The Experts below are selected from a list of 486 Experts worldwide ranked by ideXlab platform

M. Hirose - One of the best experts on this subject based on the ideXlab platform.

  • A subchronic toxicity study of dunaliella carotene in F344 rats
    Food and Chemical Toxicology, 2006
    Co-Authors: Y. Kuroiwa, Akiyoshi Nishikawa, Takayoshi Imazawa, Yasuki Kitamura, Keita Kanki, Yuji Ishii, Takashi Umemura, M. Hirose
    Abstract:

    Abstract Dunaliella carotene, extracted from dunaliella alga ( Dunaliella bardawil or Dunaliella salina ), for use as a Food-Coloring Agent, has β-carotene as its mainly constituent. As there have been no reports of toxicological evaluation, a 90-day subchronic toxicity study was here performed in F344 rats at dose levels of 0 (control), 0.63%, 1.25%, 2.5% and 5% in powdered basal diet. The average daily intakes of dunaliella carotene were 352, 696, 1420 and 2750 mg/kg/day, respectively, for males, and 370, 748, 1444 and 2879 mg/kg/day for females. No mortality or treatment-related clinical signs were observed throughout the experimental period in any of the groups. Body weight gain was slightly but significantly ( p

  • A subchronic toxicity study of shea nut color in Wistar rats.
    Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 2003
    Co-Authors: Yasuki Kitamura, Akiyoshi Nishikawa, Takayoshi Imazawa, Takashi Umemura, Fumio Furukawa, Nakamura H, Kazushi Okazaki, M. Hirose
    Abstract:

    Shea nut color, obtained from nuts of the shea tree (Butyrospermum parkii), is used as a Food-Coloring Agent. Flavonoid pigments are considered to be the responsible constituents. As there have been no reports of toxicological evaluation, a 13-week subchronic toxicity study was performed in Wistar Hannover rats at dose levels of 0 (control), 0.07, 0.31, 1.25 and 5% in powdered basal diet. The average of daily shea nut color intake was 51.3, 226.1, 986.8 and 3775.5 mg/kg/day for males and 56.4, 272.9, 1166.7 and 4387.7 mg/kg/day for females, respectively. During the administration period, daily observation of clinical signs and weekly measurement of body weights and Food consumption were performed. After the end of the treatment, hematology, serum biochemistry, organ weight and histopathological examinations were conducted. No significant toxicological changes were observed in any parameters in this study. Hence, the no adverse effect dose of shea nut color was estimated to be greater than 5.0% for both sexes (3775.5 mg/kg/day for males and 4387.7 mg/kg/day for females).

Kei Matsueda - One of the best experts on this subject based on the ideXlab platform.

  • oral administration of a Food Coloring Agent tartrazine enhances the development of hapten induced colitis and delays its healing in rats
    Gastroenterology, 2000
    Co-Authors: Ryosuke Shoda, Masayuki Uchida, Kei Matsueda
    Abstract:

    Background: Trinitrobenzene sulfonic acid (TNBS) is a hapten and its rectal admi nistration with ethanol induce s immunologically mediated colitis (TNBS-induced colitis). The colitis has been extensively used as an animal model for Crohn's disease. On the other hand, several Food Coloring Agents are still popularly used in the world, and they are known to be metabolized into hapten(s) by intestinal bacteria. For example, one of the most popular and commercially available tartrazine is metabol ized into sulfanilic acid which has a typical structure of hapten. Therefore, oral intake of such Coloring Agents may induce and/or aggrava te the immunologically mediated colitis. Aim: Aims of this study were 10 investigate whether oral administration of tartrazine influences the development of hapten-induced colitis by utilizing its metabolite, sulfanilic acid, in rats. Materials and Methods: 4 week old male SD-rats were used (20 animalsl each group). 25 mg/mllday of tartrazine was gavaged into the stomach for 12 days before the colitis induction in group I. The same amount of distilled water was given for the control animals (group 2). Sulfanili c acid-induced colitis was made by the intracolonic injection of 0.1 ml of saturated sulfanilic acid in 50% ethanol. 6 rats leach group were sacrificed to observe colonic ulcer index on the day 4 after the colitis induction . Then a half of remaining rats (7) in group 1 started to have tartrazine again for 6 additional days and all of the animals were sacrificed for measuring colonic ulcer index on the day 10. A half of the rats (7) in group 2 were also given tartrazine from the day 4 to the day 9 before sacrifice. Results: Rats in group 1 had significantly higher ulcer index than those in group 2 in the acute phase on the day 4 after the co litis induction (2 1.5::'::4.7 vs 4. 1::':: 1.1, pUlcer healing was significantly delayed in rats with than without tartrazine re-trea tment in group I (3.0 ::':: 1.1 vs 0.8::'::0.3, p< 0.05). There was no effect of tartrazine treatment on the ulcer healing of controls (group 2). Discussion & Conclusions: The results of the present study demonstrated that oral administratio n of tartrazine enhanced acute ulcer development and also delayed its healing in rat colitis induced by sulfanilic acid, which is a hapten and the metabolite of tartrazine itself. These results suggest that oral intake of Coloring Agents, such as tartrazine, may play an important role in the pathogenesis of inflammatory bowel disease.

