Levels Of Free Radicals Research Articles

Molecular Hydrogen: an Emerging Therapeutic Medical Gas for Brain Disorders.

Oxidative stress and neuroinflammation are the main physiopathological changes involved in the initiation and progression of various neurodegenerative disorders or brain injuries. Since the landmark finding reported in 2007 found that hydrogen reduced the levels of peroxynitrite anions and hydroxyl free radicals in ischemic stroke, molecular hydrogen's antioxidative and anti-inflammatory effects have aroused widespread interest. Due to its excellent antioxidant and anti-inflammatory properties, hydrogen therapy via different routes of administration exhibits great therapeutic potential for a wide range of brain disorders, including Alzheimer's disease, neonatal hypoxic-ischemic encephalopathy, depression, anxiety, traumatic brain injury, ischemic stroke, Parkinson's disease, and multiple sclerosis. This paper reviews the routes for hydrogen administration, the effects of hydrogen on the previously mentioned brain disorders, and the primary mechanism underlying hydrogen's neuroprotection. Finally, we discuss hydrogen therapy's remaining issues and challenges in brain disorders. We conclude that understanding the exact molecular target, finding novel routes, and determining the optimal dosage for hydrogen administration is critical for future studies and applications.

Integrative physiological, metabolomic and transcriptomic analysis reveals nitrogen preference and carbon and nitrogen metabolism in blackberry plants

Nitrogen (N) is an indispensable element for plant growth and development. To understand the regulation of underlying carbon (C) and N metabolism in blackberry plants, we performed integrated analyses of the physiology, metabolome and transcriptome. Blackberry plants were subjected to no N, nitrate (NO3⁻)-N, ammonium (NH4+)-N and urea treatments. Our results showed that the NH4⁺-N treatment yielded higher values for the biomass, chlorophyll, antioxidants, N contents and antioxidant enzyme activities, as well as lower levels of free radicals and the C/N ratio compared with other treatments. Transcriptome analysis showed that different N forms significantly affected photosynthesis, flavonoid biosynthesis and the TCA cycle. Metabolome analysis indicated that the levels of lipids, carbohydrates, flavonoids and amino acids were markedly changed under different N treatments. Integrated transcriptomic and metabolomic data revealed that amino acids, including proline, arginine, L-isoleucine, L-aspartate, threonine, and L-glutamate, played important roles in maintaining normal plant growth by regulating N metabolism and amino acid metabolism. Overall, blackberry plants preferentially take up NH4⁺-N. Under the NH4⁺-N treatment, N assimilation was stronger, flavonoid biosynthesis was decreased, and the promoting influence of NH4⁺-N on N metabolism was better than that of NO3⁻-N. However, the NO3⁻-N treatment enhanced the C/N ratio, accelerated the process of C metabolism and increased the synthesis of flavonoids, thereby accelerating the flow of N metabolism to C metabolism. These results provide deeper insight into coordinating C and N metabolism and improving N use efficiency in blackberry plants.

In vitro antioxidant analysis of flavonoids extracted from Artemisia argyi stem and their anti-inflammatory activity in lipopolysaccharide-stimulated RAW 264.7 macrophages

In this study, flavonoids were successfully extracted from Artemisia argyi stem, and their yield reached 15.3 mg/g dry A. argyi stem. The flavonoid extract from A. argyi stem had a purity of 88.58 % (w/w), meanwhile, which also contained 1.57 % (w/w) carbohydrates, 2.04 % (w/w) proteins and 7.81 % (w/w) polyphenols, respectively. In vitro antioxidant activity analysis showed the increased scavenging effects of flavonoid extract from A. argyi stem on 1,1-diphenyl-2-picrylhydrazyl, 2,2′-azinobis-di-(3-ethyl-benzothiazolin-6-sulfonic acid) diammonium salt, hydroxyl, and superoxide radicals in a concentration-dependent manner. Furthermore, the flavonoid extract from A. argyi stem exerted protective effects on lipopolysaccharide-stimulated RAW 264.7 macrophages via inhibiting the levels of tumor necrosis factor-alpha, interleukin-6, interleukin-1 beta, and nitric oxide free radicals. Overall, this work will provide guidance and help in the utilization of edible A. argyi as plant-based diet and its bioactive flavonoid extract as antioxidant and anti-inflammatory ingredients to improve the function, nutrition, and healthiness of foods.

