Production Of Thiobarbituric Acid Reactive Substances Research Articles

Oxidative/Nitrative Mechanism of Molsidomine Mitotoxicity Assayed by the Cytochrome c Reaction with SIN-1 in Models of Biological Membranes.

Molsidomine is currently used as a vasodilator drug for the treatment of myocardial ischemic syndrome and congestive heart failure, although still presenting some mitochondrial-targeted side effects in many human cells. As a model of molsidomine mitotoxicity, the reaction of cytochrome c with phosphatidylserine (PS)- and cardiolipin (CL)-containing liposomes was investigated in oxidative/nitrosative conditions imposed by SIN-1 decomposition, which renders peroxynitrite (ONOO-) as a main reactive product. In these conditions, the production of thiobarbituric acid-reactive substance (TBARs) and LOOH was affected by the lipid composition and the oxidative/nitrative conditions used. The oxidative/nitrative conditions were the exposure of lipids to SIN-1 decomposition, native cytochrome c after previous exposure to SIN-1, concomitantly to SIN-1 and native cytochrome c, native cytochrome c, and cytochrome c modified by SIN-1 that presents a less-rhombic heme iron (L-R cytc). TBARs and LOOH production by lipids and cytochrome c exposed concomitantly to SIN-1 differed from that obtained using L-R cytc and featured similar effects of SIN-1 alone. This result suggests that lipids rather than cytochrome c are the main targets for oxidation and nitration during SIN-1 decomposition. PS- and CL-containing liposomes challenged by SIN-1 were analyzed by Fourier transform infrared spectroscopy that revealed oxidation, trans-isomerization, and nitration. These products are consistent with reaction routes involving lipids and NOx formed via peroxynitrite or direct reaction of NO• with molecular oxygen that attacks LOOH and leads to the formation of substances that are not reactive with thiobarbituric acid.

Antioxidant enzyme activity and microRNA are associated with growth of Poa pratensis callus under salt stress

Kentucky bluegrass (Poa pratensis L.) is an important species of turfgrass that is commonly planted on golf courses and landscapes all over the world. It is sensitive to salt stress; however, details relating to its molecular mechanisms of salt resistance are not available. We, therefore, analyzed the changes in growth, antioxidant enzyme activity, and microRNA expression in the callus 1 week after treatment with 200 mM NaCl for 12 h, 24 h, 48 h, 96 h, and 144 h. The results demonstrated that callus growth declined and thiobarbituric acid-reactive substance production and cell membrane permeability increased. Treatment with salt increased ascorbate peroxidase, glutathione reductase, superoxide dismutase, catalase, peroxidase, and polyphenol oxidase activity. Changes in the expression levels of microRNAs were observed under salt treatment. The expression of miR162, miR173, miR391, miR408, miR773, and miR857 increased by 70% after 24 h of salt treatment, after which it declined to a level similar to that of the control. The expression level of miR775 and miR827 decreased by 20% after 24 h, and then further decreased by 80% after 144 h. The expression level of miR841 increased by 50% after 24 h of salt treatment, and then stabilized. In contrast, salt treatment increased the expression of the auxin response factors ARF6, ARF8, ARF10, and ARF16 in the callus from 12 to 144 h of salt treatment, during which the expression increased twofold. Gene expression analysis indicated that salt-responsive gene families were regulated by microRNAs in the callus under salinity stress. The activity of antioxidant enzymes is also changing. MiR841 is considered to be a positive regulator of antioxidant enzyme biosynthesis. The present investigation elucidates the manner in which P. pratensis responds to salt stress in the callus, and could be used to inform further studies on the molecular mechanisms of stress tolerance.

In vitro and in vivo evaluation of antioxidant activity of Petasites japonicus Maxim. flower buds extracts.

The antioxidant activity of Petasites japonicus flower buds cultivated in Tokushima, Japan, was examined in vitro and in vivo. The flower bud extracts were assayed using either oxygen radical absorbance capacity or 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Antioxidants in the 80% ethanol extract were investigated using online high-performance liquid chromatography-DPPH and were identified as caffeic acid, 3-O-caffeoylquinic acid, fukinolic acid, 3,4-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, and 4,5-di-O-caffeoylquinic acid using liquid chromatography-mass spectrometry. Fukinolic acid was the most active compound based on its activity and abundance. Administering the extracts orally to ICR mice prior to iron injection significantly suppressed plasma thiobarbituric acid reactive substance (TBARS) production. Moreover, TBARS and triglyceride concentrations in the plasma of C57BL/6 mice fed with a high fat diet were also significantly decreased by the extract. The results suggest that antioxidative compounds in P. japonicus can be used in the management of oxidative stress.

