scholarly journals Antioxidant and Prooxidant Effects of Metal Dafonates on the NADPH-Dependent Lipid Peroxidation in the Murine Hepatic Microsomal System

1999 ◽  
Vol 6 (3) ◽  
pp. 169-175 ◽  
Author(s):  
M. Gupta ◽  
R. K. Kale ◽  
P. P. Kulkarni ◽  
S. B. Padhye
Keyword(s):  
Lipid Peroxidation ◽  
Metal Ions ◽  
The Other ◽  
Inhibition Constant ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Other Hand ◽  
Significant Reversal

Dafone inhibits the lipid peroxidation significantly in a concentration dependent manner. The inhibition was found to be an uncompetitive type with the inhibition constant (Ki) of 62.5 μM On the other hand complexation with metal ions results in a significant reversal from antioxidant to pro-oxidant properties for the resulting complexes which are cationic and with associated halometallate anions. The nature of the potentiation in case of the ferric compound was of competitive type with activation constant (Ka) having the value 32.5 μM . The neutral copper-dafonate complex, however, inhibits lipid peroxidation with increase in concentration.

scholarly journals Metal Ions in Activated Carbon Improve the Detection Efficiency of Aflatoxin-Producing Fungi

Toxins ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 140 ◽  
Author(s):  
Tadahiro Suzuki ◽  
Masatoshi Toyoda
Keyword(s):  
Activated Carbon ◽  
Metal Ions ◽  
Detection Efficiency ◽  
Trace Element Analysis ◽  
The Other ◽  
Dependent Manner ◽  
Element Analysis ◽  
Concentration Dependent Manner ◽  
Key Factor ◽  
Co Addition

Aflatoxins (AF), produced by several Aspergillus species, are visible under ultraviolet light if present in high amounts. AF detection can be improved by adding activated carbon, which enhances the observation efficiency of weakly AF-producing fungi. However, commercial activated carbon products differ in their characteristics, making it necessary to investigate which characteristics affect method reproducibility. Herein, the addition of 10 activated carbon products resulted in different AF production rates in each case. The differences in the production of aflatoxin G1 (AFG1) were roughly correlated to the observation efficiency in the plate culture. Trace element analysis showed that the concentrations of several metal ions differed by factors of >100, and the carbons that most effectively increased AFG1 production contained higher amounts of metal ions. Adding 5 mg L−1 Fe or Mg ions increased AFG1 production even without activated carbon. Furthermore, co-addition of both ions increased AFG1 production stably with the addition of carbon. When varying the concentration of additives, only AFG1 production increased in a concentration-dependent manner, while the production of all the other AFs decreased or remained unchanged. These findings suggest that a key factor influencing AF production is the concentration of several metal ions in activated carbon and that increasing AFG1 production improves AF detectability.

scholarly journals Antiausterity Activity of Arctigenin Enantiomers: Importance of (2R,3R)-Absolute Configuration

2014 ◽  
Vol 9 (1) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Suresh Awale ◽  
Mamoru Kato ◽  
Dya Fita Dibwe ◽  
Feng Li ◽  
Chika Miyoshi ◽  
...  
Keyword(s):  
Cytotoxic Activity ◽  
Cancer Cells ◽  
Absolute Configuration ◽  
The Other ◽  
Dependent Manner ◽  
Meoh Extract ◽  
Concentration Dependent Manner ◽  
Akt Activation ◽  
Other Hand

From a MeOH extract of powdered roots of Wikstroema indica, six dibenzyl-γ-butyrolactone-type lignans with (2 S,3 S)-absolute configuration [(+)-arctigenin (1), (+)-matairesinol (2), (+)-trachelogenin (3), (+)-nortrachelogenin (4), (+)-hinokinin (5), and (+)-kusunokinin (6)] were isolated, whereas three dibenzyl-γ-butyrolactone-type lignans with (2 R,3 R)-absolute configuration [(-)-arctigenin (1), (-)-matairesinol (2), (-)-trachelogenin (3)] were isolated from Trachelospermum asiaticum. The in vitro preferential cytotoxic activity of the nine compounds was evaluated against human pancreatic PANC-1 cancer cells in nutrient-deprived medium (NDM), but none of the six lignans (1–6) with (2 S,3 S)-absolute configuration showed preferential cytotoxicity. On the other hand, three lignans (1*–3*) with (2 R,3 R)-absolute configuration exhibited preferential cytotoxicity in a concentration-dependent manner with PC50 values of 0.54, 6.82, and 5.85 μM, respectively. Furthermore, the effect of (-)- and (+)-arctigenin was evaluated against the activation of Akt, which is a key process in the tolerance to nutrition starvation. Interestingly, only (-)-arctigenin (1*) strongly suppressed the activation of Akt. These results indicate that the (2 R,3 R)-absolute configuration of (-)-enantiomers should be required for the preferential cytotoxicity through the inhibition of Akt activation.

