(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 (CCl 4)-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) CCl 4 dissolved in olive oil (1:1).Group 1 was untreated and served as the control group;group 2 received CCl 4 for induction of liver injury and served as the model group.In groups 3,4 and 5,rats receiving CCl 4 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 CCl 4 intoxication to determine the serum activity of alanine amino transferase.Tumour necrosis factor-α (TNF-α),interleukin-1β (IL-1β) were determined using enzyme-linked immunosorbent assay.At 24 h after CCl 4 injection,liver fibrogenesis was evaluated by hematoxylin-eosin (HE) staining and immunohistochemical analyses.Cytokine transcript levels of TNF-α,IL-1β 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 CCl 4-administered groups was induced by a single intraperitoneal injection of 2 mL/kg of 50% (v/v) CCl 4 dissolved in olive oil (1:1).The SKLB010-treated groups received oral 100 mg/kg SKLB010 before CCl 4 administration.Five rats in each group were sacrificed at 2 h,6 h,12 h after CCl 4 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 CCl 4 (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 CCl 4 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-1β,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 actinexpressed cells.CONCLUSION:These results suggest that SKLB010 is a potent therapeutic agent for the treatment of CCl 4 induced hepatic injury.