proteins-coupled to PKA pathway.

scholarly journals Experimental Assessment ofMoringa oleiferaLeaf and Fruit for Its Antistress, Antioxidant, and Scavenging Potential UsingIn VitroandIn VivoAssays

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Suaib Luqman ◽  
Suchita Srivastava ◽  
Ritesh Kumar ◽  
Anil Kumar Maurya ◽  
Debabrata Chanda
Keyword(s):  
Aqueous Extract ◽  
Moringa Oleifera ◽  
Evaluation Studies ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Ethanolic Extract ◽  
Dependent Manner ◽  
Concentration Dependent Manner

We have investigated effect ofMoringa oleiferaleaf and fruit extracts on markers of oxidative stress, its toxicity evaluation, and correlation with antioxidant properties usingin vitroandin vitroassays. The aqueous extract of leaf was able to increase the GSH and reduce MDA level in a concentration-dependent manner. The ethanolic extract of fruit showed highest phenolic content, strong reducing power and free radical scavenging capacity. The antioxidant capacity of ethanolic extract of both fruit and leaf was higher in thein vitroassay compared to aqueous extract which showed higher potentialin vivo. Safety evaluation studies showed no toxicity of the extracts up to a dose of 100 mg/kg body weight. Our results support the potent antioxidant activity of aqueous and ethanolic extract ofMoringa oleiferawhich adds one more positive attribute to its known pharmacological importance.

scholarly journals In vitro antioxidant activity of stem bark of Trichilia catigua Adr. Juss

2012 ◽  
Vol 62 (3) ◽  
pp. 371-382 ◽  
Author(s):  
Jean Paul Kamdem ◽  
Sílvio Terra Stefanello ◽  
Aline Augusti Boligon ◽  
Caroline Wagner ◽  
Ige Joseph Kade ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Ethanolic Extract ◽  
Stem Bark ◽  
Total Phenolic ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
High Concentrations ◽  
Dpph Scavenging

Antioxidant activity of the ethanolic extract and fractions from the stem bark of T. catigua was investigated. IC50 (for DPPH scavenging) by T. catigua varied from 9.17 ± 0.63 to 76.42 ± 5.87 mg mL-1 and total phenolic content varied from 345.63 ± 41.08 to 601.27 ± 42.59 mg GAE g-1 of dry extract. Fe2+-induced lipid peroxidation was significantly reduced by the ethanolic extract and fractions. Mitochondrial Ca2+-induced dichlorofluorescein oxidation was significantly reduced by the ethanolic extract in a concentration-dependent manner. Ethanolic extract reduced mitochondrial Dym only at high concentrations (40-100 mg mL-1), which indicates that its toxicity does not overlap with its antioxidant effects. Results suggest involvement of antioxidant activities of T. catigua in its pharmacological properties.

GABAB receptors presynaptically modulate excitatory synaptic transmission in the rat supraoptic nucleus in vitro

1996 ◽  
Vol 76 (2) ◽  
pp. 1166-1179 ◽  
Author(s):  
S. B. Kombian ◽  
J. A. Zidichouski ◽  
Q. J. Pittman
Keyword(s):  
Synaptic Transmission ◽  
Receptor Agonist ◽  
Supraoptic Nucleus ◽  
Gabab Receptor ◽  
Synaptic Depression ◽  
Receptor Activation ◽  
Excitatory Synaptic Transmission ◽  
Gabab Receptors ◽  
Dependent Manner

1. The effect of gamma-aminobutyric acid-B (GABAB)-receptor activation on excitatory synaptic transmission in the rat supraoptic nucleus (SON) was examined using the nystatin perforated-patch whole cell recording technique in coronal hypothalamic slices. 2. Stimulation of the hypothalamic region dorso-medial to the SON elicited glutamate and GABAA-receptor-mediated synaptic responses in electrophysiologically identified magnocellular neurosecretory cells. 3. Bath application of the GABAB-receptor agonist, +/- -baclofen reversibly reduced pharmacologically isolated, glutamate-mediated excitatory postsynaptic currents (EPSCs) in a concentration-dependent manner. At the concentrations used, baclofen altered neither the postsynaptic conductances of these cells nor their response to bath applied alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA). 4. The baclofen-induced synaptic depression was accompanied by an increase in paired pulse facilitation (PPF). This increase in PPF, as well as the synaptic depression, was blocked by the GABAB-receptor antagonists CGP36742 and saclofen. 5. In addition to blocking the actions of baclofen in this nucleus, CGP36742 caused an increase in the evoked EPSC amplitude without altering postsynaptic cell conductances or responses induced by bath-applied AMPA. Contrary to the action of CGP36742, saclofen caused a baclofen-like depression of the evoked EPSC, suggesting that it may act as a partial GABAB receptor agonist. 6. These results indicate that the activation of presynaptic GABAB receptors reduces fast excitatory synaptic transmission in the SON. They further suggest that presynaptic GABAB receptors may be tonically activated in vitro. Thus GABAB receptors may influence the level of activity and excitation of SON neurons and hence modulate the secretion of the regulatory neuropeptides vasopressin and oxytocin.

