The Role of e-NOS in Chronic Cholestasis-Induced Liver and Renal Injury in Rats: The Effect of N-Acetyl Cysteine

Impacts of n-acetyl cysteine on gibberellic acid-induced hepatorenal dysfunction through modulation of pro-inflammatory cytokines, antifibrotic and antioxidant activity

The extensive usage of gibberellic acid (GA3) in agriculture and plant growth is generally associated with enormous human and public health hazards. The present research assesses the impact of n-acetyl cysteine (NAC) on the hepatorenal injury persuaded by GA3 for this purpose, After two weeks of adaptation twenty-four rats allocated into four groups (6 rats/group) as follows: control group, supplied with saline only; n-acetyl cysteine (NAC) group, provided with 150 mg/kg/bw by stomach tube (orally) dissolved in saline; Positive GA3 group, received GA3 (55 mg/kg/bw) orally; Protective group received NAC (150 mg/kg/bw) and GA3 (55 mg/kg/bw) as in NAC and GA3 groups. Rats received their treatments for consecutive 3 weeks. On day 22, rats were anesthetized, then euthanized. Blood and tissue samples were obtained for biochemical, antioxidants markers analysis, gene expression, and histopathological examination. Our results revealed significant changes in serum AST, ALT, urea, uric acid, total protein, and albumin levels with a substantial rise of MDA and NO concentration in GA3 treated rats along with a considerable decrease of the GSH and overexpression of the inflammatory hepatic and renal cytokines (IL-10, TNF-α, NOS) and fibrotic gene expression TGF-β1, and α-SMA, with boost expression of nuclear factor-kappa (NF_k B). NAC co-administered with GA3 significantly normalized the kidney and liver function and the antioxidant state, besides normal histological structure of both liver and kidney tissue and downregulated expression of the pro-inflammatory cytokines as well as, fibrogenic gene expression. PRACTICAL APPLICATIONS: The current study confirmed that GA3 induced hepto-renal dysfunction that was ameliorated by NAC administration. Moreover, our findings confirmed the antioxidant capability of n-acetyl cysteine and afford robust evidence about the ameliorative effect of the n-acetyl cysteine to attenuate the hepatorenal injury induced by gibberellic acid through modulation of the antioxidant defense system fibrogenic, and pro-inflammatory cytokines expression.

A phase 2 trial of N-Acetylcysteine in Biliary atresia after Kasai portoenterostomy

BACKGROUND

Biliary atresia (BA) is a life-threatening liver disease of infancy, characterized by extrahepatic biliary obstruction, bile retention, and progressive liver injury. The Kasai portoenterostomy (KP) is BA's only nontransplant treatment. Its success is variable and depends on restoration of hepatic bile flow. Many adjunctive therapeutics have been studied to improve outcomes after the KP, but none demonstrate effectiveness. This study tests if N-acetylcysteine (NAC), a precursor to the choleretic glutathione, improves bile flow after KP.

METHODS

This report describes the design of an open-label, single center, Phase 2 study to determine the effect of NAC following KP on markers of bile flow and outcomes in BA. The intervention is intravenous NAC (150 mg/kg/day) administered continuously for seven days starting 0-24 h after KP. The primary outcome is normalization of total serum bile acid (TSBA) concentrations within 24 weeks of KP. The secondary objectives are to describe NAC therapy's effect on other clinical parameters followed in BA for 24 months and to report adverse events occurring with therapy. This study follows the "minimax" clinical trial design.

DISCUSSION

This is the first clinical trial to test NAC's effectiveness in improving bile flow after KP in BA. It introduces three important concepts for future BA therapeutic trials: (1) the "minimax" study design, a pertinent design for rare diseases because it detects potential effects quickly with small subject size; (2) the more sensitive bile flow marker, TSBAs, which may correlate with positive long-term outcomes better than traditional bile flow markers such as serum bilirubin; and (3) liver enzyme changes immediately after KP, which can be a guideline for potential drug-induced liver injury in other BA peri-operative adjunctive therapeutic trials.

Investigation of the therapeutic potential of N-acetyl cysteine and the tools used to define nigrostriatal degeneration in vivo

The glutathione precursor N-acetyl-L-cysteine (NAC) is currently being tested on Parkinson's patients for its neuroprotective properties. Our studies have shown that NAC can elicit protection in glutathione-independent manners in vitro. Thus, the goal of the present study was to establish an animal model of NAC-mediated protection in which to dissect the underlying mechanism. Mice were infused intrastriatally with the oxidative neurotoxicant 6-hydroxydopamine (6-OHDA; 4 μg) and administered NAC intraperitoneally (100mg/kg). NAC-treated animals exhibited higher levels of the dopaminergic terminal marker tyrosine hydroxylase (TH) in the striatum 10d after 6-OHDA. As TH expression is subject to stress-induced modulation, we infused the tracer FluoroGold into the striatum to retrogradely label nigrostriatal projection neurons. As expected, nigral FluoroGold staining and cell counts of FluoroGold(+) profiles were both more sensitive measures of nigrostriatal degeneration than measurements relying on TH alone. However, NAC failed to protect dopaminergic neurons 3 weeks following 6-OHDA, an effect verified by four measures: striatal TH levels, nigral TH levels, nigral TH(+) cell counts, and nigral FluoroGold levels. Some degree of mild toxicity of FluoroGold and NAC was evident, suggesting that caution must be exercised when relying on FluoroGold as a neuron-counting tool and when designing experiments with long-term delivery of NAC--such as clinical trials on patients with chronic disorders. Finally, the strengths and limitations of the tools used to define nigrostriatal degeneration are discussed.