Polydatin relieves paraquat-induced human MRC-5 fibroblast injury through inhibiting the activation of the NLRP3 inflammasome

Neurotoxicity of manganese via ferroptosis induced by redox imbalance and iron overload

Manganese (Mn) is an essential trace element for maintaining bodily functions. Excessive exposure to Mn can pose serious health risks to humans and animals, particularly to the nervous system. While Mn has been implicated as a neurotoxin, the exact mechanism of its toxicity remains unclear. Ferroptosis is a form of programmed cell death that results from iron-dependent lipid peroxidation. It plays a role in various physiological and pathological cellular processes and may be closely related to Mn-induced neurotoxicity. However, the mechanism of ferroptosis in Mn-induced neurotoxicity has not been thoroughly investigated. Therefore, this study aims to investigate the role and mechanism of ferroptosis in Mn-induced neurotoxicity. Using bioinformatics, we identified significant changes in genes associated with ferroptosis in Mn-exposed animal and cellular models. We then evaluated the role of ferroptosis in Mn-induced neurotoxicity at both the animal and cellular levels. Our findings suggest that Mn exposure causes weight loss and nervous system damage in mice. In vitro and in vivo experiments have shown that exposure to Mn increases malondialdehyde, reactive oxygen species, and ferrous iron, while decreasing glutathione and adenosine triphosphate. These findings suggest that Mn exposure leads to a significant increase in lipid peroxidation and disrupts iron metabolism, resulting in oxidative stress injury and ferroptosis. Furthermore, we assessed the expression levels of proteins and mRNAs related to ferroptosis, confirming its significant involvement in Mn-induced neurotoxicity.

Targeted inhibition of transforming growth factor-β type I receptor by AZ12601011 improves paraquat poisoning-induced multiple organ fibrosis

Paraquat (PQ) causes fatal poisoning that leads to systemic multiple organ fibrosis, and transforming growth factor (TGF)-β1 plays a critical role in this process. In this study, we aimed to investigate the effects of AZ12601011 (a small molecular inhibitor of TGFβRI) on PQ-induced multiple organ fibrosis. We established a mouse model of PQ in vivo and used PQ-treated lung epithelial cell (A549) and renal tubular epithelial cells (TECs) in vitro. Haematoxylin-eosin and Masson staining revealed that AZ12601011 ameliorated pulmonary, hepatic, and renal fibrosis, consistent with the decrease in the levels of fibrotic indicators, alpha-smooth muscle actin (α-SMA) and collagen-1, in the lungs and kidneys of PQ-treated mice. In vitro data showed that AZ12601011 suppressed the induction of α-SMA and collagen-1 in PQ-treated A549 cells and TECs. In addition, AZ12601011 inhibited the release of inflammatory factors, interleukin (IL)-1β, IL-6, and tumour necrosis factor-α. Mechanistically, TGF-β and TGFβRI levels were significantly upregulated in the lungs and kidneys of PQ-treated mice. Cellular thermal shift assay and western blotting revealed that AZ12601011 directly bound with TGFβRI and blocked the activation of Smad3 downstream. In conclusion, our findings revealed that AZ12601011 attenuated PQ-induced multiple organ fibrosis by blocking the TGF-β/Smad3 signalling pathway, suggesting its potential for PQ poisoning treatment.

Ferulic acid grafted into β-cyclodextrin nanosponges ameliorates Paraquat-induced human MRC-5 fibroblast injury

Paraquat (PQ) is a commercially important and effective herbicide in the world. Nevertheless, it has higher toxicity causing acute organ damage and different complications, mainly in the lungs and kidneys. Ferulic acid (FA), 4-hydroxy-3-methoxycinnamic acid imposes multiple pharmacological impacts. No protective effect of FA on PQ poisoning-caused human embryonic lung fibroblast damage has not been reported. Despite their many beneficial effects, FA is characterized by poor water solubility, low bioavailability, and phytochemical instability. To solve the problem, β-cyclodextrin nanosponge (β-CD NSs) was utilized to increase the solubility of FA so that it was grafted into β-CD NSs to establish β-CD@FA NSs. The purpose of this work was to examine for the first time the protective effect of β-CD@FA NS on MRC-5 human lung cells damages induced by PQ poisoning. MTS assay was performed to investigate the viability of MRC-5 cells at different concentrations of FA/β-CD@FA NSs when cells were co-cultured with 0.2 μg/mL PQ. The flow cytometry study was carried out to determine apoptosis. Malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) levels were detected using appropriate biochemistry kits. Compared with the PQ group, the cell activity, CAT, and SOD levels were significantly increased in the FA and chiefly in β-CD@FA NSs intervention groups, whereas apoptosis and MDA levels were markedly decreased. The inflammatory factors tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and interleukin 22 (IL-22) were detected. The results demonstrate that β-CD@FA NSs can inhibit PQ-induced cell damage by enhancing antioxidant stress capacity and regulation of inflammatory responses.

