On the Role of the Carboxyl Group to the Protective Effect of o-Dihydroxybenzoic Acids to Saccharomyces cerevisiae Cells upon Induced Oxidative Stress

In the present work, the role of the carboxyl group of o-dihydroxybenzoic acids (pyrocatechuic, 2,3-diOH-BA and protocatechuic, 3,4-diOH-BA) on the protection against induced oxidative stress in Saccharomyces cerevisiae was examined. Catechol (3,4-diOH-B) was included for comparison. Cell survival, antioxidant enzyme activities, and TBARS level were used to evaluate the efficiency upon the stress induced by H2O2 or cumene hydroperoxide. Theoretical calculation of atomic charge values, dipole moment, and a set of indices relevant to the redox properties of the compounds was also carried out in the liquid phase (water). Irrespective of the oxidant used, 2,3-diOH-BA required by far the lowest concentration (3–5 μM) to facilitate cell survival. The two acids did not activate catalase but reduced superoxide dismutase activity (3,4-diOH-BA>2,3-diOH-BA). TBARS assay showed an antioxidant effect only when H2O2 was used; equal activity for the two acids and inferior to that of 3,4-diOH B. Overall, theoretical and experimental findings suggest that the 2,3-diOH-BA high activity should be governed by metal chelation. In the case of 3,4-diOH BA, radical scavenging increases, and chelation capacity decreases. The lack of carboxyl moiety (3,4-diOH B) adds to radical scavenging, interaction with lipophilic free radicals, and antioxidant enzymes. The present study adds to our knowledge of the antioxidant mechanism of dietary phenols in biological systems.

Nitrosamines and Polycyclic Aromatic Hydrocarbons in Smoke-Cured Bacon (Larou) of Artisanal and Industrial Origin

The aim of this study was to compare the nitrosamines (NAs) and polycyclic aromatic hydrocarbons (PAHs) of Chinese smoke-cured bacon (Larou) of artisanal and industrial origin. The results showed that the average pH and Aw values of family-made Larou products were lower than those of industrial Larou, which was opposite to the TBARS level. The contents of residual nitrite and PAH4 in two artisanal Larou were significantly higher than those of the other groups (p < 0.05). The highest NA content (10.78 μg/kg) was found in family-made Larou. A correlation analysis indicated that the relationships between residual nitrite contents and total PAH8 contents (τ = 0.692, p < 0.01) and total NAs contents (τ = 0.805, p < 0.01) were characterized with a positive correlation. A principal component analysis indicated that the Larou from the industrial sources had similar safety attributes, and was more stable than the Larou processed in an artisanal manner. Our data suggest that Larou produced in industrial conditions is suitable for consumption.

Effects of Artificial Aging on Seed Vigor and Physiological Characteristics of the Invasive Alien Plant Aegilops tauschii

The control of invasive plants depends to some extent on the persistence of the soil seed bank. The high temperature (40 °C) accompanied with high humidity (95%) method was used to treat the seeds of the invasive species Aegilops tauschii Coss. The aim of our study was to evaluate the seed vigor and longevity by accelerating aging, to serve as a reference for the evaluation of invasion potential of A. tauschii and corresponding eradication strategy adoption. The results showed that with the extension of aging time, the germination rate (GR), energy (GE), and index (GI) of A. tauschii seeds reduced. All the results were significantly different from the control (CK) since the second day ( p < 0.05). During the aging process, the seed relative water content (RWC), relative electric conductivity (REC), and thiobarbituric acid (TBARS) level increased, while the superoxide dismutase (SOD) gradually decreased after second day of seed aging. In addition, the aging treatment also caused a continuous decrease in the endogenous gibberellin (GA 3 ) content and a continuous increase in the abscisic acid (ABA) content of the seeds. Thus, a sharp decrease in the GA 3 /ABA ratio was evident. Finally, the study revealed that the germination inhibitors of A. tauschii were mainly concentrated in the glumes, which was revealed during seed aging. The results of the comprehensive analysis indicated that the changes of the above-mentioned internal factors eventually led to a rapid decline of the seed vigor of A. tauschii . Based on the results of the aging test, and the distribution characteristics of A. tauschii seeds in the soil seed banks, we recommend that soil solarization is one of the effective methods to eradicate the seed bank of A. tauschii .

