scholarly journals Screening of Plants Hydro-Alcoholic Extracts from Kerman for their Inhibition of β-Glucuronidase Activity

2020 ◽  
Vol 11 (1) ◽  
pp. 7921-7931
Keyword(s):  
Spectrophotometric Method ◽  
Neonatal Jaundice ◽  
Competitive Inhibition ◽  
Inhibitory Effect ◽  
Rosa Damascena ◽  
Activation Effect ◽  
Glucuronidase Activity ◽  
Methanolic Extracts ◽  
Ipomoea Tricolor ◽  
Conjugated Bilirubin

In neonatal jaundice, β-glucuronidase converts conjugated bilirubin into the unconjugated form and increases its level in the blood. Many natural compounds have been identified as β-glucuronidase inhibitors. The aim of this study was to evaluate the effect of hydro-methanolic extracts of 100 plants on β-glucuronidase. The β-glucuronidase activity was measured by a spectrophotometric method using Phenolphthalein glucuronide and 4-nitrophenyl β-D-glucuronide. Kinetic study of the enzyme was performed in the presence and absence of the plant extract. It was revealed that from hydro-methanolic (70%) extracts, Rosa damascena and Ipomoea tricolor showed more than 85% inhibitory effect on β-glucuronidase. Rosa damascena showed competitive inhibition, and Ipomoea tricolor showed non-competitive inhibition. The Km and Vmax values for β-glucuronidase were 23.32 mM and 0.814 mM min-1, respectively. When using 4-nitrophenyl β-D-glucuronide, Stevia and Cerasus avium showed more than 65% inhibitory effect on β-glucuronidase. Both Stevia and Cerasus avium showed non-competitive inhibition. The Km and Vmax values for β-glucuronidase were 16.98 mM and 0.936 mM min-1, respectively. None of the plant extracts showed an activation effect on the enzyme. The data suggest that these plants might be good candidates for the treatment of neonatal jaundice and its related diseases.

Effects of Dipyrone on Prostaglandin Production by Human Platelets and Cultured Bovine Aortic Endothelial Cells

1983 ◽  
Vol 49 (02) ◽  
pp. 132-137 ◽  
Author(s):  
A Eldor ◽  
G Polliack ◽  
I Vlodavsky ◽  
M Levy
Keyword(s):  
Endothelial Cells ◽  
Arachidonic Acid ◽  
Competitive Inhibition ◽  
Inhibitory Effect ◽  
Human Platelets ◽  
Ionophore A23187 ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
Aortic Endothelial

SummaryDipyrone and its metabolites 4-methylaminoantipyrine, 4-aminoantipyrine, 4-acetylaminoantipyrine and 4-formylaminoan- tipyrine inhibited the formation of thromboxane A2 (TXA2) during in vitro platelet aggregation induced by ADP, epinephrine, collagen, ionophore A23187 and arachidonic acid. Inhibition occurred after a short incubation (30–40 sec) and depended on the concentration of the drug or its metabolites and the aggregating agents. The minimal inhibitory concentration of dipyrone needed to completely block aggregation varied between individual donors, and related directly to the inherent capacity of their platelets to synthesize TXA2.Incubation of dipyrone with cultured bovine aortic endothelial cells resulted in a time and dose dependent inhibition of the release of prostacyclin (PGI2) into the culture medium. However, inhibition was abolished when the drug was removed from the culture, or when the cells were stimulated to produce PGI2 with either arachidonic acid or ionophore A23187.These results indicate that dipyrone exerts its inhibitory effect on prostaglandins synthesis by platelets or endothelial cells through a competitive inhibition of the cyclooxygenase system.

Inhibition of Yeast Growth by Tryptamine and Recovery with Tryptophan

2020 ◽  
Vol 16 (1) ◽  
pp. 48-52 ◽  
Author(s):  
Chandrika Kadkol ◽  
Ian Macreadie
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Competitive Inhibition ◽  
Yeast Species ◽  
Inhibitory Effect ◽  
The Body ◽  
Inhibitory Effects ◽  
Trna Synthetases ◽  
Fermentative Growth ◽  
Biogenic Monoamine

