Chrysophanol-8-O-glucoside protects mice against acute liver injury by inhibiting autophagy in hepatic stellate cells and inflammatory response in liver-resident macrophages.

Acute liver failure (ALF) is an unfavorable condition characterized by the rapid loss of liver function and high mortality. Chrysophanol-8-O-glucoside (CPOG) is an anthraquinone derivative isolated from rhubarb. This study aims to evaluate the protective effect of CPOG on lipopolysaccharide (LPS)/D-GalN-induced ALF and its underlying mechanisms. LPS/D-GalN-induced mice ALF model and LPS treatment model in RAW 264.7 and LX2 cells were established. It was found that CPOG ameliorated LPS/D-GalN-induced liver injury and improved mortality as indicated by Hematoxylin-eosin (H&E) staining. Molecularly, qPCR and ELISA results showed that CPOG alleviated LPS/D-GalN-induced release of alanine aminotransferase and aspartate transaminase and the secretion of TNF-α and IL-1ß in vivo. LPS/D-GalN-induced intracellular ROS production was also attenuated by CPOG in liver tissue. Further, CPOG attenuated ROS generation and inhibited the expression of p-IκB and p-p65 as well as the expression of TNF-α and IL-1ß stimulated by LPS in RAW 264.7 cells. In addition, CPOG alleviated LPS-induced up-regulation of LC3B, p62, ATG5 and Beclin1 by attenuating ROS production and inhibiting MAPK signaling in LX2 cells. Taken together, our data indicated that the CPOG protected against LPS/D-GalN-induced ALF by inhibiting oxidative stress, inflammation response and autophagy. These findings suggest that CPOG could be potential drug for the treatment of ALF in clinic.

(Z)-5-(4-methoxybenzylidene)thiazolidine-2,4-dione protects rats from carbon tetrachloride-induced liver injury and fibrogenesis.

AIM: To evaluate the hepatoprotective roles of (Z)-5-(4-methoxybenzylidene)thiazolidine-2,4-dione (SKLB010) against carbon tetrachloride (CCl4)-induced acute and chronic liver injury and its underlying mechanisms of action. METHODS: In the first experiment, rats were weighed and randomly divided into 5 groups (five rats in each group) to assess the protective effect of SKLB010 on acute liver injury. For induction of acute injury, rats were administered a single intraperitoneal injection of 2 mL/kg of 50% (v/v) CCl4 dissolved in olive oil (1:1). Group 1 was untreated and served as the control group; group 2 received CCl4 for induction of liver injury and served as the model group. In groups 3, 4 and 5, rats receiving CCl4 were also treated with SKLB010 at doses of 25, 50 and 100 mg/kg, respectively. Blood samples were collected at 6, 12 and 24 h after CCl4 intoxication to determine the serum activity of alanine amino transferase. Tumour necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) were determined using enzyme-linked immunosorbent assay. At 24 h after CCl4 injection, liver fibrogenesis was evaluated by hematoxylin-eosin (HE) staining and immunohistochemical analyses. Cytokine transcript levels of TNF-α, IL-1ß and inducible nitric oxide synthase in the liver tissues of rats were measured using a reverse transcriptase reverse transcription-polymerase chain reaction technique. In the second experiment, rats were randomly divided into 2 groups (15 rats in each group), and liver injury in the CCl4-administered groups was induced by a single intraperitoneal injection of 2 mL/kg of 50% (v/v) CCl4 dissolved in olive oil (1:1). The SKLB010-treated groups received oral 100 mg/kg SKLB010 before CCl4 administration. Five rats in each group were sacrificed at 2 h, 6 h, 12 h after CCl4 intoxication and small fortions of livers were rapidly frozen for extraction of total RNA, hepatic proteins and glutathione (GSH) assays. In the hepatic fibrosis model group, rats were randomly divided into 2 groups (5 rats each group). Rats were injected intraperitoneally with a mixture of CCl4 (1 mL/kg body weight) and olive oil [1:1 (v/v)] twice a week for 4 wk. In the SKLB010-treated groups, SKLB010 (100 mg/kg) was given once daily by oral gavage for 4 wk after CCl4 administration. The rats were sacrificed one week after the last injection and the livers from each group were harvested and fixed in 10% formalin for HE and immunohistochemical staining. RESULTS: In this rat acute liver injury model, oral administration of SKLB010 blocked liver tissue injury by down-regulating the serum levels of alanine aminotransferase, suppressing inflammatory infiltration to liver tissue, and improving the histological architecture of liver. SKLB010 inhibited the activation of NF-κB by suppressing the degradation of IκB, and prevented the secretion of pro-inflammatory mediators such as tumor necrosis factor-α, interleukin-1ß, and the reactive free radical, nitric oxide, at the transcriptional and translational levels. In this chronic liver fibrosis model, treatment with 100 mg/kg per day SKLB010 attenuated the degree of hepatic fibrosis and area of collagen, and blocked the accumulation of smooth-muscle actin-expressed cells. CONCLUSION: These results suggest that SKLB010 is a potent therapeutic agent for the treatment of CCl4-induced hepatic injury.

(Z)2-(5-(4-methoxybenzylidene)-2, 4-dioxothiazolidin-3-yl) acetic acid protects rats from CCl(4) -induced liver injury.

BACKGROUND AND AIM: (Z)2-(5-(4-methoxybenzylidene)-2, 4-dioxothiazolidin-3-yl) acetic acid (MDA) is an aldose reductase (AR) inhibitor. Recent studies suggest that AR contributes to the pathogenesis of inflammation by affecting the nuclear factor κB (NF-κB)-dependent expression of cytokines and chemokines and therefore could be a novel therapeutic target for inflammatory pathology. The current study evaluated the in vivo role of MDA in protecting the liver against injury and fibrogenesis caused by CCl(4) in rats, and the underlying mechanisms. METHODS: A single injection of CCl(4) induced acute hepatitis, and repeated injections were used to induce hepatic fibrosis in rats. Therapeutic efficacy was assessed by comparison of the severity of hepatic injury and fibrosis in MDA-treated rats versus untreated controls. RESULTS: MDA significantly protected the liver from injury by reducing the activity of serum alanine aminotransferase, and improving the histological architecture of the liver. MDA modulated NF-κB-dependent activation of inflammatory cytokines by reducing hepatic mRNA levels of tumor necrosis factor-α, interleukin-1ß, inducible nitric oxide (NO) synthase and transforming growth factor-ß. In addition, MDA attenuated oxidative stress by increasing the content of hepatic glutathione. These favorable changes were associated with suppressed hepatic NF-κB activation by MDA. MDA treatment improved liver fibrosis in rats that received repeated CCl(4) injections. In vitro, MDA attenuated phosphorylation of IκB and activation of NF-κB, and thus prevented biosynthesis of NO in lipopolysaccharide-activated RAW264.7 cells. CONCLUSIONS: The present study suggests that AR is a novel therapeutic anti-inflammatory target for the treatment of hepatitis and liver fibrosis.