Expression Changes of SIRT1 and FOXO3a Significantly Correlate with Oxidative Stress Resistance Genes in AML Patients.

The increased metabolism in acute myeloid leukemia (AML) malignant cells resulted in the production of high levels of free radicals, called oxidative stress conditions. To avoid this situation, malignant cells produce a considerable amount of antioxidant agents, which will lead to the release of a continuous low level of reactive oxygen species (ROS), causing genomic damage and subsequent clonal evolution. SIRT1 has a key role in driving the adaptation to this condition, mainly through the deacetylation of FOXO3a that affects the expression of oxidative stress resistance target genes such as Catalase and Manganese superoxide dismutase (MnSOD). The aim of this study is to simultaneously investigate the expression of SIRT1, FOXO3a, and free radical-neutralizing enzymes such as Catalase and MnSOD in AML patients and measure their simultaneous change in relation to each other. The gene expression was analyzed using Real Time-PCR in 65 AML patients and 10 healthy controls. Our finding revealed that expression of SIRT1, FOXO3a, MnSOD and Catalase was significantly higher in AML patients in comparison to healthy controls. Also, there was a significant correlation between the expression of SIRT1 and FOXO3a, as well as among the expression of FOXO3a, MnSOD and Catalase genes in patients. According to the results, the expression of genes involved in oxidative stress resistance was higher in AML patients, which possibly contributed to the development of malignant clones. Also, the correlation between the expression of SIRT1 and FOXO3a gene reflects the importance of these two genes in increased oxidative stress resistance of cancer cells.

Effects of Calcium Ions on the Antimicrobial Activity of Gramicidin A.

Gramicidin A (gA) is a linear antimicrobial peptide that can form a channel and specifically conduct monovalent cations such as H+ across the lipid membrane. The antimicrobial activity of gA is associated with the formation of hydroxyl free radicals and the imbalance of NADH metabolism, possibly a consequence caused by the conductance of cations. The ion conductivity of gramicidin A can be blocked by Ca2+ ions. However, the effect of Ca2+ ions on the antimicrobial activity of gA is unclear. To unveil the role of Ca2+ ions, we examined the effect of Ca2+ ions on the antimicrobial activity of gramicidin A against Staphylococcus aureus (S. aureus). Results showed that the antimicrobial mechanism of gA and antimicrobial activity by Ca2+ ions are concentration-dependent. At the low gA concentration (≤1 μM), the antimicrobial mechanism of gA is mainly associated with the hydroxyl free radical formation and NADH metabolic imbalance. Under this mode, Ca2+ ions can significantly inhibit the hydroxyl free radical formation and NADH metabolic imbalance. On the other hand, at high gA concentration (≥5 μM), gramicidin A acts more likely as a detergent. Gramicidin A not only causes an increase in hydroxyl free radical levels and NAD+/NADH ratios but also induces the destruction of the lipid membrane composition. At this condition, Ca2+ ions can no longer reduce the gA antimicrobial activity but rather enhance the bacterial killing ability of gramicidin A.

Activity of low-molecular weight components of Larix sibirica antioxidant system under exposure to technogenic pollution.

Changes in the antioxidant protection system of Larix sibirica Ledeb at different pollution levels caused by emissions from a large aluminum smelter (BrAS) have been studied. We revealed that the content of peroxide (H2O2) in the needles is a reliable marker of oxidative stress in the trees under pollution. The crucial role of non-enzymatic components, in particular, proline, phenolic compounds, ascorbic acid, glutathione, in reducing the level of free radicals in the needles cells was found. Proline concentration in the needles significantly rises with the increase in pollution levels from low to high. Under critical level pollution, it decreases by 40% compared to the background. The total content of ascorbic acid (ASC) in the needles of polluted trees varies slightly; however, there are significant changes in its various forms. With an increase in pollution to a high level, the content of the reduced form of ASC in the needles increases by 1.5-2.9 times compared to the background content. At a critical level of pollution, the total level of ascorbic acid and its reduced form falls, the content of the oxidized form reaches minimum values. The total content of phenolic compounds in the needles increased by 50-55%, concentration of flavonoids by 1.5-1.8 times, catechins by 1.9-2.5 times, proanthocyanidins by 45% compared to the background level under low, moderate, high pollution, whereas under critical pollution their content decreased. The absolute concentration of the reduced form glutathione in the needles falls by 1.9-3.0 times, the oxidized form increases by 1.5-2.0 times compared to the background. The ratio of reduced glutathione to oxidized glutathione decreased, especially during critical pollution. The data obtained show significant activation of Siberian larch biochemical protection at low, moderate and high levels of pollution by the aluminum smelter emissions. At a critical levels of contamination, a significant depletion of the pool of low-molecular antioxidants was observed.

