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1.
Hisashi Kato-Noguchi Madoka Yamamoto Kazuya Tamura Toshiaki Teruya Kiyotake Suenaga Yoshiharu Fujii 《Plant Growth Regulation》2010,60(2):127-131
Aqueous methanol extracts of rattail fescue (Vulpia myuros) inhibited the growth of roots and shoots of cress (Lepidium sativum), lettuce (Lactuca sativa), alfalfa (Medicago sativa), timothy (Phleum pratense), Digitaria sanguinalis and Lolium multiflorum. Increasing the extract concentration increased the inhibition, suggesting that rattail fescue may have growth inhibitory
substances and possess allelopathic potential. The aqueous methanol extract of rattail fescue was purified and two main inhibitory
substances were isolated and identified by spectral data as (−)-3-hydroxy-β-ionone and (+)-3-oxo-α-ionol. Both substances
inhibited root and shoot growth of cress at concentrations greater than 0.3 μM. The concentrations required for 50% growth
inhibition on root and shoot growth of cress, lettuce, alfalfa, timothy, D. sanguinalis and L. multiflorum were 2.7–19.7 μM for (−)-3-hydroxy-β-ionone, and 2.1–34.5 μM for (+)-3-oxo-α-ionol. The concentration of (−)-3-hydroxy-β-ionone
and (+)-3-oxo-α-ionol, respectively, in rattail fescue was 7.8 and 3.7 μg g−1 fresh weight. Considering the endogenous level and the inhibitory activity, (−)-3-hydroxy-β-ionone and (+)-3-oxo-α-ionol
may work as allelopathic substances in rattail fescue through the growth inhibition of neighboring plant species. 相似文献
2.
E. A. Kosenko M. B. Abramova N. I. Venediktova I. I. Popova Yu. G. Kaminskii 《Biology Bulletin》2010,37(4):346-350
The effect of hypoxen on the oxygen consumption and activity of dehydrogenases in rat liver mitochondria has been studied.
The addition of hypoxen to mitochondria caused a reduction of the rate of phosphorylating and uncoupling respiration. The
minimal effective concentration of hypoxen was 15 μg/ml with succinate, 60 μg/ml with pyruvate or palmitoylcarnitine, and
120 μg/ml with glutamate as the substrates. The activities of malate, glutamate, and succinate dehydrogenases in mitochondria
were significantly decreased by the effect of hypoxen. 相似文献
3.
The biological properties of dihydroquercetin (DHQ) modified by including it into the ring of β-cyclodextrin (β-CD) to give
it more water-soluble properties have been investigated. It was shown that the peroral administration of the DHQ/β-CD complex
provides a long increase of DHQ concentration in rat blood (up to 7.5 h), and, unlike pure DHQ, the complex does not accumulate
in the liver. As DHQ is released from the complex, it penetrates into liposome membranes, changing their thermodynamic characteristics.
DHQ decreases the specific heat absorption, enthalpies, and temperature maximum of lipid melting and increases the transition
half-width. This property is used to estimate the stability of the DHQ/β-CD complex. It was shown that complex DHQ/β-CD is
not stable, and DHQ molecules slowly leave the complex in water environment. Seven and a half hours after the peroral injection
of drugs, DHQ was found in the blood plasma of rats to which water-soluble complex DHQ/βCD was injected and in the liver of
rats to which free DHQ was injected. Thus, DHQ/βCD not only is a more water-soluble complex but also it slowly releases DHQ,
supporting long a low concentration of the free form of DHQ and providing the penetration of DHQ into the blood stream. After
several weeks of feeding old mice with antioxidants, the activity of mitochondrial enzymes was restored to the level observed
in young animals. 相似文献
4.
