Hepatocyte Assays

Regulators are concerned about the potential for environmental chemicals such as agrochemicals/pesticides/industrial chemicals regarding their potential to induce carcinogenesis and/or to perturb hormone systems. All active compounds therefore must be screened for such properties. Concept Life Sciences are experts in regulatory studies for investigative mechanistic toxicology using cryopreserved primary hepatocytes (Rat, Mouse, Human).

We have a team of scientists with expertise in the field offer hepatocyte assays to study effect of test items and establish ‘species-differences’ in mechanism of action (MoA).

• CYP Induction (Enzyme activity and mRNA)
• In Vitro Comparative UDPGT Induction assay
• In Vitro Metabolism
• Mode of Action Studies (Nuclear Receptor Induction CAR/PXR/Ahr/PPARα)
• Cytotoxicity
• Hepatocyte Proliferation (RDS) assays
• Bespoke Hepatocyte studies

Concept Life Sciences offer hepatocyte-based toxicology mode of action and thyroid hormone modulation assays. Such modalities are assessed using the following assays, which were developed in house (bespoke):

Endocrine disruption- and thyroid modulation- assays can be offered GLP or non-GLP, as specified for each.

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Hepatocyte Mode of Action Assays - GLP or non-GLP

In vitro studies using primary hepatocytes aimed at testing the potential of test item in activating the specific nuclear receptors (CAR/PXR/AhR/PPARα). 

In vitro CYP induction investigated using primary rodent and human hepatocytes is designed for mechanism investigation by: 

1. Assessment of induction of CYP (Cytochrome P450) genes by measuring mRNA levels. 
2. Assessment of enzyme activity for specific nuclear receptor activation e.g., CAR/PXR (CYP2B, CYP3A), AhR (CYP1A) and PPARα (CYP4). 
3. Hepatocyte proliferation by evaluating Replicative DNA synthesis by measuring BrdU incorporation in primary hepatocytes.

In Vitro Comparative UDPGT/UGT Induction Assay - GLP or non-GLP

Uridine 5'-diphospho-glucuronosyltransferases (UDPGT/UGTs) are phase II enzymes found in the liver responsible for glucuronidation of metabolites to facilitate their systemic elimination. If UGTs are activated in response to presence of xenobiotics, this eventually leads to decreasing circulating concentrations of TH through induction of thyroxine (T4) glucuronidation. Ultimately, increased secretion of thyroid-stimulating hormone could lead to increased thyroid follicular cell proliferation, hypertrophy and ultimately follicular cell adenomas/carcinomas.

In vitro comparative UGT assays are used to determine if UGT induction is species-specific, and therefore can help determining the possible human relevance of adverse outcomes associated with this mechanism of action. 

UGT Induction assay is designed as an in vitro method for Primary Rat and Human hepatocytes for: 

1. Assessment of induction of CYP (Cytochrome P450) and UGT genes by measuring mRNA levels. 
2. Assessment of enzyme activity by LC-MS/MS bioanalysis of formation of T4-Glucuronide metabolite and T4 clearance in hepatocyte incubates.