НОВЫЕ ВАРИАНТЫ ДИНИТРОЗИЛЬНЫХ КОМПЛЕКСОВ ЖЕЛЕЗА. АНТИОКСИДАНТНОЕ И АНТИРАДИКАЛЬНОЕ ДЕЙСТВИЕ

Dinitrosyl iron complexes (DNICs) are important metabolites of nitric oxide (NO) with a wide range of biological activity. The properties of these complexes are determined not only by NO-ligands, but also by other components included in their composition. Using EPR spectroscopy, it was shown that iron in the DNICs can be bound to carnosine, L-ergothioneine and ADP. New variants of DNICs are formed with the participation of a nitroxyl anion, which is a product of one-electron reduction of NO. In model systems, DNICs associated with carnosine and ergothioneine reduce the level of various free radicals. These DNICs intercept the superoxide anion radical, which is a precursor to other reactive oxygen and nitrogen species. At the same time, carnosine-bound DNICs reduce the concentration of organic free radicals in a system containing a nitroxyl anion, iron ions and tert-butyl hydroperoxide. On the other hand, DNICs associated with ergothioneine and ADP may play an important role in the protection of mitochondria. It has been suggested that the new DNICs may be components of antioxidant systems localized in various tissues of the body, as well as redox triggers regulating the cellular response to oxidative stress.

4-Hydroxynonenal Modulates Blood-Brain Barrier Permeability In Vitro through Changes in Lipid Composition and Oxidative Status of Endothelial Cells and Astrocytes.

Blood brain barrier (BBB) is a dynamic interface responsible for proper functioning of brain, but also a major obstacle for effective treatment of neurological diseases. Increased levels of free radicals, in high ferrous and high lipid content surrounding, induce lipid peroxidation, leading to production of 4-hydroxynonenal (HNE). HNE modifies all key proteins responsible for proper brain functioning thus playing a major role in the onset of neurological diseases. To investigate HNE effects on BBB permeability, we developed two in vitro BBB models-'physiological' and 'pathological'. The latter mimicked HNE modified extracellular matrix under oxidative stress conditions in brain pathologies. We showed that exogenous HNE induce activation of antioxidative defense systems by increasing catalase activity and glutathione content as well as reducing lipid peroxide levels in endothelial cells and astrocytes of 'physiological' model. While in 'pathological' model, exogenous HNE further increased lipid peroxidation levels of endothelial cells and astrocytes, followed by increase in Nrf2 and glutathione levels in endothelial cells. At lipid composition level, HNE caused increase in ω3 polyunsaturated fatty acid (PUFA) level in endothelial cells, followed by decrease in ω3 PUFA level and increase in monounsaturated fatty acid level in astrocytes. Using these models, we showed for the first time that HNE in 'pathological' model can reduce BBB permeability.

Inhibitory effect of coriander (Coriandrum sativum L.) extract marinades on the formation of polycyclic aromatic hydrocarbons in roasted duck wings

Coriander (Coriandrum sativum L.) is recognized for its antioxidant property, as a kind of natural phenolic-rich ingredient. Polycyclic aromatic hydrocarbons (PAHs) present a class of heat-driven hazards in foods, especially the processed meat. In this study, the effect of coriander root and leaf extract on the formation and inhibition of PAH8 in roasted duck wings was firstly investigated. Coriander root extract (CRE) and coriander leaf extract (CLE) with five concentration groups (200, 400, 600, 800, 1000 mg/L) were prepared respectively to marinate the duck wings. CRE marinade exhibited greater inhibitory effect on PAH8 formation in roasted duck wings that ranged from 65.0 %–87.4 %. The electron spin resonance study indicated a significantly positive correlation between PAH8 and free radical level, suggesting the participation of radicals in PAHs formation. Also, it was speculated that the inhibitory effect on PAH8 was related to the phenolic compounds identified in coriander marinades. CRE made greater inhibitory effect on the formation of PAH8 and could be considered as a kind of natural source to mitigate PAHs in heat-processed meat products.