Acute oral toxicity and antioxidant studies of an amine-based diselenide

BackgroundOrganochalcogen compounds have attracted the interest of a multitude of studies for their promising Pharmacological and biological activities. The antioxidant activity and acute toxicity of an organoselenium compound, 1-(2-(2-(2-(1-aminoethyl)phenyl)diselanyl)phenyl)ethanamine (APDP) was determined in mice.MethodsMice were randomly divided into four groups, with each group comprising of seven animals. Canola oil (1ml/kg of body weight) was administered to 1st group, while 2nd, 3rd & 4th groups were administered with 10 mg/kg, 30 mg/kg & 350 mg/kg of APDP respectively. APDP was administered by Intragastric gavage as a single oral dose.ResultsThe APDP oral administration was found to be safe up to 350 mg/kg of body weight and no deaths of animals were recorded. The lethal dose 50 (LD50) for APDP was determined at 72 h and was estimated to be > 350 mg/kg. After acute treatment, all mice were sacrificed by decapitation to determine the antioxidant enzymes and lipid peroxidation values for the treated mice liver. No fluctuation in lipid peroxidation, vitamin C and non protein thiol (NPSH) levels was observed due to the administration of APDP. hepatic α-ALA-D activity, catalase (CAT), superoxide dismutase (SOD) and the biochemical parameters were evaluated. Experimental observation demonstrated that APDP protected Fe(II) induced thiobarbituric acid reactive substances (TBARS) production in liver homogenate significantly (p < 0.05). The administration of APDP (an amine-based diselenide) both in vitro and in vivo clearly demonstrated that this potential compound has no acute toxicity towards mice among all the tested parameter.ConclusionOn the basis of experimental results, it is concluded that APDP is a potential candidate as an antioxidant compound for studying pharmacological properties.

Therapeutic and protective effects of montelukast against doxorubicin-induced acute kidney damage in rats.

Objective(s):The current study was designed to investigate the therapeutic and protective effects of montelukast (ML) against doxorubicin (DOX)-induced acute kidney damage in rats.Materials and Methods:Thirty-five Wistar albino female rats were randomly divided into 5 groups as follows: Group I: Control; Group II: Control+ML; Group III: DOX; Group IV: DOX+ML; Group V: ML+DOX. At the end of the experiment, the kidney tissues of rats were collected. Thiobarbituric acid reactive substance (TBARS), reduced glutathione, superoxide dismutase (SOD), and catalase levels were determined from the kidney tissues. In addition, the kidney tissues were examined histologically.Results:DOX induced a significant increase in the kidney TBARS levels, whereas SOD contents significantly decreased when compared with the control group. On the other hand, ML administration before and after DOX injection caused significant decreases in TBARS production and also increases in SOD levels. Histologically, the most remarkable damage was glomerulosclerosis and tubular changes in the DOX group. Moreover, marked tubular necrosis and swelling in tubular epithelial cells were observed in this group. Contrarily, although glomerulosclerosis was recognized as alleviated also in both DOX+ML and ML+DOX groups, the lesions did not completely ameliorate. However, treatment with ML after DOX injection was more effective than treatment with ML before DOX injection with respect to the protection of tubular structures. Conclusion:It was determined that ML treatment after DOX injection caused therapeutic effects against DOX-induced kidney damage. Thence, ML treatment is of some clinical properties for oxidative stress damage in kidney tissues.

