Researchers from the University of Colorado Anschutz Medical Campus (Aurora, Colorado, USA) have identified a biomarker in plasma that may be utilized to predict the onset or progression of chronic seizures following an epileptogenic injury.
The study, recently published in Redox Biology, was designed to determine if the ratio of reduced and oxidized forms of an amino acid, cysteine and cystine respectively, could serve as an accurate biomarker for epilepsy.
For the investigation, the team utilized rat models of epilepsy and HPLC with electrochemical detection to measure plasma cysteine/cystine ratios.
Seizures were chemically-induced in the kainic acid and pilocarpine rat models of epilepsy, which were then monitored for behavioral changes. Plasma was then withdrawn from the rats 48 hours and 12 weeks after treatment to mimic acute and chronic epileptic conditions.
The results demonstrated that cysteine/cystine ratio was an accurate redox biomarker for epilepsy. Plasma cysteine/cystine was reduced by over 60% in rats that displayed acute epileptic responses and over 37% in rats that exhibited chronic epilepsy.
Furthermore, the team discerned that the cysteine/cystine ratio was unaltered in rats that received treatment with an antioxidant known to prevent epileptic brain injury.
The observations of the investigation suggest the decrease of cysteine and ratio of cysteine/cystine in plasma may have the capacity to serve as biomarkers in temporal lobe epilepsy.
“Currently the field of epilepsy lacks peripheral blood-based biomarkers that could predict the onset or progression of chronic seizures following an epileptogenic injury,” commented Manisha Patel (University of Colorado School of Pharmacy and SFRBM member).
“We are confident that this study is a significant step toward changing this, and will one day help those living with temporal lobe epilepsy.”
Sources: Liang L, Patel M. Plasma cysteine redox couple disruption in animal models of temporal lobe epilepsy. Redox. Bio. doi: 10.1016/j.redox.2016.05.004 (2016) (Epub ahead of print); https://www.eurekalert.org/pub_releases/2016-10/uoca-rbc100516.php