Not only does light exposure influence cell viability, but it can also activate induce cell signaling. Scientists from the Institute of Environmental Medicine determined that a tryptophan-induced photoproduct called 6-Formylindolo [3,2-b] carbazole or FICZ, acts as a ligand to the aryl hydrocarbon receptor (AhR), a transcription factor that induces expression of CYP1A1. This CYP enzyme is involved in many metabolic processes in the liver. Furthermore, the effects of light exposure to culture media is not limited to bacterial and animal cells. Scientists have also found UV and blue wavelengths in unfiltered light inhibits growth of three different plant species.
What type of cell media components are facilitating this process? There are many, but I will mention only a few here.
Riboflavin (vitamin B2): Involved in redox processes for metabolism. Upon exposure to light, riboflavin becomes highly reactive, assisting in redox reactions that generate harmful ROS.
Folic acid (vitamin B9): Acts as a coenzyme in many metabolic reactions. Degradation of folic acid is accelerated by riboflavin in the presence of UV light.
Photoeffects can be reduced if antioxidants are added to the medium and more obviously, if the medium is protected from light as much as possible. It is important to consider these details when planning your experiments so that you do not waste time or effort and can protect your precious cells!
Written by Angela
Scientific Support Specialist
