scholarly journals Effects of Diltiazem on in Vitro Cardiovascular Actions of Crude Venom Obtained from Okinawan Box-Jellyfish (Habu-kurage), Chiropsalmus quadrigatus

2002 ◽  
Vol 30 (5) ◽  
pp. 570-577 ◽  
Author(s):  
M. Sakanashi ◽  
T. Matsuzaki ◽  
J. Nakasone ◽  
T. Koyama ◽  
M. Sakanashi ◽  
...  
Keyword(s):  
Calcium Influx ◽  
Aortic Ring ◽  
Right Atrial ◽  
Dependent Manner ◽  
Crude Venom ◽  
Concentration Dependent Manner ◽  
Box Jellyfish ◽  
Beating Rate ◽  
Isolated Rat

The venom obtained from Okinawan box-jellyfish (Habu-kurage), Chiropsalmus quadrigatus, produced increases in contractions of isolated rat right atrial preparations in a concentration-dependent manner without changes in a spontaneous beating rate. These increases in contractions were significantly inhibited by diltiazem and did not show tachyphylaxis. The venom also produced increases in contractions of isolated rat aortic ring preparations (endothelium-intact) in a concentration-dependent fashion, which were reproducible with repeated application and were significantly inhibited by diltiazem or heating. These increases in vascular contractions were weakened in endothelium-denuded preparations, and almost abolished in a calcium-free medium. On the other hand, the venom at higher concentrations diminished contractions of both myocardial and vascular preparations and did not show reproducibility. These results suggest that the Habu-kurage venom is heat-labile and may increase contractions of cardiac muscle and aortic smooth muscle by increasing calcium influx into muscle cells, and that the venom at higher concentrations may produce dysfunction of muscle contractile systems due to calcium overload.

In vitro myometrial inhibition by the partitioned aqueous fraction of Anthocleista djalonensis leaves

2010 ◽  
Vol 88 (9) ◽  
pp. 880-887
Author(s):  
Enitome Evi Bafor ◽  
Lucky Osaro Okunrobo
Keyword(s):  
Uterine Contraction ◽  
Calcium Influx ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Response Curves ◽  
Concentration Dependent Manner ◽  
Aqueous Fraction ◽  
Uterine Contractions ◽  
Β Adrenergic Receptors

This study investigated the effect on the uterus of the aqueous fraction of the partitioned methanol crude extract of the leaves of Anthocleista djalonensis (AD) and the possible mechanism of AD activity. AD inhibited the concentration–response curves induced by oxytocin and CaCl2 on the rat uterus in vitro and significantly reduced the EC50 in a concentration-dependent manner (p < 0.05). A similar effect was observed with salbutamol and verapamil on the concentration–response curves obtained for oxytocin and CaCl2. The inhibitory effect of AD was not attenuated in the presence of propranolol. AD, salbutamol, and verapamil also produced a concentration-dependent relaxation on K+-induced sustained uterine contraction. In Ca2+-free medium, AD and salbutamol similarly inhibited oxytocin-induced contraction, but verapamil failed to produce this effect. The present results suggest that AD, being a mixture of phytochemicals, probably exerts inhibitory activity on in vitro uterine contractions of the nonpregnant, diethylstilboestrol-treated rat by multiple mechanisms that do not involve interaction with β-adrenergic receptors and do not solely depend on inhibition of calcium influx.

scholarly journals Inhibition of neural phospholipase D activity by aminoglycoside antibiotics

1991 ◽  
Vol 279 (1) ◽  
pp. 319-321 ◽  
Author(s):  
M Liscovitch ◽  
V Chalifa ◽  
M Danin ◽  
Y Eli
Keyword(s):  
Side Effects ◽  
Rat Brain ◽  
Phospholipase D ◽  
Aminoglycoside Antibiotics ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Brain Membranes ◽  
Rat Brain Membranes ◽  
Isolated Rat

