Effects of an environmental endocrine disruptor, para-nonylphenol on the cell growth of Euglena gracilis: association with the cellular oxidative stress.

Effects of an environmental endocrine disruptor, para-nonylphenol (NP) on the cell growth of a photosynthetic eukaryotic microorganism, Euglena gracilis were analysed under different cell culture conditions. Although NP did not show significant inhibitory effects on the cell growth of E. gracilis (Z and SM strains) under light culture condition, NP exhibited significant suppressive effects under dark culture condition.

Enhancing Effect of a Roasting Treatment on the Radical Scavenging Activity of a Marine Brown Alga Polysaccharide (Alginic acid).

We found an effective roasting method that enhances the effects on various radical scavenging activities of polysaccharide (alginic acid) derived from the marine brown alga Lessonia trabeculata. These enhancing effects were observed by a roasting treatment under relatively high temperature conditions (160ºC and 180ºC), which were measured by (i) a stable radical compound diphenylpicrylhydrazyl (DPPH), (ii) a hydroperoxide generating system of linoleic acid autooxidation, and (iii) an opsonized zymosan (Opz)-induced oxygen radical generating system in human blood neutrophils. Although a significant enhancing effect of the roasting treatment on the radical scavenging activity of the alginic acid itself was not detected under relatively low temperature conditions (100ºC and 130ºC), the roasting treatment of a mixture of alginic acid and several specific amino acids caused considerable radical scavenging activities under the same roasting conditions.

Enhancing Effect on Radical Scavenging Activity of Edible Brown Alga, Laminaria japonica (Ma-konbu) by Roasting Treatment.

Various edible algae have been traditionally consumed as healthy food stuffs in Asian countries such as China, Korea and Japan, and roasting treatments have been carried out on some of these edible algae for the improvement of their taste and flavor. In the present paper, we analyzed the effect of roasting treatments on the radical scavenging activity of a typical Japanese edible brown alga, Laminaria japonica (L. japonica, Ma-konbu).

Potent immunomodulating effects of bran extracts of traditional Japanese millets on nitric oxide and cytokine production of macrophages (RAW264.7) induced by lipopolysaccharide.

To estimate the potent immunomodulating effects of different types of traditional Japanese millet, we analyzed the effect of bran extracts of foxtail millet (Awa in Japanese), barnyard millet (Hie) and proso millet (Mochi-kibi) on nitric oxide (NO) and inflammatory cytokine production induced by lipopolysaccharide (LPS) in a mouse macrophage cell line (RAW264.7 cells). All methanol extracts of these millet brans showed suppressive activities against the production of NO and inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-6 in LPS-stimulated macrophages, which were not responsible for their cytotoxic activities.

Potent antioxidant and radical-scavenging activity of Chenpi--compensatory and cooperative actions of ascorbic acid and citric acid.

Dried peels of Satsuma mandarin (Citrus unshiu Marcov.) have been used as traditional Chinese and Japanese medicine, which are called 'Chenpi'. In our present study, cold and hot water extracts of Chenpi exhibited a strong inhibitory activity against linoleic acid peroxidation and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical-scavenging activity compared with o-methanol extract.

Immunomodulating activities in bran extracts of Japanese red, black and brown rices.

To determine the potent immunomodulating activities of different types of Japanese rice bran, we analyzed the effects of extracts of red, brown and black rice brans on the cell proliferation and cytokine production of mouse immunocompetent cells by cell culture experiments. Methanol extracts of these rice brans showed suppressive activities against the proliferative response (3H-thymidine incorporation) of mouse spleen cells induced by concanavalin A (Con A) or lipopolysaccharide (LPS) in the cell culture experiments. Although the black and brown rice bran extracts showed suppressive effects on the production of interferon gamma (IFN gamma) or interleukin 6 (IL-6) in mouse spleen cells induced by Con A or LPS, the red rice bran extract exhibited stimulatory effects on the same cytokine-producing systems.

Potent antioxidant and radical-scavenging activities of traditional Japanese cereal grains.

To estimate the preventive potential of Japanese traditional cereals against oxygen radical-related chronic diseases such as cardiovascular diseases and diabetes, antioxidant and radical-scavenging activities in the extracts of five Japanese traditional cereal grains were analyzed by using an assay system of lipid peroxidation and a radical compound, 1,1-diphenyl-2-picrylhydrazyl (DPPH). DPPH radical-scavenging activities in the extracts of Japanese cereal grains were divided into two groups. One group including Japanese sorghum, black rice and red rice showed strong radical-scavenging activities, but the other group including Japanese barnyard millet and foxtail millet did not exhibit significant radical-scavenging activities.

Potent radical-scavenging activities of thiamin and thiamin diphosphate.

