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The article investigates various mechanisms through which Arabidopsis thaliana plant's knockout mutant of a sulfate transporter acquires tolerance to the element selenium. It reports that selenate induces chlorosis and decreases chlorophyll contents as well as increases activities of ascorbate peroxidase, catalase, and peroxidase enzymes. It suggest that sulfate transporter mutation confers selenium tolerance by decreasing symplastic selenium and maintenance of antioxidant enzyme activities.

The article presents a study on artificial food colorants, which inhibit superoxide production of differentiated HL-60 cells. It notes on the experimental test on the 12 synthetic food colorants for their antioxidant possibilities through the in vitro superoxide generation assay in differentiated HL-60 cells. It is found out that among the colorants, rose bengal revealed potent inhibitory action without cytotoxicity.

The article presents a study on the effects of exogenous proline and glycinebetaine (betaine) on apoplastic flow in rice plants. The effects are determined through an apoplastic tracer composed of trisodium-8-hydroxy-1,3,6-pyrenetrisulphonic acid (PTS). It finds that rice plants absorb more TPS during light than dark condition. Salt stress increases Na+ of rice while proline and betaine decreases sodium (Na)+ and increase potassium (K)+.

The article presents a study on HL-60 cells with the induction of apoptosis by ß-carotene and dimethyl tetrasulfide with the help of ultraviolet A irradiation. It notes that Ultraviolet A (UVA) constitutes more than 90% of environmentally relevant solar UV radiation. However, UVA plays an important role in the initiation of photodamage. The results of the study show that ß-carotene was significantly degraded by UVA.

The article presents a study regarding epigallocathechin-3-gallate (EGCG). The study aims to evaluate the cytotoxicity using benzyl isothiocyanate (BITC) and hydrogen peroxide. Researchers state that cytotoxicity is inhibited by extracellular signal-regulated protein kinase (ERK) and c-jun N-terminal kinase (JNK).

The article investigate the effects of dimethyl monosulfide, dimethyl disulfide, dimethyl trisulfide and dimethyl tetrasulfide on apoptosis induction in human leukemia Jurkat cells and HL-60 cells. It notes that the study aims to provide better understanding of the biological function of dimethyl disulfides. The results reveal that dimethyl sulfides with a larger number of sulfur atoms more strongly induced apoptosis in both HL cells via ROS production and caspase-3 activation.

The article investigates the role of glutathione (GSH) in stomatal movements using the chlorinal-1 GSH-deficient mutant. It includes an in-depth analysis of the role of deficient GSH in guard cells in facilitating stomatal closure that is induced by abscisic acid, as well as a discussion on the issues' implications for the biological sciences.

The article discusses the study on structure-dependent photodegradation of carotenoids. The study aims to identify the pigments that are favorable to accelerated degradation due to sulfides under ultraviolet-a (UVA) irradiation. Crocetin and crocin decompose more rapidly with dimethyl tetrasulfide than cyanidin, while kuromanin and keracyanin were not affected. The results suggest that conjugated double bonds are favorable to accelerated photodegradation by sulfide as mediated by free radicals.

The article investigates the photodegradation of carotenoids by UVA irradiation in the presence of sulfides. The sulfides accelerated the photodegradation of carotenoids. The acceleration effect depended on light intensity, temperature, and the initial concentrations of າ-carotene and sulfide.

Describes a simple and sensitive specrophotometric method combined with solid-phase extraction (SPE) for the simultaneous determination of sodium linear-dodecyl-benzenesulfonate (DBS) and sodium dodecyl sulfate (SDS). Conditioning and washing of the SPE cartridge; Effect of the sample volume and effect of the concentration of methanol as the eluent; Application of the proposed method to the simultaneous determination of DBS and SDS in river-water samples.

Examines mushroom tyrosinase inhibitory activity of esculetin isolated from seeds of Euphorbia lathyris L. Use of silica gel column chromatography.

Studies the degradation of ethyl docosahexaenoate (DHA-Et) by γ-Ray irradiation and the suppression of degradation by antioxidants. High degradation rate of DHA-Et embedded in liposomes than DHA-Et dissolved in ethanol; Suppression of DHA-Et degradation embedded in liposomes by antioxidants; Recognition of hydrophobicity of an antioxidant as one of the determinants for antioxidative activity.

