Neuroprotective effects of tannic acid against kainic acid-induced seizures in mice

Abstract

Background: Epileptic seizures are associated with the release of potentially neurotoxic amount of glutamate, which results in the over-production of free radicals and inflammatory factors, and induction of neuronal cell death. Current study evaluated the effect of tannic acid (TA) on Kainic acid (KA)-induced seizures in mice.

Methods: Mice were divided into the six groups. Group I was administrated with normal saline (NS; 1 mL/kg, intraperitoneally (i.p.)), Group II was injected with KA (15 mg/kg, i.p.), Groups III was treated with diazepam (DZ; 20 mg/kg, i.p.) and KA (15 mg/kg, i.p.), Groups IV-VI were treated with TA (25, 50 and 100 mg/kg, i.p.) and KA (15 mg/kg, i.p.). Animals received all treatments 30 min before injection of KA. After the injection of KA, mice were observed for seizure (latency, activity and duration) and mortality for 2 h. In the brain tissue, oxidative stress, apoptosis, and inflammatory markers were evaluated in addition to the determination of histological alterations in the CA1 molecular layer of hippocampus.

Results: Treatment with TA significantly increased seizure latency and decreased seizure duration and activity, but could not significantly decrease mice mortality. This effect was associated with the reduction of oxidative stress, inflammation, and apoptosis. Furthermore, treatment with TA significantly improved KA-induced pyramidal cell loss and change in the arrangement of CA1 molecular layer.

Conclusions: Tannic acid may be useful in the control of epileptic seizures through regulating oxidative stress, inflammation and apoptosis.

Keywords: apoptosis; epilepsy; inflammation; kainic acid; oxidative stress; pharmacology; seizures; tannic acid.