Long-term abuse of caffeine sodium benzoate induces endothelial cells injury and leads to coagulation dysfunction.

Our hospital admitted a patient who had difficulty in coagulation even after blood replacement, and the patient had abused caffeine sodium benzoate (CSB) for more than 20 years. Hence, we aimed to explore whether CSB may cause dysfunction in vascular endothelial cells and its possible mechanism. Low, medium, and high concentrations of serum of long-term CSB intake patients were used to treat HUVECs, with LPS as the positive control. MTT and CCK8 were performed to verify CSB's damaging effect on HUVECs. The expression of ET-1, ICAM-1, VCAM-1, and E-selectin were measured by ELISA. TUNEL assay and Matrigel tube formation assay were carried out to detect apoptosis and angiogenesis of HUVECs. Flow cytometry was applied to analyze cell cycles and expression of CD11b, PDGF, and ICAM-1. Expression of PDGF-BB and PCNA were examined by western blot. The activation of MAPK signaling pathway was detected by qRT-PCR and western blot. Intracellular Ca2+ density was detected by fluorescent probes. CCK8 assay showed high concentration of CSB inhibited cell viability. Cell proliferation and angiogenesis were inhibited by CSB. ET-1, ICAM-1, VCAM-1, and E-selectin upregulated in CSB groups. CSB enhanced apoptosis of HUVECs. CD11b, ICAM-1 increased and PDGF reduced in CSB groups. The expression level and phosphorylation level of MEK, ERK, JUN, and p38 in MAPK pathway elevated in CSB groups. The expression of PCNA and PDGF-BB was suppressed by CSB. Intracellular Ca2+ intensity was increased by CSB. Abuse of CSB injured HUVECs and caused coagulation disorders.

Sodium benzoate induces pancreatic inflammation and ß cell apoptosis partially via benzoylation.

Epigenetics, specifically histone post-translational modification (HPTM) induced by environmental factors, plays a crucial role in the development of diabetes. Sodium benzoate (NAB) is a widely used additive, however, its potential contribution to diabetes has been largely overlooked. In 2018, a novel HPTM called benzoylation (Kbz) induced by NAB was discovered. This modification can be catalyzed by ACSS2 (acyl-CoA synthetase short-chain member 2) and acyltransferase P300/CBP, and can be reversed by erase enzymes SIRT2. Studies have indicated that Kbz may regulate insulin secretion, although the exact molecular mechanism remains unclear. In our study, C57BL/6J mice were divided into two groups: the NC group and the 1g/kg NAB water feeding group. In vivo experiments were conducted using ß-TC-6 cells, with 6 mM NAB or 100 µM benzoyl-CoA as stimuli, and 10 µM A485 (P300 inhibitor), 5 µM ACSS2 inhibitor (inhibiting benzoyl-CoA synthesis), or 5 µM AGK2 (SIRT2 inhibitor) as intervention factors. Our study found that, although the experimental concentration of NAB is below the maximum allowable concentration in food, it still damaged the insulin secretion function of C57BL/6J mice and induced inflammation and apoptosis of islet ß cells. We observed significant differences in serum benzoyl-CoA levels between healthy individuals and patients with type 2 diabetes. Furthermore, NAB concentration-dependently increases benzoyl-CoA and Kbz levels. When Kbz is down-regulated using A485 and ACSS2 inhibitor, we observed a reduction in ß cell inflammation, apoptosis, and insulin secretion damage. Conversely, up-regulating Kbz using AGK2 resulted in increased levels of ß cell inflammation and apoptosis. In conclusion, our data suggest that NAB, despite being within the safe dose range, may be an overlooked environmental risk factor contributing to the pathogenesis of diabetes through its impact on Kbz.

Sodium benzoate exacerbates hepatic oxidative stress and inflammation in lipopolysaccharide-induced liver injury in rats.

