[Chrysin alleviates cerebral ischemia-reperfusion injury by inhibiting ferroptosis in rats].

The purpose of this study is to investigate whether chrysin reduces cerebral ischemia-reperfusion injury(CIRI) by inhi-biting ferroptosis in rats. Male SD rats were randomly divided into a sham group, a model group, high-, medium-, and low-dose chrysin groups(200, 100, and 50 mg·kg~(-1)), and a positive drug group(Ginaton, 21.6 mg·kg~(-1)). The CIRI model was induced in rats by transient middle cerebral artery occlusion(tMCAO). The indexes were evaluated and the samples were taken 24 h after the operation. The neurological deficit score was used to detect neurological function. The 2,3,5-triphenyl tetrazolium chloride(TTC) staining was used to detect the cerebral infarction area. Hematoxylin-eosin(HE) staining and Nissl staining were used to observe the morphological structure of brain tissues. Prussian blue staining was used to observe the iron accumulation in the brain. Total iron, lipid pero-xide, and malondialdehyde in serum and brain tissues were detected by biochemical reagents. Real-time quantitative polymerase chain reaction(RT-qPCR), immunohistochemistry, and Western blot were used to detect mRNA and protein expression of solute carrier fa-mily 7 member 11(SLC7A11), transferrin receptor 1(TFR1), glutathione peroxidase 4(GPX4), acyl-CoA synthetase long chain family member 4(ACSL4), and prostaglandin-endoperoxide synthase 2(PTGS2) in brain tissues. Compared with the model group, the groups with drug intervention showed restored neurological function, decreased cerebral infarction rate, and alleviated pathological changes. The low-dose chrysin group was selected as the optimal dosing group. Compared with the model group, the chrysin groups showed reduced content of total iron, lipid peroxide, and malondialdehyde in brain tissues and serum, increased mRNA and protein expression levels of SLC7A11 and GPX4, and decreased mRNA and protein expression levels of TFR1, PTGS2, and ACSL4. Chrysin may regulate iron metabolism via regulating the related targets of ferroptosis and inhibit neuronal ferroptosis induced by CIRI.

[Exploration of mechanism of "simultaneous treatment of brain and heart" of Naoxintong Capsules based on Toll-like receptor signaling pathway].

This study aims to explore the mechanism of "simultaneous treatment of the brain and the heart" of Naoxintong Capsules(NXT) under cerebral ischemia based on Toll-like receptor(TLR) signaling pathway.Male SD rats were randomized into sham operation group, model group, NXT group, and positive drug group.Middle cerebral artery occlusion(MCAO) model rats were used in model group, NXT group, and positive drug group, respectively.Neurological function was scored with the Bederson scale, and brain infarct rate was measured by 2,3,5-triphenyltetrazolium chloride(TTC) staining.Brain edema was detected with wet-dry weight method.Hematoxylin-eosin(HE) staining and TdT-mediated dUTP nick-end labeling(TUNEL) staining were used to observe and count apoptotic cardiocytes.In addition, serum myocardial enzymes were measured.The expression of 8 TLR signaling pathway-related proteins interferon-α(IFN-α), interferon regulatory factor-3(IRF3), interferon regulatory factor-7(IRF7), TLR2, TLR4, TLR7, TLR9, and tumor necrosis factor-α(TNF-α) in the cerebral cortex and heart of rats was detected by Western blot. Brain infarct rate, neurological function score, and brain water content in NXT group decreased significantly compared with those in the model group. At the same time, the reduction in apoptosis rate of cardiocytes and the content of serum aspartate aminotransferase(AST), alanine aminotransferase(ALT), creatine kinase(CK), and lactate dehydrogenase(LDH) were decreased in the NXT group.Systems pharmacological results and previous research showed that TLR signaling pathway played an important role in immune inflammatory response.The study of TLR signaling pathway and related proteins is helpful to elucidate the mechanism of "simultaneous treatment of the brain and the heart". Western blot results showed that NXT significantly inhibited the expression of IRF3, IRF7, TLR2, TLR7, and TNF-α in cerebral cortex and heart under cerebral ischemia.Cerebral ischemia influences cardiac functions, and TLR signaling pathway is one of the pathways for "simultaneous treatment of the brain and the heart" of NXT.