The goal of this research was to measure in vitro the inhibitory constants of the antioxidants ascorbic and uric acid in urine, with lucigenin enhanced chemiluminescence (CL)
in Fenton’s system. Maximum CL emission is registered in urine containing H2O2 (5·10−4 M), Fe2+ (5·10−5 M), EDTA (5·10−5 M), and chemical enhancer lucigenin (10−4 M) at pH 5.5 and 36°C. Ascorbic acid exhibits up to 4-fold stronger antioxidant effect than uric acid. The constants of antioxidant
inhibition in urine were measured at concentrations 10−3 and 10−4 M: for ascorbic acid, 5.92 ± 0.04 and 24.05 ± 1.82 μmol·sec−1; for uric acid, 1.60 ± 0.02 and 21.45 ± 0.97 μmol·sec−1, respectively. Three phases of CL kinetics of urine are well observed: spontaneous CL (0–10 sec), fast flash of CL (10–50
sec), and latent period (50–300 sec). The antioxidant efficiency of ascorbic and uric acids in the final stage of catabolic
processes in the body is discussed.
Published in Russian in Biokhimiya, 2006, Vol. 71, No. 8, pp. 1062–1065. 相似文献
5.
Toshiyuki Shibata Kanji Ishimaru Shigeo Kawaguchi Hiromichi Yoshikawa Yoichiro Hama 《Journal of applied phycology》2008,20(5):705-711
The antioxidant activities of brown algal phlorotannins were evaluated using the inhibition of phospholipid peroxidation in
the liposome system, and by determining radical scavenging activities against the superoxide anion and 1,1-diphenyl-2-picrylhydrazyl
(DPPH). Oligomers of phloroglucinol (1,3,5-trihydroxybenzene), eckol (a trimer), phlorofucofuroeckol A (a pentamer), dieckol
and 8,8′-bieckol (hexamers), isolated from the Laminarian brown algae Eisenia bicyclis, Ecklonia cava and Ecklonia kurome, showed potent inhibition of phospholipid peroxidation at 1 μM in the liposome system. The phlorotannins had significant
radical scavenging activities against the superoxide anion (50% effective concentration values: 6.5–8.4 μM) and DPPH (50%
effective concentration values: 12–26 μM), and were more effective compared to ascorbic acid and α-tocopherol. For the purpose
of using phlorotannins as functional food ingredients, the antioxidant activity of a complex of crude phlorotannins and soybean
protein was examined. The complex had a pronounced DPPH-radical scavenging activity. These results suggest that phlorotannins
are potent anti-inflammatory substances, and that the Laminariaceous brown algae, which are abundant in phlorotannins, may
be useful as a new functional foodstuff or supplement with anti-inflammatory activity. 相似文献
6.
The modulation of [3H]ACh release by nicotinic compounds was studied in superfused rat hippocampal synaptosomes loaded with [3H]choline. (−)-Nicotine (0.1–10 μM) evoked a dose-dependent increase in [3H]ACh release; higher concentrations were less effective. Nicotine-evoked release was Ca2+-dependent, and blocked by the nicotinic antagonists dihydro-β-erythroidine, mecamylamine, and pempidine. The α7-selective
antagonist methyllycaconitine did not inhibit nicotine-evoked release when tested at 1 μM, although at 10 μM some attenuation
of the response was observed. Six agonists tested were equally efficacious in stimulating [3H]ACh release, as judged by the maximum responses, and gave the following EC50 values: (±)-epibatidine 0.12 μM; (+)-anatoxin-a 0.14 μM; (−)-nicotine 0.99 μM; (−)-cytisine 1.06 μM; ABT-418 2.6 μM; isoarecolone
43 μM. Each agonist generated a “bell-shaped” dose response curve, suggesting desensitisation at higher concentrations. This
is supported by analysis of repetitive stimulation with (−)-nicotine and (−)-cytisine: S2/S1 ratios declined sharply with
increasing concentration, whereas subsequent KCl-evoked release remained constant. These results are discussed in terms of
possible nicotinic receptor subtypes that might be present on hippocampal nerve terminals.
Special issue dedicated to Dr. Herman Bachelard. 相似文献
7.