The effects of aminoglycoside antibiotics on phospholipase D (PLD) activity were investigated in permeabilized NG108-15 cells and in isolated rat brain membranes. Neomycin inhibited guanosine 5′-[gamma-thio]triphosphate-stimulated PLD activity in digitonin-permeabilized NG108-15 cells in a concentration-dependent manner (50% inhibition at 100 microM). Neomycin similarly inhibited PLD activity present in rat brain membranes and assayed in vitro with [3H]phosphatidylcholine as substrate (50% inhibition at 65 microM). Other aminoglycosides tested (kanamycin, geneticin and streptomycin) were nearly equipotent inhibitors of rat brain PLD. These results indicate that aminoglycoside antibiotics inhibit phosphatidylcholine-PLD activity with comparable and sometimes greater potency than their well known inhibition of phosphoinositide-phospholipase C. The possibility that PLD inhibition could mediate some of the toxic side effects of aminoglycosides is suggested.

Effects of atriopeptin III on isolated rat afferent and efferent arterioles

1991 ◽  
Vol 261 (6) ◽  
pp. F1102-F1109 ◽  
Author(s):  
D. M. Lanese ◽  
B. H. Yuan ◽  
S. A. Falk ◽  
J. D. Conger
Keyword(s):  
Angiotensin Ii ◽  
Lumen Diameter ◽  
Dependent Manner ◽  
Ang Ii ◽  
Concentration Dependent Manner ◽  
Isolated Rat ◽  
Rat Kidneys

The effects of atriopeptin III (AP III) on in vitro prepared afferent (AA) and efferent arterioles (EA) from rat kidneys were tested in a system in which lumen diameter could be measured. AP III (10(-13)-10(-7) M) had no effect on lumen diameter of AA that were not preconstricted. When AA were preconstricted with either angiotensin II (ANG II) or norepinephrine (NE), however, AP III increased lumen diameter in a concentration-dependent manner to the preconstriction baseline value. Maximal vasodilation occurred at 10(-10) M AP III. Unlike AA, EA constricted by 50% to 10(-10) M AP III further constricted EA that were pretreated with ANG II or NE. Dilation in ANG II-preconstricted AA to AP III was not inhibited by indomethacin. Constriction of EA to AP III was not altered by [Sar1-Ala8] ANG II, enalapril, OKY 046, or phentolamine. Results indicate that in isolated renal arterioles AP III dilates preconstricted AA but constricts EA that have either not been pretreated or have been preconstricted with other agonists. The effect of AP III on preconstricted AA does not require vasodilator prostaglandin mediation. The constrictor effect of AP III on EA is not dependent on angiotensin, thromboxane, or alpha-adrenergic mediation.

α-2 And β-adrenergic receptors mediate NE's biphasic effects on rat thick ascending limb chloride flux

2001 ◽  
Vol 281 (3) ◽  
pp. R979-R986 ◽  
Author(s):  
Craig F. Plato
Keyword(s):  
Adrenergic Receptors ◽  
Receptor Activation ◽  
Thick Ascending Limb ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Chloride Flux ◽  
Concentration Dependent Manner ◽  
Β Adrenergic Receptors ◽  
Isolated Rat

