OXIDATIVE STRESS IN A RAT MODEL OF COTTON SMOKE INHALATION-INDUCED PULMONARY INJURY

In vitro toxicity and chemical analysis of e-cigarette aerosol produced amid dry hitting

Dry hitting, a phenomenon produced by e-cigarettes with refillable cartridges when the liquid in the coil is low, is a common occurrence among regular vapers despite being an unintended consequence of the device. This phenomenon's hazard to public health is still unknown and needs further investigation. Lung cells cultured at the air-liquid interface were exposed to vaped aerosol consisting of 3 % w/v ethyl maltol in propylene glycol for three-second puffs every 30 seconds for 80 total puffs with either dry hit or saturated conditions. Cytotoxicity was measured colorimetrically. The thermal degradation of the heating coils and wicks was visualized using scanning electron microscopy. The chemical byproducts in the aerosol were analyzed using proton nuclear magnetic resonance and inductively coupled plasma mass spectrometry. The results revealed a highly significant increase in cytotoxicity from dry hit treatments. Imaging showed thermal decomposition of the cotton wick after dry hitting, which was confirmed by energy dispersive x-ray spectroscopy with less oxygen in the dry hit cotton. Chemical byproducts were found via unique peaks in the dry hit condensate in the aromatic and alkene regions. Saturated condensate showed higher concentrations of detected metal species than dry-hit condensate. E-cigarette users should avoid dry hitting by refilling tanks or cartridges preemptively or by using disposable coils to avoid increased toxicity during vaping.

Unveiling the Potential of Sulfur-Containing Gas Signaling Molecules in Acute Lung Injury: A Promising Therapeutic Avenue

Acute lung injury (ALI) and its most severe form, acute respiratory distress syndrome (ARDS), are pulmonary conditions that cause significant morbidity and mortality. The common etiologies of these conditions include pneumonia, pulmonary contusion, fat embolism, smoke inhalation, sepsis, shock, and acute pancreatitis. Inflammation, oxidative stress, apoptosis, and autophagy are key pathophysiological mechanisms underlying ALI. Hydrogen sulfide (H2S) and sulfur dioxide (SO2) are sulfur-containing gas signaling molecules that can mitigate these pathogenic processes by modulating various signaling pathways, such as toll-like receptor 4 (TLR4)/nod-like receptor protein 3 (NLRP3), extracellular signal-regulating protein kinase 1/2 (ERK1/2), mitogen-activated protein kinase (MAPK), phosphatidyl inositol 3 kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR), and nuclear factor kappa B (NF-κB), thereby conferring protection against ALI. Given the limited clinical effectiveness of prevailing ALI treatments, investigation of the modulation of sulfur-containing gas signaling molecules (H2S and SO2) in ALI is imperative. This article presents an overview of the regulatory pathways of sulfur-containing gas signaling molecules in ALI animal models induced by various stimuli, such as lipopolysaccharide, gas inhalation, oleic acid, and ischemia-reperfusion. Furthermore, this study explored the therapeutic prospects of diverse H2S and SO2 donors for ALI, stemming from diverse etiologies. The aim of the present study was to establish a theoretical framework, in order to promote the new treatment of ALI.

Tissue-Protective Effect of Erdosteine on Multiple-Organ Injuries Induced by Fine Particulate Matter

Background

Fine particulate matter (PM2.5) is the air pollutant that most threatens global public health. The purpose of this study was to observe the inflammatory and oxidative stress injury of multiple organs induced by PM2.5 in rats and to explore the tissue-protective effect of erdosteine.

Material/Methods

We randomly divided 40 male Wistar rats into a blank control group, a saline group, a PM2.5 exposure group, and an erdosteine intervention group. We assessed changes in organs tissue homogenate and biomarkers of inflammation and oxidative stress in serum and bronchoalveolar lavage fluid (BALF).

Results

(1) The expressions of IL-6, IL-1β, TNF-α, 8-OHdG, 4-HNE, and PCC in serum and BALF of the PM2.5 exposure group increased, but decreased after treatment with erdosteine, suggesting that erdosteine treatment attenuates inflammatory and oxidative stress injury. (2) The expression of γ-GCS in serum and lungs in the PM2.5 exposure group increased, but did not change significantly after treatment with erdosteine. This suggests that PM2.5 upregulates the level of γ-GCS, while erdosteine does not affect this protective response. (3) The expression of T-AOC in serum, lungs, spleens, and kidneys of the PM2.5 exposure group decreased, but increased after treatment with erdosteine. Our results suggest that PM2.5 can cause imbalance of oxidation/anti-oxidation in multiple organs, and erdosteine can alleviate this imbalance.

Conclusions

PM2.5 exposure can lead to inflammatory and oxidative stress damage in serum and organ tissues of rats. Erdosteine may be an effective anti-inflammatory and antioxidant that can reduce this injury.

Aerosol inhalation of edaravone can improve inflammation, oxidative stress and pulmonary function of rats with smoke inhalation injury by down-regulating miR-320

OBJECTIVE

To explore the protective effects and related mechanism of aerosol inhalation of edaravone on inflammation, oxidative stress and pulmonary function (PF) in rats with smoke inhalation injury.

METHODS

Twenty-four rats were stochastically and equally divided into four groups: group A (edaravone-preventing group), group B (model group), group C (low-dose group) and group D (high-dose group). The serum of rats was collected to determine the expression of miR-320, inflammatory mediators (TNF-α, IL-6, IL-10), oxidative stress indexes (MDA, SOD, MPO) and oxygenation index (OI). Pulmonary tissues of rats were collected to determine the total lung water (TLW), wet-to-dry ratio (W/D) and other parameters. HE staining was adopted for pathological evaluation.

RESULTS

Compared with group B, the levels of miR-320, TNF-α, IL-6, MDA, MPO, TLW and W/D in group A were significantly down-regulated, while IL-10, SOD and OI levels were significantly up-regulated, and the trend of this change was more obvious than that in group C and group D, with notably better improvement degree in group D than group C. In HE staining, the pulmonary tissue structure was basically normal in group A, and was better than that of the other three groups. In group B, the pulmonary tissue was seriously damaged, accompanied by a large number of inflammatory cells infiltration and alveolar wall thickening. The pathological condition of group C was notably ameliorated, the extent of this improvement was more pronounced in group D, and the degree of pathological improvement in group D was superior to that in group C.

CONCLUSION

Aerosol inhalation of edaravone in advance can reduce the levels of inflammatory factors and oxidative stress indexes in serum of smoke inhalation injury rats, thus protecting PF, which may be related to the down-regulation of miR-320 by edaravone.