J Y Li

Publications (3)5.02 Total impact

• Source

  Available from: thaiscience.info

  Article: The toxic effects and fate of intravenously administered zearalenone in goats.

  M Dong, X J He, P Tulayakul, J-Y Li, K-S Dong, N Manabe, H Nakayama, S Kumagai
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  ABSTRACT: To clarify the toxic effects and fate of zearalenone (ZEA) in ruminants, we studied histopathological changes and toxicokinetic profiles in goats administered with a single intravenous (iv) injection of ZEA at doses of 2.4 mg/kg bw and 1.2 mg/kg bw, respectively. The expression of the mRNA of estrogen receptor (ER) alpha and beta in tissues was also investigated. The histopathological study revealed that ZEA caused hepatocellular swelling and lymphocytic infiltration in the liver, kidney, and uterus. The expression of ERalpha mRNA was enhanced by ZEA in association with the histopathological changes, indicating the possible involvement of ERalpha in the toxic effects of ZEA. For toxicokinetic profiles, blood plasma, urine, and feces were collected consecutively after iv injection of ZEA and analyzed for ZEA and its metabolites with high performance liquid chromatography (HPLC). alpha-Zearalenol (ZOL) and beta-ZOL were detected with ZEA, but alpha-zearalanol (ZAL), beta-ZAL, and zearalanone were below the detection limits. The distribution half-life (t(1/2alpha)) and elimination half-life (t(1/2beta)) of ZEA were 3.15 and 28.58h, respectively. ZEA, alpha-ZOL, and beta-ZOL were excreted in urine and feces, with beta-ZOL being the predominant metabolite. The ZEA and ZOL in urine were largely in their glucuronide and/or sulphate conjugated forms, while those in feces were largely in their free forms. This study showed the toxic effect of zearalenone and its metabolites, and their pharmacokinetic characteristics in goats.
  Toxicon 10/2009; 55(2-3):523-30. · 2.51 Impact Factor
• Source

  Available from: aseanfood.info

  Article: The effect of feeding piglets with the diet containing green tea extracts or coumarin on in vitro metabolism of aflatoxin B1 by their tissues.

  P Tulayakul, K S Dong, J Y Li, N Manabe, S Kumagai
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  ABSTRACT: To clarify whether enzymes involved in aflatoxin B1 (AFB1) metabolism in pigs respond to antioxidant agents, the effect of feeding piglets with diets containing green tea extracts (Sunphenon) and coumarin on in vitro AFB1 metabolism by their liver and intestinal tissues was studied. The results showed that coumarin reduced AFB1-DNA adduct formation by both liver and intestinal microsomes, while Sunphenon did not have any effects. Both coumarin and Sunphenon enhanced the glutathione S-transferase (GST) activity to conjugate AFB1 to glutathione GSH in the intestine, although no effects were noted in the liver. Changes of the expression of mRNA of GSTA2 and GSTO1 were not in parallel with the observed changes of GST activity, suggesting that other GST subtypes are involved in the GST activity toward AFB1. As for lipophilic-free AFB1 metabolites, coumarin reduced the liver microsomal conversion of AFB1 to aflatoxin M1 (AFM1) and aflatoxin Q1 (AFQ1), but Sunphenon exerted no effects. Both coumarin and Sunphenon enhanced the conversion of AFB1 to aflatoxicol in the liver. All the results suggest that feeding with a diet containing coumarin affects AFB1 metabolism to enhance AFB1 detoxification through the suppression of P450 enzyme activity in the liver and the enhancement of GST activity in the intestine. Feeding with a diet containing Sunphenon enhances AFB1 detoxification, but the effects are noted mainly in the intestine.
  Toxicon 10/2007; 50(3):339-48. · 2.51 Impact Factor
• Article: The toxic effects and fate of intravenously administered zearalenone in goats

  M. Dong, X.J. He, P. Tulayakul, J.-Y. Li, K.-S. Dong, N. Manabe, H. Nakayama, S. Kumagai
  [show abstract] [hide abstract]
  ABSTRACT: To clarify the toxic effects and fate of zearalenone (ZEA) in ruminants, we studied histopathological changes and toxicokinetic profiles in goats administered with a single intravenous (iv) injection of ZEA at doses of 2.4 mg/kg bw and 1.2 mg/kg bw, respectively. The expression of the mRNA of estrogen receptor (ER) α and β in tissues was also investigated. The histopathological study revealed that ZEA caused hepatocellular swelling and lymphocytic infiltration in the liver, kidney, and uterus. The expression of ERα mRNA was enhanced by ZEA in association with the histopathological changes, indicating the possible involvement of ERα in the toxic effects of ZEA. For toxicokinetic profiles, blood plasma, urine, and feces were collected consecutively after iv injection of ZEA and analyzed for ZEA and its metabolites with high performance liquid chromatography (HPLC). α-Zearalenol (ZOL) and β-ZOL were detected with ZEA, but α-zearalanol (ZAL), β-ZAL, and zearalanone were below the detection limits. The distribution half-life (t1/2α) and elimination half-life (t1/2β) of ZEA were 3.15 and 28.58 h, respectively. ZEA, α-ZOL, and β-ZOL were excreted in urine and feces, with β-ZOL being the predominant metabolite. The ZEA and ZOL in urine were largely in their glucuronide and/or sulphate conjugated forms, while those in feces were largely in their free forms. This study showed the toxic effect of zearalenone and its metabolites, and their pharmacokinetic characteristics in goats.
  Toxicon.