The sympathetic neurotransmitter norepinephrine (NE) influences renal sodium excretion via activation of adrenergic receptors. The thick ascending limb (THAL) possesses both α-2 and β-adrenergic receptors. However, the role(s) different adrenergic receptors play in how isolated THALs respond to NE are unclear. We tested the hypothesis that both α-2 and β-adrenergic receptors are responsive to NE in the isolated THAL, with α-2 receptors inhibiting and β-receptors stimulating chloride flux ( J Cl). THALs from male Sprague-Dawley rats were perfused in vitro, and the effects of 1) incremental NE, 2) the α-2 agonist clonidine, and 3) the β-agonist isoproterenol on J Cl were measured. Low concentrations (0.1 nM) of NE decreased J Clfrom a rate of 114.2 ± 8.1 to 93.5 ± 14.6 pmol · mm−1 · min−1( P < 0.05), with the nadir occurring at 1 nM (67.7 ± 8.8 pmol · mm−1 · min−1; P < 0.05). In contrast, greater concentrations of NE significantly increased J Cl from the nadir to a maximal rate of 131.0 ± 28.5 pmol · mm−1 · min−1 at 10 μM ( P < 0.05). To evaluate the adrenergic receptors mediating these responses, the THAL J Cl response to NE was measured in the presence of selective antagonists of β- and α-2 receptors. A concentration of NE (1 μM), which alone tended to increase J Cl, decreased THAL J Cl (from 148.9 ± 16.4 to 76.2 ± 13.6 pmol · mm−1 · min−1; P < 0.01) in the presence of the β-antagonist propranolol. In contrast, a concentration of NE (0.1 μM), which alone tended to decrease J Cl, increased THAL J Cl (from 85.5 ± 20.1 to 111.8 ± 20.1 pmol · mm−1 · min−1; P < 0.05) in the presence of the α-2 antagonist rauwolscine. To further clarify the role of different adrenergic receptors, selective adrenergic agonists were used. The α-2 agonist clonidine decreased J Cl from 102.4 ± 9.9 to 54.0 ± 15.7 pmol · mm−1 · min−1, a reduction of 49.1 ± 11.0% ( P < 0.02). In contrast, the β-agonist isoproterenol stimulated J Cl from 95.3 ± 11.6 to 144.1 ± 15.0 pmol · mm−1 · min−1, an increase of 56 ± 14% ( P < 0.01). We conclude that 1) the sympathetic neurotransmitter NE exerts concentration-dependent effects on J Cl in the isolated rat THAL, 2) selective α-2 receptor activation inhibits THAL J Cl, and 3) selective β-receptor activation stimulates THAL J Cl. These data indicate the response elicited by the isolated rat THAL to NE is dependent on the neurotransmitter concentration, such that application of NE in vitro biphasically modulates J Cl via differential activation of α-2 and β-adrenergic receptors in a concentration-dependent manner.

Chickpea (Cicer arietinum L.) Lectin Exhibit Inhibition of ACE-I, α-amylase and α-glucosidase Activity

2019 ◽  
Vol 26 (7) ◽  
pp. 494-501 ◽  
Author(s):  
Sameer Suresh Bhagyawant ◽  
Dakshita Tanaji Narvekar ◽  
Neha Gupta ◽  
Amita Bhadkaria ◽  
Ajay Kumar Gautam ◽  
...  
Keyword(s):  
Biological Effects ◽  
Exchange Chromatography ◽  
Health Concern ◽  
Carbohydrate Binding ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Ic50 Values ◽  
Chickpea Lectin

Background: Diabetes and hypertension are the major health concern and alleged to be of epidemic proportions. This has made it a numero uno subject at various levels of investigation. Glucosidase inhibitor provides the reasonable option in treatment of Diabetes Mellitus (DM) as it specifically targets post prandial hyperglycemia. The Angiotensin Converting Enzyme (ACE) plays an important role in hypertension. Therefore, inhibition of ACE in treatment of elevated blood pressure attracts special interest of the scientific community. Chickpea is a food legume and seeds contain carbohydrate binding protein- a lectin. Some of the biological properties of this lectin hitherto been elucidated. Methods: Purified by ion exchange chromatography, chickpea lectin was tested for its in vitro antioxidant, ACE-I inhibitory and anti-diabetic characteristic. Results: Lectin shows a characteristic improvement over the synthetic drugs like acarbose (oral anti-diabetic drug) and captopril (standard antihypertensive drug) when, their IC50 values are compared. Lectin significantly inhibited α-glucosidase and α-amylase in a concentration dependent manner with IC50 values of 85.41 ± 1.21 ҝg/ml and 65.05 ± 1.2 µg/ml compared to acarbose having IC50 70.20 ± 0.47 value of µg/ml and 50.52 ± 1.01 µg/ml respectively. β-Carotene bleaching assay showed antioxidant activity of lectin (72.3%) to be as active as Butylated Hydroxylanisole (BHA). In addition, lectin demonstrated inhibition against ACE-I with IC50 value of 57.43 ± 1.20 µg/ml compared to captopril. Conclusion: Lectin demonstrated its antioxidant character, ACE-I inhibition and significantly inhibitory for α-glucosidase and α-amylase seems to qualify as an anti-hyperglycemic therapeutic molecule. The biological effects of chickpea lectin display potential for reducing the parameters of medically debilitating conditions. These characteristics however needs to be established under in vivo systems too viz. animals through to humans.

