NBR1-p62-Nrf2 mediates the anti-pulmonary fibrosis effects of protodioscin.

BACKGROUND: Idiopathic pulmonary fibrosis is a persistent disease of the lung interstitium for which there is no efficacious pharmacological therapy. Protodioscin, a steroidal saponin, possesses diverse pharmacological properties; however, its function in pulmonary fibrosis is yet to be established. Hence, in this investigation, it was attempted to figure out the anti-pulmonary fibrosis influences of protodioscin and its pharmacological properties related to oxidative stress. METHODS: A mouse lung fibrosis model was generated using tracheal injections of bleomycin, followed by intraperitoneal injection of different concentrations of protodioscin, and the levels of oxidative stress and fibrosis were detected in the lungs. Multiple fibroblasts were treated with TGF-ß to induce their transition to myofibroblasts. It was attempted to quantify myofibroblast markers' expression levels and reactive oxygen species levels as well as Nrf2 activation after co-incubation of TGF-ß with fibroblasts and different concentrations of protodioscin. The influence of protodioscin on the expression and phosphorylation of p62, which is associated with Nrf2 activation, were detected, and p62 related genes were predicted by STRING database. The effects of Nrf2 inhibitor or silencing of the Nrf2, p62 and NBR1 genes, respectively, on the activation of Nrf2 by protodioscin were examined. The associations between p62, NBR1, and Keap1 in the activation of Nrf2 by protodioscin was demonstrated using a co-IP assay. Nrf2 inhibitor were used when protodioscin was treated in mice with pulmonary fibrosis and lung tissue fibrosis and oxidative stress levels were detected. RESULTS: In vivo, protodioscin decreased the levels of fibrosis markers and oxidative stress markers and activated Nrf2 in mice with pulmonary fibrosis, and these effects were inhibited by Nrf2 inhibitor. In vitro, protodioscin decreased the levels of myofibroblast markers and oxidative stress markers during myofibroblast transition and promoted Nrf2 downstream gene expression, with reversal of these effects after Nrf2, p62 and NBR1 genes were silenced or Nrf2 inhibitors were used, respectively. Protodioscin promoted the binding of NBR1 to p62 and Keap1, thereby reducing Keap1-Nrf2 binding. CONCLUSION: The NBR1-p62-Nrf2 axis is targeted by protodioscin to reduce oxidative stress and inhibit pulmonary fibrosis.

Asarinin attenuates bleomycin-induced pulmonary fibrosis by activating PPARγ.

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease that lacks effective treatment modalities. Once patients are diagnosed with IPF, their median survival is approximately 3-5 years. PPARγ is an important target for the prevention and treatment of pulmonary fibrosis. Asarinin is a lignan compound that can be extracted from food plant Asarum heterotropoides. In this study, we investigated the therapeutic effects of asarinin in a pulmonary fibrosis model constructed using bleomycin in mice and explored the underlying mechanisms. Intraperitoneal administration of asarinin to mice with pulmonary fibrosis showed that asarinin effectively attenuated pulmonary fibrosis, and this effect was significantly inhibited by the PPARγ inhibitor GW9662. Asarinin inhibited TGF-ß1-induced fibroblast-to-myofibroblast transition in vitro, while GW9662 and PPARγ gene silencing significantly inhibited this effect. In addition, asarinin inhibited not only the canonical Smad pathway of TGF-ß but also the non-canonical AKT and MAPK pathways by activating PPARγ. Our study demonstrates that asarinin can be used as a therapeutic agent for pulmonary fibrosis, and that PPARγ is its key target.

Validation a solid-phase extraction-HPLC method for determining the migration behaviour of five aromatic amines from packaging bags into seafood simulants.

The simultaneous determination of five aromatic amines and their potential migration from packaging bags into seafood simulants were investigated. A validated HPLC method was developed for the separation and qualification of five aromatic amines in seafood simulants. By combining solid-phase extraction (SPE), these amines were efficiently separated on a Halo C18 column (150 × 4.6 mm i.d., 2.7 µm, particle size) using a mobile phase of methanol/phosphate buffer solution (5 mmol l(-1), pH 6.9) with gradient elution. The linear range was 0.1-10.0 mg l(-1); the absolute recoveries ranged from 85.3% to 98.4%; and the limits of detection of the five aromatic amines were between 0.015 and 0.08 mg l(-1). In this work the migration profile of aromatic amines from black plastic bags was investigated at temperatures of 4°C with water, 3% acetic acid solution, 10% ethanol solution and 50% ethanol solution as seafood simulants, respectively. The migration of the five aromatic amines under different conditions showed that residual o-methoxyaniline, p-chloroaniline, aniline and 2,6-dimethylaniline leaching from black plastic bags increased with incubation time. No detectable 3,3´-dimethylbenzidine was found to leach from the bags.