We offer in vitro study to investigate the activity and expression of hepatic phase I and phase II metabolizing enzymes using rat or human liver microtissues
For Phase I liver enzymes
After treatment, both activities and expression levels of cytochrome P450 (CYP) are determined:
(a) Activities of different cytochrome P450 (CYP) isoforms will be determined by incubating liver microtissues with according substrates and determining substrate consumption levels via LC/MS based P450 assays. Activity of seven major cytochrome P450 (CYP) isoforms will be investigated: CYP1A, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6 and CYP3A4. Other isoforms are available if requested.
(b) The expression levels of CYP will be assessed by qRT-PCR analysis or ELISA
For Phase II liver enzymes
After treatment, expression levels of major Phase II enzymes will be determined by ELISA. The major enzymes include: glutathione S-transferases (GST), UDP-glucuronyl transferase (UGT), heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO1), Glutamate-cysteine ligase (GCL), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and glutathione-S-transferases (GSTs), glutathione S-transferase (GST), quinone reductase (QR).
Activity of UGT will be determined via LC/MS based assay.