Title : Seizure activity suppression by antioxidants in a drosophila model of Epilepsy
Abstract:
Epilepsy affects over 50 million people worldwide. Approximately one-third of patients are resistant to current treatments with many experiencing adverse side effects. Mutations in the prickle gene, particularly the prickle-spiny-legs (pksple) isoform in Drosophila, produce spontaneous seizures and ataxia similar to human PRICKLE-associated epilepsy. Because PRICKLE is evolutionarily conserved, Drosophila serves as a powerful model for studying seizure mechanisms and therapeutic strategies.
Previous research has identified a cascade linking oxidative stress to seizure activity. Oxidative stress generates reactive oxygen species (ROS), which damage cellular structures, including mitochondria, and trigger a glial-mediated innate immune response (IIR). This response promotes neuronal death and increases seizure frequency. Notably, oxidative stress precedes IIR activation, suggesting that targeting ROS may interrupt this pathological pathway. Antioxidants (AOs), which neutralize ROS, may therefore reduce seizure susceptibility.
Objective: This study systematically evaluated nine antioxidants to determine their efficacy in suppressing seizures in pksple mutant flies. As oxidative stress is most pronounced during larval stages, treatments were administered across three developmental windows—larval, adult, and combined larval+adult—to assess stage-specific effects on adult seizure outcomes.
Materials and Methods: pksple flies were raised on standard cornmeal medium supplemented with one of nine antioxidants from embryonic stages through 15 days post-eclosion. Compounds included trans-resveratrol, ibuprofen, licofelone, gallic acid, valdecoxib, allyl disulfide, genistein, curcumin, and N-acetyl cysteine (NAC).
Spontaneous seizure activity was assessed using a blinded videographic assay. Individual flies were recorded and analyzed for seizure events. Experiments used 14–16-day-old males, with ≥2 biological replicates and 8–10 flies per replicate. Statistical analysis was performed using Student’s t-test.
Results: Allyl disulfide, ibuprofen, curcumin, and trans-resveratrol significantly reduced seizure penetrance in pksple mutants. Gallic acid showed a strong trend toward significance (p ≈ 0.052), suggesting potential efficacy. In contrast, licofelone, valdecoxib, genistein, and NAC did not significantly reduce seizures. Notably, NAC failed to suppress seizures across all developmental treatment windows, despite its established antioxidant properties.
Discussion: These findings demonstrate that select antioxidants can effectively suppress seizures in a genetic model of epilepsy, supporting oxidative stress as a key driver of seizure pathology. The efficacy of allyl disulfide, ibuprofen, curcumin, and trans-resveratrol highlights their potential as therapeutic candidates, particularly for patients who do not respond to conventional anti-epileptic drugs. The lack of effect from other antioxidants, including NAC, suggests that not all ROS-targeting compounds are equally effective, emphasizing the importance of compound-specific mechanisms.