Investigates the reduction in photostability by the esterification of beta-Cryptoxanthin. Degradation rates of beta-cryptoxanthin palmitate and acetate faster than that of beta-cryptoxanthin.

Abstract: In the present study, we found that (−)-epigallocatechin-3-gallate (EGCG) significantly up-regulated the mRNA expression of the Th1/Th2 cytokines including IL-2, IFN-γ, IL-5 and IL-13 in Jurkat T cells. The EGCG-induced mRNA up-regulation of IL-2 and IL-5 was predominantly affected by the extracellular signal-regulated protein kinase (ERK) signalling, whereas IL-13 gene expression, the most responsive to the EGCG treatment, was dependent on neither ERK nor c-jun NH2-terminal kinase (JNK) signalling. IFN-γ gene expression was partially mitigated by both inhibitors of the ERK and JNK pathways. Furthermore, catalase significantly attenuated the intracellular peroxide production, phosphorylation of ERK and JNK, and all cytokine gene expressions induced by EGCG. In addition, physiologically relevant concentrations of both EGCG and H2O2-induced up-regulation of IL-5 gene expression. Our findings provide biological evidence that EGCG induces Th1/Th2 cytokine mRNA expression via H2O2 production followed by activation of ERK or JNK in Jurkat T cells. [Copyright &y& Elsevier]

Abstract: We found that glutathione (GSH) is involved in abscisic acid (ABA)-induced stomatal closure. Regulation of ABA signaling by GSH in guard cells was investigated using an Arabidopsis mutant, cad2-1, that is deficient in the first GSH biosynthesis enzyme, γ-glutamylcysteine synthetase, and a GSH-decreasing chemical, 1-chloro-2,4-dinitrobenzene (CDNB). Glutathione contents in guard cells decreased along with ABA-induced stomatal closure. Decreasing GSH by both the cad2-1 mutation and CDNB treatment enhanced ABA-induced stomatal closure. Glutathione monoethyl ester (GSHmee) restored the GSH level in cad2-1 guard cells and complemented the stomatal phenotype of the mutant. Depletion of GSH did not significantly increase ABA-induced production of reactive oxygen species in guard cells and GSH did not affect either activation of plasma membrane Ca2+-permeable channel currents by ABA or oscillation of the cytosolic free Ca2+ concentration induced by ABA. These results indicate that GSH negatively modulates a signal component other than ROS production and Ca2+ oscillation in ABA signal pathway of Arabidopsis guard cells. [Copyright &y& Elsevier]

Summary: Environmental stress, including heavy metal stress, can cause oxidative damage to plants. Up-regulation of the antioxidant defense system induced by proline and glycinebetaine (betaine) alleviates the damaging effects of oxidative stress in plants. Here, we investigated the protective effects of exogenously applied proline and betaine on growth, accumulation of proline and betaine, lipid peroxidation and activity of antioxidant enzymes in cultured tobacco Bright Yellow-2 (BY-2) cells exposed to cadmium (Cd) stress. Cadmium stress (at 100μM Cd) caused a significant inhibition of the growth of BY-2 cells, and both proline and betaine significantly mitigated this inhibition. In addition, the mitigating effect of proline was more pronounced than that of betaine. Cadmium stress leads to an accumulation of Cd and endogenous proline in cultured cells, increased lipid peroxidation and peroxidase (POX) activity, and decreased activity of superoxide dismutase (SOD) and catalase (CAT). Exogenous application of proline resulted in a decrease in lipid peroxidation and an increase in SOD and CAT activities without reducing Cd contents under Cd stress, while application of betaine resulted in a decrease in lipid peroxidation and an increase in CAT activity with reducing Cd accumulation. Furthermore, exogenous proline and betaine intensified the accumulation of proline and betaine in Cd-stressed BY-2 cells, respectively. The present study suggests that proline and betaine confer tolerance to Cd stress in tobacco BY-2 cells by different mechanisms. [Copyright &y& Elsevier]

