IN VITRO SCREEN OF INHIBITORS OF RAT BRAIN TYROSINE HYDROXYLASE

1967 ◽  
Vol 45 (1) ◽  
pp. 115-131 ◽  
Author(s):  
E. G. McGeer ◽  
P. L. McGeer
Keyword(s):  
Tyrosine Hydroxylase ◽  
Rat Brain ◽  
Inhibitory Activity ◽  
Brain Homogenate ◽  
Inhibitory Effect ◽  
Side Chain ◽  
Complexing Agents ◽  
Hydroxy Groups ◽  
Brain Tyrosine Hydroxylase

Over 600 compounds were tested at 10−4 M concentration as inhibitors of tyrosine hydroxylase activity in crude rat-brain homogenate. Most of the compounds had little or no inhibitory effect and those with strong inhibitory properties were, except for a very few oxidizing and complexing agents, all close structural analogues of tyrosine or of its catechol metabolites. Data obtained in this screen are generally in accord with previous data reported in the literature. For high inhibitory activity in the tyrosine series, side-chain substitution is critical. N-Substitution is particularly undesirable. For high inhibitory activity in the catechol series, the ring hydroxy groups should be 3,4 in relation to a C—C—N side chain. Further ring substitution is undesirable, but some side-chain substitution is permissible.

In vitro screen of inhibitors of rat brain serotonin synthesis

1969 ◽  
Vol 47 (5) ◽  
pp. 501-506 ◽  
Author(s):  
E. G. McGeer ◽  
D. A. V. Peters
Keyword(s):  
Rat Brain ◽  
Tryptophan Hydroxylase ◽  
Inhibitory Effect ◽  
Complexing Agents ◽  
Serotonin Synthesis ◽  
Structural Requirements ◽  
Class A ◽  
Numerous Data ◽  
Comparison Of The Results

Over 700 compounds were screened at 10−4 M concentration as inhibitors of the conversion of L-tryptophan-14C to serotonin-14C in crude rat brain homogenates. Most of the compounds had little or no inhibitory effect. Those with strong inhibitory properties were tested as inhibitors of 5-hydroxytryptophan decarboxylase and, if active on the decarboxylase, were assayed as tryptophan hydroxylase inhibitors. Except for a few oxidizing and complexing agents and for some substituted p-phenylenediamines, the compounds found to inhibit tryptophan hydroxylase by >50% belonged to the three types of inhibitors already known, i.e. catechols, phenylalanine and ring-substituted phenylalanines, and 6-substituted tryptophans. The numerous data in this screen make possible some comments as to the structural requirements for activity within each class. A comparison of the results on tryptophan hydroxylase with data on tyrosine hydroxylase inhibition in similar homogenates makes it clear that two separate, if somewhat similar, enzymes are involved.

In vitro anticholinesterase, antimonoamine oxidase and antioxidant properties of alkaloid extracts from kola nuts (Cola acuminata and Cola nitida)

2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Ganiyu Oboh ◽  
Ayokunle O. Ademosun ◽  
Opeyemi B. Ogunsuyi ◽  
Esther T. Oyedola ◽  
Tosin A. Olasehinde ◽  
...  
Keyword(s):  
Side Effects ◽  
Neurodegenerative Diseases ◽  
Rat Brain ◽  
Brain Homogenate ◽  
Oh Radicals ◽  
Mao Inhibitors ◽  
Alkaloid Extracts ◽  
Cola Nitida ◽  
Cola Acuminata

Abstract Background The development of cholinesterase (ChE) and monoamine oxidase (MAO) inhibitors for management of neurodegenerative diseases such as Alzheimer’s disease (AD) has come with their undesirable side effects. Hence, research for potent but natural ChE and MAO inhibitors with little or no side effects is essential. This study investigated the potentials of alkaloid extracts from two Cola species as nutraceuticals for prevention and management of AD. Methods Alkaloid extracts were obtained from two Cola species (Cola nitida [KN] and Cola acuminata [KA]) by solvent extraction method. The extracts were characterized for their alkaloid contents using gas chromatography (GC). The effects of the extracts on ChE and MAO activities were investigated in vitro. Also, the extracts’ ability to inhibit Fe2+-induced lipid peroxidation in rat brain homogenate, scavenge DPPH and OH radicals, as well as chelate Fe2+ were determined. Results GC characterization revealed the presence of augustamine and undulatine as the predominant alkaloids in the extracts. There was no significant (P > 0.05) difference in the inhibitory effects of the extracts on ChE activities. However, KA extract exhibited significantly higher (P < 0.05) MAO inhibitory effect than KN. Also, KA extract inhibited Fe2+- induced malondialdehyde (MDA) production in rat brain homogenate more significantly than KN, while there was no significant difference in DPPH and OH radicals scavenging, as well as Fe2+-chelating abilities of the extracts. Conclusions Our findings revealed that KN and KA alkaloid extracts exhibited significant effect in vitro on biological pathways that may contribute to neuroprotection for the management of neurodegenerative diseases.

