Nacre extract prevents scopolamine-induced memory deficits in rodents

Objective: To investigate whether the extract from the nacreous layer of pearl oysters (nacre extract) improves impairments in memory caused by scopolamine administration in rodents. Methods: Nacre extract was prepared from the inner shell layer of pearl oyster. Effects of nacre extract on scopolamine-induced memory impairment were estimated using novel object recognition test, Y-maze test, and Barnes maze test. Effect of nacre extract on mRNA expressions which are genes associated with memory in the hippocampus was investigated using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) analysis. Results: Administration of nacre extract led to the protection against scopolamine-induced impairments in object recognition, short-term memory, and spatial memory. Treatment with nacre extract reversed the mRNA expression of brain-derived neurotrophic factor (BDNF) and Homer protein homolog 1 (Homer-la) in the hippocampus, which decreased with the treatment of scopolamine. Conclusions: These results suggest that nacre extract has attenuating effects on memory impairments induced by scopolamine through the increase in mRNA expression of BDNF and Homer-1a.