A highly sensitive turn‐off fluorescent probe based on 2D Eu(III)‐MOFs nanosheets for glutathione in vitro and living cells

AbstractGlutathione (GSH) is generally used as an effective and sensitive tumor marker because its abnormal levels are associated with high free radical level in tumor. In this work, GSH could be easily detected by a kind of designed Eu‐based metal–organic frameworks (Eu‐MOFs, named Eu(DTBA)) fluorescent sensor. Due to the “antenna effect” of 4,4′‐dithiobenzoic acid (4,4′‐DTBA) ligands on Eu3+, Eu(DTBA) emits the strong characteristic red light of Eu3+ under ultraviolet excitation. Moreover, the emission intensity strongly depends on GSH concentrations. Thus, Eu(DTBA) can serve as a turn‐off fluorescent switch of GSH because its framework structure can easily be destroyed by GSH that leads to the fluorescence quenching. Remarkably, during sensing GSH, Eu(DTBA) has shown many appealing performances, such as broad a response window (0–20 mM), fast response (3 min), high sensitivity (LOD = 0.35 µM), and excellent anti‐interference ability. The real bioimaging application has demonstrated that the reported Eu(DTBA) can be used as an excellent bioimaging agent to successfully distinguish tumor cells from normal cells in clinical diagnosis.

Preclinical studies on melanogenesis proteins using a resveratrol-nanoformula as a skin whitener

A naturally occurring polyphenol called trans-resveratrol has received a lot of attention due to its possible health advantages for humans. The low solubility of trans-resveratrol and its isomerization upon UV exposure strongly limit its application as a skin-whitening agent. In the present study, to increase trans-resveratrol solubility, a new nanoformula was created by combining hydrophilic surfactants and oils. Trans-Resveratrol nanoformula has been prepared, characterized, and applied as a skin-whitening agent on the dorsal skin of Guinea pigs. The optimized trans-resveratrol nanoformula with a particle size of 63.49 nm displayed a single peak and a polydispersity index [0.36 ± 0.02]. In addition, the zeta potential of the optimized formula was −30.4 mV, confirming the high stability of this nanoformula. The melanin contents in the trans-resveratrol nanoformula-treated group were substantially lower than those of the control and the blank nanoformula-treated groups after staining of the dorsal skins [black areas] of guinea pigs with Fontana Mountain dye. The pigmentation index in the control, blank nanoformula, and optimized trans-resveratrol nanoformula were 329.4 ± 36.9, 335.8 ± 71.4, and 124.8 ± 19.6 respectively. Confirming this finding, immunohistochemistry analysis of skin tissues revealed that the expressions of melanogenesis-regulating proteins such as tyrosinase and microphthalmia-associated transcription factor were down-regulated. The safety of topical application of trans-resveratrol nanoformula was validated by no changes in free radical levels and oxidative stress markers proteins in the livers and kidneys of guinea pigs at the end of the experiment. Conclusions: A novel trans-resveratrol nanoformula as well as the mechanism whereby it promotes skin whitening effects were presented. Furthermore, the study illustrated that trans-resveratrol nanoformula is safe, non-toxic, and can be applied for skin whitening, although more research on human skin is needed.

Protective effect of ginsenoside Rd on military aviation noise-induced cochlear hair cell damage in guinea pigs.

Noise pollution has become one of the important social hazards that endanger the auditory system of residents, causing noise-induced hearing loss (NIHL). Oxidative stress has a significant role in the pathogenesis of NIHL, in which the silent information regulator 1(SIRT1)/proliferator-activated receptor-gamma coactivator 1α (PGC-1α) signaling pathway is closely engaged. Ginsenoside Rd (GSRd), a main monomer extract from ginseng plants, has been confirmed to suppress oxidative stress. Therefore, the hypothesis that GSRd may attenuate noise-induced cochlear hair cell loss seemed promising. Forty-eight male guinea pigs were randomly divided into four groups: control, noise exposure, GSRd treatment (30mg/kg Rd for 10d + noise), and experimental control (30mg/kg glycerol + noise). The experimental groups received military helicopter noise exposure at 115dB (A) for 4h daily for five consecutive days. Hair cell damage was evaluated by using inner ear basilar membrane preparation and scanning electron microscopy. Terminal dUTP nick end labeling (TUNEL) and immunofluorescence staining were conducted. Changes in the SIRT1/PGC-1α signaling pathway and other apoptosis-related markers in the cochleae, as well as oxidative stress parameters, were used as readouts. Loss of outer hair cells, more disordered cilia, prominent apoptosis, and elevated free radical levels were observed in the experimental groups. GSRd treatment markedly mitigated hearing threshold shifts, ameliorated outer hair cell loss and lodging or loss of cilia, and improved apoptosis through decreasing Bcl-2 associated X protein (Bax) expression and increasing Bcl-2 expression. In addition, GSRd alleviated the noise-induced cochlear redox injury by upregulating superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels, decreasing malondialdehyde (MDA) levels, and enhancing the activity of SIRT1 and PGC-1α messenger ribonucleic acid (mRNA) and protein expression. In conclusion, GSRd can improve structural and oxidative damage to the cochleae caused by noise. The underlying mechanisms may be associated with the SIRT1/PGC-1α signaling pathway.

