OBJECTIVE

This study is aimed to determine the metabolomic effects of the hybrid medicine formula Yi-Qi-Bu-Shen (YQBS) on the neurotransmitter aspects of cognitive impairment in diabetic rats.

METHODS

In the current study, streptozotocin (STZ) was used to induce diabetic animal model in male Sprague Dawley (SD) rats. After successful establishment of diabetic SD rats' model, age-matched healthy SD rats and diabetic SD rats were treated with low and high doses of YQBS, and then tested for learning memory ability and analyzed for pathological changes. In addition, neurotransmitter metabolic changes in hippocampal subdivisions of rats from different treated groups were analyzed using liquid chromatography-mass spectrometry (LC-MS) technique.

RESULTS

YQBS could significantly improve memory-cognitive impairment in diabetic rats as evidenced by the shortening of latency to target and the reduction of latency first entrance to target. Moreover, YQBS also improved the pathological alterations in the hippocampal region in the brains of diabetic rats. Metabolomic analysis showed that the expression of noradrenaline hydrochloride was down-regulated and the expressions of levodopa and 5-hydroxytryptophan were up-regulated in the hippocampal tissues of diabetic rats treated with YQBS.

CONCLUSION

These findings demonstrate that YQBS has protective effects against diabetic cognitive dysfunction, which might act through alteration in tyrosine and tryptophan metabolism.