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Quercetin, a natural flavonoid, has been used as a nutritional supplement for its anti-inflammatory and antioxidative properties. Quercetin was reported to exhibit a wide range of pharmacological properties, including its effect on anti-hepatic fibrosis. However, the anti-fibrotic mechanisms of quercetin have not been well-characterized to date. This study aimed to investigate the protective effects of quercetin on carbon tetrachloride (CCl 4 )-induced liver fibrosis in rats and to clarify its anti-hepatofibrotic mechanisms. We demonstrated that quercetin exhibited in-vivo hepatoprotective and anti-fibrogenic effects against CCl 4 -induced liver injury by improving the pathological manifestations, thereby reducing the activities of serum total bilirubin (TBIL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and decreasing the serum levels of hyaluronic acid (HA), laminin (LN), type IV collagen (IV-C) and procollagen III peptide (PIIIP). Furthermore, treatment with quercetin 5–15 mg/kg inhibited the activation of NF-κB in a dose-dependent manner via inhibition of IкBα degradation and decreased the expression of p38 MAPK by inhibiting its phosphorylation. Additionally, in a dose-dependent manner, quercetin down-regulated Bax, up-regulated Bcl-2, and subsequently inhibited caspase-3 activation. Moreover, quercetin regulated inflammation factors and hepatic stellate cells (HSCs)-activation markers, such as TNF-α, IL-6, IL-1β, Cox-2, TGF-β, α-SMA, Colla1, Colla2, TIMP-1, MMP-1, and desmin. Taken together, quercetin prevented the progression of liver fibrosis in SD rats. The anti-fibrotic mechanisms of quercetin might be associated with its ability to regulate NF-кB/IкBα, p38 MAPK anti-inflammation signaling pathways to inhibit inflammation, and regulate Bcl-2/Bax anti-apoptosis signaling pathway to prevent liver cell apoptosis. [ABSTRACT FROM AUTHOR]

• Astilbin attenuates OGD-induced cell injury. • Astilbin ameliorates OGD-induced cell apoptosis. • Astilbin diminishes OGD-induced ROS-NLRP3 inflammasome axis activation. • Astilbin suppresses the MAPK pathway and activated the PI3K/AKT pathway. • Astilbin ameliorates brain damage in I/R rats. Ischaemic stroke is a lethal cerebrovascular disease that occurs worldwide. Astilbin is a natural flavonoid compound with various physiological activities. The purpose of this study was to investigate the neuroprotective effects of Astilbin after cerebral ischaemia reperfusion (I/R) injury. The oxygen and glucose deprivation (OGD) model was used to simulate cerebral I/R injury in vitro. Cell viability was measured via CCK-8 and LDH release assays. Cell apoptosis was measured via Hoechst 33258 staining and flow cytometry assays. ROS was detected via flow cytometry assay. The protein expression levels were determined by western blotting. The middle cerebral artery occlusion (MCAO) model was used to simulate cerebral I/R injury in vivo. Cerebral ischaemic volume was measured by TTC staining. The Zea-Longa score, rota-rod test, and foot-fault test were used to evaluate behavioural changes and neurological deficits in rats. Astilbin significantly enhanced cell viability and decreased LDH release after OGD treatment in vitro. Astilbin effectively curbed cell apoptosis induced by OGD via inhibiting the activation of caspase-3, decreasing the ratio of Bax/Bcl-2 and decreasing FADD. Astilbin also inhibited OGD-induced inflammation by suppressing ROS-NLRP3 inflammasome axis activation. Further results revealed that Astilbin could suppress the MAPK pathway and activate the PI3K/AKT pathway. Finally, Astilbin significantly reduced the cerebral infarction volume and relieved neurological deficits in rats in vivo. Astilbin could defend against cerebral I/R injury by inhibiting apoptosis and inflammation via suppressing the MAPK pathway and activating the AKT pathway. [ABSTRACT FROM AUTHOR]

Liver fibrosis is a major pathological feature of chronic liver diseases, and effective therapies are limited at present. Asiatic acid (AA) is a triterpenoid isolated from Centella asiatica , which exhibits efficient anti-inflammatory and anti-oxidative activities. In this study, we attempted to evaluate the potential therapeutic effect of AA on CCl 4 -induced liver fibrosis in rats and to investigate the underlying molecular mechanisms. Liver fibrosis-related indexes including body weight, biochemical parameters, histological changes, the mRNA expression levels of inflammatory cytokines and biomarkers, and changes in the expression of related proteins in liver tissue were assessed. The results showed that AA treatment effectively ameliorated CCl 4 -induced liver injury and fibrosis. Mechanistically, AA treatment attenuated CCl 4 -induced oxidative stress, inflammation, and hepatocyte apoptosis and regulated the Bcl-2/Bax signaling pathway in the liver. Additionally, we demonstrated that AA also inhibited hepatic stellate cell activation and extra cellular matrix (ECM) synthesis by regulating the PI3K/AKT/mTOR signaling pathway. In conclusion, these findings suggest that AA prevents the progression of liver fibrosis through multiple mechanisms and indicate that AA might be used for the treatment of liver fibrosis in the future. [ABSTRACT FROM AUTHOR]