Improved Method for Obtaining of Arctigenin from Arctium Lappa L. and its Antiproliferative Effect on Human Hepatocarcinoma HepG2 Cells

2020 ◽  
Vol 16 (3) ◽  
pp. 358-362
Author(s):  
Renan S. Teixeira ◽  
Paulo H.D. Carvalho ◽  
Jair A.K. Aguiar ◽  
Valquíria P. Medeiros ◽  
Ademar A. Da Silva Filho ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Crude Extract ◽  
Hepg2 Cells ◽  
Liver Carcinoma ◽  
Adhesion Assay ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Arctium Lappa ◽  
Nih 3T3

Background: Arctigenin is a lignan found in Arctium lappa L. (Asteraceae) that displays anti-inflammatory activities. Previous studies showed that the crude extract of A. Lappa has antitumor activity in human liver carcinoma, lung and stomach cancer cells. The aim of this study was to obtain arctigenin from A. lappa L., as well as to evaluate its antiproliferative effects in cells of liver carcinoma (HepG2) and fibroblasts (NIH/3T3). Methods: Arctigenin was obtained from the hydrolysis of arctiin, which was isolated from the crude extract of A. lappa. The effects of arctigenin and arctiin on HepG2 cell viability and cell adhesion were analyzed by MTT method. Adhesion assay was also carried out to evaluate the antitumor activity. Results: Our results showed that the analytical process to obtain arctigenin was fast and easy. In vitro experiments showed that arctigenin (107-269 μM) decreased HepG2 cells viability and did not cause cytotoxicity on NIH/3T3 cells. Arctigenin (27-269 μM) demonstrated anti-adhesion in HepG2 cells in a concentration-dependent manner, when compared with control. Conclusion: These results suggest a promising pharmacological activity for arctigenin as an antiproliferative compound.

scholarly journals Human Neuronal Cell Lines as An In Vitro Toxicological Tool for the Evaluation of Novel Psychoactive Substances

2021 ◽  
Vol 22 (13) ◽  
pp. 6785
Author(s):  
Valeria Sogos ◽  
Paola Caria ◽  
Clara Porcedda ◽  
Rafaela Mostallino ◽  
Franca Piras ◽  
...  
Keyword(s):  
Cell Death ◽  
Neuronal Cell ◽  
In Vitro Study ◽  
Dependent Manner ◽  
Novel Psychoactive Substances ◽  
Psychoactive Substances ◽  
Concentration Dependent Manner ◽  
Mechanisms Of Toxicity ◽  
Neuronal Cell Lines

Novel psychoactive substances (NPS) are synthetic substances belonging to diverse groups, designed to mimic the effects of scheduled drugs, resulting in altered toxicity and potency. Up to now, information available on the pharmacology and toxicology of these new substances is very limited, posing a considerable challenge for prevention and treatment. The present in vitro study investigated the possible mechanisms of toxicity of two emerging NPS (i) 4′-methyl-alpha-pyrrolidinoexanophenone (3,4-MDPHP), a synthetic cathinone, and (ii) 2-chloro-4,5-methylenedioxymethamphetamine (2-Cl-4,5-MDMA), a phenethylamine. In addition, to apply our model to the class of synthetic opioids, we evaluated the toxicity of fentanyl, as a reference compound for this group of frequently abused substances. To this aim, the in vitro toxic effects of these three compounds were evaluated in dopaminergic-differentiated SH-SY5Y cells. Following 24 h of exposure, all compounds induced a loss of viability, and oxidative stress in a concentration-dependent manner. 2-Cl-4,5-MDMA activates apoptotic processes, while 3,4-MDPHP elicits cell death by necrosis. Fentanyl triggers cell death through both mechanisms. Increased expression levels of pro-apoptotic Bax and caspase 3 activity were observed following 2-Cl-4,5-MDMA and fentanyl, but not 3,4-MDPHP exposure, confirming the different modes of cell death.