Oxidative Stress of in-Ovo Ochratoxin A Administered during Chick Embryonic Development

ABSTRACT The present work was carried out to study the effect of in-ovo injection of ochratoxin A (OTA) as an oxidative stress and its consequences on hepatic and kidney functions, thyroid activity, and histological examination of brain and liver in chicken embryos and subsequently in the hatching chicks. On the 10th day of incubation, one hundred and sixty-two fertile eggs were randomly divided into two equal treatments. Control treatment, (injected by 50 µl sodium carbonate) and OTA treatment (injected by 12.5 ng OTA dissolved in 50 µl sodium carbonate). OTA treatement group significantly reduced glutathione (GSH) and significantly increased thiobarbituric acid reactive substances production (TBARS) in embryonic and hatched chicks regarding livers, spleen, bursa of Fabricius, heart, and brain as an indicator of oxidative stress. OTA injection increased TBARS and decreased GSH levels in both allantoic and amniotic fluids. On the 14th and 16th days of incubation and at the hatch, a significant lower concentration in cholesterol and higher concentrations of alanine amino transferase, aspartate amino transferase, alkaline phosphatase, gamma glutamyl transferase, acid phosphatase enzymes activities and triglycerides in the hepatic tissues of the OTA group were observed. Histological examination of OTA group of brain and liver tissues showed some degenerative changes through the experimental period. In conclusion, in-ovo OTA treated had teratogenic and embryotoxic effects.

The lipid peroxidation in patients with nephrolithiasis before and after extracorporeal shock wave lithotripsy.

To evaluate the level of lipid peroxidation in patients with nephrolithiasis before and after extracorporeal shock wave lithotripsy (ESWL). Isoprostane concentration (8-isoPGF2α) was measured in urine, and thiobarbituric acid reactive substance production in serum and erythrocytes. In addition, the concentrations of selected compounds (uric acid, glucose and creatinine) were measured in serum. The patients (before and after ESWL) demonstrated significantly higher levels of two different biomarkers of lipid peroxidation compared with the control group. A correlation was identified between increased amounts of uric acid and biomarkers of lipid peroxidation in patients with nephrolithiasis, both before and after ESWL. Uric acid may be associated with lipid peroxidation in patients with nephrolithiasis.

A standardised Andrographis paniculata Burm. Nees aqueous extract prevents Lipopolysaccharide-induced cognitive deficits through suppression of inflammatory cytokines and oxidative stress mediators

Substantial evidence has shown that most cases of memory impairment are associated with increased neuroinflammation and oxidative stress. In this study, the potential of a standardised Andrographis paniculata aqueous extract (APAE) to reverse neuroinflammation and cognitive impairment induced by lipopolysaccharide (LPS) was examined in vivo. Rats were treated with APAE (50, 100, 200, and 400 mg·kg−1, p.o.) for 7 consecutive days prior to LPS (1 mg·kg−1, i.p.)-induced neuroinflammation and cognitive impairment. Spatial learning and memory were evaluated using the Morris water maze (MWM) test, while neuroinflammation and oxidative stress were assessed through the measurement of specific mediators, namely, tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1β, superoxide dismutase (SOD), catalase (CAT), antioxidant glutathione (GSH), reactive oxygen species (ROS), and thiobarbituric acid reactive substance (TBARS). Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were also evaluated. LPS caused significant memory deficits in the 2-day MWM protocol, whereas pretreatment with standardised APAE dose-dependently improved performance in the MWM test. APAE treatment also blocked the LPS-induced hippocampal increase in the concentration and expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) and production of ROS and TBARS and enhanced the activities of AChE and BChE. Furthermore, APAE enhanced the decrease in the levels and expression of hippocampal antioxidant enzymes (SOD and CAT) following LPS-induced neuroinflammation and cognitive deficit. The findings from these studies suggested that standardised APAE improved memory and had potent neuroprotective effects against LPS-induced neurotoxicity.

Phenolic content and antioxidant activity of wholegrain breads from modern and old wheat (Triticum aestivum L.) cultivars and ancestors enriched with wheat sprout powder

In this study, we compared nutritional characteristics of breads from wholegrain flours of three modern cultivars, four old cultivars and one landrace population of common wheat (Triticum aestivum), one Khorasan (Triticum turgidum var turanicum) accession and one einkorn (Triticum monococcum) cultivar. One bread from refined flour was also included. All flours were enriched or not with 5% (w:w) of wheat sprout powder (WSP) to obtain enriched breads (EB) or control breads (CB), respectively. Total phenolics and flavonoids, reducing power, radical scavenging and thiobarbituric acid reactive substances production inhibition were measured on bread aqueous extracts. CB from old cultivars were generally higher in phenolic content and antioxidant activity than CB from modern cultivars. All EB showed increased phenolic content and antioxidant activity compared to CB, but the increase varied with the source flour, despite WSP supplementation was the same for all breads. In particular, the increase in phenolic content was much relevant for EB of modern cultivars.