Summary: Salt stress causes oxidative damage and cell death in plants. Plants accumulate proline and glycinebetaine (betaine) to mitigate detrimental effects of salt stress. The aim of this study was to investigate the protective effects of proline and betaine on cell death in NaCl-unadapted tobacco (Nicotiana tabacum) Bright Yellow-2 suspension-cultured cells subjected to salt stress. Salt stress increased reactive oxygen species (ROS) accumulation, lipid peroxidation, nuclear deformation and degradation, chromatin condensation, apoptosis-like cell death and ATP contents. Neither proline nor betaine affected apoptosis-like cell death and G1 phase population, and increased ATP contents in the 200mM NaCl-stressed cells. However, both of them effectively decreased ROS accumulation and lipid peroxidation, and suppressed nuclear deformation and chromatin condensation induced by severe salt stress. Evans Blue staining experiment showed that both proline and betaine significantly suppressed increment of membrane permeability induced by 200mM NaCl. Furthermore, among the ROS scavenging antioxidant defense genes studied here, mRNA levels of salicylic acid-binding (SAbind) catalase (CAT) and lignin-forming peroxidase (POX) were found to be increased by proline and betaine under salt stress. It is concluded that both proline and betaine provide a protection against NaCl-induced cell death via decreasing level of ROS accumulation and lipid peroxidation as well as improvement of membrane integrity. [Copyright &y& Elsevier]

Abstract: Docosahexaenoic acid (22: 6n-3; DHA) is a long chain polyunsaturated fatty acid that exists highly enriched in fish oil, and it is one of the low molecular weight food chemicals which can pass a blood brain barrier. A preliminary survey of several fatty acids for expression of growth-associated protein-43 (GAP-43), a marker of axonal growth, identified DHA as one of the most potent inducers. The human neuroblastoma SH-SY5Y cells exposed to DHA showed significant and dose-dependent increases in the percentage of cells with longer neurites. To elucidate signaling mechanisms involved in DHA-enhanced basal neuritogenesis, we examined the role of extracellular signal-regulated kinase (ERK)1/2 and intracellular reactive oxygen species (ROS) production using SH-SY5Y cells. From immunoblotting experiments, we observed that DHA induced the ROS production, protein tyrosine phosphatase inhibition, mitogen-activated protein kinase (MAPK)/ERK kinase (MEK) phosphorylation, and sequentially ERK1/2 phosphorylation, the last of which was significantly reduced by MEK inhibitor U0126. Both antioxidants and MEK inhibitor affected DHA-induced GAP-43 expression, whereas the specific PI3K inhibitor LY294002 did not. We found that total protein tyrosine phosphatase activity was also downregulated by DHA treatment, which was counteracted by antioxidant pretreatment. These results suggest that the ROS-dependent ERK pathway, rather than PI3K, plays an important role during DHA-enhanced neurite outgrowth. [Copyright &y& Elsevier]

Summary: Salt stress impairs reactive oxygen species (ROS) and methylglyoxal (MG) detoxification systems, and causes oxidative damage to plants. Up-regulation of the antioxidant and glyoxalase systems provides protection against NaCl-induced oxidative damage in plants. Thiol–disulfide contents, glutathione content and its associated enzyme activities involved in the antioxidant defense and glyoxalase systems, and protein carbonylation in tobacco Bright Yellow-2 cells grown in suspension culture were investigated to assess the protection offered by proline and glycinebetaine against salt stress. Salt stress increased protein carbonylation, contents of thiol, disulfide, reduced (GSH) and oxidized (GSSG) forms of glutathione, and the activity of glutathione-S-transferase and glyoxalase II enzymes, but decreased redox state of both thiol–disulfide and glutathione, and the activity of glutathione peroxidase and glyoxalase I enzymes involved in the ROS and MG detoxification systems. Exogenous application of proline or glycinebetaine resulted in a reduction of protein carbonylation, and in an increase in glutathione redox state and activity of glutathione peroxidase, glutathione-S-transferase and glyoxalase I under salt stress. Neither proline nor glycinebetaine, however, had any direct protective effect on NaCl-induced GSH-associated enzyme activities. The present study, therefore, suggests that both proline and glycinebetaine provide a protective action against NaCl-induced oxidative damage by reducing protein carbonylation, and enhancing antioxidant defense and MG detoxification systems. [Copyright &y& Elsevier]

