Frankincense improves memory retrieval and down-regulates the hippocampal synaptophysin mRNA during the development of the rat brain

Frankincense expands memory performance in different experimental models of learning. Nevertheless, the causal molecular mechanisms have not been well investigated. The expression levels of some of the synaptic proteins might probably change following the consumption of frankincense. The present study investigated the effect of maternal injection of frankincense during gestation and lactation periods on memory performance and the mRNA expression levels of syntaxin1A and synaptophysin in the hippocampus of the offspring rats.

Adult female Wistar rats weighing 180-220g received two doses (50 or 100mg/kg) of the aqueous extract of frankincense by gavage during gestation and lactation periods for 45 consecutive days, except three days after labor. The control group received water. Spatial memory was assessed in the male offspring rats using the Morris water maze. Quantitative PCR was used to measure mRNAs expression levels of syntaxin1A and synaptophysin.

Frankincense improved spatial memory retrieval in the offspring rats. Data analysis by one-way ANOVA demonstrated that frankincense did not change the expression levels of the hippocampal syntaxin1A mRNA in the offspring rats. However, it significantly decreased the expression levels of the hippocampal synaptophysin mRNA.

The results indicate that consumption of frankincense during both gestation and lactation periods has a beneficial impact on spatial memory performance, which is accompanied by the down-regulation of the hippocampal synaptophysin mRNA. Nevertheless, this down-regulation did not change the improving effect of frankincense in memory.