  • Oral administration of a Food Coloring Agent, tartrazine, enhances the development of hapten-induced colitis and delays its healing in rats
    Gastroenterology, 2000
    Co-Authors: Ryosuke Shoda, Masayuki Uchida, Tsunematsu, Kei Matsueda
    Abstract:

    Background: Trinitrobenzene sulfonic acid (TNBS) is a hapten and its rectal admi nistration with ethanol induce s immunologically mediated colitis (TNBS-induced colitis). The colitis has been extensively used as an animal model for Crohn's disease. On the other hand, several Food Coloring Agents are still popularly used in the world, and they are known to be metabolized into hapten(s) by intestinal bacteria. For example, one of the most popular and commercially available tartrazine is metabol ized into sulfanilic acid which has a typical structure of hapten. Therefore, oral intake of such Coloring Agents may induce and/or aggrava te the immunologically mediated colitis. Aim: Aims of this study were 10 investigate whether oral administration of tartrazine influences the development of hapten-induced colitis by utilizing its metabolite, sulfanilic acid, in rats. Materials and Methods: 4 week old male SD-rats were used (20 animalsl each group). 25 mg/mllday of tartrazine was gavaged into the stomach for 12 days before the colitis induction in group I. The same amount of distilled water was given for the control animals (group 2). Sulfanili c acid-induced colitis was made by the intracolonic injection of 0.1 ml of saturated sulfanilic acid in 50% ethanol. 6 rats leach group were sacrificed to observe colonic ulcer index on the day 4 after the colitis induction . Then a half of remaining rats (7) in group 1 started to have tartrazine again for 6 additional days and all of the animals were sacrificed for measuring colonic ulcer index on the day 10. A half of the rats (7) in group 2 were also given tartrazine from the day 4 to the day 9 before sacrifice. Results: Rats in group 1 had significantly higher ulcer index than those in group 2 in the acute phase on the day 4 after the co litis induction (2 1.5::'::4.7 vs 4. 1::':: 1.1, p

Shigeru Ohta - One of the best experts on this subject based on the ideXlab platform.

  • Production of superoxide radical in reductive metabolism of a synthetic Food-Coloring Agent, indigocarmine, and related compounds.
    Life sciences, 2005
    Co-Authors: Yoichi Kohno, Shigeyuki Kitamura, Tsuyoshi Yamada, Kazumi Sugihara, Shigeru Ohta
    Abstract:

    Indigocarmine, which is widely used as a synthetic colouring Agent for Foods and cosmetics in many countries, was reduced to its leuco form and decolorized by rat liver microsomes with NADPH under anaerobic conditions. The reductase activity was enhanced in liver microsomes of phenobarbital-treated rats, and inhibited by diphenyliodonium chloride, a NADPH-cytochrome P450 reductase (P450 reductase) inhibitor, but was not inhibited by SKF 525-A or carbon monoxide. Indigocarmine reductase activity was exhibited by purified rat P450 reductase. In contrast, when indigocarmine was incubated with rat liver microsomes and NADPH under aerobic conditions, superoxide radical was produced and its production was inhibited by superoxide dismutase and diphenyliodonium chloride. When indigocarmine was incubated with purified rat P450 reductase in the presence of NADPH, superoxide radical production was enhanced 17.7-fold (similar to the enhancement of indigocarmine-reducing ability) as compared with that of rat liver microsomes. A decrease of one molecule of NADPH was accompanied with formation of about two molecules of superoxide radical. P450 reductase exhibited little reductase activity towards indigo and tetrabromoindigo, which also afforded little superoxide radical under aerobic conditions. These results indicate that indigocarmine is reduced by P450 reductase to its leuco form, and superoxide radical is produced by autoxidation of the leuco form, through a mechanism known as futile redox cycling.

Yasuki Kitamura - One of the best experts on this subject based on the ideXlab platform.