Immune defense mechanisms against a systemic bacterial infection in the cat flea (Ctenocephalides felis)

A significant amount of work has been devoted towards understanding the cellular and humoral immune responses in arthropod vectors. Although fleas (Siphonaptera) are vectors of numerous bacterial pathogens, few studies have examined how these insects defend themselves from infection. In this study, we investigated the immune defense mechanisms in the hemocoel of cat fleas (Ctenocephalides felis), currently the most important flea pest of humans and many domestic animals. Using model species of bacteria (Micrococcus luteus, Serratia marcescens, and Escherichia coli), we delivered a systemic infection and measured the following: antimicrobial activity of hemolymph, levels of free radicals resulting from the induction of oxidase-based pathways, number of circulating hemocytes, phagocytosis activity of circulating hemocytes, and in vivo bacteria killing efficiency when phagocytosis activity is limited. Our results show that the antimicrobial activity of flea hemolymph increases in response to certain species of bacteria; yet, a systemic infection with the same bacterial species did not influence levels of hydrogen peroxide (H2O2), a reactive intermediate of oxygen, at the same time. Additionally, the number of circulating hemocytes increases in response to E. coli infection, and these cells display strong phagocytic activity against this bacterium. Moreover, limiting phagocytosis by injecting polystyrene beads subsequently increases flea susceptibility to E. coli infection when compared to injury controls; however, impairing the cellular immune response itself did not increase flea susceptibility to infection when compared to untreated fleas. Overall, this work yields significant insight into how fleas interact with bacterial pathogens in their hemocoel, and suggests that cellular and humoral immune responses cooperate to combat systemic bacterial infections.

The Protective Effect of Berberine Against Memory Impairment Induced by Intrahippocampal Injection of Aluminium Chloride in Rats

Background and Objectives: Aluminum is a component of environmental pollutants, which causes neurotoxicity. Berberine is in the group of plant-derived alkaloids such as barberry and its beneficial therapeutic properties in various diseases have been proven. The aim of the present study was to investigate the protective effect of berberine on aluminum-induced neurotoxicity. Methods: In this experimental study, 32 male Wistar rats were randomly divided into 4 groups: sham, berberine-receiving sham, lesions-seeing and berberine-receiving lesions. To induce neurotoxicity, a solution of aluminum chloride (AlCl3) dissolved in distilled water was injected at 5 µL at a dose of 0.37 mg/kg to the left of the dorsal hippocampus. The treated rats received 100 mg/kg of berberine daily from one hour before surgery to one week after surgery and orally. In the fourth week, all groups were tested for behavioral learning and memory using the shuttle box. At the end, malondialdehyde, protein, ROS levels and acetylcholinesterase activity were measured. The results were analyzed using one-way ANOVA test and Tukey test. Results: In the treated AlCl3 group compared to the AlCl3 group, the initial delay was not significantly different but the delay during transit was significantly increased. MDA and ROS levels and acetylcholinesterase activity showed a significant decrease. Conclusion: The results of this study showed that although treatment with berberine in the lesion group by aluminum chloride did not cause a significant difference in learning in rats, but it significantly improved memory, significantly reduced malondialdehyde, significantly reduced oxygen free radical levels and significantly reduced activity. Acetylcholinesterase and it can be said that berberine with antioxidant properties improved memory and neuroprotection against neurotoxicity caused by aluminum chloride.