scholarly journals Functional Characterization of Acetylcholine Receptors Expressed in Human Neurons Differentiated from Hippocampal Neural Stem/Progenitor Cells

2016 ◽  
Vol 21 (10) ◽  
pp. 1065-1074 ◽  
Author(s):  
Kazuyuki Fukushima ◽  
Kazuto Yamazaki ◽  
Norimasa Miyamoto ◽  
Kohei Sawada
Keyword(s):  
Progenitor Cells ◽  
Hippocampal Neurons ◽  
Acetylcholine Receptors ◽  
Functional Characterization ◽  
Calcium Flux ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Human Neurons ◽  
Neural Stem Progenitor Cells

Neurotransmission mediated by acetylcholine receptors (AChRs) plays an important role in learning and memory functions in the hippocampus. Impairment of the cholinergic system contributes to Alzheimer’s disease (AD), indicating the importance of AChRs as drug targets for AD. To improve the success rates for AD drug development, human cell models that mimic the target brain region are important. Therefore, we characterized the functional expression of nicotinic and muscarinic AChRs (nAChRs and mAChRs, respectively) in human hippocampal neurons differentiated from hippocampal neural stem/progenitor cells (HIP-009 cells). Intracellular calcium flux in 4-week differentiated HIP-009 cells demonstrated that the cells responded to acetylcholine, nicotine, and muscarine in a concentration-dependent manner (EC50 = 13.4 ± 0.5, 6.0 ± 0.4, and 35.0 ± 2.5 µM, respectively). In addition, assays using subtype-selective compounds revealed that major AD therapeutic target AChR subtypes—α7 and α4β2 nAChRs, as well as M1 and M3 mAChRs—were expressed in the cells. Furthermore, neuronal network analysis demonstrated that potentiation of M3 mAChRs inhibits the spontaneous firing of HIP-009 neurons. These results indicate that HIP-009 cells are physiologically relevant for AD drug screening and hence are loadstars for the establishment of in vitro AD models.

scholarly journals In vitro alpha-glucosidase and alpha-amylase enzyme inhibitory effects of Andrographis paniculata extract and andrographolide.

2008 ◽  
Vol 55 (2) ◽  
pp. 391-398 ◽  
Author(s):  
Rammohan Subramanian ◽  
M Zaini Asmawi ◽  
Amirin Sadikun
Keyword(s):  
Inhibitory Activity ◽  
Ethanolic Extract ◽  
Andrographis Paniculata ◽  
Alpha Amylase ◽  
In Vivo Studies ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Alpha Glucosidase

There has been an enormous interest in the development of alternative medicines for type 2 diabetes, specifically screening for phytochemicals with the ability to delay or prevent glucose absorption. The goal of the present study was to provide in vitro evidence for potential inhibition of alpha-glucosidase and alpha-amylase enzymes, followed by a confirmatory in vivo study on rats to generate a stronger biochemical rationale for further studies on the ethanolic extract of Andrographis paniculata and andrographolide. The extract showed appreciable alpha-glucosidase inhibitory effect in a concentration-dependent manner (IC(50)=17.2+/-0.15 mg/ml) and a weak alpha-amylase inhibitory activity (IC(50)=50.9+/-0.17 mg/ml). Andrographolide demonstrated a similar (IC(50)=11.0+/-0.28 mg/ml) alpha-glucosidase and alpha-amylase inhibitory activity (IC(50)=11.3+/-0.29 mg/ml). The positive in vitro enzyme inhibition tests paved way for confirmatory in vivo studies. The in vivo studies demonstrated that A. paniculata extract significantly (P

scholarly journals Endothelial Nitric Oxide Mediates the Anti-Atherosclerotic Action of Torenia concolor Lindley var. Formosama Yamazaki

