Pentoxifylline protects against cerebral ischaemia-reperfusion injury through ferroptosis regulation via the Nrf2/SLC7A11/GPX4 signalling pathway.

OBJECTIVE: To investigate whether pentoxifylline (PTX) attenuates cerebral ischaemia-reperfusion injury (IRI) in rats by inhibiting ferroptosis and to explore the underlying molecular mechanisms. METHODS: Cerebral IRI was induced in male Sprague-Dawley (SD) rats using middle cerebral artery occlusion (MCAO). The effects of PTX on cerebral ischaemia-reperfusion brain samples were detected through neurological deficit score, staining and electron microscopy; levels of ferroptosis biomarkers from brain samples were detected using kits. Additionally, the expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), transferrin receptor protein 1, divalent metal transporter 1, solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) were determined by immunohistochemistry, real-time quantitative polymerase chain reaction and western blotting. RESULTS: Pre-treatment with PTX was found to improve neurological function, evidenced by reduced neurological deficit scores, decreased infarct volume and alleviated pathological features post-MCAO. This improvement was accompanied by reduced lipid peroxidation levels and mitigated mitochondrial damage. Notably, PTX's inhibitory effect on ferroptosis was characterised by enhanced Nrf2 nuclear translocation and regulation of ferroptosis-related proteins. Moreover, inhibition of Nrf2 using ML385 (an Nrf2-specific inhibitor) reversed PTX's neuroprotective effect on MCAO-induced ferroptosis via the SLC7A11/GPX4 signalling pathway. CONCLUSIONS: Ferroptosis is evident following cerebral ischaemia-reperfusion in rats. Pentoxifylline confers protection against IRI in rats by inhibiting ferroptosis through the Nrf2/SLC7A11/GPX4 signalling pathway.

Butylphthalide protects against ischemia-reperfusion injury in rats via reducing neuron ferroptosis and oxidative stress.

Local ischemia in the cerebra leads to vascular injury and necrosis. Ferroptosis is involved in the pathophysiological process of many diseases and widely exists when ischemia-reperfusion injury occurs in many organs. The aim of this study was to evaluate the effect of Butylphthalide (NBP) on middle cerebral artery occlusion (MCAO) rats model-caused neuron injury. Sprague Dawley Rats were randomly allocated to receive sham and MCAO operation. NBP low-dose (40 mg/kg b.w), and high-dose (80 mg/kg b.w) were administrated in MACO rats. Results showed NBP improves infarct volume, attenuates neuronal apoptosis in the brain tissue of MCAO rats. The tumor necrosis factor (TNF-α), IL-6, and malondialdehyde (MDA) levels decreased after NBP administration, while the activity of superoxide dismutase (SOD) and the ratio of GSH/GSSG in MACO rats increased. MACO caused non-heme iron accumulation in the brain tissue and Perl's staining confirmed NBP attenuates ferroptosis in MACO rats. The protein expressions of SCL7A11 and glutathione peroxidase 4 (GPX4) decreased following MCAO, and NBP treatment subsequently increased the expression of SCL7A11 and GPX4. In vitro analysis in cortical neuron cells indicated that the GPX4 inhibitor reverses the inhibition of ferroptosis by NBP, which suggested that the SCL7A11/GPX4 pathway majorly contributed to the NBP ferroptosis protection effect.

Antitumor activity of cobrotoxin in human lung adenocarcinoma A549 cells and following transplantation in nude mice.

The aim of the present study was to investigate cobra neurotoxin (cobrotoxin) activity in A549 cell lines transplanted into nude mice, and to explore its molecular mechanism. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method was used to detect the growth inhibition rate of cobrotoxin in human lung A549 adenocarcinoma cells and HFL1 lung fibroblasts. Cell colony formation assays were performed to determine the effect of cobrotoxin on A549 cell colony formation, and transmission electron microscopy was used to detect cobrotoxin autophagy. In addition, western blot analysis was performed to determine the effect of 3-methyl adenine (3-MA) activity on the inhibition of autophagy, SB203580 inhibition of the p38-mitogen-activated protein kinase (MAPK) pathway, and Beclin 1, LC3, p62, p38 and phosphorylated (p)-p38 protein expression. Nude mice were injected with human lung A549 cells, and intervention and control groups were compared with regard to tumor suppression. The MTT assay revealed that various concentrations of cobrotoxin inhibited growth of A549 cells, but not HFL1 cells. A549 cell colony formation decreased and autophagosome activity was significantly increased compared with the controls. Following 3-MA administration, SB203580 autophagosome activity decreased, and following cobrotoxin administration, Beclin 1, p-p38, and LC3-II protein expression significantly increased, whereas p62 expression significantly decreased. Following 3-MA inhibition of autophagy, Beclin 1, LC3-II and p62 expression increased. Furthermore, following SB203580 inhibition of the p38-MAPK pathway, Beclin 1, p-p38, LC3-II and p62 protein expression increased. Cobrotoxin exhibited inhibitory activity on the human lung cancer A549 cells transplanted into the nude mice, suppressing the tumor growth rate by 43.4% (cobrotoxin 40 µg/kg group). However, following the addition of 3-MA (10 mmol/kg) and SB203580 (5 mg/kg), the suppression of the tumor growth rate decreased significantly. Cobrotoxin inhibits the growth of human lung cancer A549 cells in vitro and A549 cells transplanted into nude mice. Furthermore, the induction of autophagy may be associated with the activation of the p38-MAPK pathway.