Various radical-scavenging activities of thiamin and thiamin diphosphate (TDP) were found in some in vitro experiments. Thiamin and TDP caused considerable suppressive effects on superoxide generation in hypoxanthine and xanthine oxidase system which was measured by a sensitive chemiluminescence method using 2-methyl-6-[p-methylphenyl]-3,7-dihydroimidazo[1,2-alpha]pyrazin-3-one (MCLA), and their 50% inhibition (IC(50)) values were estimated to be 158 and 56 microM, respectively. They also showed the significant suppression against hydroperoxide generation derived from oxidized linoleic acid which was estimated by aluminum chloride method and their IC(50) values were calculated to be 260 and 46 microM.

Potentiating effect of an endocrine disruptor, paranonylphenol, on the generation of reactive oxygen species (ROS) in human venous blood -- association with the activation of signal transduction pathway.

An endocrine disruptor, para-nonylphenol (NP), caused a dose-dependent stimulatory effect on the generation of reactive oxygen species (ROS) in human whole blood from 50 to 1000 microM, which was measured by chemiluminescence generation. ROS-scavenging enzymes such as catalase and superoxide dismutase, and the lipophilic antioxidative agents, alpha-tocopherol and beta-carotene, showed preventive effects on NP-induced ROS generation. To analyze the biochemical mechanism of NP-induced ROS generation in human blood, we investigated the effects of different types of metabolic inhibitors on the activation pathways of ROS generation.

Antioxidant and prooxidant activities of B group vitamins in lipid peroxidation.

The antioxidant and prooxidant activities of six B group vitamins against hydroperoxide generation in linoleic acid peroxidation were analyzed by the aluminum chrolide method. The B group vitamins were divided into three types by their antioxidant and prooxidant properties. The first type, including B1, B2 vitamin, nicotinic acid and folic acid, showed prooxidant activities in the early phase (1 week) of the linoleic acid peroxidation at concentrations of 2.

Radical-scavenging activity of hot water extract of Japanese rice bran--association with phenolic acids.

A strong radical-scavenging activity against a stable radical compound, 1,1-diphenyl-2-picrylhydrazyl (DPPH) was found in the hot water extract of Japanese rice bran. When the extract was treated with ethanol, a dominant radical-scavenging activity was observed in the ethanol-soluble (ES) fraction in a dose-dependent manner, but a weak radical-scavenging activity was detected in the ethanol-precipitable (EP) fraction. Their activities were proportional to the amounts of phenolic substances in each fraction.

Potent antioxidative and antigenotoxic activity in aqueous extract of Japanese rice bran--association with peroxidase activity.

To estimate the preventive potential of Japanese rice bran (Oryza sativa japonica) against the oxygen radical-related chronic diseases such as cardio-vascular diseases and cancer, antioxidative and antigenotoxic activities of the rice bran extracts were analyzed by using assay systems for lipid peroxidation and genotoxin-induced umu gene expression. When effects of the rice bran extracts under different extraction conditions on hydroperoxide generation from auto-oxidized linoleic acid were examined using aluminum chloride method, the water extract showed strong antioxidant activity, but the methanol and acetone extracts did not exhibit significant activity. The water extract of rice bran was divided into the ethanol-precipitable (EP) and supernatant fractions, and EP fraction showed the dominant antioxidant activity, but the supernatant fraction did not exhibit significant antioxidant activity.

Effect of endocrine disruptor para-nonylphenol on the cell growth and oxygen radical generation in Escherichia coli mutant cells deficient in catalase and superoxide dismutase.

para-Nonylphenol (NP) had previously been found to have strong suppressive effects of growth of bacterial and yeast cells, and these effects were associated with NP-induced generation of radical oxygen species (ROS). In the present study, we determined that wild-type strains of Escherichia coli (CSH 7, SY-11, and IFO-3545) were resistant to NP compared with other sensitive microorganisms reported previously. To elucidate the relationship between NP-induced ROS generation and cell growth inhibition in more detail, we analyzed the effect of NP on cell growth and survival of wild-type and mutant E.

Enhancing effect of the endocrine disruptor para-nonylphenol on the generation of reactive oxygen species in human blood neutrophils.

Although para-nonylphenol (NP) is known as an endocrine disruptor, the immunologic effect of NP has been poorly analyzed. We found that NP from 5 to 50 microM caused a dose-dependent stimulatory effect on the generation of reactive oxygen species (ROS) in human blood neutrophils, which was measured by using a chemiluminescence reagent, luminol. Furthermore, ROS-scavenging enzymes such as catalase and superoxide dismutase and antioxidative agents alpha-tocopherol and beta-carotene showed strong preventive effects on NP-induced ROS generation.

Potent suppressive activity of fresh and dried peels from Satsuma mandarin Citrus unshiu (Marcorv.) on hydroperoxide generation from oxidized linoleic acid.

The effects of various extracts prepared from fresh and dried peels of Satsuma mandarin (Citrus unshiu Marcov.) on hydroperoxide generation from oxidized linoleic acid were compared under different extraction conditions. The cold-and hot-water extracts of fresh peels showed significant suppressive activity against hydroperoxide generation in a dose-dependent manner.