scholarly journals Suppression of progesterone-enhanced hyperactivation in hamster spermatozoa by estrogen

Reproduction ◽  
2010 ◽  
Vol 140 (3) ◽  
pp. 453-464 ◽  
Author(s):  
Masakatsu Fujinoki
Keyword(s):  
Steroid Hormones ◽  
Sperm Head ◽  
The Other ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Other Hand ◽  
Sperm Proteins ◽  
17Β Estradiol

In this study, I examined whether sperm hyperactivation in hamster is regulated by steroid hormones such as estrogen (estradiol, E2) and progesterone. Although sperm hyperactivation was enhanced by progesterone, 17β-estradiol (17βE2) itself did not affect sperm hyperactivation. However, 17βE2 suppressed progesterone-enhanced hyperactivation in a concentration-dependent manner through non-genomic pathways when spermatozoa were exposed to 17βE2 at the same time or before exposure to progesterone. When spermatozoa were exposed to 17βE2 after exposure to progesterone, 17βE2 did not suppress progesterone-enhanced hyperactivation. Moreover, 17α-estradiol, an inactive isomer of E2, did not suppress progesterone-enhanced hyperactivation. Observations using a FITC-conjugated 17βE2 showed that it binds to the acrosome region of the sperm head. Binding of 17βE2 to spermatozoa was not inhibited by progesterone, although 17βE2 did not suppress progesterone-enhanced hyperactivation when spermatozoa were exposed to 17βE2 after exposure to progesterone. On the other hand, binding of progesterone to spermatozoa was also not inhibited by 17βE2 even if progesterone-enhanced hyperactivation was suppressed by 17βE2. Although tyrosine phosphorylations of sperm proteins were enhanced by progesterone, enhancement of tyrosine phosphorylations by progesterone was suppressed by 17βE2. Moreover, tyrosine phosphorylations were inhibited by 17βE2 when only 17βE2 was added to the medium. From these results, it is likely that 17βE2 competitively suppresses progesterone-enhanced hyperactivation through the inhibition of tyrosine phosphorylations via non-genomic pathways.

Antioxidant Activity of Resveratrol Compared with Common Food Additives

2001 ◽  
Vol 64 (3) ◽  
pp. 379-384 ◽  
Author(s):  
M. ANTONIA MURCIA ◽  
MAGDALENA MARTÍNEZ-TOMÉ
Keyword(s):  
Lipid Peroxidation ◽  
Antioxidant Activity ◽  
Sodium Tripolyphosphate ◽  
Food Additives ◽  
The Other ◽  
Butylated Hydroxytoluene ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Scavenger Activity ◽  
Inhibit Lipid Peroxidation

Resveratrol is a phenolic compound of the stilbene family present in wines and various parts of the grape, including the skin. In this study, the antioxidant and prooxidant activities of resveratrol were compared with other antioxidants (butylated hydroxytoluene [BHT], butylated hydroxyacetone [BHA], phenol, propyl gallate [PG], sodium tripolyphosphate [TPP], α-tocopherol, and vanillin) widely used in foods. The ability of these compounds to inhibit lipid peroxidation was as follows: BHA > resveratrol > PG > tripolyphosphate > vanillin > phenol > BHT > α-tocopherol, the first three inhibiting the peroxidation in a concentration-dependent manner. The order of OH scavenger activity of the tested compounds was BHA > TPP > BHT. Resveratrol and vanillin produced between 10 to 7% and 16 to 10% inhibition of the deoxyribose attack, respectively, but they do not scavenge OH▪. Neither the resveratrol analyzed nor PG or the rest of compounds reacted with H2O2 and must be considered inefficient in catalyzing any subsequent oxidation. The ability to scavenge HOCl was, in decreasing order, PG > resveratrol > α-tocopherol > phenol. The other compounds did not scavenge HOCl.