Nitric Oxide Is Required for Melatonin-Enhanced Tolerance against Salinity Stress in Rapeseed (Brassica napus L.) Seedlings.

Although melatonin (N-acetyl-5-methoxytryptamine) could alleviate salinity stress in plants, the downstream signaling pathway is still not fully characterized. Here, we report that endogenous melatonin and thereafter nitric oxide (NO) accumulation was successively increased in NaCl-stressed rapeseed (Brassica napus L.) seedling roots. Application of melatonin and NO-releasing compound not only counteracted NaCl-induced seedling growth inhibition, but also reestablished redox and ion homeostasis, the latter of which are confirmed by the alleviation of reactive oxygen species overproduction, the decreases in thiobarbituric acid reactive substances production, and Na+/K+ ratio. Consistently, the related antioxidant defense genes, sodium hydrogen exchanger (NHX1), and salt overly sensitive 2 (SOS2) transcripts are modulated. The involvement S-nitrosylation, a redox-based posttranslational modification triggered by NO, is suggested. Further results show that in response to NaCl stress, the increased NO levels are strengthened by the addition of melatonin in seedling roots. Above responses are abolished by the removal of NO by NO scavenger. We further discover that the removal of NO does not alter endogenous melatonin content in roots supplemented with NaCl alone or together with melatonin, thus excluding the possibility of NO-triggered melatonin production. Genetic evidence reveals that, compared with wild-type Arabidopsis, the hypersensitivity to NaCl in nia1/2 and noa1 mutants (exhibiting null nitrate reductase activity and indirectly reduced endogenous NO level, respectively) cannot be rescued by melatonin supplementation. The reestablishment of redox homeostasis and induction of SOS signaling are not observed. In summary, above pharmacological, molecular, and genetic data conclude that NO operates downstream of melatonin promoting salinity tolerance.

Modulatory effect of Cashew (Anacardium occidentale L.) nut supplemented diet on fertility activity of clomiphene citrate in male rats

ContextIncreasing concern has been expressed about the declining sperm count of humans and the potential fertility effects of clomiphene citrate, a synthetic oestrogen‐antagonist on human reproductive health in the last few decades.AimThis study aims to investigate the influence of cashew nut supplemented diet on fertility activity of clomiphene citrate in male rats.MethodsThe rats were divided into six groups (n=6): rats fed basal diet; rats fed basal diet and then given clomiphene citrate (cc) orally; rats fed diet supplemented with 10% processed cashew nut and given cc orally; and rat fed diet supplemented with 20% processed cashew nut and given cc orally; rats fed diet supplemented with 10% processed cashew nut and rat fed diet supplemented with 20% processed cashew nut.ResultsThe results revealed that there was a significant (p&lt;0.05) improvement of total testosterone level and epididymal sperm count, viability and progressive motility in all the groups, in comparison to control, with more significance in combination therapy group. Similarly, increased testicular and epididymal total antioxidant capacity (TAC), nitric oxide (NO), total thiol (T‐SH), nonprotein thiol (NPSH) levels, Glutathione‐S‐transferase (GST) and steroidogenic enzymes activities with concomitant decrease in reactive oxygen species (ROS) level, thiobarbituric acid reactive substances (TBARS) production and arginase activity were observed in all the groups when compared with control, with more significance in combination therapy group.ConclusionTherefore, the combination therapy with cashew nut boosts the fertility potentials of clomiphene citrate. Thus, this combination therapy can be used to treat male partners suffering from infertility.Support or Funding InformationnilThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effect of Acute Resistance Exercise with Different Level of Blood Flow Restriction on Acute Changes in Muscle Thickness, Blood Lactate, CK, and Oxidative Stress in Male Adults