Background: Tryptamine, a biogenic monoamine that is present in trace levels in the mammalian central nervous system, has probable roles as a neurotransmitter and/or a neuromodulator and may be associated with various neuropsychiatric disorders. One of the ways tryptamine may affect the body is by the competitive inhibition of the attachment of tryptophan to tryptophanyl tRNA synthetases. Methods: This study has explored the effects of tryptamine on growth of six yeast species (Saccharomyces cerevisiae, Candida glabrata, C. krusei, C. dubliniensis, C. tropicalis and C. lusitaniae) in media with glucose or ethanol as the carbon source, as well as recovery of growth inhibition by the addition of tryptophan. Results: Tryptamine was found to have an inhibitory effect on respiratory growth of all yeast species when grown with ethanol as the carbon source. Tryptamine also inhibited fermentative growth of Saccharomyces cerevisiae, C. krusei and C. tropicalis with glucose as the carbon source. In most cases the inhibitory effects were reduced by added tryptophan. Conclusion: The results obtained in this study are consistent with tryptamine competing with tryptophan to bind mitochondrial and cytoplasmic tryptophanyl tRNA synthetases in yeast: effects on mitochondrial and cytoplasmic protein synthesis can be studied as a function of growth with glucose or ethanol as a carbon source. Of the yeast species tested, there is variation in the sensitivity to tryptamine and the rescue by tryptophan. The current study suggests appropriate yeast strains and approaches for further studies.

scholarly journals Kinetic Spectrophotometric Method for the Determination of Trace Amounts of Oxalate by an Activation Effect

2006 ◽  
Vol 22 (2) ◽  
pp. 333-336 ◽  
Author(s):  
Mansour Arab CHAMJANGALI ◽  
Vahid KELEY ◽  
Ghadamali BAGHERIAN
Keyword(s):  
Spectrophotometric Method ◽  
Activation Effect ◽  
Kinetic Spectrophotometric

Mortality and Inhibitory Effects of Aqueous and Methanolic Extracts of Artemisia annua L. on Biomphalaria pfeifferi (Krauss) and Shedding of Cercariae

2021 ◽  
Vol 42 (1) ◽  
pp. 25-30
Author(s):  
I.M. Ado ◽  
Z.A. Ali ◽  
M.M. Dogara ◽  
K. Abdullahi ◽  
S.A Luka ◽  
...  
Keyword(s):  
Methanolic Extract ◽  
Artemisia Annua ◽  
Scientific Evidence ◽  
Standard Procedure ◽  
Inhibitory Effect ◽  
Control Group ◽  
Inhibitory Effects ◽  
Biomphalaria Pfeifferi ◽  
Artemisia Annua L ◽  
Methanolic Extracts

The search for bioactive plants which can be used as non-conventional anthelmintics has received considerable attention in recent times because of the increasing, worldwide development of resistance to synthetic anthelminthes worm populations. However, scientific evidence to validate the use of raw plants materials remain limited. This study evaluated the mortality and inhibitory effects of the crude aqueous and methanolic extract of Artemisia annua L. against the shedding of cercariae of Schistosoma mansoni from Biomphalaria pfeifferi. The phytochemical screening of the plant was done using standard procedure, after which the mortality effects of the plant extracts and effects on the shedding of cercariae from B. pfeifferi snails were assessed for 24 hour of exposure. Methanolic extract with the highest concentration of 1.77mg/µL had an inhibitory effect of 63.06±1.84 while the least concentration with 0.12mg/µL had 22.41±2.17 inhibitory effect. For the aqueous extract, the highest concentration with 2.73mg/µL had an inhibitory effect of  55.75±1.94 while the least concentration of 0.23mg/µL had 21.80±1.45. Inhibitory effect of cercariae in the snail vector was  concentration dependent, and there was significance difference (P<0.05) between the treatment mean when compared with the control group. This study has shown that this plant material has some inhibitory effect on the shedding of of S. mansoni cercariae and toxicityeffect on the B. pfeifferisnails, and can therefore be used for the control of the disease causing agent as well as the vector. Keywords: Artemisia annua, Inhibitory effects, cercariae, Biomphalaria pfeifferi

Antibacterial activity of Urena lobata against uropathogens

2021 ◽  
Vol 25 (1) ◽  
pp. 43-46
Author(s):  
Taofeeq Garuba ◽  
Nency Katrodiya ◽  
Nikita Patel ◽  
Swetal Patel ◽  
Dhanji. P. Rajani ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Agar Plate ◽  
Soxhlet Extraction ◽  
Inhibitory Effect ◽  
Urine Samples ◽  
Herbal Extract ◽  
Mannitol Salt Agar ◽  
Methanolic Extracts ◽  
Tract Infections