Serotonin relaxes porcine pial veins

1994 ◽  
Vol 266 (3) ◽  
pp. H1000-H1006 ◽  
Author(s):  
T. J. Lee ◽  
M. Ueno ◽  
N. Sunagane ◽  
M. H. Sun
Keyword(s):  
Muscle Tone ◽  
The Other ◽  
Receptor Subtypes ◽  
Dependent Manner ◽  
Pial Arteries ◽  
Concentration Dependent Manner ◽  
Vasoactive Substances ◽  
Other Hand ◽  
Mechanical Stretching ◽  
Or Applications

The effect of serotonin [5-hydroxytryptamine (5-HT)] on pial venous tone of the pig was examined using in vitro tissue bath techniques. Isolated pial venous rings exhibited spontaneous rhythmic contractions (SRC) on mechanical stretching and/or applications of several vasoactive substances, including norepinephrine. On the other hand, KCl induced sustained active muscle tone (SAT) without SRC. The SRC induced by mechanical stretching were not affected by tetrodotoxin, nitro-L-arginine, alpha- and beta-adrenergic, histaminergic, and muscarinic receptor antagonists, indicating that the SRC in porcine pial veins are of myogenic origin. The SRC induced by stretching or applications of vasoactive substances and SAT induced by KCl were inhibited by 5-HT in a concentration-dependent manner. The inhibition was prevented by methysergide and methiothepin but not by ketanserin, propranolol, 3 alpha-tropanyl-1H-indole-3-carboxylic acid ester, hemoglobin, or nitro-L-arginine. The SRC and SAT were inhibited by 5-carboxamidotryptamine (5-CT), 8-hydroxy-2-di-N-propylaminotetralin HBr (8-OHDPAT), 1-[3-(trifluoromethyl)phenyl]piperazine (TFMPP), and 5-methoxytryptamine (5-MT), but not by sumatriptan, alpha-methylserotonin, or 2-methylserotonin. On the other hand, 5-CT, 8-OHDPAT, TFMPP, 5-MT, and sumatriptan constricted the porcine pial arteries exclusively. In 15% of pial venous preparations examined, 5-HT at low concentrations induced ketanserin-sensitive constrictions. These results indicate that the porcine pial venous smooth muscle contains multiple subtypes of 5-HT receptors. The 5-HT inhibition of SRC and SAT is predominant and is mediated by 5-HT1-like receptors, which, however, do not seem to correspond to 5-HT1A, 5-HT1B, 5-HT1C, 5-HT1D, 5-HT1E, or 5-HT1F receptor subtypes.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Antispasmodic effect of hydroalcoholic and flavonoids extracts of Dracocephalum kotschyi on rabbit bladder

2020 ◽  
Vol 9 (2) ◽  
pp. 145-152
Author(s):  
Hassan Sadraei ◽  
Seyed Ebrahim Sajjadi ◽  
Arefe Tarafdar
Keyword(s):  
Smooth Muscle ◽  
The Other ◽  
Organ Bath ◽  
Dependent Manner ◽  
Bladder Smooth Muscle ◽  
Concentration Dependent Manner ◽  
Standard Drug ◽  
Other Hand ◽  
Dracocephalum Kotschyi ◽  
Rabbit Bladder