PURPOSE To evaluate the effects of low-load resistance exercise (RE) with intermittent blood flow restriction (BFR) on the muscle thickness, blood lactate, creatine kinase (CK) and thiobarbituric acid-reactive substance (TBARS) levels in male. METHODS The study included 10 male college students aged 23.5 ± 1.0 years who underwent the following experimental protocols in random order on separate days (72 hour): 3 sessions at a 30% one-repetition maximum (1RM) RE with BFR (individual systolic blood pressure, 150% systolic blood pressure and 200% systolic blood pressure); 1 session at 60% 1RM RE without BFR (CON). The thigh circumference, TBARS and CK levels were measured before exercise (pre-exercise) and post-exercise and lactate, heart rate (HR), systolic (SP) and diastolic blood pressure were measured pre-, post-exercise, 5-, 15- and 30-minutes recovery. RESULTS Thigh circumference significantly increased following 30% 1RM with SP (p=.10) and SP 200% (p=.36) BFR compared to 60% 1RM without BFR but there was an increasing tendency in 30% 1RM with SP 150% (p = .83) BFR. Additionally, there were significant increases in TBARS (p<.05) and CK (p<.05) in the all protocols post-exercise samples compared with the pre-exercise samples but no significant group (p = .113, p = .870, respectively) or interaction (p = .385, p = .132, respectively) effect. CONCLUSIONS 30% 1-RM with BFR may effectively increase the circumference of the thigh muscle compared to 60% 1RM without BFR. Although both 30% 1RM with BFR (SP, SP 150%, SP 200%) and 60% 1RM without BFR temporarily increased TBARS production and CK, It does not cause damage. 색인어: ì €í•­ì„± 운동, í˜ˆë¥˜ì œí•œ, ì –ì‚°, CK, ì‚°í™”ìŠ¤íŠ¸ë ˆìŠ¤ Keywords: Resistance exercise, Blood flow restriction, Lactate, Creatine kinase, Oxidative stress

Protective Effects of Topiroxostat on an Ischemia-Reperfusion Model of Rat Hearts.

Ischemia/reperfusion (I/R) injury triggers cardiac dysfunctions via creating reactive oxygen species (ROS). Because xanthine oxidase (XO) is one of the major enzymes that generate ROS, inhibition of XO is expected to suppress ROS-induced I/R injury. However, it remains unclear whether XO inhibition really yields cardioprotection during I/R. The protective effects of the XO inhibitors, topiroxostat and allopurinol, on cardiac I/R injury were evaluated.Methods and Results:Using isolated rat hearts, ventricular functions, occurrence of arrhythmias, XO activities and thiobarbituric acid reactive substances (TBARS) productions and myocardial levels of adenine nucleotides before and after I/R, and cardiomyocyte death markers during reperfusion, were evaluated. Topiroxostat prevented left ventricular dysfunctions and facilitated recovery from arrhythmias during I/R. Allopurinol and the antioxidant, N-acetylcysteine (NAC), exhibited similar effects at higher concentrations. Topiroxostat inhibited myocardial XO activities and TBARS productions after I/R. I/R decreased myocardial levels of ATP, ADP and AMP, but increased that of xanthine. While topiroxostat, allopurinol or NAC did not change myocardial levels of ATP, ADP or AMP after I/R, all of the agents decreased the level of xanthine. They also decreased releases of CPK and LDH during reperfusion. Topiroxostat showed protective effects against I/R injury with higher potency than allopurinol or NAC. It dramatically inhibited XO activity and TBARS production, suggesting suppression of ROS generation.

Phenolic Content and Antioxidant Activity in Raw and Denatured Aqueous Extracts from Sprouts and Wheatgrass of Einkorn and Emmer Obtained under Salinity.

Total phenolic content (TPC), reducing power (RP), superoxide radical scavenging (RS), and thiobarbituric acid reactive substances (TBARS) production inhibition were measured in raw and denatured aqueous extracts from sprouts and wheatgrass of einkorn and emmer obtained at increasing salinity. Grains were incubated and kept at 0, 25, 50, and 100 mM NaCl until either sprout or wheatgrass stage. Additionally, a recovery treatment was included, in which sprouts obtained at 100 mM NaCl were then transferred at 0 mM NaCl until wheatgrass stage. All parameters (TPC, RP, RS, and TBARS production inhibition) increased with sprouting and were highest in wheatgrass. Salinity increased all parameters, but the effect varied with NaCl concentration, genotype, developmental stage, and plant material processing (raw or denatured). Overall, given the delay and limitation of growth at high NaCl concentration, the best compromise appears to be the application of a moderate salinity (25 to 50 mM NaCl). In denatured extracts, TPC, RP, and RS slightly decreased, and TBARS was not affected, which means that antioxidant activity was mainly related to compounds other than enzymes and peptides, and thus it can be assumed to remain after digestion. Thus, supplementing the human diet with einkorn or emmer sprouts and wheatgrass can actually benefit health.

