ABSTRACT
Cerebral ischemia-reperfusion injury （CIRI） has a very high incidence， disability， and mortality rates， which seriously affects human life and health. In recent years， modern medicine has made some progress in the diagnosis and treatment of CIRI， but there are still problems such as difficulties in postoperative rehabilitation and adverse drug reactions， and new therapeutic drugs for CIRI are urgently needed. As an important class of active ingredients in traditional Chinese medicine， flavonoids can play antioxidant， apoptosis inhibition， anti-inflammatory， and other pharmacological effects to improve brain tissue damage， which is important for improving the quality of life of CIRI patients and slowing down the aging of the social population. Numerous studies have found that flavonoids in traditional Chinese medicine can regulate cell surface receptors Toll-like receptor 4/nuclear factor-kappaB （TLR4/NF-κB）， phosphatidylinositol 3-kinase/protein kinase B （PI3K/Akt）， adenylate-activated protein kinase/mammalian target of rapamycin protein （AMPK/mTOR）， Ras homologous gene family member A/Rho-associated coiled-coil protein kinase （RhoA/ROCK）， nuclear factor E2-associated factor 2/Kelch-like epoxychloropropane-associated protein-1/haemoglobin oxygenase 1 （Nrf2/Keap1/ HO-1）， Notch， and other signaling pathways， so as to regulate the transcription and expression of related proteins after CIRI， alleviate brain tissue injury， and improve CIRI. This paper analyzed the relevant literature in China and abroad in recent years， reviewed the mechanism of action and related pathways of flavonoids in traditional Chinese medicine to improve CIRI， and explored the new therapeutic direction of CIRI at the metabolic level， with a view to providing a basis for the further development and application of flavonoids in traditional Chinese medicine.
ABSTRACT
ObjectiveTo decipher the mechanism of Wenxiao powder in alleviating corticosterone-induced depression-like behaviors in mice. MethodMale ICR mice were randomized into normal， model， paroxetine （20 mg·kg-1）， and low- and high-dose （3.27， 6.54 g·kg-1， respectively） Wenxiao powder groups. The mice in normal and model groups received equal volume of saline. Other groups except the normal group were injected with corticosterone subcutaneously 0.5 h after gavage to induce depression. Mice were tested for depression-like behaviors after drug administration. Enzyme-linked immunosorbent assay （ELISA） was performed to measure the corticosterone content in the serum. Nissl staining was performed to observe the damage of hippocampal neurons. Immunofluorescence staining was employed to observe the expression of double cortin （DCX） in the dentate gyrus （DG） of the hippocampus. Western blot was employed to determine the expression of proteins in the brain-derived neurotrophic factor （BDNF）/tyrosine kinase receptor B （TrkB）/extracellular signal-regulated kinase （ERK）/cAMP-response element-binding protein （CREB） pathway in the hippocampus. ResultCompared with the normal group， the model group showed decreased sucrose preference rate， increased immobility time in the tail suspension test （P<0.01）， and reduced residence time in the central area of the open field and the total movement distance （P<0.05， P<0.01）. In addition， the modeling elevated the corticosterone level in the serum （P<0.01）， decreased the volume and intensified the nuclear staining of hippocampal neurons in the DG area， reduced the expression of DCX in the DG area， and down-regulated the protein levels of BDNF， phosphorylated （p）-TrkB， p-ERK， and p-CREB in the hippocampus （P<0.05， P<0.01）. Compared with the model group， low-dose Wenxiao powder improved the mouse behavivors in the sucrose preference， open field， and tail suspension tests （P<0.05， P<0.01）， and high-dose Wenxiao powder improved the behaviors in the sucrose preference and open field tests （P<0.05， P<0.01）. In addition， Wenxiao powder lowered the serum corticosterone level （P<0.01） and recovered the structure and morphology of neurons with obvious nuclei and presence of Nissl bodies in the DG area of the hippocampus. Moreover， Wenxiao powder at both doses promoted the expression of DCX in the DG area， and high-dose Wenxiao powder up-regulated the protein levels of BDNF， p-TrkB， p-ERK， and p-CREB in the hippocampus （P<0.05， P<0.01）. ConclusionWenxiao powder can alleviate corticosterone-induced depression-like behaviors and promote neurogenesis in mice possibly by activating the BDNF/TrkB/ERK/CREB signaling pathway.