Effect of exogenous melatonin on the antioxidant defense system in the liver and small intestine of the Syrian hamster (Mesocricetus auratus)

Background. Due to the growing light pollution and the development of new territories, including northern ones, the search for drugs that increase the adaptive capacity of the organism is promising.The aim. We studied the effects of the exogenous melatonin (100 µg/day/animal) on antioxidant status of liver and small intestine in Syrian hamsters (Mesocricetus auratus) in the light conditions of North-West of Russia (Petrozavodsk, northern lighting – NL).Materials and methods. Female hamsters were exposed to a 12/12 light/dark cycle (LD; n = 12) or NL for 3 months. In NL light conditions hamsters were divided into two groups: NL-control (received placebo; n = 12) and NL-mel (received melatonin; n = 12). The study was conducted from the period of the summer solstice – June 25 (NL: 19.36/4.24) to September 25 (NL: 12/12) (autumn equinox).Results. Animals were kept in the NL conditions had decreased the levels of GSH and activities of antioxidant enzymes (superoxide dismutase (SOD) and catalase) at initial stage of experiment as well as increased TBA reactive substances (TBARS) level at the beginning and after a month of the experiment in the liver in comparison to control (LD). It was observed that in the small intestine the activities of SOD and the levels of GSH (initial and intermediate stages) and TBARS (end of the experiment) were significantly higher in NL in comparison to LD. Liver and small intestine TBARS concentrations after one and three months of the experiment were decreased in NL-mel in comparison to NL-control.Conclusion. The results of the study indicate the sensitivity of the antioxidant defense system in the tissues of the liver and small intestine of Syrian hamster to the photoperiod and exogenous melatonin. The present study revealed that exogenous melatonin was able to reduce the level of TBARS and increase the activity of SOD and CAT in the light conditions of North-West of Russia.

ANTIMICROBIAL, ANTIOXIDANT AND CYTOTOXIC EVALUATION OF VARIOUS EXTRACTS OF IFLOGA SPICATA (FORSSK.) SCH.BIP

The current study reveals the pharmacological and phytochemical potential of different solvent fractions of Ifloga spicata. Antimicrobial and free radical scavenging activities, DPPH (1, 1-diphenyl-2-picrylhydrazyl), hydrogen peroxide scavenging assay, and cytotoxic effects of plant samples on lymphocytes stressed with hydrogen were performed. Ifloga spicata ethyl acetate fraction markedly showed higher antibacterial potential against P. aeruginosa (ATCC 27853) and E. Coli (ATCC 25922) bacteria. While higher antifungal potential was shown by the chloroform fraction against all three different a strain A. fumigates (ATCC 204305), A. flavus (ATCC 9643) and A. niger (ATCC 16404) as compared to others fractions of sample. DPPH maximum antioxidant potential was noted for methanolic extract followed by ethyl acetate and chloroform. Similarly, hydrogen peroxide effect was significantly decreased by ethyl acetate fraction. In blood lymphocytes the raise in ROS and TBARS level due to stress given by H2O2 was also recovered by different extracts of I. spicata. The decrease level of CAT, SOD and POD was also restored

Relationship between lipid peroxidation and antioxidants in rats with experimental acute generalized peritonitis against the background of streptozotocin-induced diabetes