Sensitivity and toxic mode of action of dietary organic and inorganic selenium in Atlantic salmon (Salmo salar)

Depending on its chemical form, selenium (Se) is a trace element with a narrow range between requirement and toxicity for most vertebrates. Traditional endpoints of Se toxicity include reduced growth, feed intake, and oxidative stress, while more recent finding describe disturbance in fatty acid synthesis as underlying toxic mechanism. To investigate overall metabolic mode of toxic action, with emphasis on lipid metabolism, a wide scope metabolomics pathway profiling was performed on Atlantic salmon (Salmo salar) (572±7g) that were fed organic and inorganic Se fortified diets. Atlantic salmon were fed a low natural background organic Se diet (0.35mg Se kg−1, wet weight (WW)) fortified with inorganic sodium selenite or organic selenomethionine-yeast (SeMet-yeast) at two levels (∼1–2 or 15mgkg−1, WW), in triplicate for 3 months. Apparent adverse effects were assessed by growth, feed intake, oxidative stress as production of thiobarbituric acid-reactive substances (TBARS) and levels of tocopherols, as well as an overall metabolomic pathway assessment. Fish fed 15mgkg−1 selenite, but not 15mgkg−1 SeMet-yeast, showed reduced feed intake, reduced growth, increased liver TBARS and reduced liver tocopherol. Main metabolic pathways significantly affected by 15mgkg−1 selenite, and to a lesser extent 15mgkg−1 SeMet-yeast, were lipid catabolism, endocannabinoids synthesis, and oxidant/glutathione metabolism. Disturbance in lipid metabolism was reflected by depressed levels of free fatty acids, monoacylglycerols and diacylglycerols as well as endocannabinoids. Specific for selenite was the significant reduction of metabolites in the S-Adenosylmethionine (SAM) pathway, indicating a use of methyl donors that could be allied with excess Se excretion. Dietary Se levels to respectively 1.1 and 2.1mgkg−1 selenite and SeMet-yeast did not affect any of the above mentioned parameters. Apparent toxic mechanisms at higher Se levels (15mgkg−1) included oxidative stress and altered lipid metabolism for both inorganic and organic Se, with higher toxicity for inorganic Se.

Adrenomedullin and Angiotensin II in Rat Cerebellar Vermis: Reactive Oxygen Species Production

Adrenomedullin (AM) is a peptide involved in blood pressure regulation. AM exerts its effects through the activation of three receptors, the AM type 1 (AM1), type 2 (AM2) and calcitonin gene-related peptide 1 (CGRP1) receptors. AM triggers several signaling pathways such as adenylyl cyclase (AC), guanylyl cyclase (GC), extracellular signalregulated kinases (ERK) and modulates reactive oxygen species (ROS) metabolism. In brain, AM and their receptors are expressed in several localized areas, including the cerebellum. AM has been reported as an antioxidant. Recent evidence suggests the presence of an adrenomedullinergic and angiotensinergic system of physiological relevance in cerebellum vermis. To establish the role of AM in the regulation of cerebellar ROS metabolism, it was assessed the effect of AM and angiotensin II (ANG II) on three antioxidant enzymes activity: catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD), and on thiobarbituric acid reactive substances (TBARS) production in rat cerebellar vermis. The findings demonstrated that in cerebellar vermis, AM decreased and ANG II increased CAT, GPx and SOD activity and TBARS production. Likewise, AM antagonized ANG II-induced increase antioxidant enzyme activity. AM(22-50) and CGRP(8-37) blunted AM-induced decrease of antioxidant enzymes activity and TBARS production indicating that these actions are mediated through AM and CGRP1 receptors. Further, PKA inhibitor (PKAi) blunted AM action whilst apocynin and chelerythrine reverted ANG II action, suggesting that AM antioxidant action is mediated through stimulation of protein kinase A (PKA) activity, while ANG II stimulation occurs through protein kinase C/nicotinamide adenine dinucleotide phosphate oxidase (PKC/NAD(P)H oxidase) pathway. These results support the role of AM in the regulation of cerebellar antioxidant enzymes activity and suggest a physiological role for AM in cerebellum.

