Huanglian Jiedutang Regulates HIF-1α/VEGF Signaling Pathway to Improve Learning and Memory Abilities of APP/PS1 Transgenic Mice / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo reveal the effects of Huanglian Jiedutang （HLJDT） on the learning and memory abilities of APP/PS1 transgenic mice via hypoxia-inducible factor-1α （HIF-1α）/vascular endothelial growth factor （VEGF） signaling pathway. MethodForty 5-month-old β-amyloid precursor protein （APP）/presenilin 1（PS1） mice were randomized into the model， donepezil （0.001 g·kg-1·d-1）， and low-， medium-， and high-dose （1.5， 3， 6 g·kg-1·d-1， respectively） HLJDT groups， and 8 C57BL/6 mice were taken as the normal group. After 45 days of continuous administration， Morris water maze test was conducted， and the organ indexes were calculated. The morphological structure of cerebral vascular endothelial cells in mice was observed under a transmission electron microscope. Western blot was employed to measure the protein levels of APP， HIF-1α， VEGF，VEGFA， and brain-derived neurotrophic factor （BDNF） in the hippocampus. The mRNA levels of APP， HIF-1α， and VEGF were determined by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. ResultCompared with the normal group， the model group showed prolonged escape latency （P<0.05）， reduced distance and time around the target platform （P<0.05）， decrease brain and spleen indexes （P<0.05）， vascular endothelial cells with karyopyknosis and not abundant cytoplasm， up-regulated protein levels of APP， HIF-1α， VEGF， and VEGFA （P<0.05）， down-regulated protein level of BDNF （P<0.05）， and up-regulated mRNA levels of APP， HIF-1α， and VEGF （P<0.05） in the hippocampus. Compared with the model group， high-dose HLJDT shortened the escape latency （P<0.05）， increased the distance and time around the target platform （P<0.05）， raised the brain and spleen indexes （P<0.05）， repaired the organelles of vascular endothelial cells， down-regulated the protein levels of APP， HIF-1α， VEGF， and VEGFA （P<0.05）， up-regulated the protein level of BDNF （P<0.05）， and down-regulated the mRNA levels of APP， HIF-1α， and VEGF （P<0.05） in the hippocampus. ConclusionHLJDT can improve the learning and memory abilities of mice by reducing the expression of HIF-1α and VEGF， thus protecting the nerves.