Urinary tract infections (UTI) are one of the most common form of bacterial infections but the treatment becomes cumbersome as the etiological bacteria are developing resistance against antibiotics. This present study evaluated the efficacy of antimicrobial   activity of Urena lobata against uropathogens. Six urine samples from UTI patients were collected from Pathological Laboratory, G.B. Vaghani Multispecialty Hospital, Surat. Bacteria were isolated from these samples using Nutrient agar, Mac Conkey agar plate, Blood agar, Mannitol salt agar, Eosin Methylene Blue agar and King’s agar. The bacterial isolates were identified using cultural  characteristics, microscopic features and biochemical characteristics. Leaf extract of Urena lobata was prepared using Soxhlet Extraction Method whereby methanol and distilled water were the extractants used. Herbal extract disc was prepared at  concentrations of 50,75, and100 mg/ml and tested against all the isolates. DMSO and antibiotics (Nitrofurantion, Amikacin, Levofloxacin, Norofloxacin, Ofloxacin and Cephalosporins) were used as negative and positive controls respectively.Staphylococcus aureus, Escherichia coli, Bacillus cereus, Streptococcus pneumoniae, Klebsiella spp. and Brevibacillus panacihumi were isolated from the urine samples. All concentrations of aqueous and methanolic extracts of U. lobata leaf displayed highest zone of inhibition against B. cereus. No inhibitory effect was observed against the growth of Klebsiella except at the highest concentrations. Further study is encouraged on the in-vivo study of efficacy of U. lobata on etiological agent of UTI.

scholarly journals In vitro inhibitory effect of obtusofolin on the activity of CYP3A4, 2C9, and 2E1

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Na Liu ◽  
Ping Chen ◽  
Xiaojun Du ◽  
Junxia Sun ◽  
Shasha Han
Keyword(s):  
Human Liver ◽  
Competitive Inhibition ◽  
Liver Microsomes ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Cytochrome P450 Enzymes ◽  
Inhibition Model ◽  
Dose Dependent

Abstract Background Obtusofolin is the major active ingredient of Catsia tora L., which possesses the activity of improving eyesight and protecting the optic nerve. Investigation on the interaction of obtusofolin with cytochrome P450 enzymes (CYP450s) could provide a reference for the clinical application of obtusofolin. Methods The effect of obtusofolin on the activity of CYP450s was investigated in the presence of 100 μM obtusofolin in pooled human liver microsomes (HLMs) and fitted with the Lineweaver–Burk plots to characterize the specific inhibition model and kinetic parameters. Results Obtusofolin was found to significantly inhibited the activity of CYP3A4, 2C9, and 2E1. In the presence of 0, 2.5, 5, 10, 25, 50, and 100 μM obtusofolin, the inhibition of these CYP450s showed a dose-dependent manner with the IC50 values of 17.1 ± 0.25, 10.8 ± 0.13, and 15.5 ± 0.16 μM, respectively. The inhibition of CYP3A4 was best fitted with the non-competitive inhibition model with the Ki value of 8.82 μM. While the inhibition of CYP2C9 and 2E1 was competitive with the Ki values of 5.54 and 7.79 μM, respectively. After incubating for 0, 5, 10, 15, and 30 min, the inhibition of CYP3A4 was revealed to be time-dependent with the KI value of 4.87 μM− 1 and the Kinact value of 0.0515 min− 1. Conclusions The in vitro inhibitory effect of obtusofolin implying the potential drug-drug interaction between obtusofolin and corresponding substrates, which needs further in vivo validations.

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 Effect of anti-thyroid peroxidase (TPO) antibodies on TPO activity measured by chemiluminescence assay

1997 ◽  
Vol 43 (8) ◽  
pp. 1392-1396 ◽  
Author(s):  
V Kaczur ◽  
Gy Vereb ◽  
I Molnár ◽  
G Krajczár ◽  
E Kiss ◽  
...  
Keyword(s):  
Western Blotting ◽  
Competitive Inhibition ◽  
High Sensitivity ◽  
Inhibitory Effect ◽  
Thyroid Peroxidase ◽  
Chemiluminescence Detection ◽  
Chemiluminescence Method ◽  
Blotting Technique ◽  
Hypothyroid Patients

Abstract A chemiluminescence method was developed to measure thyroid peroxidase (TPO) activity and the inhibitory effect of anti-TPO antibodies in purified porcine TPO. The TPO preparation was characterized kinetically and controlled by Western-blotting technique. The chemiluminescence method proved to be reproducible and much more sensitive than the widely used guaiacol method, being able to detect TPO concentrations of 2.21 × 10−5 g/L vs 6.63 × 10−2g/L with the latter. Otherwise, the determinations with the two methods correlated well (r = 0.76). Investigating the effect of IgGs from 23 hypothyroid patients on measured TPO activity, we detected inhibition in 19 cases with the chemiluminescence technique (15 with the guaiacol method). Anti-TPO antibodies showed competitive inhibition of TPO activity with respect to the substrate guaiacol. In both systems, the inhibition is present in the IgG F(ab′)2 fragment. We conclude that the high sensitivity of chemiluminescence detection allows routine determination of the inhibition of TPO activity by anti-TPO antibodies.

scholarly journals Psoromic Acid, a Lichen-Derived Molecule, Inhibits the Replication of HSV-1 and HSV-2, and Inactivates HSV-1 DNA Polymerase: Shedding Light on Antiherpetic Properties