Anthocyanins in Dairy Cow Nutrition: A Review

Oxidative stress is a condition in dairy cows characterized by an imbalance of prooxidants and antioxidants, abnormally high levels of free radicals, or a decline in antioxidant defense mechanisms. Moreover, dairy cows are more inclined to oxidative stress status, which causes damage to the body and DNA damage resulting in a decline in antioxidant potential. Anthocyanins are effective antioxidants and free radical scavengers derived from fruit, purple corn, and other purple plants in nature. Many studies have shown that anthocyanins have favorable antioxidation effects in dairy cows and prevent lipid oxidation to improve milk quality. Accordingly, in the present paper, we mainly review (1) the definition of anthocyanins and the possible absorption and metabolic pathways; (2) the effect of anthocyanins on rumen fermentation parameters and methane production; (3) the mechanism by which anthocyanins enhance antioxidant potential and alleviate oxidative stress by scavenging free radicals and regulating signalling pathways; and (4) the effect of anthocyanins on milk production and milk lipid oxidation in dairy cows. This paper may provide an important rationale for the modulation of dairy cow health and productivity by anthocyanins in the future.

Bioremoval and Detoxification of the Anticancer Drug Mitoxantrone Using Immobilized Crude Versatile Peroxidase (icVP/Ba) Bjerkandera adusta CCBAS 930.

The aim of this study was to evaluate the biodecolorization and detoxification of the anticancer drug mitoxantron (MTX) by immobilized crude versatile peroxidase of Bjerkandera adusta CCBAS 930 (icVP/Ba). The concentrated crude VP was obtained from B. adusta CCBAS 930 culture on medium with MTX (µg/mL) addition, immobilized with 4% sodium alginate. MTX removal degree (decolorization), levels of phenolic compounds and free radicals were determined during MTX biotransformation. Moreover, the phytotoxicity (Lepidium sativum L.), biotoxicity (multi-species microbial assay, MARA), and genotoxicity (SOS Chromotest) of MTX were evaluated before and after the biological treatment. The use of icVP/Ba (95 U/mL) significantly shortened the bioremoval of 10 µg/mL MTX (95.57% after 72 h). MTX removal by icVP/Ba was correlated with an 85% and 90% decrease in the levels of phenolic compounds and free radicals, respectively. In addition, the use of icVP/Ba contributed to a decrease in the phyto-, bio-, and genotoxicity of MTX. This is the first study to describe the possibility of removing MTX using immobilized crude fungal peroxidase.

Recent Studies on Protective Effects of Walnuts against Neuroinflammation.

Neuroinflammation plays a significant role in the aging process and the pathophysiology of neurodegenerative diseases, such as Alzheimer’s disease. Accordingly, possible therapeutic strategies aimed at anti-inflammatory effects may be beneficial to brain health. Walnut kernels contain large quantities of unsaturated fatty acids, peptides, and phenolic compounds that have anti-inflammatory effects. The long-term intake of walnuts has been found to improve cognitive function and memory in rats and humans. However, the modulatory effect of walnuts on neuroinflammation has received much less attention. This review focuses on the potential influence and main regulating mechanisms of walnuts and their active ingredients on neuroinflammation, including the regulation of microglia activation induced by amyloid β or lipopolysaccharides, inhibition of peripheral inflammation mediated by macrophages, reduction in oxidative stress by decreasing free radical levels and boosting antioxidant defenses, and control of gut microbes to maintain homeostasis. However, the majority of evidence of the beneficial effects of walnuts or their components on neuroinflammation and neurodegeneration comes from experimental work, whereas evidence from clinical studies on the beneficial effects is scarcer and less conclusive. This review aims to provide new insights into the neuroinflammation-regulating mechanisms and natural active ingredients of walnuts and the development of walnut-based functional foods for the alleviation of neurodegenerative diseases.

Effects of Different Antioxidants of Bamboo Leaves Treatments on Lipid Oxidation of Scallop (Argopecten irradians) Adductor Muscle During Hot Air Drying

ABSTRACT The effect of different antioxidants of bamboo leaves (AOB) treatment on lipid oxidation of scallop (Argopecten irradians) adductor muscle during hot air drying was investigated. The results demonstrated that the marinated sample had the lowest peroxide value, thiobarbituric acid-reactive substances, polyunsaturated fatty acids loss, free radical level, and lipoxygenase activity during drying, indicating that the marination process maximized the antioxidant effects of AOB. The results indicate that this process could interfere with free radical chain reaction and inhibit lipoxygenase activity since AOB is correctly distributed on the site of lipid oxidation. After drying, eicosapentaenoic acid + docosahexaenoic acid content in control, unmarinated, and marinated samples decreased by 26.10%, 11.25%, and 7.29%, respectively, suggesting that the marination process maintained more efficiently its high nutritive value in terms of lipid content. Overall, the use of AOB provides a more effective strategy to control lipid oxidation in seafood, mainly scallops, during drying.

