The protective effects of apocynin in hyperoxic lung injury in neonatal rats

Alpha-lipoic acid, apocynin or probiotics influence glutathione status and selected inflammatory parameters in C57/BL6 mice when combined with a low-fat diet

BACKGROUND

The aim of the study was to determine the potential of a low-fat diet (LFD) to protect against oxidative and inflammatory damage in the course of asthma and obesity when combined with antioxidants (alpha-lipoic acid-ALA, apocynin-APO) or a probiotic (P) (Lactobacillus casei).

METHODS

The experiments were carried out on ten groups of male C57/BL6 mice that were fed standard fat (SFD), low-fat (LFD), or high-fat (HFD) diets. Ovalbumin (OVA, administered subcutaneously and by inhalation) was used to sensitize the animals. IL-1α, IL-10, eotaxin-1, leptin, and TNF-α concentrations were examined in blood, while total glutathione (GSHt), reduced glutathione (GSH), oxidized glutathione (GSSG) and -SH groups were measured in lung homogenates.

RESULTS

LFD in combination with the analyzed compounds (APO, P, ALA) significantly decreased the concentration of IL-1α compared to the OVA + HFD group (p < 0.01; p = 0.025; p = 0.002, respectively). Similarly, the treated mice demonstrated lower eotaxin-1 concentrations compared to the HFD group (p < 0.001). Moreover, supplementation of LFD with probiotics significantly increased the concentration of IL-10 vs. controls (p < 0.001) and vs. untreated OVA-sensitized and challenged/obese mice (p < 0.001). Animals administered APO/ALA with LFD displayed a significant decrease in TNF-α concentration compared to OVA + HFD mice (p = 0.013; p = 0.002 respectively). Those treated with ALA displayed significantly improved GSH levels (p = 0.035) compared to OVA + HFD mice.

CONCLUSIONS

Supplementation of the tested compounds with LFD appears to have a positive influence on the glutathione redox status of pulmonary tissues and selected inflammatory parameters in mouse blood.

Cryptotanshinone affects HFL-1 cells proliferation by inhibiting cytokines secretion in RAW264.7 cells and ameliorates inflammation and fibrosis in newborn rats with hyperoxia induced lung injury

Objective: Bronchopulmonary dysplasia (BPD) is a common complication of prematurity and has no specific treatment option. Moreover, inflammation and fibrosis play a vital role in the development of BPD. Thus, this study aimed to explore the role of the anti-inflammatory and anti-fibrotic drug cryptotanshinone (CTS) in the treatment of inflammation and fibrosis in BPD. Methods: In vivo, Sprague-Dawley rats (male) were divided into air, hyperoxia and CTS groups with different dose interventions (7.5, 15, and 30 mg/kg). A BPD rat model was induced by continuous inhalation of hyperoxia (95%) for 7 days, during which different doses of CTS were injected intraperitoneally. Furthermore, histological examination, hydroxyproline content measurement, Western blot and real-time quantitative polymerase chain reaction were used to detect the levels of inflammation and fibrosis in the tissues. RAW264.7 cells exposed to 95% oxygen were collected and co-cultured with fibroblasts to determine the expression levels of α-SMA, collagen-Ⅰ and MMPs. The levels of pro-inflammatory cytokines such as TNF-α, IL-6 and pro-fibrotic factor TGF-β1 in the supernatants were measured using enzyme-linked immunosorbent assay. Results: Haematoxylin and eosin staining revealed that CTS reduced the inflammatory response in rat lungs. Masson staining revealed that CTS alleviated the level of pulmonary fibrosis. CTS also reduced the levels of TNF-α, IL-6 and TGF-β1 along with the expression of the fibrosis marker α-SMA in lung tissue. Similarly, in vitro analysis revealed that CTS decreased the levels of TNF-α, IL-6 and TGF-β1 expressed in RAW 264.7 cells, and reduced α-SMA, collagen-Ⅰ, MMPs concentrations in HFL-1 cells co-cultured with the supernatant of RAW264.7 cells after hyperoxia. Conclusion: CTS can attenuate the hyperoxia-induced inflammatory response and the level of fibrosis by regulating the levels of inflammatory factors and fibrotic factor TGF-β1 expressed by macrophages, thereby highlighting the therapeutic potential of CTS in the treatment of BPD.

Molecular mechanisms of cell death in bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) in neonates is the most common pulmonary disease that causes neonatal mortality, has complex pathogenesis, and lacks effective treatment. It is associated with chronic obstructive pulmonary disease, pulmonary hypertension, and right ventricular hypertrophy. The occurrence and development of BPD involve various factors, of which premature birth is the most crucial reason for BPD. Under the premise of abnormal lung structure and functional product, newborns are susceptible to damage to oxides, free radicals, hypoxia, infections and so on. The most influential is oxidative stress, which induces cell death in different ways when the oxidative stress balance in the body is disrupted. Increasing evidence has shown that programmed cell death (PCD), including apoptosis, necrosis, autophagy, and ferroptosis, plays a significant role in the molecular and biological mechanisms of BPD and the further development of the disease. Understanding the mode of PCD and its signaling pathways can provide new therapeutic approaches and targets for the clinical treatment of BPD. This review elucidates the mechanism of BPD, focusing on the multiple types of PCD in BPD and their molecular mechanisms, which are mainly based on experimental results obtained in rodents.