THE INFLUENCE OF COOKING ON THE NEUROPROTECTIVE PROPERTIES OF SOME PEPPER VARIETIES (Capsicum spp) IN SCOPOLAMINE-INDUCED NEUROTOXICITY IN RATS

Abstract

This study evaluated the influence of cooking on the neuroprotective properties of two pepper (Bird and Cayenne pepper) varieties in scopolamine-induced neurotoxic rats. Rats were pre-treated with dietary inclusions of 2% Bird pepper (BP) and Cayenne pepper (CP) (raw and cooked) for 21 days, after which neurotoxicity was induced by single administration (i.p) of scopolamine (1 mg/kg body weight). Thereafter, the spatial working memory of the rats was evaluated, after which the rats were sacrificed to isolate the brain tissue. The activities of acetylcholinesterase (AChE), Ecto-Nucleoside triphosphate diphosphohydrolase (E-NTPDase), Ecto-5' nucleotidase (E-NTDase), as well as the malondialdehyde (MDA) content of their brain homogenates were determined. Furthermore, the effect of cooking on the Vit C and carotenoid contents of the pepper samples was determined. Also, the GC-MS capsinoid characterization of the pepper samples (raw and cooked) was determined. The result showed that dietary inclusions of BP and CP significantly ameliorated (p < 0.05) the memory index induced by scopolamine. Also, the results showed that the significant elevations in the activities of brain AChE, E-NTDase, E-NTPDase and malondialdehyde (MDA) content induced by scopolamine were significantly (p < 0.05) reversed in rats pre-treated with dietary inclusions of studied pepper. However, there was no significant difference (p > 0.05) in the ameliorative effects of the cooked pepper samples on scopolamine-induced impaired memory index, enzyme activities and MDA contents, compared to the raw samples. Furthermore, the Vit C and carotenoid contents in both samples were not significantly affected by cooking. In addition, capsaicin, dihydrocapsaicin and 8-Nordihydrocapsaicin were the main capsaicinoids found in the raw, as well as the cooked samples. This study therefore, revealed that pre-treatment with dietary inclusions of BP and CP significantly ameliorated scopolamine-induced impaired cognitive function, neuronal enzyme activities and MDA content. However, these ameliorative effects were not significantly influenced by cooking suggesting that this processing method could conserve the neuroprotective properties of these pepper varieties.