Potential of resveratrol in the treatment of interstitial lung disease

Interstitial lung disease (ILD) is a heterogeneous group of diseases characterized by lung injury caused by lung fibroblast proliferation, interstitial inflammation, and fibrosis. Different cell signal transduction pathways are activated in response to various proinflammatory or fibrotic cytokines, such as IL-6, and these cytokines are increased in different ILDs. The overexpressed cytokines and growth factors in ILD can activate TGF-β/Smad2/3/4, NF-κB, and JAK/STAT signal transduction pathways, promote the activation of immune cells, increase the release of pro-inflammatory and pro-fibrotic factors, differentiate fibroblasts into myofibroblasts, and promote the occurrence and development of ILD. This finding suggests the importance of signal transduction pathways in patients with ILD. Recent evidence suggests that resveratrol (RSV) attenuates excessive inflammation and pulmonary fibrosis by inhibiting the TGF-β/Smad2/3/4, NF-κB, and JAK/STAT signal transduction pathways and overactivation of immune cells. In this review, advances in lung protection and the underlying mechanisms of RSV are summarized, and the potential efficacy of RSV as a promising treatment option for ILD is highlighted.

Radiation Protection of Polydatin Against Radon Exposure Injury of Epithelial Cells and Mice

Radon exposure is significantly associated with lung cancer. Radon concentration is currently reduced mainly by physical methods, but there is a lack of protective drugs or biochemical reagents for radon damage. This study aimed to explore the protective effect of polydatin (PD) on the radon-exposed injury. The results showed that PD can significantly reduce ROS level, raise SOD activity, weaken the migration ability, increase E-cad, and decrease mesenchymal cell surface markers (FN1, Vimentin, N-cad, α-SMA, and Snail) in radon-exposed epithelial cells. In vivo, PD increased the mice weight, promoted SOD activity, and decreased MDA content, the number of bullae, pulmonary septum thickness, lung collagenous fibers, and mesenchymal cell surface markers. Furthermore, PD inhibited p-PI3K, p-AKT, and p-mTOR expression. Compared with directly adding PD on radon-exposed cells, adding PD before and after radon exposure could more obviously improve the adhesion of radon-exposed cells, significantly alleviate the migration ability, and more significantly reduce mesenchyme markers and p-AKT and p-mTOR. These results indicate that PD can reduce oxidative stress, weaken epithelial-mesenchymal transition (EMT) and lung fibrosis in radon-exposed cells/mice, and have good radiation protection against radon injury. The mechanism is related to the inhibition of the PI3K/AKT/mTOR pathway.

Trehalose prevents glyphosate-induced hepatic steatosis in roosters by activating the Nrf2 pathway and inhibiting NLRP3 inflammasome activation

Glyphosate (Gly) is a globally spread herbicide that can cause toxic injuries to hepatocytes. Dietary trehalose (Tre) exerts cytoprotective effect in numerous liver diseases through anti-oxidant and anti-inflammatory properties. However, it is yet to be investigated whether Tre affords protection against Gly-induced hepatotoxicity. To evaluate the negative effect of Gly in liver and assess the possible protective role of Tre, sixty Hy-line Brown roosters were allocated into three groups: the first group presented the control with a normal diet, the second group fed normal feed containing 200mg/kg Gly, and the third group fed normal feed containing 200 mg/kg Gly and 5 g/kg Tre. Plasma and liver tissues were collected and analyzed after 120 days. Firstly, Gly-elevated serum levels of hepatic injury markers and liver histopathological damages were evidently alleviated by Tre administration. Also, Tre normalized Gly-altered serum and hepatic lipid profiles and Oil Red O-stained lipid levels, suggesting the improvement of hepatic steatosis. The severely accumulated malondialdehyde levels and impaired antioxidant status in Gly-exposed roosters were markedly improved by administration with Tre. Simultaneously, Gly-inhibited nuclear factor erythroid 2-related factor 2 (Nrf2) level and consequent reduced levels of Nrf2-downstream targets in liver were markedly normalized by Tre treatment. Additionally, Tre treatment evidently mitigated Gly-induced inflammasome response via inhibiting NLRP3 inflammasome activation. Overall, these observations provide novel insights that the protective action of Tre against Gly-induced hepatic steatosis is attributed to activation of Nrf2 pathway and inhibition of NLRP3 inflammasome activation.