  • A subchronic toxicity study of dunaliella carotene in F344 rats
    Food and Chemical Toxicology, 2006
    Co-Authors: Y. Kuroiwa, Akiyoshi Nishikawa, Takayoshi Imazawa, Yasuki Kitamura, Keita Kanki, Yuji Ishii, Takashi Umemura, M. Hirose
    Abstract:

    Abstract Dunaliella carotene, extracted from dunaliella alga ( Dunaliella bardawil or Dunaliella salina ), for use as a Food-Coloring Agent, has β-carotene as its mainly constituent. As there have been no reports of toxicological evaluation, a 90-day subchronic toxicity study was here performed in F344 rats at dose levels of 0 (control), 0.63%, 1.25%, 2.5% and 5% in powdered basal diet. The average daily intakes of dunaliella carotene were 352, 696, 1420 and 2750 mg/kg/day, respectively, for males, and 370, 748, 1444 and 2879 mg/kg/day for females. No mortality or treatment-related clinical signs were observed throughout the experimental period in any of the groups. Body weight gain was slightly but significantly ( p

  • A subchronic toxicity study of shea nut color in Wistar rats.
    Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 2003
    Co-Authors: Yasuki Kitamura, Akiyoshi Nishikawa, Takayoshi Imazawa, Takashi Umemura, Fumio Furukawa, Nakamura H, Kazushi Okazaki, M. Hirose
    Abstract:

    Shea nut color, obtained from nuts of the shea tree (Butyrospermum parkii), is used as a Food-Coloring Agent. Flavonoid pigments are considered to be the responsible constituents. As there have been no reports of toxicological evaluation, a 13-week subchronic toxicity study was performed in Wistar Hannover rats at dose levels of 0 (control), 0.07, 0.31, 1.25 and 5% in powdered basal diet. The average of daily shea nut color intake was 51.3, 226.1, 986.8 and 3775.5 mg/kg/day for males and 56.4, 272.9, 1166.7 and 4387.7 mg/kg/day for females, respectively. During the administration period, daily observation of clinical signs and weekly measurement of body weights and Food consumption were performed. After the end of the treatment, hematology, serum biochemistry, organ weight and histopathological examinations were conducted. No significant toxicological changes were observed in any parameters in this study. Hence, the no adverse effect dose of shea nut color was estimated to be greater than 5.0% for both sexes (3775.5 mg/kg/day for males and 4387.7 mg/kg/day for females).

Akiyoshi Nishikawa - One of the best experts on this subject based on the ideXlab platform.

  • A subchronic toxicity study of dunaliella carotene in F344 rats
    Food and Chemical Toxicology, 2006
    Co-Authors: Y. Kuroiwa, Akiyoshi Nishikawa, Takayoshi Imazawa, Yasuki Kitamura, Keita Kanki, Yuji Ishii, Takashi Umemura, M. Hirose
    Abstract:

    Abstract Dunaliella carotene, extracted from dunaliella alga ( Dunaliella bardawil or Dunaliella salina ), for use as a Food-Coloring Agent, has β-carotene as its mainly constituent. As there have been no reports of toxicological evaluation, a 90-day subchronic toxicity study was here performed in F344 rats at dose levels of 0 (control), 0.63%, 1.25%, 2.5% and 5% in powdered basal diet. The average daily intakes of dunaliella carotene were 352, 696, 1420 and 2750 mg/kg/day, respectively, for males, and 370, 748, 1444 and 2879 mg/kg/day for females. No mortality or treatment-related clinical signs were observed throughout the experimental period in any of the groups. Body weight gain was slightly but significantly ( p

  • A subchronic toxicity study of shea nut color in Wistar rats.
    Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 2003
    Co-Authors: Yasuki Kitamura, Akiyoshi Nishikawa, Takayoshi Imazawa, Takashi Umemura, Fumio Furukawa, Nakamura H, Kazushi Okazaki, M. Hirose
    Abstract:

    Shea nut color, obtained from nuts of the shea tree (Butyrospermum parkii), is used as a Food-Coloring Agent. Flavonoid pigments are considered to be the responsible constituents. As there have been no reports of toxicological evaluation, a 13-week subchronic toxicity study was performed in Wistar Hannover rats at dose levels of 0 (control), 0.07, 0.31, 1.25 and 5% in powdered basal diet. The average of daily shea nut color intake was 51.3, 226.1, 986.8 and 3775.5 mg/kg/day for males and 56.4, 272.9, 1166.7 and 4387.7 mg/kg/day for females, respectively. During the administration period, daily observation of clinical signs and weekly measurement of body weights and Food consumption were performed. After the end of the treatment, hematology, serum biochemistry, organ weight and histopathological examinations were conducted. No significant toxicological changes were observed in any parameters in this study. Hence, the no adverse effect dose of shea nut color was estimated to be greater than 5.0% for both sexes (3775.5 mg/kg/day for males and 4387.7 mg/kg/day for females).