scholarly journals The Modulation of PCSK9 and LDLR by Supercritical CO2 Extracts of Mentha longifolia and Isolated Piperitone Oxide, an In Vitro Study

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3886
Author(s):  
Stefania Sut ◽  
Irene Ferrarese ◽  
Maria Giovanna Lupo ◽  
Nicola De Zordi ◽  
Elisa Tripicchio ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cell Lines ◽  
Hepatoma Cell ◽  
Density Lipoprotein ◽  
In Vitro Study ◽  
Volatile Constituent ◽  
Dependent Manner ◽  
Human Hepatoma Cell ◽  
Concentration Dependent Manner

In the present study the ability of supercritical carbon dioxide (SCO2) extracts of M. longifolia L. leaves to modulate low-density lipoprotein receptor (LDLR) and proprotein convertase subtilisin/kexin type 9 (PCSK9) expression was evaluated in cultured human hepatoma cell lines Huh7 and HepG2. Two SCO2 extracts, one oil (ML-SCO2) and a semisolid (MW-SCO2), were subjected to detailed chemical characterization by mono- and bidimensional nuclear magnetic resonance (1D, 2D-NMR), gas chromatography coupled with mass spectrometry (GC-MS) and liquid chromatography coupled with mass spectrometry (LC-MS). Chemical analysis revealed significant amounts of fatty acids, phytosterols and terpenoids. ML-SCO2 was able to induce LDLR expression at a dose of 60 µg/mL in HuH7 and HepG2 cell lines. Furthermore, ML-SCO2 reduced PCSK9 secretion in a concentration-dependent manner in both cell lines. Piperitone oxide, the most abundant compound of the volatile constituent of ML-SCO2 (27% w/w), was isolated and tested for the same targets, showing a very effective reduction of PCSK9 expression. The overall results revealed the opportunity to obtain a new nutraceutical ingredient with a high amount of phytosterols and terpenoids using the SCO2 extraction of M. longifolia L., a very well-known botanical species used as food. Furthermore, for the first time we report the high activity of piperitone oxide in the reduction of PCSK9 expression.

scholarly journals Cannabidiol (CBD) Alters the Functionality of Neutrophils (PMN). Implications in the Refractory Epilepsy Treatment

2021 ◽  
Vol 14 (3) ◽  
pp. 220
Author(s):  
Claudia Taborda Gómez ◽  
Fabiana Lairion ◽  
Marisa Repetto ◽  
Miren Ettcheto ◽  
Amalia Merelli ◽  
...  
Keyword(s):  
Refractory Epilepsy ◽  
Polymorphonuclear Neutrophils ◽  
Dependent Manner ◽  
Nuclear Condensation ◽  
Concentration Dependent Manner ◽  
Superoxide Anion Production ◽  
Excretory Function ◽  
Psychoactive Effects ◽  
Stress Damage

Cannabidiol (CBD), a lipophilic cannabinoid compound without psychoactive effects, has emerged as adjuvant of anti-epileptic drugs (AEDs) in the treatment of refractory epilepsy (RE), decreasing the severity and/or frequency of seizures. CBD is considered a multitarget drug that could act throughout the canonical endocannabinoid receptors (CB1-CB2) or multiple non-canonical pathways. Despite the fact that the CBD mechanism in RE is still unknown, experiments carried out in our laboratory showed that CBD has an inhibitory role on P-glycoprotein excretory function, highly related to RE. Since CB2 is expressed mainly in the immune cells, we hypothesized that CBD treatment could alter the activity of polymorphonuclear neutrophils (PMNs) in a similar way that it does with microglia/macrophages and others circulating leukocytes. In vitro, CBD induced PMN cytoplasmatic vacuolization and proapoptotic nuclear condensation, associated with a significantly decreased viability in a concentration-dependent manner, while low CBD concentration decreased PMN viability in a time-dependent manner. At a functional level, CBD reduced the chemotaxis and oxygen consumption of PMNs related with superoxide anion production, while the singlet oxygen level was increased suggesting oxidative stress damage. These results are in line with the well-known CBD anti-inflammatory effect and support a potential immunosuppressor role on PMNs that could promote an eventual defenseless state during chronic treatment with CBD in RE.

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