0000000000968340
AUTHOR
Gabriela Pérez
Customised in vitro model to detect human metabolism-dependent idiosyncratic drug-induced liver injury
Drug-induced liver injury (DILI) has a considerable impact on human health and is a major challenge in drug safety assessments. DILI is a frequent cause of liver injury and a leading reason for post-approval drug regulatory actions. Considerable variations in the expression levels of both cytochrome P450 (CYP) and conjugating enzymes have been described in humans, which could be responsible for increased susceptibility to DILI in some individuals. We herein explored the feasibility of the combined use of HepG2 cells co-transduced with multiple adenoviruses that encode drug-metabolising enzymes, and a high-content screening assay to evaluate metabolism-dependent drug toxicity and to identify…
Mangifera indica L. Extract and Mangiferin Modulate Cytochrome P450 and UDP-Glucuronosyltransferase Enzymes in Primary Cultures of Human Hepatocytes
The aqueous stem bark extract of Mangifera indica L. (MSBE) has been reported to have antioxidant, anti-inflammatory and analgesic properties. In previous studies, we showed that MSBE and mangiferin, its main component, lower the activity of some cytochrome P-450 (P450) enzymes in rat hepatocytes and human liver microsomes. In the present study, the effects of MSBE and mangiferin on several P450 enzymes and UDP-glucuronosyltransferases (UGTs) in human-cultured hepatocytes have been examined. After hepatocytes underwent a 48-h treatment with sub-cytotoxic concentrations of the products (50-250 µg/mL), a concentration-dependent decrease of the activity of the five P450 enzymes measured (CYP1A…
Semi-automatic quantitative RT-PCR to measure CYP induction by drugs in human hepatocytes
An assay has been developed for the quantitative measurement of CYP mRNA content of the major human isoforms (1A1, 1A2, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, 3A4 and 3A5) in human hepatocytes. The method is based on the conversion of mRNAs into their corresponding cDNAs, followed by PCR amplification using appropriate primers. Making use of appropriate internal and external standards it is possible to estimate changes in CYP mRNA content of hepatocytes. The technique has been standardised to run semi-automatically. This procedure can be used to assess the CYP induction potential of new pharmaceuticals at a pre-clinical stage of development. To this aim, human hepatocytes obtained from functional l…
Modulation of biotransformation and elimination systems by BM-21, an aqueous ethanolic extract from Thalassia testudinum, and thalassiolin B on human hepatocytes
Abstract BM-21 is an extract obtained from Thalassia testudinum marine plant with pharmacological properties. The effects of BM-21 and thalassiolin B (TB), its main component, on enzyme and transport proteins involved in drug metabolism and excretion in human cultured hepatocytes were evaluated. Cells were exposed for 48 h to sub-cytotoxic concentrations of BM-21 or TB. Effects on P450 isoforms revealed significant reductions of CYP1A2, 3A4 and 2D6 activities (up to 56%, 66% and 44% inhibition, respectively) after exposition to BM-21, no changes on CYP2A6 and 2C9 activities. TB produced a concentration-dependent reduction of all P450 activities. In addition, a decrease in total UGT and UGT2…