Neuroprotective effects of Royal Jelly (RJ) against pentylenetetrazole (PTZ)-induced seizures in rats by targeting inflammation and oxidative stress

Abstract

Epilepsy is a chronic neurological condition in which inflammation and oxidative stress play a key role in the pathogenesis. Recently, several studies have suggested that Royal Jelly (RJ) has antioxidant effects. Nevertheless, there is no evidence of its effectiveness against epilepsy. Here, we evaluated its neuroprotective effects at different doses (100 and 200 mg/kg) against pentylenetetrazole (PTZ)-induced seizures. Fifty male Wistar rats were randomly divided into five groups: control, PTZ, RJ100 + PTZ, RJ200 + PTZ and RJ100. In order to establish epilepsy model, 45 mg/kg of PTZ was injected intraperitoneally for 10 consecutive days. Seizure parameters were graded based on Racine's 7-point classification. Elevated-plus maze, Y maze and shuttle box tests were carried out to assess anxiety-like behavior, short-term memory, and passive avoidance memory, respectively. We used ELISA technique to measure the expression of the pro-inflammatory cytokines and oxidative stress factors. Also, neuronal loss in the hippocampal CA3 region was determined using Nissl staining. Our findings showed that PTZ-treated rats had more seizure intensity, anxiety-like behavior, memory dysfunction, higher levels of TNF-α, IL-1β, and oxidative markers. RJ could allay seizure severity and duration. It also improved memory function as well as anxiety level. In terms of biochemical assessment, RJ gave rise to a significant decrease in the level of IL-1β, TNF-α and MDA and it restored the activities of GPX and SOD enzymes. Hence, our study shows that RJ contains anti-inflammatory and antioxidative effects which contribute to less neuronal damage in the PTZ-induced epilepsy model.

Keywords: Epilepsy; Inflammation; Memory function; Oxidative stress; Pentylenetetrazole; Royal jelly.