I. L. Lisovskaya R. I. Volkova V. M. Nesterenko I. M. Shcherbachenko F. I. Ataullakhanov 《Biochemistry (Moscow) Supplemental Series A: Membrane and Cell Biology》2011,5(1):37-44
This study is focused on the effect of the antifungal drug clotrimazole (CLT), also possessing anti-malarial and anticancer
activities, on hemin-induced hemolysis and changes in ion permeability and filter-ability of human erythrocytes. In the presence
of 10 μM clotrimazole, the hemolytic response of erythrocytes to exogenous hemin at concentrations as low as 2–8 μM was considerably
potentiated and their filterability, as measured by passing them through a 5-μm nuclepore filter, dropped sharply. Flavonoids
quercetin (Q) and taxifolin (DHQ), unlike the standard antioxidant Trolox, abolished the effects of clotrimazole, suggesting
that protection of hemin-treated erythrocytes by flavonoids is not related to their antioxidant properties. 相似文献
8.
Ionized COOH groups are present in molecular structures involved in the process of formation of mitochondrial permeability
transition pores (MPTPs), in particular, in the ADP/ATP antiporter and/or voltage-dependent anion channels. In experiments
on preparations of isolated mitochondria obtained from rat hepatocytes, we found that, in the case of induction of nonspecific
permeability through mitochondrial membranes under the action of Cа2+ in a relatively low concentration (15 μM), modulation of the activity of COOH groups with the use of 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline
(1 mM) led to unidirectional effects, namely to acceleration of the processes of formation of MPTPs and transport of incubation
solution and Са2+ through these megachannels, prolongation of the open state of the latter, as well as to increases in the final volume (swelling)
of the mitochondria and to a rise in the amount of Са2+ released from these organelles. In contrast, when calcium was used in a high concentration (100 μM), the directions of the
above processes were dissimilar. Slowing down of the flow of incubation solution through MPTPs and the process of their formation
was observed; at the same time, Са2+ release from the mitochondria was accelerated. However, the final volume of the mitochondria and the amount of Са2+ released from these cellular structures increased. Differences between the effects of the used modulator of the activity
of COOH groups on the nonspecific permeability of the mitochondria induced by calcium applied in low and high concentrations
are perhaps determined by the following. The process of swelling of the mitochondria is saturable, while Са2+ release from these organelles shows an unlimited pattern. The latter process (Са2+ release) probably undergoes calcium-initiated inactivation. The mechanisms of induction of nonspecific permeability of the
mitochondrial membranes under the action of low and high calcium concentrations differ from each other. The calcium uniporter
in the mitochondria is sensitive to the modulator of the activity of COOH groups. Diffusion of water through the inner mitochondrial
membrane and/or other systems provides some contribution to the studied processes; this can lead to changes in the transport
of liquids in these organelles. 相似文献
9.
Adams KL Maxson MM Mellander L Westerink RH Ewing AG 《Cellular and molecular neurobiology》2010,30(8):1235-1242
Fast neuromodulatory effects of 17-β-estradiol (E2) on cytosolic calcium concentration ([Ca2+]
i
) have been reported in many cell types, but little is known about its direct effects on vesicular neurotransmitter secretion
(exocytosis). We examined the effects of E2 on depolarization-evoked [Ca2+]
i
in PC12 cells using fluorescence measurements. Imaging of [Ca2+]
i
with FURA-2 revealed that depolarization-evoked calcium entry is inhibited after exposure to 10 nM and 10 μM E2. Calcium
entry after exposure to 50 μM E2 decreases slightly, but insignificantly. To relate E2-induced changes in [Ca2+]
i
to functional effects, we measured exocytosis using amperometry. It was observed that E2 in some cells elicits exocytosis
upon exposure. In addition, E2 inhibits depolarization-evoked exocytosis with a complex concentration dependence, with inhibition
at both physiological and pharmacological concentrations. This rapid inhibition amounts to 45% at a near physiological level
(10 nM E2), and 50% at a possible pharmacological concentration of 50 μM. A small percentage (22%) of cells show exocytosis
during E2 exposure (“Estrogen stimulated”), thus vesicle depletion could possibly account (at least partly) for the E2-induced
inhibition of depolarization-evoked exocytosis. In cells that do not exhibit E2-stimulated release (“Estrogen quiet”), the
E2-induced inhibition of exocytosis is abolished by a treatment that eliminates the contribution of N-type voltage-gated calcium
channels (VGCCs) to exocytosis. Overall, the data suggest that E2 can act on N-type VGCCs to affect secretion of neurotransmitters.