Introduction: Dracocephalum kotschyi extract has antispasmodic activities on smooth muscle including ileum, uterus and trachea. The objective of this research was to investigate antispasmodic activity of hydroalcoholic and flavonoids extracts of D. kotschyi on rabbit bladder contractions. Methods: Rabbits were euthanized by carbon dioxide asphyxiation and the whole bladder was dissected out and immersed in the Tyrode’s solution. Longitudinal bladder strips were mounted vertically in an organ bath at 37°C and gassed continuously with O2 . Bladder strips were contracted with acetylcholine (ACh), KCl, or electrical field stimulation (EFS). Isotonic tension of the tissue was recorded before and after addition of hydroalcoholic or flavonoids rich extracts of D. kotschyi. Nifedipine and propantheline were used as standard drugs. Results: Standard drug propantheline, prevented bladder phasic contraction induced by ACh (1µM) without affecting KCl response. On the other hand, cumulative addition of nifedipine attenuated the tonic contractions induced by KCl (20mM) on bladder smooth muscle. Hydroalcoholic and flavonoids extracts of D. kotschyiat concentration ranges of 10-320 µg/ mL in a concentration dependent way inhibited bladder tonic contraction induced by KCl (n=6). Both extracts also in a concentration-dependent manner relaxed EFS and ACh-induced contractions (range, 20–1280 µg/mL) of bladder smooth muscle in vitro. Complete inhibition was achieved with the highest used concentrations of the extracts. The inhibitory effect of the extract was reversible following washing the tissues with fresh Tyrode’s solution. Conclusion: This study clearly demonstrated that D. kotschyi extracts were able to prevent contractions induced by ACh, KCl or EFS in isolated rabbit bladder. This means that people consuming this medicinal plant may face urinary retention which could be a problem for patients with prostate hypertrophy. On the other hand, this plant might be useful in patients with urinary incontinence. However, its usefulness must be assessed in the controlled clinical trials.

Differential responses of hydrogen peroxide, lipid peroxidation and antioxidant enzymes in Azolla microphylla exposed to paraquat and nitric oxide

Biologia ◽  
2012 ◽  
Vol 67 (6) ◽  
Author(s):  
Anjuli Sood ◽  
Charu Kalra ◽  
Sunil Pabbi ◽  
Prem Uniyal
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Lipid Peroxidation ◽  
Antioxidative Enzymes ◽  
Guaiacol Peroxidase ◽  
Dependent Manner ◽  
Oxygen Species ◽  
Concentration Dependent Manner ◽  
No Donor ◽  
Azolla Microphylla

AbstractThe present investigation was carried out to decipher the interplay between paraquat (PQ) and exogenously applied nitric oxide (NO) in Azolla microphylla. The addition of PQ (8 μM) increased the activities of superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPX), ascorbate peroxidase (APX) by 1.7, 2.7, 3.9 and 1.9 folds respectively than that control in the fronds of Azolla. The amount of H2O2 was also enhanced by 2.7 times in the PQ treated plants than that of control. The supplementation of sodium nitroprusside (SNP) from 8–100 μM along with PQ, suppressed the activities of antioxidative enzymes and the amount of H2O2 compared to PQ alone. The drop in the activity of antioxidative enzymes — SOD, GPX, CAT and APX was highest (39.9%, 48.4%, 41.6% and 41.3% respectively) on the supplementation of 100 μM SNP with PQ treated fronds compared to PQ alone. The addition of NO scavengers along with NO donor in PQ treated fronds neutralized the effect of exogenously supplied NO. This indicates that NO can effectively protect Azolla against PQ toxicity by quenching reactive oxygen species. However, 200 μM of SNP reversed the protective effect of lower concentration of NO donor against herbicide toxicity. Our study clearly suggests that (i) SNP released NO can work both as cytoprotective and cytotoxic in concentration dependent manner and (ii) involvement of NO in protecting Azolla against PQ toxicity.

scholarly journals Fluorescein-Labeled Starch Maleate Nanoparticles as Sensitive Fluorescent Sensing Probes for Metal Ions

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Suk Fun Chin ◽  
Aressa Azman ◽  
Suh Cem Pang ◽  
Sing Muk Ng
Keyword(s):  
Particle Size ◽  
Metal Ions ◽  
Self Assembly ◽  
Detection Limits ◽  
Emission Wavelength ◽  
Dependent Manner ◽  
Ethanolic Solution ◽  
Concentration Dependent Manner ◽  
Maximum Emission ◽  
Fluorescent Sensing

