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.