BACKGROUND: Liver damage is a global health concern associated with a high mortality rate. Sodium benzoate (SB) is a widely used preservative in the food industry with a wide range of applications. However, there's a lack of scientific reports on its effect on lipopolysaccharide-induced hepatic dysfunction. OBJECTIVE: The present study investigated the influence of SB on lipopolysaccharide (LPS)-induced liver injury. MATERIALS AND METHODS: Twenty-eight rats were randomly allocated into four groups: control (received distilled water), SB (received 600 mg/kg), LPS (received 0.25 mg/kg), and LPS + SB (received LPS, 0.25 mg/kg, and SB, 600 mg/kg). SB was administered orally for 14 days while LPS was administered intraperitoneally for 7 days. RESULTS: Administration of SB to rats with hepatocyte injury exacerbated liver damage with a significant increase in the activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). We also observed that SB aggravated LPS-mediated hepatic oxidative stress occasioned by a marked decrease in antioxidant status with a concomitant increase in lipid peroxidation. Furthermore, LPS - mediated increase in inflammatory biomarkers as well as histological deterioration in the liver was exacerbated following the administration of SB to rats. CONCLUSION: Taken together, the study provides experimental evidence that SB exacerbates hepatic oxidative stress and inflammation in LPS-mediated liver injury.

Protective role of the dandelion extract against the blood-liver axis, cell membranes, and anemia disorder in sodium benzoate-exposed rats.

Sodium benzoate (SB) as an additive in various food products prevents the growth of microbes. Although SB is considered safe, many studies have reported adverse effects. The aim of this study was to investigate the effect of dandelion extract on cell damage and hematological and biochemical disorders induced by SB in male albino rats. Different doses of SB (200 and 600 mg/kg) and ethanolic dandelion root extract (D) (40 mg/kg) were used in a 2-week treatment of rats. Rat mortality and a higher frequency of behavioral alterations such as apathy, anxiety, and aggression have been reported at a higher dose of SB. Changes in urine pH, proteinuria, nitrituria, and bilirubinemia caused by SB were regulated by adding dandelion extract. Analysis of specific serum and urine parameters, as well as microscopic analysis of hepatocytes, showed liver and kidney failure. Anemia associated with hemolytic disorder due to erythrocyte impaired the presence of acanthocytes, and decreased values of erythrocyte blood count, hemoglobin concentration, average red blood cell size, hemoglobin amount per red blood cell, and mean corpuscular hemoglobin concentration were caused by SB treatment. As a dietary supplement, dandelion extract can be useful in the prevention of SB-induced liver and kidney injury, and also a remedy against induced anemia, neutropenia, thrombocytopenia, hyperproteinemia, hyperglycemia, and reduction of inflammatory responses.

Alleviation of Huntington pathology in mice by oral administration of food additive glyceryl tribenzoate.

Huntington's disease (HD) is a neurodegenerative disorder characterized by accumulation of mutant huntingtin protein and significant loss of neurons in striatum and cortex. Along with motor difficulties, the HD patients also manifest anxiety and loss of cognition. Unfortunately, the clinically approved drugs only offer symptomatic relief and are not free from side effects. This study underlines the importance of glyceryl tribenzoate (GTB), an FDA-approved food flavoring ingredient, in alleviating HD pathology in transgenic N171-82Q mouse model. Oral administration of GTB significantly reduced mutant huntingtin level in striatum, motor cortex as well as hippocampus and increased the integrity of viable neurons. Furthermore, we found the presence of sodium benzoate (NaB), a FDA-approved drug for urea cycle disorders and glycine encephalopathy, in the brain of GTB-fed HD mice. Accordingly, NaB administration also markedly decreased huntingtin level in striatum and cortex. Glial activation is found to coincide with neuronal death in affected regions of HD brains. Interestingly, both GTB and NaB treatment suppressed activation of glial cells and inflammation in the brain. Finally, neuroprotective effect of GTB and NaB resulted in improved motor performance of HD mice. Collectively, these results suggest that GTB and NaB may be repurposed for HD.

Production of the Carboxylate Reductase from Nocardia otitidiscaviarum in a Soluble, Active Form for in†vitro Applications.