Introduction. There are evidence that oxidative stress is involved in the pathogenesis of the acute generalized peritonitis and diabetes mellitus.The aim of study was to examine levels of the products of lipid peroxidation and the antioxidants in rats with experimental acute generalized peritonitis against the background of streptozotocin-induced diabetes.Material and methods. The experiment was performed on 66 adult white male rats weighing 220-300 g. Diabetes mellitus in experimental animals was simulated by a single intraperitoneal injection of streptozotocin (Sigma) at the dose of 60 mg/kg. Acute generalized peritonitis was induced with 10% faecal suspension in a dose of 0.5 ml per 100 g of animal weight in the abdominal cavity of laboratory animals by puncture method. The thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LOOHs), superoxide dismutase (SOD) activity, catalase (CAT) and ceruloplasmin (CP) were estimated and compared.Results. Our results showed that during all stages of development of acute generalized peritonitis on the background of streptozotocin-induced diabetes there is the LOOHs decrease and the TBARS increase. We observed statistically significant inverse correlations between the level of LOOHs and SOD in the animals of subgroup 1 (r = -0.88; p <0.05) and inverse correlations between the TBARS level and the SOD level in the subgroup 3 of animals (r = -0.74; p <0.05). We also found a statistically significant inverse correlation between the CAT level and the TBARS level (r = -0.86; p <0.05) and between the CP level and the TBARS level in the blood of animals in the subgroup 3 (r = -0.87; p <0.05).Conclusion. Negative statistically significant correlations between the TBARS level and the antioxidants (SOD, CAT, CP) in the blood of animals with acute generalized peritonitis on the background of streptozotocin-induced diabetes indicate a predictor role of lipid peroxidation processes in the depletion of antioxidant resources

Protective Effects of Pterostilbene Against Cardiac Oxidative Stressand Dysfunctionin Nicotine-Induced Cardiac Injury Rat Model

Prolonged nicotine exposureescalates the onset and development of cardiovascular diseasesin both active and passive smokers via cardiac injury. Pterostilbene, a resveratrol derivative, has been shown to exhibit high anti-inflammatory,antioxidant and antitumor properties. Nevertheless, its role as a cardioprotective agent in a nicotine-induced rat model is still scarce. Therefore, our study was aimed to investigatethe effects of co-administered pterostilbene against nicotine-induced cardiac injury rat model.Twenty-six male Sprague-Dawley rats were randomly allotted and treated with nicotine (0.6 mg/kg)orin-combination with pterostilbene (10 mg/kg) for 28 consecutive days. Non-invasive tail cuff blood pressure measurements were taken atday-0, day-14 and day-28. Rat hearts were harvested at study endpoint and thechanges in cardiac function parameters and oxidative stress markers were evaluated. The findings have shown that pterostilbene co-administration significantly (P<0.05) reduced the blood pressure and ameliorated nicotine-induced cardiac systolic dysfunction by improving the left ventricular developed pressure (LVDP). In addition, pterostilbene also significantly (P <0.05)attenuatedthe thiobarbituric acid reactive substances (TBARS) level, indicative of protection against nicotine-induced cardiac oxidative stress. In summary, our findings suggest that pterostilbene has the potential to be developed as a natural alternative in protecting the cardiac injuryinduced by nicotine. However further studies are warranted to investigate its efficacy and the underlying mechanism in cardioprotection.

HYDROGEN SULFIDE-RELEASING ANTI-INFLAMMATORY DRUG ATB-340 TREATMENT POTENTIALLY REDUCES MESENTERIC METAFLAMMATION IN THE EXPERIMENTAL AGE- AND HIGH FRUCTOSE DIETARY-INDUCED INJURY

Metaflammation (MF) is associated with visceral adiposities involved in the metabolic, cardiovascular, and gastrointestinal disease pathogenesis while their target therapeutic strategy is still limited. The link between mesenteric white adipocytes (MA) and stromal-vascular cellular remodeling in advanced age and Western diet consumption which is the base of MF remain undiscovered. Hydrogen Sulfide (H2S) non-steroidal anti-inflammatory drugs (H2S-NSAIDs) are a promising novel class of drugs regarding their cytoprotective, regulatory redox signaling, vasodilatory, and anti-inflammatory effects. Aim. To study the effectiveness of novel H2S-NSAIDs ATB-340, a hybrid compound of H2S and aspirin (ASA) over conventional ASA, and combination of ASA and NaHS on mesenteric cellular adaptive changes in experimental age- and high fructose dietary (HFD)-induced injury. Methods: Mesenteric subcellular adaptive responses of aged male rats on a standard diet (SD) or 4 weeks HFD that underwent acute water-immersion restraint stress (WIRS) were evaluated by electron microscopy. The effects of 9 days exogenous administration of ATB-340 (17.5 mg/kg/day), ASA (10 mg/kg/day) and sodium hydrosulfide (NaHS, 5.6 mg/kg/day) were investigated. Serum glucose level, thiobarbituric acid reactive substances (TBARS), and activities of cystathionine γ-lyase (CSE) and cystathionine β-synthase (CBS), thiosulfate-dithiol sulfurtransferase (TST), and sulfite oxidase (SO) were examined biochemically using spectrophotometry. Results: In HFD groups exposed to WIRS treatment with ATB-340 protected MA, as well their mitochondria, microvascular endothelial, and sub-endothelial structures, fibroblasts were observed vs the ASA and H2S+ASA-treated groups that had signs of endothelial dysfunction, MA damage with dysfunctional mitochondria, and mitochondria with fat incorporation. In rats fed with HFD and ASA treatment, low activities of CSE, CBS, TST and the rise of TBARS level and SO activity were observed. Treatment with ASA+NaHS, ATB-340 of aged rats lowered TBARS and enhanced H2S enzyme activities in contrast to the vehicle-treated group (p < 0.05). Conclusions. Mitochondrial alterations, endothelial damage, and redox disbalance are key factors for aged rat mesenteric adipose tissue remodeling during Western diet consumption. Our results contributing to identifying powerful intervention by effective compound H2S-ASA, novel H2S-NSAIDs, which has the potential to modulate mesenteric metaflammation, vascular function by enhancement H2S synthesis and redox regulatory and cytoprotective activities

