Protective Effect of Compound Tongluo Decoction on Brain Vascular Endothelial Cells after Ischemia-Reperfusion by Inhibition of Ferroptosis Through Regulating Nrf2/ARE/SLC7A11 Signaling Pathway.

Cerebral infarction is one of the most common diseases for aged people. Compound Tongluo Decoction (CTLD), a classic traditional Chinese Medicine prescription, has been widely used in the treatment of ischemic cerebral infarction. Transient middle cerebral artery occlusion (tMCAO) rat model is established for the animal experiment and oxygen-glucose deprivation and reperfusion (OGD/R) human umbilical vein endothelial cells (HUVECs) model are established for the cell experiment. This also use Nrf2-/- rats to detect the role of nuclear factor erythroid 2-related factor 2 (Nrf2). Longa score, Evans blue staining, brain water content measurement, and histological observation are done. The levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and other ferroptosis-related components are detected respectively. In the vivo experiment, CTLD relieved ischemia-reperfusion (IR) injury symptoms and attenuated IR injury in brain tissues of tMCAO rats by relieving peroxidation injury in brain tissues and inhibiting ferroptosis in tMCAO rats. Moreover, CTLD reversed OGD/R-induced oxidative damage of endothelial cells via suppressing ferroptosis. After knocking out the Nrf2 gene, the protective effect of CTLD is sharply reduced. This study put forward that CTLD can inhibit ferroptosis in I/R-injured vascular endothelium by regulating Nrf2/ARE/SLC7A11 signaling to improve the relative symptoms of rats after cerebral I/R injury, thus providing a viable treatment option for cerebrovascular disease.

Glycyrrhizic acid alleviates liver fibrosis in vitro and in vivo via activating CUGBP1-mediated IFN-γ/STAT1/Smad7 pathway.

BACKGROUND: Hepatic fibrosis, a common pathological feature of chronic liver injuries, is a serious public health problem and lacks effective therapy. Glycyrrhizic acid (GA) is a bioactive ingredient in the root of traditional Chinese medicine licorice, and exhibits remarkable anti-viral, anti-inflammatory and hepatoprotective actions. PURPOSE: Here we aimed to investigated whether GA provided a therapeutic efficacy in hepatic fibrosis and uncover its molecular mechanisms. STUDY DESIGN AND METHODS: We investigated the anti-fibrosis effects of GA using CCl4-induced mouse mode of liver fibrosis as well as TGF-ß1-activated human LX-2 cells and primary hepatic stellate cells (HSCs). CUGBP1-mediated IFN-γ/STAT1/Smad7 signaling was examined with immunofluorescence staining and western blot analysis. We designed and studied the binding of GA to CUGBP1 using in silico docking, and validated by microscale thermophoresis (MST) assay. RESULTS: GA obviously attenuated CCl4-induced liver histological damage, and reduced serum ALT and AST levels. Meanwhile, GA decreased liver fibrogenesis markers such as α-SMA, collagen α1, HA, COL-III, and LN in the hepatic tissues. Mechanistically, GA remarkably elevated the levels of IFN-γ, p-STAT1, Smad7, and decreased CUGBP1 in vivo and in vitro. Over-expression of CUGBP1 completely abolished the anti-fibrotic effect of GA and regulation on IFN-γ/STAT1/Smad7 pathway in LX-2 cells and primary HSCs, confirming CUGBP1 played a pivotal role in the protection by GA from liver fibrosis. Further molecular docking and MST assay indicated that GA had a good binding affinity with the CUGBP1 protein. The dissociation constant (Kd) of GA and CUGBP1 was 0.293 µM. CONCLUSION: Our study demonstrated for the first time that GA attenuated liver fibrosis and hepatic stellate cell activation by promoting CUGBP1-mediated IFN-γ/STAT1/Smad7 signalling pathways. GA may be a potential candidate compound for preventing or reliving liver fibrosis.