Mechanistic insights into Fe(II)-citric acid complex catalyzed CaO2 Fenton-like process for enhanced benzo[a]pyrene removal from black-odor sediment at circumneutral pH

Polycyclic aromatic hydrocarbons (PAHs) are found ubiquitously in contaminated aquatic sediments. They are difficult to degrade, particularly the high-molecular-weight PAHs (e.g., benzo[a]pyrene, BaP). In this study, CaO2 assisted with ferrous ion (Fe(II))-citric acid (CA) was applied for the first time in BaP degradation in aquatic sediment. Among the treatment processes we studied, CaO2/Fe(Ⅱ)/CA could effectively degrade BaP at circumneutral pH (7.0 ± 0.3), reaching a maximum of nearly 80% under optimal conditions (0.84 mM CaO2, 0.21 mM Fe(Ⅱ), and 0.35 mM CA in per gram of dry sediment). Contrary to some external environmental factors such as temperature, common metal ions, and natural organic matters, a certain amount of moisture content and inorganic anions (Cl−, SO42−) exhibited a positive effect on BaP degradation, which can probably be contributed to the improved mass transfer rate in the non-homogeneous sediment-water mixture and a higher level of free radicals. The degradation kinetic dominated by hydroxyl radicals included three main stages contribution ∼29.4%, ∼43.1%, and ∼2.4% to BaP degradation, respectively. Based on the theoretical calculations of density functional theory, a pathway for BaP degradation was proposed. For the treatment of actual contaminated sediment, the CaO2/Fe(II)/CA process could realize the elimination of black-odor and effective removal of PAHs from the sediment, as well as negligible ecotoxicity on benthic organisms. This study provides a reference and guidance for the use of CaO2 based Fenton-like systems in treating PAH-contaminated black-odor river sediments.

S2643 Rare Gastrointestinal Bleeding in a Patient With Severe Plasmodium Falciparum Malaria

Introduction: Malaria clinically presents as a systemic febrile illness; the most severe form is caused by Plasmodium Falciparum. In addition to hematologic manifestations such as severe anemia, thrombocytopenia, and coagulopathy, malaria patients uncommonly experience gastrointestinal complications such as GI bleeds, splenic rupture and subacute intestinal obstruction. We report a severe case of P. falciparum malaria complicated by a GI bleed. Case Description/Methods: A 66-year-old male with recent travel to Nigeria and a medical history of hypertension was brought to the ER with altered mental status, abdominal pain and a 25lb weight loss in the last month. In the ED he spiked a fever to 102F, prompting a thorough infectious workup. An LP was remarkable for many RBCs, glucose 81 and protein 47. CSF was negative for meningitis/encephalitis; he did not have EBV, CMV or HIV. Blood and fungal cultures were negative. Due to his recent travel history, our patient had a 5-thin and 2-thick malarial smear which showed P. falciparum malaria ring forms. He was started on cefepime, vancomycin, metronidazole, atovaquone/proguanil. Over the next 12-hours, the patient rapidly deteriorated with a large coffee ground emesis, a hemoglobin drop from 12.1 to 8.6, and a thrombocytopenia from 135 to 15. Hemolysis labs were positive: haptoglobin < 30, LDH 607, reticulocyte 14.6%, fibrinogen 112. Upper endoscopy showed Grade-C esophagitis, an oozing duodenal ulcer and hematin all throughout the stomach wall. Abdominal ultrasound and CT showed no acute intra-abdominal pathologies. With new ongoing hematemesis and melena, he went into progressive septic vs hemorrhagic shock and required vasopressors and stress-dose steroids. Discussion: The hematologic manifestations often seen in malaria rarely lead to massive GI bleeds. Our patient did not use NSAIDS, he was not tested for H. Pylori, and despite the stress of his acute severe illness, he had no other risk factors for duodenal ulceration. High levels of free oxygen radicals and tumor necrosis factor may have played a role in the etiology of his peptic ulcer formation. Malarial hemolysis results from the release of cytokines, macrophage recruitment, causing a cytokine storm and activation of endothelial adhesion molecule type 1, E-selectin, enhancing cytoadherence of parasitized cells, mediating lactic acidemia, shock, gut mucosal damage and increased permeability. Despite aggressive measures, our patient ultimately developed shock and died.