Using predictive in vitro assays to measure hepatotoxicity

One of the key challenges that continues to stand in the way of the advancement of drug treatment is the effect that these treatments can have on the human body. Toxicity is one of the major concerns, particularly hepatotoxicity, which takes place in the liver. Around one third of all liver toxicity cases in the United States are said to be caused by pharmaceuticals, and over 1,000 drugs are considered to be harmful to the liver. This presents a significant obstacle to drug development since a new medicine cannot be introduced unless there is sufficient proof that it will not be harmful to the liver. Standards are ever increasing as drugs continue making it onto the market, only later to face recalls due to cases of hepatotoxicity. Because of this increased need to make sure drugs are safe for the liver before their release to the general public, researchers have been working to try and find an effective way to measure a drug's effect on the liver and determine if it could cause hepatotoxicity. However, until now, an effective method has remained elusive. Up until this study, most tests for hepatotoxicity were conducted using either liver cells or cells from humans, rodents or dogs, though the limited availability, high cost, and possibility of individual variation make these methods insufficient and raise the need for more accurate ways of testing the toxicity levels of the liver in relation to drug use.

To accomplish this goal, Sirenko et al. from the University of North Carolina and Molecular Devices LLC. have developed a method for using predictive in vitro assays with Human Induced Pluripotent Stem Cells. This investigative technique provides an improvement over previous methods in that it allows for primary tissue-like phenotypes, eliminates the problem of availability or cost, decreases dependence on humans or animals, and offers the potential to establish genotype-specific cells from different individuals. To test toxicity using a predictive assay, Sirenko and her team studied readings of Ca²⁺ content, cell count, nuclear shape, cell permeability, and mitochondrial membrane potential. For this last variable, they used cell imaging and the fluorescent mitochondrial membrane potential indicator JC-10™. Part of their justification for doing so was the faster loading and incubation time. Instead of needing 72 hours, the JC-10™ indicator only requires an hour . This helps to reduce the chance of interference with the cells and to guarantee more accurate results.

The results of the study indicate that predicative in vitro assays are in fact effective methods of testing hepatotoxicity. They applied their method with several drugs known to cause liver toxicity and were able to verify the effectiveness of the assays in demonstrating harmful effects on the liver. Implications from this study are significant; drug researchers are now getting closer to being able to effectively test for hepatotoxicity, which will aid in making drugs safer for all. By implementing materials such as JC-10™ into the study, researchers were able to clearly read results and be confident in their accuracy because JC-10™ has significantly higher signal to background ratios and does not precipitate easily in aqueous solutions. Thanks to this, results obtained are robust and can be trusted. This is essential as its use in fields like drug testing means the results obtained have implications in the general population who receive medication, assuming it has been accurately tested and is safe for them to take. Studies like these are helping to increase confidence and make drugs safer.

References

---

1. Sirenko, Oksana, et al. "High-content assays for hepatotoxicity using induced pluripotent stem cell–derived cells." Assay and drug development technologies 12.1 (2014): 43-54.