Methanolic Extract of Citrullus lanatus Seed Ameliorates Sodium Benzoate-Induced Memory Impairment, Anxiety Disorder, and Histoarchitectural Disruptions in Rattus norvegicus Frontal-Lobe Cortex

Sodium-benzoate (SB) is a widely used food preservative whose effects on health, especially on the memory and nervous system, are quite controversial. This study investigated the neuroprotective effects of Citrullus lanatus (C. lanatus) seed methanolic-extract on SB-induced memory/anxiety disorder in Rattusnorvegicus along with its effects on the histoarchitecture of cerebral-frontal lobe. Fifty-six Wistar rats were divided into seven groups. Group A served as control; SB-treated groups (B, D, F) were administered 200mg, 647mg and 900mg/kg body weight (bw) of SB orally respectively for 21 days; while the extract-treated group (C, E, G) received 150mg, 500mg and 800mg/kgbw of extract respectively for 14 days (orally), following SB-exposure for 21days. Neurobehavioral tests (open field and Y-maze test) were conducted to assess anxiety and memory functions, after which, the animals were sacrificed at the end of the 35-day experiment, after which histological investigations were done. SB caused increased anxiety levels, impairment in memory functions, neuron degeneration and vacoulation of varying degrees, in the frontal-lobe cortex of the treated rats, from histological findings. Administration of methanolic-extract of C. lanatus seed revitalized the degenerated neurons, ameliorated memory function impairment, but could not reduce the anxiety level. This study showed that extracts of C. lanatus seeds conferred corrective and neuroprotective effects on the treated rats. The extract served as a negative-effect-lowering agent with respect to the silent accumulative effects of SB on the neurons.