Accessing aldehydes from carboxylate moieties is often a challenging task. In this regard, carboxylate reductases (CARs) are promising catalysts provided by nature that are able to accomplish this task in just one step, avoiding over-reduction to the alcohol product. However, the heterologous expression of CARs can be quite difficult due to the excessive formation of insoluble protein, thus hindering further characterization and application of the enzyme. Here, the heterologous production of the carboxylate reductase from Nocardia otitidiscaviarum (NoCAR) was optimized by a combination of i) optimized cultivation conditions, ii) post-translational modification with a phosphopantetheinyl transferase and iii) selection of an appropriate expression strain. Especially, the selection of Escherichia coli tuner cells as host had a strong effect on the final 110-fold increase in the specific activity of NoCAR. This highly active NoCAR was used to reduce sodium benzoate to benzaldehyde, and it was successfully assembled with an in vitro regeneration of ATP and NADPH, being capable of reducing about 30 mM sodium benzoate with high selectivity in only 2 h of reaction.

Sodium Benzoate, a Food Additive and a Metabolite of Cinnamon, Enriches Regulatory T Cells via STAT6-Mediated Upregulation of TGF-ß.

Upregulation and/or maintenance of regulatory T cells (Tregs) during autoimmune insults may have therapeutic efficacy in autoimmune diseases. Earlier we have reported that sodium benzoate (NaB), a metabolite of cinnamon and a Food and Drug Administration-approved drug against urea cycle disorders, upregulates Tregs and protects mice from experimental allergic encephalomyelitis, an animal model of multiple sclerosis. However, mechanisms by which NaB increases Tregs are poorly understood. Because TGF-ß is an important inducer of Tregs, we examined the effect of NaB on the status of TGF-ß. In this study, we demonstrated that NaB induced the expression of TGF-ß mRNA and protein in normal as well as proteolipid protein-primed splenocytes. The presence of a consensus STAT6 binding site in the promoter of the TGF-ß gene, activation of STAT6 in splenocytes by NaB, recruitment of STAT6 to the TGF-ß promoter by NaB, and abrogation of NaB-induced expression of TGF-ß in splenocytes by small interfering RNA knockdown of STAT6 suggest that NaB induces the expression of TGF-ß via activation of STAT6. Furthermore, we demonstrated that blocking of TGF-ß by neutralizing Abs abrogated NaB-mediated protection of Tregs and experimental allergic encephalomyelitis. These studies identify a new function of NaB in upregulating TGF-ß via activation of STAT6, which may be beneficial in MS patients.

Modelling the effects of lactic acid, sodium benzoate and temperature on the growth of Candida maltosa.

The growth of the oxidatively imperfect yeast Candida maltosa Komagata, Nakase et Katsuya was studied experimentally and modelled mathematically in relation to sodium benzoate and lactic acid concentrations at different temperatures. Application of gamma models for the growth rate resulted in determination of cardinal temperature parameters for the growth environment containing lactic acid or sodium benzoate (Tmin  = 0·7/1·3°C, Tmax  = 45·3/45·0°C, Topt  = 36·1/37·0°C, µopt  = 0·88/0·96 h-1 ) as well as the maximal lactic acid concentration for growth (1·9%) or sodium benzoate (1397 mg kg-1 ). Based on the model, the times to reach the density of C. maltosa at the level of 105  CFU per ml can be determined at each combination of storage temperature and preservative concentration. The approach used in this study can broaden knowledge of the microbiological quality of fermented milk products during storage as well as the preservation efficacy of mayonnaise dressing for storage and consumption. SIGNIFICANCE AND IMPACT OF THE STUDY: The strain of Candida maltosaYP1 was originally isolated from air filters that ensured clean air overpressure in yoghurt fermentation tanks. Its growth in contaminated yoghurts manifested outwardly through surface growth, assimilation lactic acid and slight production of carbon dioxide. This was the opportunity to model the effects of lactic acid and sodium benzoate on growth and predict its behaviour in foods. The approach used in this study provides knowledge about microbiological quality development during storage of the fermented milk products as well as some preserved foods for storage and consumption.

Effects of sodium benzoate, a widely used food preservative, on glucose homeostasis and metabolic profiles in humans.