This provides an additional mechanism for the modulation of neuronal communication and plasticity by steroids. 相似文献
10.
Fulvic acid (FA) is class of compounds of humic substances formed through the degradation of organic substances by chemical
and biological processes. FA has been utilized in traditional Chinese medicine and possesses various pharmacological properties.
Previously, we reported that FA extracted from solubilized excess sludge (SS-FA) had an inhibitory effect on β-hexosaminidase
release in human leukemia basophilic (KU812) cells. In this study, we investigated the effects of SS-FA on the immediate-type
allergic reaction and studied its possible mechanisms of action in KU812 cells following activation with phorbol myristate
acetate (20 nmol L−1) plus calcium ionophore A23187 (1 μmol L−1) (PMACI). The inhibitory effect of SS-FA on degranulation in PMACI-stimulated KU812 cells was examined using histamine release
assay. SS-FA significantly decreased the histamine release in KU812 cells at concentrations of 0.1–10.0 μg mL−1. To gain more information regarding the mechanism of the suppression of degranulation following SS-FA treatment, microarray
was conducted to determine which genes were differentially expressed in response to SS-FA in PMACI-activated KU812 cells.
From a total of 201 genes in the DNA chip, 28 genes were up-regulated and 173 genes were down-regulated in cells pretreated
with SS-FA for 15 min and stimulated with PMACI. From the 71 genes that showed more than two fold change in expression, 16
genes were significantly down-regulated that were subjected to hierarchical clustering. SS-FA affected the expression of genes
that were involved in the following pathways: signal transduction, cytokine–cytokine receptor interaction, immune response,
cell adhesion molecules and IgE receptor β subunit response. 相似文献
11.
Zoccarato F Miotto C Cavallini L Alexandre A 《Journal of bioenergetics and biomembranes》2011,43(4):359-366
In brain mitochondria succinate activates H2O2 release, concentration dependently (starting at 15 μM), and in the presence of NAD dependent substrates (glutamate, pyruvate,
β-hydroxybutyrate). We report that TCA cycle metabolites (citrate, isocitrate, α-ketoglutarate, fumarate, malate) individually
and quickly inhibit H2O2 release. When they are present together at physiological concentration (0.2, 0.01, 0.15, 0.12, 0.2 mM respectively) they
decrease H2O2 production by over 60% at 0.1–0.2 mM succinate. The degree of inhibition depends on the concentration of each metabolite.
Acetoacetate is a strong inhibitor of H2O2 release, starting at 10 μM and acting quickly. It potentiates the inhibition induced by TCA cycle metabolites. The action
of acetoacetate is partially removed by β-hydroxybutyrate. Removal is minimal at 0.1 mM acetoacetate, and is higher at 0.5 mM
acetoacetate. We conclude that several inhibitors of H2O2 release act jointly and concentration dependently to rapidly set the required level of H2O2 generation at each succinate concentration. 相似文献
12.
Summary It is known that estrogen can protect neurons from excitotoxicity. Since isoflavones possess estrogen-like activity, it is
of interest to determine whether isoflavones can also protect neurons from glutamate-induced neuronal injury. Morphological
observation and lactate dehydrogenase (LDH) release assay were used to estimate the cellular damage. It is surprising that,
contrary to estrogen, isoflavones, specifically genistein and daidzein, are toxic to primary neuronal culture at high concentration.
Treatment of neurons with 50 μM genistein and daidzein for 24 h increased LDH release by 90% and 67%, respectively, indicating a significant cellular damage.
