Induction of Nrf2-dependent Antioxidation and Protection Against Carbon Tetrachloride-induced Liver Damage by Andrographis Herba (chuān xīn lián) Ethanolic Extract

Immuno-Kachiks formula immunomodulates and ameliorates hepatic damage induced by monosodium glutamate in rats

The immune system plays a vital role in controlling liver fibrosis and enhancing the pathogenesis of liver inflammation. Monosodium glutamate is a common flavor-enhancement food additive. This study evaluated the immunomodulatory and hepato-curative effects of the Immuno-Kachiks polyherbal formulation against monosodium glutamate-induced immune suppression and hepatic damage in rats. Monosodium glutamate was given orally at a 2000 mg/kg dose to male Wistar rats for three months to induce liver damage and immune suppression. After three months of successful induction, three groups were separately administered orally with Immuno-Kachiks formula at 400, 800, and 1500 mg/kg/day for 28 days. At the end of the treatment period, liver and blood samples were collected for histological and biochemical analysis. The lymphocyte count remained significantly low while the neutrophil count and the neutrophil-to-lymphocyte ratio increased significantly, despite the cessation of monosodium glutamate ingestion for 28 days. The Immuno-Kachiks formula (IKF) significantly increased the lymphocyte count, reduced the neutrophil-to-lymphocyte ratio, and normalized the neutrophil count. Neither monosodium glutamate nor the IKF significantly caused alpha-fetoprotein levels to rise or fall below normal. High doses (800 and 1500 mg/kg) of the Immuno-Kachiks formula significantly raised serum levels of aspartate aminotransferase, alkaline phosphatase, and total bilirubin. 1500 mg/kg of the IKF caused mild liver inflammation. The IKF restored the liver morphologic alterations observed in monosodium glutamate-induced liver damage in rats. The results suggest that the Immuno-Kachiks herbal formulation is a potential curative agent for early-stage liver damage and could restore suppressed adaptive immunity.

GSK-3β RNAi Lentivirus Affects Neuronal Damage and Nuclear Factor E2-Related Factor 2 (Nrf2) Expression in Cerebral Infarction Rats

We investigated the effect of GSK-3β RNAi lentivirus on neuronal damage and Nrf2 level in rats with cerebral infarction. 40 rats were assigned into sham group, CI group, Vector group and GSK-3β RNAi group followed by analysis of cell damage and oxidative stress, neurological scores, cerebral infarction volume, and brain water content as well as brain morphology by H&E staining and Nrf2 protein level by Western blot. Compared with sham group, GSK-3β mRNA in neurons of CI group and Vector group was significantly elevated (P < 0.05) with reduced level in GSK-3β RNAi group (P < 0.05); 3 hours after surgery, there was no change in neuroethology scores of rats in CI group, Vector group and GSK-3β RNAi group (P > 0.05). While 1 and 3 days later, the scores of rats were significantly improved (P < 0.05) and brain water content was reduced in GSK-3β RNAi group (P < 0.05) without difference between CI group and Vector group (P > 0.05). Compared with sham group, infarct size in CI group and Vector group was increased (P < 0.05) and reduced in GSK-3β RNAi group (P < 0.05) without difference between CI group and Vector group (P > 0.05). Meanwhile, CI group and Vector group showed significantly downregulated Nrf2, Srx1 and Trx1 proteins (P < 0.05), which were increased in GSK-3β RNAi group (P < 0.05). In conclusion, GSK-3β RNAi lentivirus can promote the expression of Nrf2 and exert an inhibitory effect on neurons of rats with cerebral infarction, therefore protecting brain tissue.

Nrf2 in liver toxicology

Liver plays essential roles in the metabolism of many endogenous chemicals and exogenous toxicants. Mechanistic studies in liver have been at the forefront of efforts to probe the roles of bioactivation and detoxication of environmental toxins and toxicants in hepatotoxicity. Moreover, idiosyncratic hepatoxicity remains a key barrier in the clinical development of drugs. The now vast Nrf2 field emerged in part from biochemical and molecular studies on chemical inducers of hepatic detoxication enzymes and subsequent characterization of the modulation of drug/toxicant induced hepatotoxicities in mice through disruption of either Nrf2 or Keap1 genes. In general, loss of Nrf2 increases the sensitivity to such toxic chemicals, highlighting a central role of this transcription factor and its downstream target genes as a modifier to chemical stress. In this review, we summarize the impact of Nrf2 on the toxicology of multiple hepatotoxicants, and discuss efforts to utilize the Nrf2 response in predictive toxicology.