Sodium benzoate is a widely used preservative found in many foods and soft drinks. It is metabolized within mitochondria to produce hippurate, which is then cleared by the kidneys. We previously reported that ingestion of sodium benzoate at the generally regarded as safe (GRAS) dose leads to a robust excursion in the plasma hippurate level [1]. Since previous reports demonstrated adverse effects of benzoate and hippurate on glucose homeostasis in cells and in animal models, we hypothesized that benzoate might represent a widespread and underappreciated diabetogenic dietary exposure in humans. Here, we evaluated whether acute exposure to GRAS levels of sodium benzoate alters insulin and glucose homeostasis through a randomized, controlled, cross-over study of 14 overweight subjects. Serial blood samples were collected following an oral glucose challenge, in the presence or absence of sodium benzoate. Outcome measurements included glucose, insulin, glucagon, as well as temporal mass spectrometry-based metabolic profiles. We did not find a statistically significant effect of an acute oral exposure to sodium benzoate on glucose homeostasis. Of the 146 metabolites targeted, four changed significantly in response to benzoate, including the expected rise in benzoate and hippurate. In addition, anthranilic acid, a tryptophan metabolite, exhibited a robust rise, while acetylglycine dropped. Although our study shows that GRAS doses of benzoate do not have an acute, adverse effect on glucose homeostasis, future studies will be necessary to explore the metabolic impact of chronic benzoate exposure.

Short communication: Use of a mixture of sodium nitrite, sodium benzoate, and potassium sorbate in aerobically challenged silages.

Aerobic instability is still a common problem with many types of silages, particularly well-fermented silages. This study evaluated the effect of adding an additive mixture based on sodium nitrite, sodium benzoate, and potassium sorbate to a variety of crop materials on fermentation quality and aerobic stability of silages. Ensiling conditions were challenged by using a low packing density (104±4.3kg of dry matter/m(3)) of forage and allowing air ingression into silos (at 14 and 7 d before the end of the storage, for 8 h per event). Additive-treated silages were found to have significantly lower pH and reduced formation of ammonia-N, 2.3-butanediol, and ethanol compared with untreated control silages. Yeast growth was significantly reduced by additive treatment in comparison with untreated control silage. Consequently, additive-treated silages were considerably more aerobically stable (6.7 d) than untreated control silages (0.5 d). Overall, adding 5mL/kg of fresh crop of the additive based on sodium nitrite, sodium benzoate, and potassium sorbate reduced undesirable microorganisms in silages and thereby provided suitable ensiling conditions and prolonged aerobic stability, even under air-challenged laboratory ensiling conditions.

Multi-omics insights into the function and evolution of sodium benzoate biodegradation pathway in Benzoatithermus flavus gen. nov., sp. nov. from hot spring.

Biodegradation stands as an eco-friendly and effective approach for organic contaminant remediation. However, research on microorganisms degrading sodium benzoate contaminants in extreme environments remains limited. In this study, we report to display the isolation of a novel hot spring enriched cultures with sodium benzoate (400 mg/L) as the sole carbon source. The results revealed that the phylum Pseudomonadota was the potential sodium benzoate degrader and a novel genus within the family Geminicoccaceae of this phylum. The isolated strain was named Benzoatithermus flavus SYSU G07066T and was isolated from HNT-2 hot spring samples. Genomic analysis revealed that SYSU G07066T carried benABC genes and physiological experiments indicated the ability to utilize sodium benzoate as a sole carbon source for growth, which was further confirmed by transcriptomic data with expression of benABC. Phylogenetic analysis suggested that Horizontal Gene Transfer (HGT) plays a significant role in acquiring sodium benzoate degradation capability among prokaryotes, and SYSU G07066T might have acquired benABC genes through HGT from the family Acetobacteraceae. The discovery of the first microorganism with sodium benzoate degradation function from a hot spring enhances our understanding of the diverse functions within the family Geminicoccaceae. This study unearths the first novel genus capable of efficiently degrading sodium benzoate and its evolution history at high temperatures, holding promising industrial applications, and provides a new perspective for further exploring the application potential of hot spring "microbial dark matter".