Naturally occurring layered-mineral magnesium as a bactericidal against Escherichia coli

Escherichia coli (E. coli) is a versatile organism that can colonize and adapt in the environment, and an example of antibiotic resistant bacteria, persistent throughout the world because they have evolved to express various defense mechanisms to cope with antibiotics and the immune system, therein the need to find good strategies for their treatment, such as the application of industrial minerals. Located in the outer section of the external membrane of E. coli, gram-negative bacteria, is lipid A, the lipid component of an endotoxin that consists of lipopolysaccharides, which is responsible for its toxicity of the bacteria. Arguably, the antibacterial activity of naturally occurring minerals is mediated by surface interactions with lipid A. Here, we study the antibacterial activity of layered mineral Mg against E. coli using in vitro and in vivo tests, and report on: (i) in-vitro E. coli (ATCC 25922) growth behavior (bacteriostatic or bactericidal activity); and (ii) in-vitro RAW264.7 cells growth. Furthermore, the oxidative stress, oxidative degradation of lipids in cell membrane resulting in cell damage via lipid peroxidation (LP), was quantified in vivo using the Thiobarbituric Acid Reactive Substances (TBARS) assay. Finally, since inflammation is the first reaction of an organism to defend itself from outside attack by microorganisms or toxic compounds, clinical tests for inflammation using two independent methods, namely to quantify the inhibition of edema [12-O-tetradecanoylphorbol-13-acetate (TPA) method] and the migration of neutrophils [Myeloperoxidate (MPO) method] were in turn assessed. Growth curves (log phase) for E. coli showed that adding brucite or talc in concentrations as low as 20μgmL−1 cause death. Absorbance values at λ=600nm were found to be significantly lower in magnitude relative to positive controls, with no evidence for the presence of Colony Forming Units (CFUs) in agar plates at 24 or 48h. Critical to E. coli growth, Mg acts as a cofactor of alkaline-phosphatase metaloenzyme(s); however, as a layered mineral, Mg exerts irreversible negative effects. Meanwhile, results showed a poor bactericidal activity of sepiolite, owing a higher microporosity and number of surface reaction sites, which were then attributed to gelification at the surface vicinity, provoked by dislocations at inversion sites of the tetrahedral sheet. Taken together these results showed that the bactericidal activity of layered mineral Mg was restricted by physical transport over chemical transfer processes, instigated by specific structural properties, namely stacking over bioavailability Mg and by existing surface interactions with lipid A. On the other hand, in vitro viability tests for RAW264.7 cells showed significant decreases if replacing the source of mineral Mg, talc for brucite which, however, was restored after treatment with EDTA. In vivo tests showed that brucite induced LP. The opposite found to be true for talc, with brucite inducing the quantitative production of TBARS by 9.4±1.2nmolTBARSmgprot−1. Brucite surfaces are uncharged and facilitate the stabilization of hydroxyl radical species (HO), a neutral radical species, consequently contributing to lower the overall activation energy for LP. Finally, clinical tests on the effect of mineral Mg on inflammation, as the first immune reaction were conducted. Layered-Mg minerals effectively inhibited edema (edema forms due to increases in the liquid level within the stroma, which changes vascular permeability, especially for capillaries). Exposing inflamed tissue to brucite, talc, and sepiolite inhibited inflammation by 8.3±2.4, 30.2±7.8, and 61.4±8.6%, respectively. Besides, as evidenced by the MPO model, short-time exposure to mineral Mg inhibited the migration of neutrophils. In all, the anti-inflammatory activity by mineral Mg decreased according to: sepiolite≫talc˃brucite. Competing mechanisms thus prevailed, with structural dislocations favoring an abatement of inflammation in tissue while notably deterring its bactericidal properties.

