Comparison of intranasal and intraperitoneal administration of Eugenia caryophyllata (clove) essential oil on spatial memory, anxiety-like behavior and locomotor activity in a pilocarpine-induced status epilepticus rat model

BACKGROUND: Epilepsy induces behavioral effects and histological changes in the hippocampus. Eugenol, the main component of clove essential oil, has modulatory effects on seizure. We aimed to investigate the effect of intraperitoneal (IP) and intranasal (IN) clove essential oil on cognitive and histological changes during the chronic phase of temporal lope epilepsy. METHODS: Male Wistar rats were divided into eight groups of seven including control, pilocarpine (PLC), clove oil (IP and IN), sesame oil (IP and IN), phenobarbital (positive control) and saline. Rats were injected with 350 mg/kg PLC to induce status epilepticus (SE). We evaluated the effects of 14 days IP (0.1 ml/kg) and IN (0.02 ml/kg) administration of clove essential oil on locomotor/explorative activity, anxiety-like behavior, spatial recognition memory, and hyperexcitability, as well as hippocampal cell survival in PLC-treated rats. RESULTS: Our findings indicated that clove oil could effectively ameliorate PLC-induced behavioral deficits, and also alleviate neuronal death in the cornu ammonis 1 (CA1) region of the hippocampus. Behavioral results as in the Y-maze, Open field and elevated plus maze featured significant differences between control and treated groups. Post-seizure behavioral battery (PBSS) results explicated that behavioral hyperexcitability were less in clove oil groups (both IN and IP) compared to PLC-treated rats. Moreover, results of this study demonstrated that IN administration of clove oil was more potent in alleviating behavioral impairment at a lower dosage than by IP route. The results of this study, also demonstrated that intranasal administration of clove oil could reduce duration of recurrent seizures. CONCLUSION: In summary, clove oil treatment ameliorated histopathological and behavioral consequences of PLC-induced SE.