Under the same conditions, estrogen such as 17β-estradiol did not show any effect on primary culture of brain cells. At 100 μM, both genistein and daidzein increased LDH release by 2.6- and 3-fold, respectively with a 30-min incubation. Furthermore,
both genistein and daidzein at 50 μM increased the intracellular calcium level, [Ca2+]i, significantly. To determine their mode of action, genistein and daidzein were tested on glutamate and GABAA receptor binding. Both genistein and daidzein were found to have little effect on glutamate receptor binding, while the binding
of [3H]muscimol to GABAA receptors was markedly inhibited. However, 17β-estradiol did not affect GABAA receptor binding suggesting that the toxic effect of genistein and daidzein could be due to their inhibition of the GABAA receptor resulting in further enhancement of excitation by glutamate and leading to cellular damage.
Ying Jin, Heng Wu contributed equally to this article. 相似文献
13.
A two-wave technique of calciometry with the use of a fluorescence dye, fura-2/AM, was applied for examination of the effect
of a protein, β-amyloid (the main component of senile plaques in Alzheimer’s disease), on calcium homeostasis in cultured
neurons of the rat hippocampus; β-amyloid was added to the culture medium. In most neurons, the effect of β-amyloid appeared
as a more than twofold increase in the basic calcium concentration, as compared with the control (153.4 ± 11.5 and 71.7 ±
5.4 nM, respectively; P < 0.05). The characteristics of calcium transients induced by application of hyperpotassium solution also changed; the amplitude
of these transients decreased, and the duration of a part corresponding to calcium release from the cell (rundown of the transient)
increased. The mean amplitude of calcium transients under control conditions was 447.5 ± 20.1 nM, while after incubation in
the presence of β-amyloid this index dropped to 278.4 ± 22.6 nM. Under control conditions, the decline phase of calcium transients
lasted, on average, 100 ± 6 sec, while after incubation of hippocampal cell cultures in the presence of β-amyloid this phase
lasted 250 ± 10 sec. Therefore, an excess of β-amyloid influences significantly calcium homeostasis in the nerve cells by
disturbing functions of the calcium-controlling systems, such as voltage-operated calcium channels of the plasma membrane
and calcium stores of the mitochondria and endoplasmic reticulum.
Neirofiziologiya/Neurophysiology, Vol. 40, No. 1, pp. 9–12, January–February, 2008. 相似文献
14.
Seil M El Ouaaliti M Fontanils U Etxebarria IG Pochet S Dal Moro G Marino A Dehaye JP 《Purinergic signalling》2010,6(4):405-416
The response to ATP of peritoneal macrophages from wild-type (WT) and P2X7-invalidated (KO) mice was tested. Low concentrations (1–100 μM) of ATP transiently increased the intracellular concentration
of calcium ([Ca2+]i) in cells from both mice. The inhibition of the polyphosphoinositide-specific phospholipase C with U73122 inhibited this
response especially in WT mice suggesting that the responses coupled to P2Y receptors were potentiated by the expression of
P2X7 receptors. One millimolar ATP provoked a sustained increase in the [Ca2+]i only in WT mice. The response to 10 μM ATP was potentiated and prolonged by ivermectin in both mice. One millimolar ATP increased
the influx of extracellular calcium, decreased the intracellular concentration of potassium ([K+]i) and stimulated the secretion of interleukin-1β (IL-1β) only in cells from WT mice. Ten micromolar ATP in combination with
3 μM ivermectin reproduced these responses both in WT and KO mice. The secretion of IL-1β was also increased by nigericin
in WT mice and the secretory effect of a combination of ivermectin with ATP in KO mice was suppressed in a medium containing
a high concentration of potassium. In WT mice, 150 μM BzATP stimulated the uptake of YOPRO-1. Incubation of macrophages from
WT and KO mice with 10 μM ATP resulted in a small increase of YOPRO-1 uptake, which was potentiated by addition of 3 μM ivermectin.
The uptake of this dye was unaffected by pannexin-1 blockers. In conclusion, prolonged stimulation of P2X4 receptors by a combination of low concentrations of ATP plus ivermectin produced a sustained activation of the non-selective
cation channel coupled to this receptor. The ensuing variations of the [K+]i triggered the secretion of IL-1β. Pore formation was also triggered by activation of P2X4 receptors. Higher concentrations of ATP elicited similar responses after binding to P2X7 receptors. The expression of the P2X7 receptors was also coupled to a better response to P2Y receptors. 相似文献
15.