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2912 ◽  
Author(s):  
Sherif T. S. Hassan ◽  
Miroslava Šudomová ◽  
Kateřina Berchová-Bímová ◽  
Karel Šmejkal ◽  
Javier Echeverría
Keyword(s):  
Dna Polymerase ◽  
Active Sites ◽  
Inhibitory Action ◽  
Inhibitory Concentration ◽  
Competitive Inhibition ◽  
Inhibitory Effect ◽  
Standard Drug ◽  
Key Enzyme ◽  
Hsv 1

Psoromic acid (PA), a bioactive lichen-derived compound, was investigated for its inhibitory properties against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), along with the inhibitory effect on HSV-1 DNA polymerase, which is a key enzyme that plays an essential role in HSV-1 replication cycle. PA was found to notably inhibit HSV-1 replication (50% inhibitory concentration (IC50): 1.9 μM; selectivity index (SI): 163.2) compared with the standard drug acyclovir (ACV) (IC50: 2.6 μM; SI: 119.2). The combination of PA with ACV has led to potent inhibitory activity against HSV-1 replication (IC50: 1.1 µM; SI: 281.8) compared with that of ACV. Moreover, PA displayed equivalent inhibitory action against HSV-2 replication (50% effective concentration (EC50): 2.7 μM; SI: 114.8) compared with that of ACV (EC50: 2.8 μM; SI: 110.7). The inhibition potency of PA in combination with ACV against HSV-2 replication was also detected (EC50: 1.8 µM; SI: 172.2). Further, PA was observed to effectively inhibit HSV-1 DNA polymerase (as a non-nucleoside inhibitor) with respect to dTTP incorporation in a competitive inhibition mode (half maximal inhibitory concentration (IC50): 0.7 μM; inhibition constant (Ki): 0.3 μM) compared with reference drugs aphidicolin (IC50: 0.8 μM; Ki: 0.4 μM) and ACV triphosphate (ACV-TP) (IC50: 0.9 μM; Ki: 0.5 μM). It is noteworthy that the mechanism by which PA-induced anti-HSV-1 activity was related to its inhibitory action against HSV-1 DNA polymerase. Furthermore, the outcomes of in vitro experiments were authenticated using molecular docking analyses, as the molecular interactions of PA with the active sites of HSV-1 DNA polymerase and HSV-2 protease (an essential enzyme required for HSV-2 replication) were revealed. Since this is a first report on the above-mentioned properties, we can conclude that PA might be a future drug for the treatment of HSV infections as well as a promising lead molecule for further anti-HSV drug design.

scholarly journals Effects of 2-mercaptoacetate in isolated liver mitochondria in vitro. Competitive inhibition of 3-hydroxybutyrate dehydrogenase and depression of the β-oxidation pathway

1982 ◽  
Vol 206 (1) ◽  
pp. 53-59 ◽  
Author(s):  
F Bauché ◽  
D Sabourault ◽  
Y Giudicelli ◽  
J Nordmann ◽  
R Nordmann
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Competitive Inhibition ◽  
Liver Mitochondria ◽  
Inhibitory Effect ◽  
Acid Oxidation ◽  
Membrane Bound ◽  
Energy Dependent ◽  
Isolated Liver

The effects of 2-mercaptoacetate on the respiration rates induced by different substrates were studied in vitro in isolated liver mitochondria. With palmitoyl-L-carnitine or 2-oxoglutarate as the substrate, the ADP-stimulated respiration (State 3) was dose-dependently inhibited by 2-mercaptoacetate. with glutamate or succinate as the substrate. State-3 respiration was only slightly inhibited by 2-mercaptoacetate. In contrast, the oxidation rate of 3-hydroxybutyrate was competitively inhibited by 2-mercaptoacetate in both isolated mitochondria and submitochondrial particles. In uncoupled mitochondria and in mitochondria in which ATP- and GTP-dependent acyl-CoA biosynthesis was inhibited, the inhibitory effect of 2-mercaptoacetate on palmitoyl-L-carnitine oxidation was abolished; under the same conditions, however, inhibition of 3-hydroxybutyrate oxidation by 2-mercaptoacetate still persisted. These results led to the following conclusions: 2-mercaptoacetate itself enters the mitochondrial matrix, inhibits fatty acid oxidation through a mechanism requiring an energy-dependent activation of 2-mercaptoacetate and itself inhibits 3-hydroxybutyrate oxidation through a competitive inhibition of the membrane-bound 3-hydroxybutyrate dehydrogenase. This study also strongly suggests that the compound responsible for the inhibition of fatty acid oxidation is 2-mercaptoacetyl-CoA.

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