Polydatin attenuates tubulointerstitial fibrosis in diabetic kidney disease by inhibiting YAP expression and nuclear translocation

The activation of Yes-associated protein (YAP) pathway is mutually causal with the increase of extracellular matrix (ECM) stiffness. Polydatin (PD) has been proved to have anti-fibrosis effect in diabetic kidney disease (DKD), but it is still a mystery whether PD participates in YAP-related mechano-transduction. Therefore, this study intends to solve the following two problems: 1) To construct an in vitro system of polyacrylamide hydrogels (PA gels) based on the true stiffness of kidneys in healthy and DKD rats, and observe the effect of PD on pathological matrix stiffness-induced YAP expression in renal fibroblasts; 2) Compared with verteporfin (VP), a pharmacological inhibitor of YAP, to explore whether the therapeutic effect of PD on DKD in vivo model is related to the regulation of YAP. In this study, the in vitro system of PA gels with 3 kPa, 12 kPa and 30 kPa stiffness was constructed and determined for the first time to simulate the kidney stiffness of healthy rats, rats with DKD for 8 weeks and 16 weeks, respectively. Compared with the PA gels with 3 kPa stiffness, the PA gels with 12 kPa and 30 kPa stiffness significantly increased the expression of YAP, α-smooth muscle actin (α-SMA) and collagen I, and the production of reactive oxygen species (ROS) in renal fibroblasts, and the PA gels with 30 kPa stiffness were the highest. PD significantly inhibited the above-mentioned changes of fibroblasts induced by pathological matrix stiffness, suggesting that the inhibition of PD on fibroblast-to-myofibroblast transformation and ECM production was at least partially associated with regulating YAP-related mechano-transduction pathway. Importantly, the inhibitory effect of PD on YAP expression and nuclear translocation in kidneys of DKD rats is similar to that of VP, but PD is superior to VP in reducing urinary protein, blood glucose, blood urea nitrogen and serum creatinine, as well as decreasing the expression of α-SMA and collagen I, ROS overproduction and renal fibrosis. Our results prove for the first time from the biomechanical point of view that PD is a potential therapeutic strategy for delaying the progression of renal fibrosis by inhibiting YAP expression and nuclear translocation.

Polydatin: Pharmacological Mechanisms, Therapeutic Targets, Biological Activities, and Health Benefits

Polydatin is a natural potent stilbenoid polyphenol and a resveratrol derivative with improved bioavailability. Polydatin possesses potential biological activities predominantly through the modulation of pivotal signaling pathways involved in inflammation, oxidative stress, and apoptosis. Various imperative biological activities have been suggested for polydatin towards promising therapeutic effects, including anticancer, cardioprotective, anti-diabetic, gastroprotective, hepatoprotective, neuroprotective, anti-microbial, as well as health-promoting roles on the renal system, the respiratory system, rheumatoid diseases, the skeletal system, and women's health. In the present study, the therapeutic targets, biological activities, pharmacological mechanisms, and health benefits of polydatin are reviewed to provide new insights to researchers. The need to develop further clinical trials and novel delivery systems of polydatin is also considered to reveal new insights to researchers.

Inflammasome Activation in Parkinson’s Disease

Chronic sterile inflammation and persistent immune activation is a prominent pathological feature of Parkinson’s disease (PD). Inflammasomes are multi-protein intracellular signaling complexes which orchestrate inflammatory responses in immune cells to a diverse range of pathogens and host-derived signals. Widespread inflammasome activation is evident in PD patients at the sites of dopaminergic degeneration as well as in blood samples and mucosal biopsies. Inflammasome activation in the nigrostriatal system is also a common pathological feature in both neurotoxicant and α-synuclein models of PD where dopaminergic degeneration occurs through distinct mechanisms. The NLRP3 (NLR Family Pyrin Domain Containing 3) inflammasome has been shown to be the primary driver of inflammatory neurotoxicity in PD and other neurodegenerative diseases. Chronic NLRP3 inflammasome activation is triggered by pathogenic misfolded α-synuclein aggregates which accumulate and spread over the disease course in PD. Converging lines of evidence suggest that blocking inflammasome activation could be a promising therapeutic strategy for disease modification, with both NLRP3 knockout mice and CNS-permeable pharmacological inhibitors providing robust neuroprotection in multiple PD models. This review summarizes the current evidence and knowledge gaps around inflammasome activation in PD, the pathological mechanisms by which persistent inflammasome activation can drive dopaminergic degeneration and the therapeutic opportunities for disease modification using NLRP3 inhibitors.

