Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P17174 (aspartate aminotransferase)
 14,872 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this work, 100 living related donor kidney transplant recipients under cyclosporin (CsA) therapy were randomly distributed to two groups. Group 1 were administered ketoconazole, with group 2 serving as the control. Ketoconazole was given orally, 100 mg/day, while the dose of CsA was adjusted for a CsA whole blood trough level of 100-150 ng/ml. Patients and controls were assessed regularly in an outpatient clinic for 12 months and compared statistically for CsA dose, graft and liver functions, cholesterol, blood sugar, CsA nephrotoxicity, acute rejection episodes, chronic rejection and fungal skin infections. Statistical analysis showed a significant reduction in the CsA dose in the ketoconazole-treated group (73-76%), along with significantly lower alanine aminotransferase, aspartate aminotransferase, bilirubin, and serum creatinine values. CsA chronic nephrotoxicity and chronic rejections were also significantly lower in the ketoconazole-treated group, as was fungal skin infection (6.6 vs 63.2%). From this study, we conclude that addition of a low dose of ketoconazole to CsA-treated kidney transplant recipients not only saves costs, but may also have a favorable effect on graft function, chronic CsA nephrotoxicity, chronic rejection and fungal skin infection.
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PMID:Coadministration of ketoconazole to cyclosporin-treated kidney transplant recipients: a prospective randomized study. 854 71

Dauricine is the major bioactive component isolated from the roots of Menispermum dauricum D.C. and has shown promising pharmacological activities with a great potential for clinic use. However, the adverse effects and toxicity of the alkaloid are unfortunately ignored. The objective of the current study was to evaluate the toxicity of dauricine in vitro and in vivo. Mice (CD-1) were treated intraperitoneally with dauricine at various doses, and sera and lung lavage fluids were collected after 24 h of treatment. No changes in serum aspartate aminotransferase, alanine aminotransferase, and blood urea nitrogen were noticed, whereas a dose-dependent increase in lactate dehydrogenase activity was observed in lung lavage fluids. Ethidium-based staining studies showed that remarkable cells lost membrane integrity in the lungs of the animals treated with dauricine at 150 mg/kg. Histopathological evaluation of lungs of mice showed that dauricine at the same dose caused significant alveolar edema and hemorrhage. Exposure to dauricine at 40 muM for 24 h resulted in up to 60% cell death in human lung cell lines BEAS-2B, WI-38, and A549. Ketoconazole showed protective effect on the pulmonary injury in mice given dauricine. A quinone methide metabolite of dauricine was identified in mouse lung microsomal incubations, and the presence of ketoconazole in the microsomal incubations suppressed the formation of the quinone methide metabolite. In conclusion, dauricine produced pulmonary injury in CD-1 mice. The pulmonary toxicity appears to depend on the metabolism of dauricine mediated by CYP3A. The electrophilic quinone methide metabolite probably plays an important role in the pulmonary toxicity induced by dauricine.
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PMID:Pulmonary toxicity and metabolic activation of dauricine in CD-1 mice. 2000 63

Columbin, a furanoid compound, is the major bioactive ingredient of Tinospora sagittata (Oliv.) Gagnep, a traditional Chinese medicine that has been reported to cause liver injury in the clinic. The aim of this study was to investigate the hepatotoxicity caused by columbin and its underlying mechanism. Our results indicated that columbin could result in a dose-dependent increase of mice serum alanine aminotransferase and aspartate aminotransferase after oral treatment with columbin, as well as local spotty necrosis in the liver of mice treated with columbin. No hepatotoxicity was observed in mouse treated with the same dose of tetrahydrocolumbin. Pretreatment with ketoconazole preserved the mice from columbin-induced hepatotoxicity. Further studies suggested that bioactivation of the furan ring played an indispensable role in columbin-caused hepatotoxicity. In vitro and in vivo metabolism studies demonstrated that columbin could be metabolized into the cis-butene-1,4-dial intermediate, which readily reacted with glutathione and N-acetyllysine to form stable adducts. Ketoconazole displayed strong inhibitory effect on the generation of M4 and M5 both in vitro and in vivo. Further recombinant human CYP450 screening demonstrated that CYP3A4 was the major enzyme responsible for columbin bioactivation. The present study demonstrated that columbin was hepatotoxic and CYP3A4-mediated bioactivation of the furan ring would serve as an underlying mechanism for columbin-induced hepatotoxicity.
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PMID:Cytochrome P450 Enzyme-Mediated Bioactivation as an Underlying Mechanism of Columbin-Induced Hepatotoxicity. 3216 8

Fraxinellone, a furanoid, is one of the bioactive and potentially hepatotoxic constituents from Dictamnus dasycarpus Turcz, which is extensively spread throughout Asian countries. This herb was reported to cause liver injury in clinical application. However, the mechanism behind is still not fully understood. This study mainly focused on the hepatotoxicity of fraxinellone and the underlying mechanism. The current study demonstrated that fraxinellone resulted in a significant elevation of serum alanine aminotransferase and aspartate aminotransferase in a dose-dependent manner in mice after oral administration. Pretreatment with ketoconazole for three successive days could significantly alleviate the hepatotoxicity of fraxinellone. Considering that fraxinellone has a structural alert of furan ring, it is believed that the hepatotoxicity caused by fraxinellone required cytochrome P450-mediated bioactivation. Bioactivation studies were subsequently carried out in vitro and in vivo. Fraxinellone was metabolized into cis-enedial intermediate, an electrophile that was prone to react with glutathione or N-acetyl-lysine through 1,2- or 1,4-addition to form stable conjugates. Ketoconazole significantly inhibited the formation of the glutathione conjugates (M1 and M2) in microsomal incubation and similar finding was obtained in vivo. Phenotyping study indicated that CYP3A4 was the principal enzyme responsible for the bioactivation of fraxinellone. This study suggested that CYP3A4-mediated bioactivation plays an indispensable role in fraxinellone-induced hepatotoxicity. The work performed herein enables us to better understand the hepatotoxicity of fraxinellone as well as the mechanism behind.
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PMID:Cytochrome P450-Mediated Bioactivation: Implication for the Liver Injury Induced by Fraxinellone, A Bioactive Constituent from Dictamni Cortex. 3248 42