Efficiency of biological activator formulated material (BAFM) for volatile organic compounds removal--preliminary batch culture tests with activated sludge.

During biological degradation, such as biofiltration of air loaded with volatile organic compounds, the pollutant is passed through a bed packed with a solid medium acting as a biofilm support. To improve microorganism nutritional equilibrium and hence to enhance the purification capacities, a Biological Activator Formulated Material (BAFM) was developed, which is a mixture of solid nutrients dissolving slowly in a liquid phase. This solid was previously validated on mineral pollutants: ammonia and hydrogen sulphide. To evaluate the efficiency of such a material for biodegradation of some organic compounds, a simple experiment using an activated sludge batch reactor was carried out. The pollutants (sodium benzoate, phenol, p-nitrophenol and 2-4-dichlorophenol) were in the concentration range 100 to 1200 mg L(-1). The positive impact of the formulated material was shown. The improvement of the degradation rates was in the range 10-30%. This was the consequence of the low dissolution of the nutrients incorporated during material formulation, followed by their consumption by the biomass, as shown for urea used as a nitrogen source. Owing to its twofold interest (mechanical resistance and nutritional supplementation), the Biological Activator Formulated Material seems to be a promising material. Its addition to organic or inorganic supports should be investigated to confirm its relevance for implementation in biofilters.

Sodium benzoate, a metabolite of cinnamon and a food additive, reduces microglial and astroglial inflammatory responses.

Upon activation, microglia and astrocytes produce a number of proinflammatory molecules that participate in the pathophysiology of several neurodegenerative disorders. This study explores the anti-inflammatory property of cinnamon metabolite sodium benzoate (NaB) in microglia and astrocytes. NaB, but not sodium formate, was found to inhibit LPS-induced expression of inducible NO synthase (iNOS), proinflammatory cytokines (TNF-alpha and IL-1beta) and surface markers (CD11b, CD11c, and CD68) in mouse microglia. Similarly, NaB also inhibited fibrillar amyloid beta (Abeta)-, prion peptide-, double-stranded RNA (polyinosinic-polycytidylic acid)-, HIV-1 Tat-, 1-methyl-4-phenylpyridinium(+)-, IL-1beta-, and IL-12 p40(2)-induced microglial expression of iNOS. In addition to microglia, NaB also suppressed the expression of iNOS in mouse peritoneal macrophages and primary human astrocytes. Inhibition of NF-kappaB activation by NaB suggests that NaB exerts its anti-inflammatory effect through the inhibition of NF-kappaB. Although NaB reduced the level of cholesterol in vivo in mice, reversal of the inhibitory effect of NaB on iNOS expression, and NF-kappaB activation by hydroxymethylglutaryl-CoA, mevalonate, and farnesyl pyrophosphate, but not cholesterol and ubiquinone, suggests that depletion of intermediates, but not end products, of the mevalonate pathway is involved in the anti-inflammatory effect of NaB. Furthermore, we demonstrate that an inhibitor of p21(ras) farnesyl protein transferase suppressed the expression of iNOS, that activation of p21(ras) alone was sufficient to induce the expression of iNOS, and that NaB suppressed the activation of p21(ras) in microglia. These results highlight a novel anti-inflammatory role of NaB via modulation of the mevalonate pathway and p21(ras).

Construction of Genetic Logic Gates Based on the T7 RNA Polymerase Expression System in Rhodococcus opacus PD630.

