1.Mechanism of Ferroptosis in Cerebral Ischemia-reperfusion and Interventional Mechanism of Huoxue Huayu Jiedu Prescription Based on "Blood Stasis and Toxin" Pathogenesis
Jiayue HAN ; Danyi PAN ; Jiaxuan XIAO ; Yuchen LIU ; Jiyong LIU ; Yidi ZENG ; Jinxia LI ; Caixing ZHENG ; Hua LI ; Wanghua LIU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(8):51-60
ObjectiveTo explore the material basis of the "interaction of blood stasis and toxin" mechanism in cerebral ischemia-reperfusion injury, as well as the protective role of Huoxue Huayu Jiedu prescription (HXHYJDF) against ferroptosis. MethodsSixty SPF-grade male SD rats were randomly divided into six groups: sham group, model group, deferoxamine (DFO) group (100 mg·kg-1), low-dose HXHYJDF group (4.52 g·kg-1), medium-dose HXHYJDF group (9.04 g·kg-1), and high-dose HXHYJDF group (18.07 g·kg-1), with ten rats in each group. Except for the sham group, the other groups were used to replicate the model of focal cerebral ischemia-reperfusion in the middle cerebral artery of rats by the reforming Longa method. Neurological function was assessed at 1st, 3rd, 5th, and 7th days post-reperfusion using the modified neurological severity scores (m-NSS). Brain tissue pathology and the morphology of mitochondria were observed using hematoxylin-eosin (HE) staining and transmission electron microscopy. The contents of malondialdehyde (MDA), glutathione (GSH), divalent iron ions (Fe2+), and reactive oxygen species (ROS) in the ischemic cerebral tissue were detected using enzyme-linked immunosorbent assay (ELISA). Immunohistochemistry and Western blot (WB) were used to detect the expression of iron death marker proteins glutathione peroxidase 4 (GPX4), ferroportin-1 (FPN1), transferrin receptor protein 1 (TfR1), and ferritin mitochondrial (FtMt) in brain tissue. ResultsCompared with the sham group, the mNSS score of the model group was significantly increased (P<0.01). HE staining showed that the number of neurons in the cortex of brain tissue was seriously reduced, and the intercellular space was widened. The nucleus was fragmented, and the cytoplasm was vacuolated. The results of transmission electron microscopy showed that the mitochondria in the cytoplasm contracted and rounded, and the mitochondrial cristae decreased. The matrix was lost and vacuolated, and the density of the mitochondrial bilayer membrane increased. The results of ELISA showed that the content of GSH decreased significantly (P<0.01), and the contents of MDA, Fe2+, and ROS increased significantly (P<0.01). The results of immunohistochemistry and WB showed that the expression of GPX4 and FPN1 proteins was significantly decreased (P<0.01), and the expression of FtMt and TfR1 proteins was significantly increased (P<0.01). Compared with those of the model group, the m-NSS scores of the high-dose and medium-dose HXHYJDF groups began to decrease on the 3rd and 5th days, respectively (P<0.05, P<0.01). The results of HE and transmission electron microscopy showed that the intervention of HXHYJDF improved the pathological changes of neurons and mitochondria. The results of ELISA showed that the content of GSH in the medium-dose and high-dose HXHYJDF groups increased significantly (P<0.01), and the contents of MDA, Fe2+, and ROS decreased significantly (P<0.05, P<0.01). The content of GSH in the low-dose HXHYJDF group increased significantly (P<0.01), and the contents of MDA and ROS decreased significantly (P<0.01). The results of immunohistochemistry showed that the expression of GPX4 and FPN1 in the high-dose HXHYJDF group increased significantly (P<0.01), and the expression of FtMt and TfR1 decreased significantly (P<0.01). The expression of GPX4 and FPN1 in the medium-dose HXHYJDF group increased significantly (P<0.05), and the expression of TfR1 decreased significantly (P<0.01). WB results showed that the expression levels of FPN1 and GPX4 proteins in the high-dose, medium-dose, and low-dose HXHYJDF groups were significantly up-regulated (P<0.01), and the expression levels of FtMt and TfR1 proteins were significantly down-regulated (P<0.01). ConclusionHXHYJDF can significantly improve neurological dysfunction symptoms in rats with cerebral ischemia-reperfusion injury, improve the pathological morphology of the infarcted brain tissue, and protect the brain tissue of rats with cerebral ischemia-reperfusion injury to a certain extent. Neuronal ferroptosis is involved in cerebral ischemia-reperfusion injury, with increased levels of MDA, Fe2+, ROS, and TfR1 and decreased levels of FtMt, FPN1, GPX4, and GSH potentially constituting the material basis of the interaction of blood stasis and toxin mechanism in cerebral ischemia-reperfusion injury. HXHYJDF may exert brain-protective effects by regulating iron metabolism-related proteins, promoting the discharge of free iron, reducing brain iron deposition, alleviating oxidative stress, and inhibiting ferroptosis.