scholarly journals Development of mouthwash with Rosmarinus officinalis extract

2014 ◽  
Vol 50 (4) ◽  
pp. 851-858 ◽  
Author(s):  
Isabela Moreira Baumgratz de Paula ◽  
Flávia Costa Moraes ◽  
Orlando Vieira de Souza ◽  
Célia Hitomi Yamamoto
Keyword(s):  
Sodium Fluoride ◽  
Inhibitory Activity ◽  
Raw Materials ◽  
Ethanol Extract ◽  
Inhibitory Effect ◽  
Rosmarinus Officinalis ◽  
Hexane Fraction ◽  
Diffusion Method ◽  
Oral Infections

Rosmarinus officinalis, which belongs to the Lamiaceaefamily, is a species of medicinal flora with therapeutic properties. In order to exploit the benefits of these properties, a mouthwash formulation was developed, with careful selection of raw materials to meet pharmacotechnical requirements. Extracts of the plant were incorporated into a mouthwash, which was shown to have inhibitory action in vitro against the micro-organisms commonly found in periodontics. Controls for assessing the quality of the drugs were carried out, quantifying phenols and flavonoids as chemical markers. Mouthwash solutions were formulated containing 0.1, 5 and 10% ethanol extract of R. officinalis; and 0.05, 5 and 10% of the hexane fraction of R. officinalis. In order to evaluate synergism, ethanol extract and hexane fraction were also added to formulations containing 0.05% sodium fluoride and 0.12% chlorhexidine digluconate. These formulations were assessed for inhibitory effect against the specific microorganisms involved in the process of bacterial plaque formation, S. mutans(ATCC25175) and C. albicans(ATCC 10231), frequently found in cases of oral infections. The agar diffusion method was used to evaluate the inhibitory activity of extracts and formulations. All mouthwash solutions displayed inhibitory activity having higher sensitivity to S. mutansfor the 5% ethanol extract+0.05% sodium fluoride, and greater sensitivity to C. albicansfor the 10% hexane fraction. Results were characterized by the appearance of a growth inhibition halo, justifying the utilization and association of extracts of R. officinalis.

scholarly journals In vivo hypotensive effect and in vitro inhibitory activity of some Cyperaceae species

2013 ◽  
Vol 49 (4) ◽  
pp. 803-809
Author(s):  
Monica Lacerda Lopes Martins ◽  
Henrique Poltronieri Pacheco ◽  
Iara Giuberti Perini ◽  
Dominik Lenz ◽  
Tadeu Uggere de Andrade ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Colorimetric Assay ◽  
Hypotensive Effect ◽  
Ace Inhibition ◽  
Inhibitory Effect ◽  
Positive Control ◽  
Total Phenolic ◽  
Before And After

In 1820, French naturalist August Saint Hillaire, during a visit in Espírito Santo (ES), a state in southeastern Brazil, reported a popular use of Cyperaceae species as antidote to snake bites. The plant may even have a hypotensive effect, though it was never properly researched. The in vitro inhibitory of the angiotensin converting enzyme (ACE) activity of eigth ethanolic extracts of Cyperaceae was evaluated by colorimetric assay. Total phenolic and flavonoids were determined using colorimetric assay. The hypotensive effect of the active specie (Rhychonospora exaltata, ERE) and the in vivo ACE assay was measured in vivo using male Wistar Kyoto (ERE, 0.01-100mg/kg), with acetylcholine (ACh) as positive control (5 µg/kg, i.v.). The evaluation of ACE in vivo inhibitory effect was performed comparing the mean arterial pressure before and after ERE (10 mg/kg) in animals which received injection of angiotensin I (ANG I; 0,03, 03 and 300 µg/kg, i.v.). Captopril (30 mg/kg) was used as positive control. Bulbostylis capillaris (86.89 ± 15.20%) and ERE (74.89 ± 11.95%, ERE) were considered active in the in vitro ACE inhibition assay, at 100 µg/mL concentration. ACh lead to a hypotensive effect before and after ERE's curve (-40±5% and -41±3%). ERE showed a dose-dependent hypotensive effect and a in vivo ACE inhibitory effect. Cyperaceae species showed an inhibitory activity of ACE, in vitro, as well as high content of total phenolic and flavonoids. ERE exhibited an inhibitory effect on both in vitro and in vivo ACE. The selection of species used in popular medicine as antidotes, along with the in vitro assay of ACE inhibition, might be a biomonitoring method for the screening of new medicinal plants with hypotensive properties.

