Apigenin Attenuates Inflammation in Experimentally Induced Acute Pancreatitis-Associated Lung Injury

Retracted article: Protective effects of ulinastatin on rats with acute lung injury induced by lipopolysaccharide

Qitong Lu, Zhiyong Liu, Wei He and Xin Chu. Protective effects of ulinastatin on rats with acute lung injury induced by lipopolysaccharide. Bioengineered. 2021 Oct. doi: 10.1080/21655979.2021.1987083.Since publication, significant concerns have been raised about the compliance with ethical policies for human research and the integrity of the data reported in the article.When approached for an explanation, the authors provided some original data but were not able to provide all the necessary supporting information. As verifying the validity of published work is core to the scholarly record's integrity, we are retracting the article. All authors listed in this publication have been informed.We have been informed in our decision-making by our editorial policies and the COPE guidelines. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as 'Retracted.'

Decabromodiphenyl ether causes insulin resistance and glucose and lipid metabolism disorders in mice

BACKGROUND

Decabromodiphenyl ether (BDE-209) is the most commonly used brominated flame retardant. Recently, BDE-209 has been suspected of being an environmental risk factor for metabolic diseases such as obesity, insulin resistance (IR), type 2 diabetes mellitus, and hypertension.

AIM

To investigate the effects of BDE-209 on IR and glucose and lipid metabolism in C57BL/6 mice.

METHODS

Adult male C57BL/6 mice were randomly divided into high, medium-high, medium, medium-low, and low dose BDE-209 groups, and a control group (n = 6 per group), which received 1000, 800, 600, 450, 300, and 0 mg/kg BDE-209, respectively. After BDE-209 exposure for 60 d, the mice were fasted overnight, and then sacrificed to obtain tissues. An automatic biochemical analyzer was used to detect serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high density lipoprotein cholesterol (HDL-C); enzyme-linked immunosorbent assay kits were used to detect fasting serum insulin (FINS), leptin (LEP), and adiponectin (Adp) levels; a blood glucose meter was used to detect fasting blood glucose (FBG). Morphological changes of the liver were observed by hematoxylin and eosin staining. Real-time quantitative polymerase chain reaction and Western blot were used to determine the messenger ribonucleic acid (mRNA) and protein levels, respectively, of LEP, Adp, and peroxisome proliferators activated receptor-γ (PPARγ) in mouse liver and adipose tissues.

RESULTS

There was a statistically significant difference in the weight of mice in each group after 45 and 60 d of exposure (P < 0.05). After 60 d of exposure, the weight of liver and adipose tissues in the exposure groups were greater than that of the control group (P < 0.05). The liver tissue structure was disordered and the liver tissues were accompanied by local inflammatory cell infiltration in the high, medium-high, and medium dose BDE-209 groups. The levels of FINS, insulin sensitivity index, Adp, and HDL-C were decreased in the BDE-209 group compared with the control group, as were the mRNA and protein levels of Adp in liver and adipose tissues (P < 0.05). Serum level of FBG and LEP were higher in the BDE-209 group than in controls. TC, TG, and LDL-C levels as well as the mRNA and protein expression of LEP and PPARγ in liver and adipose tissues were higher than those in the control group (P < 0.05). Homeostatic assessment model of IR was higher in the medium and medium-low dose BDE-209 groups (P < 0.05).

CONCLUSION

BDE-209 increases the body weight, fat and liver tissue weight, TC, TG, and LDL-C, reduces HDL-C, and causes IR in mice, which may be related to activating the PPARγ receptor.

Apigenin Exerts Anti-inflammatory Effects in an Experimental Model of Acute Pancreatitis by Down-regulating TNF-α

BACKGROUND/AIM

This study investigated the anti-inflammatory effect of apigenin in an experimental model of acute pancreatitis. Inflammatory response was reflected by tissue expression of the cytokine TNF-α coupled with histological examination.

MATERIALS AND METHODS

Wistar rats were divided into three groups: Sham-group animals underwent laparotomy only, without any other interventions. Control-group animals underwent laparotomy and bilio-pancreatic duct ligation to induce pancreatitis without apigenin administration. Apigenin group animals were further treated with apigenin. Euthanasia was performed at 6, 12, 24, 48 and 72 h post-operatively.

RESULTS

Over-expression of TNF-α in relation to postoperative time was observed in the control group (p<0.001). In the apigenin group, under-expression of TNF-α in relation to postoperative time was observed (p<0.013). At 72 h, apigenin reduced pancreatic TNF-α expression and prevented pancreatic necrosis.

CONCLUSION

Apigenin slows progression and reduces severity of acute pancreatitis. Apigenin may serve as an adjunct to a more successful therapeutic strategy in acute pancreatitis.

Transforming growth factor-β in pancreatic diseases: Mechanisms and therapeutic potential

Pancreatic diseases, such as acute pancreatitis, chronic pancreatitis, and pancreatic cancer, are common gastrointestinal diseases resulting in the development of local and systemic complications with a high risk of death. Numerous studies have examined pancreatic diseases over the past few decades; however, the pathogenesis remains unclear, and there is a lack of effective treatment options. Recently, emerging evidence has suggested that transforming growth factor beta (TGF-β) exerts controversial functions in apoptosis, inflammatory responses, and carcinogenesis, indicating its complex role in the pathogenesis of pancreas-associated disease. Therefore, a further understanding of relevant TGF-β signalling will provide new ideas and potential therapeutic targets for preventing disease progression. This is the first systematic review of recent data from animal and human clinical studies focusing on TGF-β signalling in pancreas damage and diseases. This information may aid in the development of therapeutic agents for regulating TGF-β in this pathology to prevent or treat pancreatic diseases.

