Epilepsy is a neurological disorder affecting around 1%–2% of population worldwide and its treatment includes use of antiepileptic drugs to control seizures. Failure to respond to antiepileptic drug therapy is a major clinical problem and over expression of ATP-binding cassette transporters is considered one of the major reasons for pharmacoresistance. In this review, we have summarized the regulation of ABC transporters in response to oxidative stress due to disease and antiepileptic drugs. Further, ketogenic diet and antioxidants were examined for their role in pharmacoresistance. The understanding of signalling pathways and mechanism involved may help in identifying potential therapeutic targets and improving drug response.

ABC transporters have a significant role in drug disposition and response and various studies have implicated their involvement in epilepsy pharmacoresistance. Since genetic studies till now are inconclusive, we thought of investigating the role of xenobiotics as transcriptional modulators of ABC transporters. Here, we investigated the effect of six antiepileptic drugs (AEDs) viz. phenytoin, carbamazepine, valproate, lamotrigine, topiramate and levetiracetam, on the expression and function of ABCB1, ABCC1, ABCC2 and ABCG2 in Caco2 and HepG2 cell lines through real time PCR, western blot and functional activity assays. Further, the interaction of AEDs with maximally induced ABCC2 was studied. Carbamazepine caused a significant induction in expression of ABCB1 and ABCC2 in HepG2 and Caco2 cells, both at the transcript and protein level, together with increased functional activity. Valproate caused a significant increase in the expression and functional activity of ABCB1 in HepG2 only. No significant effect of phenytoin, lamotrigine, topiramate and levetiracetam on the transporters under study was observed in either of the cell lines. We demonstrated the interaction of carbamazepine and valproate with ABCC2 with ATPase and 5,6-carboxyfluorescein inhibition assays. Thus, altered functionality of ABCB1 and ABCC2 can affect the disposition and bioavailability of administered drugs, interfering with AED therapy.

Oxidative stress is known to be associated with epilepsy, and antiseizure medication treatment, albeit with limited consensus on the specific oxidative stress pathways/proteins involved. Identifying these can reveal novel therapeutic targets for epilepsy management. This study utilized network pharmacology to identify potential protein targets of carbamazepine and valproic-acid that are implicated in oxidative stress and epilepsy, thereby highlighting their therapeutic potential. Drug targets for carbamazepine and valproic-acid were predicted using SuperPred/SwissTargetPrediction, while genes associated with epilepsy and oxidative stress were obtained from DisGeNET and GeneCards. Common proteins were identified, and a protein–protein interaction network was constructed using STRING, followed by analysis via Cytoscape. Hub proteins identified were EGFR, GSK3B, and STAT3 for carbamazepine, and PTGS2, mTOR, and TLR4 for valproic-acid. Molecular docking revealed a strong binding affinity of carbamazepine to its targets (ΔG_bind > − 5 kcal/mol) and binding of valproic-acid to its targets (ΔG_bind > − 3 kcal/mol), with PTGS2 showing the strongest interaction with valproic-acid (− 5.06 kcal/mol). These findings underscore EGFR, GSK3B, and STAT3, for carbamazepine and PTGS2, mTOR, and TLR4 for valproic-acid as pivotal therapeutic targets in oxidative stress-associated epilepsy. These identified proteins can be targeted by add on antioxidants to alleviate oxidative stress generated by chronic antiseizure medication.