Fluorescein 5(6)-isothiocyanate starch maleate (FISM) nanoparticles were prepared by covalently attached fluorescein 5(6)-isothiocyanate (FITC) with starch maleate. FISM nanoparticles with a mean particle size of 87 nm were formed via self-assembly upon precipitation in ethanolic solution. FISM nanoparticles were strongly fluorescent with maximum emission wavelength of 518 nm. The fluorescence of FISM nanoparticles can be quenched by silver (Ag+) and lead (Pb2+) ions in a concentration dependent manner. We have demonstrated the first use of FISM nanoparticles as cheap and effective fluorescent sensing probes for Ag+and Pb2+ions with detection limits as low as 2.55×10−5 M and 3.64×10−5 M, respectively.

scholarly journals The Lipid Peroxidation By-product 4-Hydroxynonenal is Toxic to Axons and Oligodendrocytes

2000 ◽  
Vol 20 (11) ◽  
pp. 1529-1536 ◽  
Author(s):  
Eileen McCracken ◽  
V. Valeriani ◽  
C. Simpson ◽  
T. Jover ◽  
James McCulloch ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Cell Death ◽  
White Matter ◽  
Injection Site ◽  
Subcortical White Matter ◽  
Intracerebral Injection ◽  
Dependent Manner ◽  
Concentration Dependent Manner

Lipid peroxidation and the cytotoxic by-product 4-hydroxynonenal (4-HNE) have been implicated in neuronal perikaryal damage. This study sought to determine whether 4-HNE was involved in white matter damage in vivo and in vitro. Immunohistochemical studies detected an increase in cellular and axonal 4-HNE within the ischemic region in the rat after a 24-hour period of permanent middle cerebral artery occlusion. Exogenous 4-HNE (3.2 nmol) was stereotaxically injected into the subcortical white matter of rats that were killed 24 hours later. Damaged axons detected by accumulation of β-amyloid precursor protein (β-APP) were observed transversing medially and laterally away from the injection site after intracerebral injection of 4-HNE. In contrast, in the vehicle-treated animals, axonal damage was restricted to an area immediately surrounding the injection site. Exogenous 4-HNE produced oligodendrocyte cell death in culture in a time-dependent and a concentration-dependent manner. After 4 hours, the highest concentration of 4-HNE (50 μmol/L) produced 100% oligodendrocyte cell death. Data indicate that lipid peroxidation and production of 4-HNE occurs in white matter after cerebral ischemia and the lipid peroxidation by-product 4-HNE is toxic to axons and oligodendrocytes.

scholarly journals Inhibitory effect of Sphagnum palustre extract and its bioactive compounds on aromatase activity

2016 ◽  
Vol 11 (3) ◽  
pp. 661
Author(s):  
Hee Jeong Eom ◽  
Yong Joo Park ◽  
Hee Rae Kang ◽  
Ha Ryong Kim ◽  
In Jae Bang ◽  
...  
Keyword(s):  
Video Clip ◽  
Inhibitory Effect ◽  
The Other ◽  
Aromatase Activity ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Aromatase Inhibition ◽  
Concentration Dependent Manner ◽  
Cardiac Pain ◽  
Sphagnum Palustre

<p><em>Sphagnum palustre</em> (a moss) has been traditionally used in Korea for the cure of several diseases such as cardiac pain and stroke. In this research, the inhibitory effect of <em>S. palustre</em> on aromatase (cytochrome P<sub>450</sub> 19, CYP19) activity was studied. [1β-<sup>3</sup>H] androstenedione was used as a substrate and incubated with <em>S. palustre</em> extract and recombinant human CYP19 in the presence of NADPH. <em>S. palustre</em> extract inhibited aromatase in a concentration-dependent manner (IC<sub>50</sub> value: 36.4 ± 8.1 µg/mL). To elucidate the major compounds responsible for the aromatase inhibitory effects of <em>S. palustre</em> extract, nine compounds were isolated from the extract and tested for their inhibition of aromatase activity. Compounds <strong>1</strong>, <strong>6</strong>, and <strong>7</strong> displayed aromatase inhibition, while the inhibition by the other compounds was negligible.</p><p><strong>Video Clip</strong></p><p><a href="https://youtube.com/v/n6xeo3RXJVY">Aromatase enzyme activity:</a> 4 min 16 sec  </p>

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