Inhibition of the mitochondrial KATP (mitoKATP) channel abrogates the beneficial effects of preconditioning induced by a brief episode of sublethal ischemia. We studied
the effect of 5-hydroxydecanoate, a well-known inhibitor of the mitoKATP channel, on swelling of isolated liver and brain mitochondria. Volume changes were determined by measurement of light absorbance
at 540 nm. Mitochondrial swelling induced by adding Ca2+ ions correlated with opening of the permeability transition pore as shown by modulation by 1 μM cyclosporin A. In brain mitochondria,
5-hydroxydecanoate did not significantly affect Ca2+-induced swelling. In contrast, 50 or 500 μM 5-hydroxydecanoate increased swelling of liver mitochondria by 9.7 ± 5.1% (n = 6, P = 0.057) and 29.4 ± 1.4% (n = 5, P < 0.0001), respectively. The effect of 5-hydroxydecanoate was blocked by cyclosporin A and was dependent on the presence
of potassium in the medium. In medium containing 200 μM ATP to inhibit the mitoKATP channel, 5–hydroxydecanoate did not further increase Ca2+-induced swelling. We conclude that inhibition of the mitoKATP channel exerts its detrimental effect by facilitation of permeability transition pore opening. 相似文献
16.
17.
Tatiana Borisova Roman Sivko Arseniy Borysov Natalia Krisanova 《Cellular and molecular neurobiology》2010,30(7):1013-1023
The effect of the cholesterol-depleting agent methyl-β-cyclodextrin (MβCD) on exocytotic, transporter-mediated, tonic release,
the ambient level and uptake of l-[14C]glutamate was assessed in rat brain synaptosomes using different methodological approaches of MβCD application. The addition
of 15 mM MβCD to synaptosomes (the acute treatment, AT) immediately resulted in the extraction of cholesterol and in a two
times increase in the extracellular l-[14C]glutamate level. When 15 mM MβCD was applied to synaptosomes for 35 min followed by washing of the acceptor (the long-term
pretreatment, LP), this level was only one-third higher than in the control. The opposite effects of MβCD on tonic l-[14C]glutamate release and glutamate transporter reversal were found in AT and LP. Tonic release was dramatically enlarged in
AT, but decreased after LP. Transporter-mediated release was increased several times in AT, but attenuated in LP. Depolarization-evoked
exocytotic release of l-[14C]glutamate was completely lost in AT, whereas after LP, it was decreased by half in comparison with the control. Na+-dependent l-[14C]glutamate uptake was decreased by ~60% in AT, whereas in LP, it was lowered by ~40% only. The presence of MβCD in the incubation
media during AT caused dramatic dissipation of the proton gradient of synaptic vesicles that was shown with the pH-sensitive
dye acridine orange, whereas after LP, no statistically significant changes were registered in synaptic vesicle acidification.
It was concluded that the diverse changes in glutamate transport in AT and LP were associated with the difference in the functional
state of synaptic vesicles. 相似文献
18.
Calcium currents through the somatic membrane of cultivated (a low-density culture) hippocampal neurons of rats were studied
with the use of a patch-clamp technique in the whole-cell configuration. Low- and high-threshold components of calcium currents
were found in the somata of all studied cells. Low-threshold currents were activated at a membrane potential of about−75 mV
and reached the maximum amplitude at −45±4 mV, while the maximum amplitude of high-threshold currents was observed at 17±6
mV. Low-threshold calcium currents differed from high-threshold current in weak suppression by low Cd2+ concentration (10–20 μM), while Ni2+ inhibited both types of calcium currents to an equal extent. Experiments with organic channel blockers showed that in most
neurons at least four channel types were expressed: these were L, N, P, and channels insensitive to the used blockers (presumably,
R-type). A blocker of L-type calcium channels, nifedipine (10 μM), blocked, on the average, 22.7±5.2%; a blocker of N-type
channels, ω-CTx-GVIA (1.0 μM), blocked 30.0±5.0% and a blocker of P/Q channels, ω-Aga-IVA (200 nM), blocked 37.2±13.3% of
the integral high-threshold current. A resistive component equalled 15.7±5.1% of the latter current. It is concluded that
hippocampal neurons cultivated with a low density express a pharmacologically heterogeneous population of calcium channels,
and the relative proportions of different type channels are close to the earlier described channel type composition in rat
hippocampal slices. Our study shows that the low-density culture can be used as an adequate model for studying calcium channels
in the somatic membrane of hippocampal neurons. 相似文献
19.
