Protective Effects of N-Acetylcysteine on Lipopolysaccharide-Induced Respiratory Inflammation and Oxidative Stress

Abstract

As the leading cause of bovine respiratory disease (BRD), bacterial pneumonia can result in tremendous losses in the herd farming industry worldwide. N-acetylcysteine (NAC), an acetylated precursor of the amino acid L-cysteine, has been reported to have anti-inflammatory and antioxidant properties. To explore the protective effect and underlying mechanisms of NAC in ALI, we investigated its role in lipopolysaccharide (LPS)-induced bovine embryo tracheal cells (EBTr) and mouse lung injury models. We found that NAC pretreatment attenuated LPS-induced inflammation in EBTr and mouse models. Moreover, LPS suppressed the expression of oxidative-related factors in EBTr and promoted gene expression and the secretion of inflammatory cytokines. Conversely, the pretreatment of NAC alleviated the secretion of inflammatory cytokines and decreased their mRNA levels, maintaining stable levels of antioxidative gene expression. In vivo, NAC helped LPS-induced inflammatory responses and lung injury in ALI mice. The relative protein concentration, total cells, and percentage of neutrophils in BALF; the level of secretion of IL-6, IL-8, TNF-α, and IL-1β; MPO activity; lung injury score; and the expression level of inflammatory-related genes were decreased significantly in the NAC group compared with the LPS group. NAC also ameliorated LPS-induced mRNA level changes in antioxidative genes. In conclusion, our findings suggest that NAC affects the inflammatory and oxidative response, alleviating LPS-induced EBTr inflammation and mouse lung injury, which offers a natural therapeutic strategy for BRD.

Nutraceutical Effect of Resveratrol on the Mammary Gland: Focusing on the NF-κb /Nrf2 Signaling Pathways

“…As bacterial LPS causes a variety of cell types to generate inflammatory cytokines, including IL 6 and IL 1, it has been widely employed to create an inflammatory model. [ 31 ]. It has been observed that ROS plays a dynamic role in mastitis and its pathophysiology [ 36 ], in lung injury, and in cancers [ 37 ].…”

“…Using commercially available kits, malondialdehyde concentrations were measured spectrophotometrically at 532 nm (Nanjing Jiancheng Bioengineering Institute, Nanjing, China). MDA activity was measured by a previously described technique, the thiobarbituric acid reaction method described by Chen et al [ 31 ].…”

“…To quantify NF-κB, IL-1β, Jnk, IL-6, Erk, TNF-α and Nrf2 transcripts, the primer sequence for the specified genes and β-actin as a reference gene were derived from a previous study [ 31 , 32 , 33 , 34 ]. All the analyses were conducted in triplicate, and a gel electrophoresis was performed to confirm the particular PCR products on a 3.0% agarose gel.…”

Downregulation of ROR2 attenuates LPS‐induced A549 cell injury through JNK and ERK signaling pathways

“…It has been reported that TNF‐α, IL‐1β, and IL‐8 are important pro‐inflammatory mediators in inflammatory responses, moreover, excessive release of the pro‐inflammatory cytokines play crucial roles in the pathogenesis and development of ALI. 21 , 22 , 23 CCNB1 and CDC2 are known to be important cell cycle regulatory proteins, and play key roles in promoting cell cycle progression. 24 , 25 Caspases, especially caspase‐3 and caspase‐9, are considered as crucial effectors of cell apoptosis.…”

N-Acetyl-L-Cysteine Protects Airway Epithelial Cells during Respiratory Syncytial Virus Infection against Mucin Synthesis, Oxidative Stress, and Inflammatory Response and Inhibits HSPA6 Expression

“…N-acetyl-L-cysteine (NAC) is a thiol compound that can be directly used as a free radical scavenger and a precursor of reduced glutathione [ 8 ]. The antioxidant and anti-inflammatory actions of NAC in diverse respiratory diseases have been proved [ 9 ]. NAC is associated with alleviation in symptoms and delay in exacerbations of chronic obstructive pulmonary disease [ 10 ].…”