Summary: Up-regulation of the antioxidant system provides protection against NaCl-induced oxidative damage in plants. Antioxidants and activity of enzymes involved in the ascorbate–glutathione (ASC–GSH) cycle in tobacco Bright Yellow-2 (BY-2) were investigated to assess the antioxidant protection offered by exogenous proline and glycinebetaine (betaine from now on) against salt stress using cells grown in suspension culture. Reduced ascorbate (ASC) was detected in BY-2 cells but dehydroascorbate (DHA) was not. Large quantities of a reduced form of glutathione (GSH) and smaller quantities of an oxidized form of glutathione (GSSG) were detected in BY-2 cells. Salt stress significantly reduced the contents of ASC and GSH as well as activities of ASC–GSH cycle enzymes such as ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR). Exogenous proline or betaine increased the activities of all enzymes except MDHAR involved in NaCl-induced ASC–GSH cycle. Levels of ASC and GSH in BY-2 cells under salt stress were lower in the presence of proline or betaine than in the absence of proline or betaine whereas there was no difference in redox status. Proline proved more effective than betaine in maintaining the activity of enzymes involved in NaCl-induced ASC–GSH cycle. Neither proline nor betaine had any direct protective effect on NaCl-induced enzyme activity involved in the antioxidant system; however, both improved salt tolerance by increasing enzyme activity. The present study, together with our earlier findings [Hoque MA, Okuma E, Banu MNA, Nakamura Y, Shimoishi Y, Murata Y. Exogenous proline mitigates the detrimental effects of salt stress more than exogenous betaine by increasing antioxidant enzyme activities. J Plant Physiol 2006;164:553–61.], suggests that proline offered greater protection against salt stress than betaine did because proline was more effective in increasing the activity of enzymes involved in the antioxidant system. [Copyright &y& Elsevier]

Summary: Proline and betaine accumulate in plant cells under environmental stresses including salt stress. Here, we investigated effects of proline and betaine on the growth and activities of antioxidant enzymes in tobacco Bright Yellow-2 (BY-2) culture cells in suspension under salt stress. Both proline and betaine mitigated the inhibition of growth of BY-2 cells under salt stress and the mitigating effect of proline was more than that of betaine. Salt stress significantly decreased the activities of superoxide dismutase (SOD), catalase and peroxidase in BY-2 cells. Exogenous application of proline or betaine alleviated the reduction in catalase and peroxidase activities but not SOD activity under salt stress. In addition, proline was found to be effective in alleviating the inhibition of salt stress-induced catalase and peroxidase activities in BY-2 cells. Neither proline nor betaine directly scavenged superoxide (O2 −) or hydrogen peroxide (H2O2). It is concluded that exogenous proline mitigates the detrimental effects of salt stress more than exogenous betaine because of its superior ability to increase the activities of antioxidant enzymes. [Copyright &y& Elsevier]

We tested synthetic food colorants for their antioxidative potential by the in vitro superoxide generation assay in differentiated HL-60 cells in response to phorbol ester. Among the 12 colorants tested, such fluorescein-type red colorants as rose bengal showed potent inhibitory activity without any cytotoxicity under dark conditions. The intracellular accumulation and superoxide anion scavenging effect of rose bengal were at least partly involved in the inhibitory activity.

The application of exogenous proline and glycinebetaine (betaine) confers salt tolerance on plants under salt stress. The effects of exogenous proline and betaine on apoplastic flow in rice plants under saline conditions were investigated using trisodium-8-hydroxy-1,3,6-pyrenetrisulphonic acid (PTS), an apoplastic tracer. Rice plants took up more PTS under light conditions than under dark conditions. Salt stress increased PTS uptake and Na(+) content of rice leaves, but did not affect K(+) content, resulting in a lower K(+)/Na(+) ratio. Addition of proline or betaine to the saline medium suppressed Na(+)-induced PTS uptake and Na(+) accumulation, while the K(+) content was slightly increased, which led to a high K(+)/Na(+) ratio under saline conditions. These results suggest that exogenous proline and betaine suppressed Na(+)-enhanced apoplastic flow to reduce Na(+) uptake in rice plants.

