Transcriptomic analysis of EGb 761-regulated neuroactive receptor pathway in vivo

EGb 761, a well-defined extract from Ginkgo biloba, has been widely used in patients with cerebral disorders.

Although EGb 761 exhibits neuroprotective effects and exerts beneficial effects on many neurological disorders, its mechanism on the neuronal functions is unclear so far.

In this study, we used oligonucleotide microarray technique to investigate the effect of EGb 761 on the transcriptional profile of mouse genes. RNA samples were obtained from frontal cortex, straitum, and kidneys after the oral administration of EGb 761 for seven consecutive days.

Our data showed that EGb 761 significantly altered the neuroactive ligand-receptor interaction pathway in frontal cortex but not in straitum and kidney. Then we analyzed 26 receptor genes that were significantly altered by EGb 761 in this pathway and found that EGb 761 treatment highly up-regulated the subgroup of dopamine receptors, especially dopamine receptor 1a (Drd1a), in frontal cortex. Quantitative real-time reverse transcription-polymerase chain reaction and immunohistochemical staining confirmed the increased level of Drd1a expression after EGb 761 treatment.

In summary, we investigated for the first time the overall effects of EGb 761 on the gene expression in brain using a powerful systemic biological technique. Our results suggested that EGb 761 altered unique pathways and regulated the expressions of some specific neuronal receptor genes exclusively in frontal cortex.