Evaluation of different almond (Terminalia catappa) extracts against oxidative stress induced by cyclosporine in brain and liver of rats

Objectives This study was designed to evaluate the ameliorative effect of almond (Terminalia catappa) leaf (ALE) and stem bark (ABE) extracts on the enzyme activities and oxidative stress markers in the brain and liver tissues of cyclosporine-A (CsA) stressed male albino rats. Methods Eighty-eight adult male rats weighing between 200 and 220 g were randomly distributed to into 11 groups (n=8) and different doses (100 and 200 mg/kg bwt.) of ALE and ABE were administered through oral gavages to the normal rats and 50 mg/kg/bwt/day CsA-stressed, while normal control rats was given a saline solution (p.o), and the treatment lasted for 14 days. Blood plasma, liver and brain tissues were prepared for biochemical analysis. Results Neuronal [acetylcholinesterase (AChE) and butrylcholinesterase (BChE) and arginase] enzyme activities and thiobarbituric acid reactive species (TBARS) level, plasma aspartate transferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities, liver non-protein thiol (NPSH) level were analyzed. The results revealed that, the administration of CsA induced a significant increase in neuronal AChE, BChE, arginase, TBARS level, but decreased nitric oxide (NO) level. CsA also increased ALT, AST, and ALP activities in the blood plasma of CsA stress rats compared to normal control, but were significantly reversed respectively (p<0.001) upon treatment with the ALE and ABE dose-dependently. Conclusions The study revealed that ALE and ABE could prevent neuronal dysfunction and liver toxicity induced by CsA administration, however, higher dose (200 mg/kg) of the studied extracts appears to be more potent.

Profile of Heavy Metals and Antioxidant Defense in the Muscle Tissues of Pigeons (Columba livia f. urbana) from Anthropogenically Transformed Areas in the Pomeranian Region (Northern Poland)

Pigeons can be successfully used as bioindicators of a contaminated environment. We studied the relationship between the functioning of the pro/antioxidant balance in muscle tissues (skeletal muscle and cardiac tissues) of pigeons (Columba livia f. urbana) living in areas with different levels of pollution (Pomeranian Voivodeship, Northern Poland). The current study demonstrated the impact of the environment with preferential high Pb contamination in soil and feathers of pigeons on the formation of adaptive redox mechanisms in muscle tissues. An increase in the intensity of lipid peroxidation (estimated by the TBARS level) accompanied by enhancement of the oxidative modification of proteins (aldehydic and ketonic derivatives) and an important decrease in the activity of antioxidant enzymes (SOD, CAT, and GR) in pigeon muscle tissue was observed. These changes in enzyme activities were dependent on the type of muscle tissue (skeletal muscle and cardiac tissues). Our results confirm the concept of the recalculation of the De Ritis ratio (AsAT/AlAT) in both types of muscles indicating the tendency to cardio- and hepatocellular damage and toxicity caused by heavy metals from the polluted environment.