Nigella sativa oil ingestion mitigates aluminum chloride induced cerebella oxidative, neurogenic damages and impaired motor functions in rats

Abstract

Varying neurological effects, and impairments to motor functions, neurochemistry and neuromorphology have been associated with Aluminium  chloride (AlCl₃) induced neurotoxicity. This study aims to investigate the efficacy of Nigella sativa oil (NSO) in AlCl₃ induced cerebellar toxicity in rats.  Thirty-two male Wistar rats were randomly divided into four groups and received: normal saline; 100 mg/kg.bw of AlCl₃; 100 mg/kg.bw AlCl₃ and 1  ml/kg.bw of NSO; and 1 ml/kg.bw, orally and daily for fourteen days. On the 13th day of the experiment, the rats were each exposed to a single trial  of the Open Field Test (OFT), of which line crossing frequency, rearing frequency, and freezing period were recorded as measures of exploratory and  locomotive behaviours of the animals. By day 15, the rats were euthanized, their brains were excised, the cerebellum dissected from five brains of  each group, and homogenized for iochemical evaluations of nitric oxide (NO) metabolites and total reactive oxygen species (ROS) levels. The  remaining three brains in each group were processed for histology and Ki67 immunohistochemistry investigations. The results of this study shows  that AlCl₃ impaired motor related behaviours in the AlCl₃ exposed animals, by significantly reducing the line crossing and rearing frequencies, and  increasing the freezing period. This effect was observed to be  mitigated in the animal group that received NSO following AlCl₃ administration, as the animals showed improved motor behaviours. AlCl₃ also caused an increase in the cerebellar activities of NO and ROS, while it depleted Ki67  expressions and caused neurodegenerative-like effects in the cerebellar histoarchitecture of the exposed animals. Intervention with NSO depleted ROS/NO levels and protected the cerebellum from the nitrosative and oxidative stress induced by AlCl₃. NSO was also observed to preserve the  cerebellar cortex histoarchitecture and neurogenic morphology against the neurodegenerative effect of AlCl₃. It can be concluded that NSO, with its  high efficacy against oxidative stress and neuroinflammation, is a potent natural therapeutic agent in aluminum and heavy metal neurotoxicity.