Stem Girdling Affects the Carbon/Nitrogen Imbalance and Oxidative Stress, and Induces Leaf Senescence in Phenological Forms of Beech (Fagus sylvatica)

AbstractGirdling was applied to 5-year-old potted beech individuals of early, intermediate and late phenological forms to block assimilate export from leaves. Phloem severance caused accumulation of soluble carbohydrates and starch in leaves and increased the C/N ratio. While the hexose content increased continuously until the end of the experiment, the sucrose and starch contents peaked earlier, depending on the plant’s phenological features. Different rates of chlorophyll degradation and H2O2and TBARS (thiobarbituric acid-reactive substances) production in different phenological forms implied that phloem girdling was the source of oxidative stress and, depending on the phenological form, accelerated leaf senescence to different degrees. The variable rate of the increase in soluble carbohydrate and starch content, characteristic of the different phenological forms, had different modifying effects on the antioxidant activity in leaves. Compared with the early phenological form, the late form was characterized by a smaller increase in H2O2and TBARS content and delayed and slowed chlorophyll and carotenoid degradation. In conjunction with the larger increase in the activity of antioxidant enzymes (catalase, ascorbate peroxidase and superoxide dismutase) induced by carbohydrate accumulation and slower carotenoid degradation, these changes led to the late form having greater resistance to oxidative stress and slower senescence.

Strawberry (cv. Romina) Methanolic Extract and Anthocyanin-Enriched Fraction Improve Lipid Profile and Antioxidant Status in HepG2 Cells.

Dyslipidemia and oxidation of low density lipoproteins (LDL) are recognized as critical factors in the development of atherosclerosis. Healthy dietary patterns, with abundant fruit and vegetable consumption, may prevent the onset of these risk factors due to the presence of phytochemical compounds. Strawberries are known for their high content of polyphenols; among them, flavonoids are the major constituents, and it is presumed that they are responsible for the biological activity of the fruit. Nevertheless, there are only a few studies that actually evaluate the effects of different fractions isolated from strawberries. In order to assess the effects of two different strawberry extracts (whole methanolic extract/anthocyanin-enriched fraction) on the lipid profile and antioxidant status in human hepatocellular carcinoma (HepG2) cells, the triglycerides and LDL-cholesterol content, lipid peroxidation, intracellular reactive oxygen species (ROS) content and antioxidant enzymes’ activity on cell lysates were determined. Results demonstrated that both strawberry extracts not only improved the lipid metabolism by decreasing triglycerides and LDL-cholesterol contents, but also improved the redox state of HepG2 cells by modulating thiobarbituric acid-reactive substances production, antioxidant enzyme activity and ROS generation. The observed effects were more pronounced for the anthocyanin-enriched fraction.

Intracerebroventricular administration of the (1→6)-β-d-glucan (lasiodiplodan) in male rats prevents d-penicillamine-induced behavioral alterations and lipoperoxidation in the cortex

Context: Lasiodiplodan, an exocellular (1→6)-β-d-glucan of molecular weight >1.4 × 106 Da produced by MMPI strain of Lasiodiplodia theobromae (Pat.) Griffon & Maubl. (Brotyosphaeriaceae) is known to exhibit anti-proliferative activity on breast cancer cells (MCF-7), anticoagulant activity when sulfonylated, and reduction in transaminase activity when administered in rats. Objective: The effect of intracerebroventricular (I.C.V) injection of lasiodiplodan on neurotoxicity and behavioural changes induced by d-penicillamine was investigated. Materials and methods: Twenty-four male Wistar rats were initially separated in groups of six and treated with 0.15 μmol/μL of NaCl (Groups Ct and d-Pen) and 0.01 μg/μL of lasiodiplodan (Groups Las and Las + d-Pen). After 15 min, they received 6 μmol/μL of NaCl (Groups Ct and Las) and 2 μmol/μL of d-penicillamine (Groups d-Pen and Las + d-Pen). The animal behavior was observed in an open-field test for 60 min. Twenty-four h later, the animals were sacrificed and histopathological analysis and Thiobarbituric acid reactive substances (TBARS) production measurements were performed. Results: Lasiodiplodan prevented neurotoxicity induced by d-penicillamine significantly reducing the production of TBARS (308%; p < 0.05), and behavioural signs; convulsive and pre-convulsive. No histopathological alterations in the cerebral cortex were observed. Discussion and conclusion: The reduction of TBARS production and convulsive episodes suggests that the protector effect provided by lasiodiplodan passes thought an antioxidant path, possibly interfering in a cascade of neurochemical events, triggering cell death and convulsive episodes. These results demonstrated that lasiodiplodan can be effective in treating neurotoxicity, and reducing damage triggered by convulsions in neuropathies related to GABAergic system.