Phenols and terpenoids: natural products as inhibitors of NLRP3 inflammasome in cardiovascular diseases

Inflammatory infiltration has been implicated in the pathogenesis of cardiovascular diseases (CVDs). The NLRP3 inflammasome is involved in the development of several types of CVDs, including myocardial infarction, myocardial ischemia-reperfusion damage, heart failure, atrial fibrillation, and hypertension. Inhibiting the activity of NLRP3 inflammasome can inhibit the progress of CVDs. However, there is no NLRP3 inflammasome inhibitor in clinic, and it is very important to find a safe and effective NLRP3 inhibitor. Phenols and terpenoids are naturally natural products that have many anti-inflammatory effects in CVDs by modulating the NLRP3 inflammatory pathway. Thus, 20 natural products from phenols and terpenoids for the treatment of cardiovascular disease based on the inhibition of NLRP3 inflammasome were summarized and screened. Docking results showed salvianolic acid B and ellagic acid in phenols, and oridonin and triptolide in terpenoids had a better binding activity with NLRP3, which can provide theoretical support for finding novel NLRP3 inflammasome inhibitors or lead compounds in the future.

The herbicide paraquat-induced molecular mechanisms in the development of acute lung injury and lung fibrosis

The herbicide paraquat (PQ; 1,1'-dimethyl-4,4'-bipyridylium dichloride) is a highly toxic organic heterocyclic herbicide that has been widely used in agricultural settings. Since its commercial introduction in the early 1960s, numerous cases of fatal PQ poisonings attributed to accidental and/or intentional ingestion of PQ concentrated formulations have been reported. The clinical manifestations of the respiratory system during the acute phase of PQ poisoning mainly include acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), followed by pulmonary fibrosis in a later phase. The focus of this review is to summarize the most recent publications related to PQ-induced lung toxicity as well as the underlying molecular mechanisms for PQ-mediated pathologic processes. Growing sets of data from in vitro and in vivo models have demonstrated the involvement of the PQ in regulating lung oxidative stress, inflammatory response, epigenetics, apoptosis, autophagy, and the progression of lung fibrosis. The article also summarizes novel therapeutic avenues based on a literature review, which can be explored as potential means to combat PQ-induced lung toxicity. Finally, we also presented clinical studies on the association of PQ exposure with the incidence of lung injury and pulmonary fibrosis.

Resveratrol alleviates bleomycin-induced pulmonary fibrosis via suppressing HIF-1α and NF-κB expression

The absence of a gold standard for treating pulmonary fibrosis makes its management challenging. We established a rat model to study the effect of resveratrol (Res) on bleomycin-induced pulmonary fibrosis. Rats were randomly divided into control, model, low-Res, middle-Res, high-Res, and dexamethasone groups and treated with various concentrations of these drugs. Rats showed typical features of pulmonary fibrosis; i.e., alveolitis, fibrous hyperplasia, and fibrosis on days 7, 14, and 28, respectively. Expression of HIF-1α and NF-κB was higher in the middle-Res, high-Res, and dexamethasone groups than in the control group, but was less than that in the model and low Res groups. We conclude that different levels of HIF-1α and NF-κB expression at different stages of pulmonary fibrosis in rats is positively correlated with the disease severity. Furthermore, resveratrol alleviates bleomycin-induced pulmonary fibrosis by suppressing HIF-1α and NF-κB expression, indicating its potential as a promising therapeutic drug candidate.

Polydatin attenuates Mycoplasma gallisepticum (HS strain)-induced inflammation injury via inhibiting the TLR6/ MyD88/NF-κB pathway

Mycoplasma gallisepticum (MG) infection is the main cause of chronic respiratory disease (CRD) characterized by severe respiratory inflammation in chickens. Polydatin (PD) is a resveratrol glycoside isolated from Polygonum cuspidatum, which has prominent anti-inflammatory effect. The purpose of this study was to investigate the therapeutic effect of PD against MG-induced inflammation in chicken and its underlying mechanism. Histopathological analysis showed that PD treatment (15, 30, and 45 mg/kg) apparently alleviated MG-induced pathological changes of chicken embryonic lung. In chicken embryo fibroblast (DF-1) cells, PD treatment (15, 30, and 60 μg/mL) could effectively suppress MG propagation, promote MG-infected cell proliferation and cell cycle progress, and inhibit MG-induced cell apoptosis. ELISA and qPCR assays showed that PD treatment significantly suppressed the expression of interleukin-6 (IL-6), IL-1β and tumor necrosis factor-α (TNF-α) induced by MG both in vivo and in vitro. Besides, molecular studies indicated that the MG-induced levels of toll-like receptor-6 TLR6, myeloid differentiation-88 (MyD88) and nuclear factor κB (NF-κB) were significantly decreased by PD treatment. Moreover, immunofluorescence analysis showed that PD treatment restrained the MG-induced NF-κB-p65 nuclear translocation. Taken together, these results indicate the protective effects of PD against MG-induced inflammation injury in chicken were mainly by inhibiting the TLR6/MyD88/NF-κB pathway.