Rhodococcus opacus PD630 (R. opacus) is a nonmodel, Gram-positive bacterium that holds promise as a biological catalyst for the conversion of lignocellulosic biomass to value-added products. In particular, it demonstrates both a high tolerance for and an ability to consume inhibitory lignin-derived aromatics, generates large quantities of lipids, exhibits a relatively rapid growth rate, and has a growing genetic toolbox for engineering. However, the availability of genetic parts for tunable, high-activity gene expression is still limited in R. opacus. Furthermore, genetic logic circuits for sophisticated gene regulation have never been demonstrated in Rhodococcus spp. To address these shortcomings, two inducible T7 RNA polymerase-based expression systems were implemented for the first time in R. opacus and applied to the construction of AND and NAND genetic logic gates. Additionally, three isopropyl ß-d-1-thiogalactopyranoside (IPTG)-inducible promoters were created by inserting LacI binding sites into newly characterized constitutive promoters. Furthermore, four novel aromatic sensors for 4-hydroxybenzoic acid, vanillic acid, sodium benzoate, and guaiacol were developed, expanding the gene expression toolbox. Finally, the T7 RNA polymerase platform was combined with a synthetic IPTG-inducible promoter to create an IMPLY logic gate. Overall, this work represents the first demonstration of a heterologous RNA polymerase system and synthetic genetic logic in R. opacus, enabling complex and tunable gene regulation in this promising nonmodel host for bioproduction.

Biodegradation of sodium benzoate by a Gram-negative consortium in a laboratory-scale fluidized bed bioreactor.

Gram-negative bacteria with the potential to metabolize n-alkanes and cyclic hydrocarbons were isolated from local soils and identified using 16S rDNA sequence analysis. Three isolates (CS1CO, GL1CO, GCI1CO) were identified as strains of Pseudomonas (P.) aeruginosa and a further strain (DSS2) as P. putida. Isolates were co-cultured in a laboratory-scale fluidized bed biofilm bioreactor (FBBR) utilizing sodium benzoate as the sole carbon source, under two batch and/or one continuous growth conditions. Biofilm and planktonic bacterial growth dynamics were monitored by plate counts, and optical density measurements (230 nm) determined benzoate biodegradation. Overall higher attached and planktonic bacterial counts, and benzoate depletion, were determined under batch compared to continuous conditions, and the bioreactor performed better during the second batch phase when compared to the first batch phase. It thus appeared that both the planktonic and biofilm components of the system were necessary for the most successful sodium benzoate degradation in this system.

Formation of ortho-benzoquinone from sodium benzoate by Pseudomonas mendocina P2d.

Pseudomonas mendocina P2d grew in sodium benzoate at as high as 1% concentration and formed a quinonoid compound, identified as ortho-benzoquinone, that rendered the medium orange to wine-red in colour. The quinone was not metabilised further by the organism. Sodium benzoate was converted to catechol, which was a central metabolite forming ortho-benzoquinone and 2- hydroxymuconic semialdehyde (2-HMS) via. meta ring cleavage pathway.

From laboratory to environmental conditions: a new approach for chemical's biodegradability assessment.

With thousands of organic chemicals released every day into our environment, Europe and other continents are confronted with increased risk of health and environmental problems. Even if a strict regulation such as REgistration, Authorization and restriction of CHemicals (REACH) is imposed and followed by industry to ensure that they prove the harmlessness of their substances, not all testing procedures are designed to cope with the complexity of the environment. This is especially true for the evaluation of persistence through biodegradability assessment guidelines. Our new approach has been to adapt "in the lab" biodegradability assessment to the environmental conditions and model the probability for a biodegradation test to be positive in the form of a logistic function of both the temperature and the viable cell density. Here, a proof of this new concept is proposed with the establishment of tri-dimensional biodegradability profiles of six chemicals (sodium benzoate, 4-nitrophenol, diethylene glycol, 2,4,5-trichlorophenol, atrazine, and glyphosate) between 4 to 30 °C and 10(4) to 10(8) cells ml(-1) as can be found in environmental compartments in time and space. The results show a significant increase of the predictive power of existing screening lab-scale tests designed for soluble substances. This strategy can be complementary to those current testing strategies with the creation of new indicators to quantify environmental persistence using lab-scale tests.

Influence of low-frequency massage device on transdermal absorption of ionic materials.