2020 ◽  
Vol 21 (4) ◽  
pp. 1532
Author(s):  
Li-Ching Cheng ◽  
Bei-Chia Guo ◽  
Chia-Hui Chen ◽  
Chi-Jen Chang ◽  
Ta-Sen Yeh ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Inflammatory Response ◽  
Ethanolic Extract ◽  
No Production ◽  
Dependent Manner ◽  
Akt Inhibitor ◽  
Concentration Dependent Manner ◽  
Compound C ◽  
Endothelial Nitric Oxide

Torenia concolor Lindley var. formosama Yamazaki ethanolic extract (TCEE) is reported to have anti-inflammatory and anti-obesity properties. However, the effects of TCEE and its underlying mechanisms in the activation of endothelial nitric oxide synthase (eNOS) have not yet been investigated. Increasing the endothelium-derived nitric oxide (NO) production has been known to be beneficial against the development of cardiovascular diseases. In this study, we investigated the effect of TCEE on eNOS activation and NO-related endothelial function and inflammation by using an in vitro system. In endothelial cells (ECs), TCEE increased NO production in a concentration-dependent manner without affecting the expression of eNOS. In addition, TCEE increased the phosphorylation of eNOS at serine 635 residue (Ser635) and Ser1179, Akt at Ser473, calmodulin kinase II (CaMKII) at threonine residue 286 (Thr286), and AMP-activated protein kinase (AMPK) at Thr172. Moreover, TCEE-induced NO production, and EC proliferation, migration, and tube formation were diminished by pretreatment with LY294002 (an Akt inhibitor), KN62 (a CaMKII inhibitor), and compound C (an AMPK inhibitor). Additionally, TCEE attenuated the tumor necrosis factor-α-induced inflammatory response as evidenced by the expression of adhesion molecules in ECs and monocyte adhesion onto ECs. These inflammatory effects of TCEE were abolished by L-NG-nitroarginine methyl ester (an NOS inhibitor). Moreover, chronic treatment with TCEE attenuated hyperlipidemia, systemic and aortic inflammatory response, and the atherosclerotic lesions in apolipoprotein E-deficient mice. Collectively, our findings suggest that TCEE may confer protection from atherosclerosis by preventing endothelial dysfunction.

scholarly journals Inhibition of Cgkii Suppresses Seizure Activity and Hippocampal Excitation by Regulating the Postsynaptic Delivery of Glua1

2018 ◽  
Vol 46 (1) ◽  
pp. 160-177 ◽  
Author(s):  
Juan Gu ◽  
Xin Tian ◽  
Wei Wang ◽  
Qin Yang ◽  
Peijia Lin ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Seizure Activity ◽  
Epileptic Seizures ◽  
Postsynaptic Membrane ◽  
Excitatory Synaptic Transmission ◽  
Ampa Receptor Subunit ◽  
Dependent Protein ◽  
And Function

Background/Aims: The imbalance between excitation and inhibition is a defining feature of epilepsy. GluA1 is an AMPA receptor subunit that can strengthen excitatory synaptic transmission when upregulated in the postsynaptic membrane, which has been implicated in the pathogenesis of epilepsy. cGKII, a cGMP-dependent protein kinase, regulates the GluA1 levels at the plasma membrane. Methods: To explore the role of cGKII in epilepsy, we investigated the expression of cGKII in patients with temporal lobe epilepsy (TLE) and in a pilocarpine-induced rat model and then performed behavioral, histological, and electrophysiological analyses by applying either a cGKII agonist or inhibitor in the hippocampus of the animal model. Results: cGKII expression was upregulated in the epileptogenic brain tissues of both humans and rats. Pharmacological activation or inhibition of cGKII induced changes in epileptic behaviors in vivo and epileptic discharges in vitro. Further studies indicated that cGKII activation disrupted the balance of excitation and inhibition due to strengthened AMPAR-mediated excitatory synaptic transmission. Moreover, cGKII regulated epileptic seizures by phosphorylating GluA1 at Ser845 to modulate the expression and function of GluA1 in the postsynaptic membrane. Conclusion: These results suggest that cGKII plays a key role in seizure activity and could be a potential therapeutic target for epilepsy.

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