Apigenin Decreases Acinar Cell Damage in Pancreatitis

OBJECTIVE

Chronic pancreatitis is the consequence of multiple episodes of recurrent acute pancreatitis (RAP). We hypothesized that apigenin can minimize the sequelae of RAP by limiting acinar cells' proinflammatory signaling pathways.

METHODS

AR42J acinar cells were treated in vitro with transforming growth factor β (TGF-β), apigenin, and other inhibitors. Dual luciferase reporter assay measured parathyroid hormone-related protein (PTHrP) promoter activity. MAPK/ERK pathway activity was assessed by immunoblotting and in vivo by immunohistochemistry with a cerulein-induced RAP mouse model. Nuclear factor κ B nuclear localization was analyzed in vitro in cells stimulated with tumor necrosis factor α. Primary acini were isolated and treated with cerulein; interleukin 6 messenger RNA was measured comparing PTHrP wild-type and knockout mice.

RESULTS

Apigenin and PD98059 each downregulated TGF-β stimulation of PTHrP P3 promoter activity. In a RAP mouse model, apigenin reduced pERK nuclear localization in acinar cells and preserved acinar cell architecture. Apigenin suppressed tumor necrosis factor α-mediated signaling by decreasing nuclear factor κ B nuclear localization and decreased interleukin 6 messenger RNA levels via a PTHrP-dependent mechanism.

CONCLUSIONS

Apigenin reduced inflammatory responses in experimental models of RAP. The mechanisms mediating the actions of apigenin, in part, are owing to attenuation of PTHrP and TGF-β proinflammatory signaling.

Apigenin Reduces NF-κB and Subsequent Cytokine Production as Protective Effect in a Rodent Animal Model of Lung Ischemia-Reperfusion Injury

PURPOSE

Lung ischemia-reperfusion injury (LIRI) can complicate lung transplantation or cardiac surgery with cardiopulmonary bypass, increasing morbidity and mortality. In LIRI, pro-inflammatory cytokines are activated, reactive oxygen species are generated and nuclear factor-κB (NF-κB) is up-regulated, altering lung mechanics. We tested the effect of the flavonoid apigenin on a rodent model of LIRI.

METHODS

Thirty-seven Wistar rats were subjected to LIRI with or without a single or double dose of apigenin. Induction of LIRI involved sternotomy and clamping of either the left lung hilum or the pulmonary artery alone for 30 min, followed by 60 min of reperfusion. Control groups consisted of LIRI plus NaCl, a sham group and a baseline group. At the end of the experiments, both lungs were analyzed by RT-PCR, Western blot, and light microscopy.

RESULTS

In placebos, the expression levels of pro-inflammatory markers were increased in both lungs significantly, whereas NF-κB was markedly up-regulated. Administration of apigenin reduced the activation of NF-κB and the expression of TNFα, iNOS, and IL-6. These effects were observed in total lung ischemia. Histology showed greater hemorrhage and exudation in the pulmonary periphery of all groups, whereby damage was practically absent in the central lung regions of the apigenin animals. A second dose of apigenin did not outclass a single one.

CONCLUSIONS

We conclude that apigenin given intraperitoneally can reduce activation of NF-κB and also attenuate the expression of TNFα, IL-6, and iNOS in a surgical model of LIRI. The surgical procedure itself can induce significant damage to the lungs.

Chronic Pancreatitis Associated Acute Respiratory Failure

Pancreatitis is a condition characterized by parenchymal inflammation of the pancreas, which is often associated with lung injury due to low level of oxygen and the condition is termed as acute pancreatitis-associated lung injury (APALI). Clinical reports indicated that ~ 20% to 50% of patients from low oxygen levels in blood with acute respiratory distress syndrome (ARDS). ARDS is a severe form of acute lung injury (ALI), a pulmonary disease with impaired airflow making patients difficult to breathe. ALI is frequently observed in patients with severe acute pancreatitis. Approximately one third of severe pancreatitis patients develop acute lung injury and acute respiratory distress syndrome that account for 60% of all deaths within the first week. The major causes of ALI and ARDS are sepsis, trauma, aspiration, multiple blood transfusion, and most importantly acute pancreatitis. The molecular mechanisms of ALI and ARDS are still not well explored, but available reports indicate the involvement of several pro-inflammatory mediators including cytokines (TNF-α, IL-1β, IL-6) and chemokines [like interleukin-8 (IL-8) and macrophage inhibitory factor (MIF)], as well as macrophage polarization regulating the migration and pulmonary infiltration of neutrophils into the pulmonary interstitial tissue, causing injury to the pulmonary parenchyma. Acute lung injury and acute respiratory distress syndrome in acute pancreatitis remains an unsolved issue and needs more research and resources to develop effective treatments and therapies. However, recent efforts have tested several molecules in an experimental model and showed promising results as a treatment option. The current review summarized the mechanism that is operational in pancreatitis-associated acute respiratory failure and respiratory distress syndrome in patients and current treatment options.