The influence of a low-frequency massage device on transdermal absorption of sodium benzoate, ketoprofen and diclofenac sodium was investigated in rats. Electrode pads spread with a hydroxypropyl cellulose gel containing the drug model were placed on excised skin in vitro. The transdermal permeation studies were carried out in the treatment group with the pulse applied through electrode pads spread with the gel, the pretreatment group with the gel applied after the application of the pulse and in the control group in which the gel was applied without the pulse. In vivo, transdermal absorption of ketoprofen was examined in the same groups used for the in vitro study. The pharmacokinetics of ketoprofen in plasma after intravenous injection was also studied. The treatment group showed higher cumulative permeated amounts of the drug models than the control in vitro. However, the enhancing effect was not observed in the pretreatment group. In vivo, the plasma ketoprofen level increased temporarily after the pulse was applied and then increased gradually as compared with the control. Since the distribution of ketoprofen from the central to the peripheral compartment was enhanced by the pulse in the injection study, enhancement of the biodistribution of ketoprofen by the low-frequency pulse was suggested.

Cinnamon and Its Metabolite Sodium Benzoate Attenuate the Activation of p21rac and Protect Memory and Learning in an Animal Model of Alzheimer's Disease.

This study underlines the importance of cinnamon, a commonly used natural spice and flavoring material, and its metabolite sodium benzoate (NaB) in attenuating oxidative stress and protecting memory and learning in an animal model of Alzheimer's disease (AD). NaB, but not sodium formate, was found to inhibit LPS-induced production of reactive oxygen species (ROS) in mouse microglial cells. Similarly, NaB also inhibited fibrillar amyloid beta (Aß)- and 1-methyl-4-phenylpyridinium(+)-induced microglial production of ROS. Although NaB reduced the level of cholesterol in vivo in mice, reversal of the inhibitory effect of NaB on ROS production by mevalonate, and geranylgeranyl pyrophosphate, but not cholesterol, suggests that depletion of intermediates, but not end products, of the mevalonate pathway is involved in the antioxidant effect of NaB. Furthermore, we demonstrate that an inhibitor of p21rac geranylgeranyl protein transferase suppressed the production of ROS and that NaB suppressed the activation of p21rac in microglia. As expected, marked activation of p21rac was observed in the hippocampus of subjects with AD and 5XFAD transgenic (Tg) mouse model of AD. However, oral feeding of cinnamon (Cinnamonum verum) powder and NaB suppressed the activation of p21rac and attenuated oxidative stress in the hippocampus of Tg mice as evident by decreased dihydroethidium (DHE) and nitrotyrosine staining, reduced homocysteine level and increased level of reduced glutathione. This was accompanied by suppression of neuronal apoptosis, inhibition of glial activation, and reduction of Aß burden in the hippocampus and protection of memory and learning in transgenic mice. Therefore, cinnamon powder may be a promising natural supplement in halting or delaying the progression of AD.

Method for the measurement of antioxidant activity in human fluids.

AIM: To develop a new, simple, and cheap method for estimating antioxidant activity in human fluids. METHODS: The assay measured the capacity of the biological fluids to inhibit the production of thiobarbituric acid reactive substances (TBARS) from sodium benzoate under the influence of the free oxygen radicals derived from Fenton's reaction. A solution of 1 mmol/litre uric acid was used as standard. RESULTS: The following mean (SD) antioxidative activities were found (as uric acid) in the various biological fluids: serum, 2.04 (0.20) mmol/litre; urine, 176.5 (25.6) micromol/litre; cerebrospinal fluid, 95.0 (26.9) micromol/litre; aqueous humour oculi, 61.25 (9.9) micromol/litre; saliva, 838.5 (48.2) micromol/litre; tears, 247.0 (17.0) micromol/litre; ascites fluid, 270.0 (63.3) micromol/litre; kidney cyst fluid, 387.1 (28.1) micromol/litre. Small samples of the biological material were needed for the analyses: 10 microl of serum and 50-100 microl of other body fluids. In the sera of 48 healthy individuals there was a significant positive correlation between values obtained with the Randox method (as a reference method) and the new method proposed here (correlation coefficient, 0.8728; mean difference between methods, <0.4%). CONCLUSIONS: This method is easy, rapid, reliable, and practical for the routine measurement of total antioxidant activity in serum and other human body fluids. Small samples of biological material are needed for the analyses and the results are comparable with the reference (Randox) method.