Targeting AngII/AT1R signaling pathway by perindopril inhibits ongoing liver fibrosis in rat

The renin-angiotensin system (RAS) has a substantial role in liver fibrosis, cirrhosis, and portal hypertension. Hence, targeting RAS through angiotensin-converting enzyme (ACE) inhibitors can mend hepatic fibrosis; the current study was designed to examine the potential fibrosis inhibition activity of perindopril using a rat model of liver fibrosis induced by thioacetamide (TAA). Four groups of rats were used throughout this study, Group I (control group); rats received the vehicle. TAA was used for inducing liver fibrosis in rats by intraperitoneal injection of 200-mg/kg body weight twice a week for 6 weeks. Group II served as (TAA group). Rats of Groups III and IV were given perindopril at doses of 2 and 8 mg/kg 2 weeks after TAA administration and continued concomitantly with TAA till the end of the experiment. Injection of TAA resulted in a significant increase in aminotransferases' activities and bilirubin with a significant decrease in serum albumin and total protein and a significant decrease in hepatic content of GSH and SOD. Additionally, TAA injection raised the hepatic content of TGF-β1, α-SMA, TNF-α, and level of MDA. Histological and immunohistochemical data presented marked fibrosis in liver sections of TAA-administrated rats with increased collagen deposition, elevated METAVIR scoring, and increased expression of α-SMA, caspase-3, and AT1R. Oral dosing of perindopril for 4 weeks concomitant with TAA could mend the altered parameters near to normal values and abolished the ongoing fibrosis extension. In conclusion, these results demonstrated that perindopril, as ACE inhibitor, could grant a superior remedial nominee in preventing liver fibrosis progression through targeting angiotensin II formation.

Lipoic Acid Prevents High-Fat Diet-Induced Hepatic Steatosis in Goto Kakizaki Rats by Reducing Oxidative Stress Through Nrf2 Activation

Prevention of hepatic fat accumulation may be an important approach for liver diseases due to the increased relevance of hepatic steatosis in this field. This study was conducted to investigate the effects of the antioxidant α-lipoic acid (α-LA) on hepatic steatosis, hepatocellular function, and oxidative stress in a model of type 2 diabetes fed with a high fat diet (HFD). Goto-Kakizaki rats were randomly divided into four groups. The first group received only a standard rat diet (control GK) including groups 2 (HFD), 3 (vehicle group), and 4 (α-LA group), which were given HFD, ad libitum during three months. Wistar rats are the non-diabetic control group. Carbohydrate and lipid metabolism, liver function, plasma and liver tissue malondialdehyde (MDA), liver GSH, tumor necrosis factor-α (TNF-α) and nuclear factor E2 (erythroid-derived 2)-related factor-2 (Nrf2) levels were assessed in the different groups. Liver function was assessed using quantitative hepatobiliary scintigraphy, serum aspartate, and alanine aminotransferases (AST, ALT), alkaline phosphatase, gamma-glutamyltranspeptidase, and bilirubin levels. Histopathologically steatosis and fibrosis were evaluated. Type 2 diabetic animals fed with HFD showed a marked hepatic steatosis and a diminished hepatic extraction fraction and both were fully prevented with α-LA. Plasma and liver tissue MDA and hepatic TNF-α levels were significantly higher in the HFD group when compared with the control group and significantly lower in the α-LA group. Systemic and hepatic cholesterol, triglycerides, and serum uric acid levels were higher in hyperlipidemic GK rats and fully prevented with α-LA. In addition, nuclear Nrf2 activity was significantly diminished in GK rats and significantly augmented after α-LA treatment. In conclusion, α-LA strikingly ameliorates steatosis in this animal model of diabetes fed with HFD by decrementing the inflammatory marker TNF-α and reducing oxidative stress. α-LA might be considered a useful therapeutic tool to prevent hepatic steatosis by incrementing antioxidant defense systems through Nrf2 and consequently decreasing oxidative stress and inflammation in type 2 diabetes.