D. A. Guseva Yu. Yu. Khudoklinova N. V. Medvedeva V. S. Baranova T. S. Zakharova E. B. Artyushkova T. I. Torkhovskaya O. M. Ipatova 《Biochemistry (Moscow) Supplemental Series B: Biomedical Chemistry》2016,10(2):138-144
Bioavailability and activity of natural polyphenols, resveratrol (RES) and dihydroquercetin (DHQ), included in phospholipid nanoparticles have been investigated. Specific features of RES and DHQ in these compositions have been analyzed in vivo and in vitro experiments in comparison with free substances. Preincubation of low density lipoproteins (LDL), isolated from plasma of healthy donors, with RES or DHQ included in phospholipid nanoparticles caused a more pronounced delay in Cu2+ induced lipid oxidation compared with the free substances, and reduced the formation of lipid peroxidation (LPO) products. In phospholipid formulations bioavailability of RES and DHQ orally administered to rats were 1.5–2-fold higher than that of free substances. Prophylactic administration of phospholipid formulations containing RES or DHQ for two weeks resulted in the 25% increase of animal survival in the acute hypoxia model and 1.5-fold increase of catalase activity assayed in brain homogenates as compared with free substances. Using the model of endothelial dysfunction in rats induced by L-NAME, nitric oxide synthase inhibitor, it was shown, that RES markedly attenuated the inhibitory effect of L-NAME on NO synthesis. RES administered in phospholipid nanoparticles demonstrated the same efficiency at a dose one order of magnitude lower compared than that of free RES. The load test with resistance (clamping of the ascending aorta for 30 s) showed that the phospholipid formulation of RES exhibited a more pronounced protective effect due to stimulation of endothelial NO-synthase. 相似文献
20.
Mannan Hajimahmoodi Mohammad Ali Faramarzi Najmeh Mohammadi Neda Soltani Mohammad Reza Oveisi Nastaran Nafissi-Varcheh 《Journal of applied phycology》2010,22(1):43-50
Antioxidant activities of both cells and extracellular substances were evaluated in 12 soil-isolated strains of microalgae
according to FRAP and DPPH-HPLC assays. Their total phenolic contents were also determined by Folin–Ciocalteu method. Extractions
were performed with hexane, ethyl acetate, and water. The results of FRAP assay showed that algal cells contained considerable
amounts of antioxidants from 0.56 ± 0.06 to 31.06 ± 4.00 μmol Trolox g−1 for Microchaete tenera hexane extract and Chlorella vulgaris water extract, respectively. In water fractions of extracellular substances, the antioxidants were from 1.30 ± 0.15 μmol
Trolox g−1 for Fischerella musicola to 73.20 ± 0.16 μmol Trolox g−1 for Fischerella ambigua. Also, DPPH-HPLC assay represented high antioxidant potential of water fractions. The measured radical-scavenging activities
of the studied microalgae were at least 0.15 ± 0.02 in Nostoc ellipsosporum cell mass to a maximum of 109.02 ± 8.25 in C. vulgaris extracellular substance. The amount of total phenolic contents varied in different strains of microalgae and ranged from
zero in hexane extract to 19.15 ± 0.04 mg GAE g−1 in C. vulgaris extracellular water fraction. Significant correlation coefficients between two measured parameters indicated that phenolic
compounds were a major contributor to the microalgal antioxidant capacities. 相似文献