Study on protective effect of ketogenic diet against hippocampal neurons of kainic acid-induced epileptic rats

Abstract

Objective To investigate the protective effects of ketogenic diet on hippocampal neurons of kainic acid (KA)-induced epileptic rats.  Methods A total of 40 healthy male specific pathogen free (SPF) Sprague-Dawley (SD) rats were randomly divided into 4 groups, with each group containing 10 rats. Epileptic rat models were formed by injection of KA through lateral ventricle with brain stereotactic instrument. According to Racine classification, epileptic seizures in rats above grade Ⅳ were defined successful. Then the rats were given different dietary treatment: Group C with normal saline and normal diet, Group K with normal saline and ketogenic diet, Group E with KA and normal diet, Group EK with KA and ketogenic diet. All rats were observed for 21 d, and were recorded each body weight. The epileptic seizure frequency and duration were observed at 12:00-15:00 daily. At the 21st day, all rats were put to death, and the brain hippocampus tissues were separated. Neuron injury of rat hippocampal CA3 region in Group E and EK was observed by HE staining. Normal neuron number of rat hippocampal CA3 region in Group E and EK was counted by Nissl staining. Results Group C and K had no epileptic seizures, and the neuron number in hippocampal CA3 region was normal. Rats in both Group E and EK had grade Ⅳ or Ⅴ seizures. The number of seizures in Group EK [(17.90 ± 4.12) times] after 21-day ketogenic diet was decreased significantly compared to Group E [(30.50 ± 4.40) times] after 21-day normal diet (t = 6.606, P = 0.000). The seizure duration in Group EK [(212.70 ± 17.75) s] after 21-day ketogenic diet was shortened compared to Group E [(335.00 ± 14.21) s] after 21-day normal diet (t = 17.011, P = 0.000). The normal neuron number in hippocampal CA3 region in Group EK (117.67 ± 7.51) was more than those in Group E (71.33 ± 6.11), with statistically significant difference (t = 9.614, P = 0.000).  Conclusions Ketogenic diet has protective effect on hippocampal neurons of kainic acid-induced epileptic rats.

DOI: 10.3969/j.issn.1672-6731.2015.11.011