Turmeric (Curcuma longa L.) Extract may Prevent the Deterioration of Spatial Memory and the Deficit of Estimated Total Number of Hippocampal Pyramidal Cells of Trimethyltin-Exposed Rats.

Context: Protection of neurons from degeneration is an important preventive strategy for dementia. Much of the dementia pathology implicates oxidative stress pathways. Turmeric (Curcuma longa L.) contains curcuminoids which has anti-oxidative and neuro-protective effects. These effects are considered to be similar to those of citicoline which has been regularly used as one of standard medications for dementia. Objective: This study aimed at investigating the effects of turmeric rhizome extract on the hippocampus of trimethyltin (TMT)-treated Sprague-Dawley rats. Materials and methods: The rats were divided randomly into six groups, i.e., a normal control group (N); Sn group, which was given TMT chloride; Sn-Cit group, which was treated with citicoline and TMT chloride; and three Sn-TE groups, which were treated with three different dosages of turmeric rhizome extract and TMT chloride. Morris water maze test was carried out to examine the spatial memory. The estimated total number of CA1 and CA2–CA3 pyramidal cells was calculated using a stereological method. Results: The administration of turmeric extract at a dose of 200 mg/kg bw has been shown to prevent the deficits in the spatial memory performance and partially inhibit the reduction of the number of CA2–CA3 regions pyramidal neurons. Discussion: TMT-induced neurotoxic damage seemed to be mediated by the generation of reactive oxygen species and reactive nitrogen species. Turmeric extract might act as anti inflammatory as well as anti-oxidant agent. Conclusions: The effects of turmeric extract at a dose of 200 mg/kg bw seem to be comparable to those of citicoline. Keywords: Curcuma longa L.; trimethyltin; Morris water maze; pyramidal cell; stereolog