IN VITRO STUDIES OF SOME EDIBLE SPICES ON PANCREATIC LIPASE INHIBITORY ACTIVITY

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (02) ◽  
pp. 62-68
Author(s):  
S Mhatre ◽  
◽  
A. Bhagit ◽  
R. P Yadav
Keyword(s):  
Pancreatic Lipase ◽  
Inhibitory Activity ◽  
Inhibitory Effect ◽  
Syzygium Aromaticum ◽  
High Potency ◽  
Good Source ◽  
Zanthoxylum Armatum ◽  
Methanolic Extracts ◽  
Cinnamomum Tamala

Pancreatic lipase inhibitory effect of some edible spices in light of percent inhibition, efficacy, reversibility/ irreversibility and effect of pH on inhibition is presented here. Lipase inhibitory activities of methanolic extracts of eighteen spices were evaluated. Extracts of Zanthoxylum armatum, Cinnamomum tamala, Syzygium aromaticum and Myristica fragrans were considered to be of high potency in synthetic substrate assay. Only Syzygium aromaticum showed high potency in natural substrate based lipase assay. Zanthoxylum armatum extract displayed lowest IC50 of 9.0 μg/mL. On dialysis, all extracts lost their lipase inhibitory activity indicating reversible nature of inhibition. pH significantly affected the performance of spice extracts during inhibition of pancreatic lipase. Most of the extracts lost their pancreatic lipase inhibitory activity at pH 3.0 with the exception of Brassica nigra and Cinnamomum tamala. Results showed spice are good source of pancreatic lipase inhibitor and its potential as drug for obesity can be explored by addressing various issues.

scholarly journals Phenolic Acids from Lycium barbarum Leaves: In Vitro and In Silico Studies of the Inhibitory Activity against Porcine Pancreatic α-Amylase

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1388
Author(s):  
Luna Pollini ◽  
Alessandra Riccio ◽  
Cristina Juan ◽  
Carmela Tringaniello ◽  
Federica Ianni ◽  
...  
Keyword(s):  
Phenolic Acids ◽  
Inhibitory Activity ◽  
Leaf Extract ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Lycium Barbarum ◽  
Plant Materials ◽  
Vitro Assay ◽  
In Silico Studies

Nowadays, bioactive compounds from vegetable food and waste are of great interest for their inhibitory potential against digestive enzymes. In the present study, the inhibitory activity of methanolic extract from Lycium barbarum leaves on porcine pancreas α-amylase has been studied. The α-amylase inhibitory activity of the constituent phenolic acids was also investigated. The leaves were extracted by ultrasound-assisted method, one of the most efficient techniques for bioactive extraction from plant materials, and then the phenolic acids were identified by Accurate-Mass Quadrupole Time-of-Flight (Q-TOF) Liquid Chromatography/Mass Spectrometry (LC/MS). Chlorogenic and salicylic acids were the most abundant phenolic acids in L. barbarum leaf extract. The inhibitory effect against α-amylase, determined for individual compounds by in vitro assay, was higher for chlorogenic, salicylic, and caffeic acids. L. barbarum leaf extract showed an appreciable α-amylase inhibitory effect in a concentration-dependent manner. Docking studies of the considered phenolic acids into the active site of α-amylase suggested a conserved binding mode that is mainly stabilized through H-bonds and π-π stacking interactions.

Synthesis of Novel Benzimidazole and Benzothiazole Derivatives Bearing a 1,2,3-triazole Ring System and their Acetylcholinesterase Inhibitory Activity

2017 ◽  
Vol 41 (1) ◽  
pp. 30-35 ◽  
Author(s):  
Laleh Faraji ◽  
Shiva Shahkarami ◽  
Hamid Nadri ◽  
Alireza Moradi ◽  
Mina Saeedi ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Docking Simulation ◽  
Triazole Ring ◽  
Copper Catalysts ◽  
Inhibitory Effect ◽  
Ring System ◽  
Benzothiazole Derivatives ◽  
Ache Inhibitory Activity ◽  
Group A

A series of 20 novel benzimidazole and benzothiazole derivatives linked to a 1,2,3-triazole ring system was synthesised, characterised and evaluated for in vitro acetylcholinesterase (AChE) inhibitory activity. Several copper catalysts and solvents were screened to establish the optimal conditions for the preparation of the target compounds. Three different linkers were used to optimise the enzyme inhibitory effect. Out of the 20 compounds, 13 showed some AChE inhibition. The most potent compound, which showed 84% inhibition at 100 μM, contained a 1-(2-fluorobenzyl)-1,2,3-triazole linked to a benzimidazole group. A docking simulation study showed that the most active compound bound preferentially to the catalytic anionic subsite of the AChE enzyme.

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