Cellular phototoxicity induced by UVA irradiation and its potential application to therapy has been reported. In the present study, the induction of apoptosis induced by beta-carotene and dimethyl tetrasulfide (Me(2)S(4)) assisted by UVA irradiation in HL-60 cells was assessed. beta-carotene assisted by UVA significantly decreased the cell viability and induced DNA fragmentation in HL-60 cells. Me(2)S(4) combined with beta-carotene and assisted by UVA significantly inhibited the cell viability, and enhanced the caspase-3 activity which was completely inhibited by N-acety-L-cysteine. beta-carotene was significantly degraded by UVA, but this was not accelerated by Me(2)S(4) in a cell culture system. The photodegradation products of beta-carotene prepared by UVA irradiation regardless of the addition of Me(2)S(4) showed lower cytotoxicity than beta-carotene itself in HL-60 cells. These results suggest that the ROS- and caspase-3-dependent apoptosis induced by beta-carotene and Me(2)S(4) assisted by UVA was due to a synergistic action rather than to the sole effect of the photodegradation products of beta-carotene in HL-60 cells.

In the present study, we found that (-)-epigallocatechin-3-gallate (EGCG) significantly up-regulated the mRNA expression of the Th1/Th2 cytokines including IL-2, IFN-gamma, IL-5 and IL-13 in Jurkat T cells. The EGCG-induced mRNA up-regulation of IL-2 and IL-5 was predominantly affected by the extracellular signal-regulated protein kinase (ERK) signalling, whereas IL-13 gene expression, the most responsive to the EGCG treatment, was dependent on neither ERK nor c-jun NH(2)-terminal kinase (JNK) signalling. IFN-gamma gene expression was partially mitigated by both inhibitors of the ERK and JNK pathways. Furthermore, catalase significantly attenuated the intracellular peroxide production, phosphorylation of ERK and JNK, and all cytokine gene expressions induced by EGCG. In addition, physiologically relevant concentrations of both EGCG and H(2)O(2)-induced up-regulation of IL-5 gene expression. Our findings provide biological evidence that EGCG induces Th1/Th2 cytokine mRNA expression via H(2)O(2) production followed by activation of ERK or JNK in Jurkat T cells.

Organosulfur compounds have been established to possess anticancer effects. To provide a better understanding of the biological function of dimethyl sulfides, dimethyl monosulfide (Me(2)S), dimethyl disulfide (Me(2)S(2)), dimethyl trisulfide (Me(2)S(3)) and dimethyl tetrasulfide (Me(2)S(4)) were used as experimental materials to investigate their effects on apoptosis induction in human leukemia Jurkat cells and HL-60 cells. Treatment with 20 muM dimethyl sulfides for 24 h decreased the viability of both cells. The cell viability-reducing effect of these sulfides was in the following order: Me(2)S(4) asymptotically equal to Me(2)S(3) > Me(2)S(2) asymptotically equal to Me(2)S for Jurkat cells and Me(2)S(4) > Me(2)S(3) > Me(2)S(2) asymptotically equal to Me(2)S for HL-60 cells. Me(2)S(3) and Me(2)S(4) significantly induced DNA fragmentation and caspase-3 activation. The addition of GSH or NAC completely suppressed the sulfide-induced apoptosis. Our results indicate that dimethyl sulfides with a larger number of sulfur atoms more strongly induced apoptosis in both human leukemia cells via ROS production and caspase-3 activation.

(-)-Epigallocatechin-3-gallate (EGCG)-induced apoptosis was along both the extracellular signal-regulated protein kinase (ERK) and c-jun N-terminal kinase (JNK) pathways in Jurkat cells. Co-treatment with EGCG potentiated the cytotoxicity induced by benzyl isothiocyanate (BITC) and H(2)O(2), both being inhibited by ERK and JNK inhibitors. These results suggest the significant role of mitogen-activated protein kinase (MAPK) signaling in the apoptosis induction regulated by EGCG alone and in combination.

In the present study, papaya (Carica papaya) seed and edible pulp were carefully separated and then the contents of benzyl isothiocyanate and the corresponding glucosinolate (benzyl glucosinolate, glucotropaeolin) quantified in each part. The papaya seed with myrosinase inactivation contained >1 mmol of benzyl glucosinolate in 100 g of fresh seed. This content is equivalent to that of Karami daikon (the hottest Japanese white radish) or that of cress. The papaya seed extract also showed a very high activity of myrosinase and, without myrosinase inactivation, produced 460 micromol of benzyl isothiocyanate in 100 g of seed. In contrast, papaya pulp contained an undetectable amount of benzyl glucosinolate and showed no significant myrosinase activity. The n-hexane extract of the papaya seed homogenate was highly effective in inhibiting superoxide generation and apoptosis induction in HL-60 cells, the activities of which are comparable to those of authentic benzyl isothiocyanate.