Protective effects of naringin against paraquat-induced acute lung injury and pulmonary fibrosis in mice

Melittin Exerts Beneficial Effects on Paraquat-Induced Lung Injuries In Mice by Modifying Oxidative Stress and Apoptosis

Melittin (MEL) is a 26-amino acid peptide with numerous biological activities. Paraquat (PQ) is one of the most widely used herbicides, although it is extremely toxic to humans. To date, PQ poisoning has no effective treatment, and therefore the current study aimed to assess for the first time the possible effects of MEL on PQ-induced lung injuries in mice. Mice received a single intraperitoneal (IP) injection of PQ (30 mg/kg), followed by IP treatment with MEL (0.1 and 0.5 mg/kg) twice per week for four consecutive weeks. Histological alterations, oxidative stress, and apoptosis in the lungs were studied. Hematoxylin and eosin (H&E) staining indicated that MEL markedly reduced lung injuries induced by PQ. Furthermore, treatment with MEL increased superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity, and decreased malonaldehyde (MDA) and nitric oxide (NO) levels in lung tissue homogenates. Moreover, immunohistochemical staining showed that B-cell lymphoma-2 (Bcl-2) and survivin expressions were upregulated after MEL treatment, while Ki-67 expression was downregulated. The high dose of MEL was more effective than the low dose in all experiments. In summary, MEL efficiently reduced PQ-induced lung injuries in mice. Specific pharmacological examinations are required to determine the effectiveness of MEL in cases of human PQ poisoning.

Protective effects of febuxostat against paraquat-induced lung toxicity in rats: Impact on RAGE/PI3K/Akt pathway and downstream inflammatory cascades

AIMS

The herbicide paraquat causes fatal lung toxicity by induction of xanthine oxidase, production of free radicals and inflammation. Febuxostat, a xanthine oxidase inhibitor and anti-gout has recently shown anti-inflammatory activity. Accordingly, this study was carried out to investigate whether febuxostat may attenuate paraquat-induced lung toxicity and to explore the possible underlying mechanisms.

MAIN METHODS

Rats were administered either vehicle, a single dose of paraquat (30 mg/kg, i.p.), febuxostat (15 mg/kg, oral), or both for 14 successive days. Serum LDH and sRAGE were estimated. Lung tissue xanthine oxidase activity, SOD, TAC, MDA, and RAGE, HMGB1 gene expression, PI3K/Akt and β-catenin protein expression, MMP-9, IL-8, VEGF and COX-2 gene expression were estimated.

KEY FINDINGS

Results showed that paraquat induced lung injury characterized by enhanced oxidative stress and inflammation, upregulated RAGE, HMGB1 gene expression, PI3K/Akt and β-catenin protein expression. Administration of febuxostat inhibited the deleterious effects of paraquat on lung through inhibition of xanthine oxidase activity and related oxidative stress, downregulation of RAGE/PI3K/Akt pathway, and suppression of β-catenin protein expression and its downstream inflammatory mediators.

SIGNIFICANCE

The present study showed that febuxostat may abrogate paraquat-induced lung toxicity and demonstrated a novel mechanism for its ameliorative effects.

Protective Effect of Anthocyanin on Paraquat-Induced Apoptosis and Epithelial-Mesenchymal Transition in Alveolar Type II Cells

BACKGROUND Paraquat (PQ) can over-accumulate in alveolar epithelial cells. Anthocyanin (An) can exert anti-oxidative properties. The role of An in PQ-induced toxicity is unclear, so we aimed to explore whether An could inhibit epithelial mesenchymal transition (EMT) induced by PQ in alveolar cells. MATERIAL AND METHODS lveolar epithelial cells were treated with PQ and An with concentration gradient for 12, 24, and 48 h. The cell viability, ROS level, and apoptosis rate were determined using the Cell Counting Kit-8 (CCK-8) and flow cytometry, respectively. The lactate dehydrogenase (LDH) leakage, methane dicarboxylic aldehyde (MDA) level, glutathione peroxidase (GPx), and superoxide dismutase (SOD) activities were determined by spectrophotometric method. The mRNA and protein expressions were detected using quantitative real-time PCR (qPCR) and Western blot, respectively. RESULTS An reduced the PQ-induced apoptosis in a dose-dependent manner. Moreover, An reduced the ratio of Bax/Bcl-2 to ROS level. We found that An suppressed the activity of LDH and MDA and improved SOD and GPX levels. Additionally, the level of PQ-induced E-cadherin was decreased by An while the expressions of vimentin, α-smooth muscle actin (α-SMA), and collagens type I (col-I) were increased. Furthermore, An inhibited the levels of transforming growth factor β1 (TGF-β1) and activin receptor-like kinase 5 (ALK5) and reduced the phosphorylation of smad2. CONCLUSIONS Our study shows newly discovered effects of anthocyanidins on EMT and supports their chemopreventive effects in paraquat-induced apoptosis in alveolar type II cells.

Identification of naringin metabolites mediated by human intestinal microbes with stable isotope-labeling method and UFLC-Q-TOF-MS/MS

Widely presented in medicinal plants, naringin is one of the major flavanones with various pharmaceutical bioactivities. After oral administration, naringin predominantly undergoes metabolisms mediated by liver cytochrome P450 and gut microbes, while its human microbes-mediated metabolic profiling is still largely obscure due to the endogenous interferences, which makes it extremely difficult to analyze metabolites precisely. In this study, we aim of systematically investigating the biotransformation of naringin mediated by human intestinal microbes through applying stable isotope-labeling method. [2',3',5',6'-D₄]naringin was synthesized and incubated anaerobically with human gut microbes. A total of 13 microbial metabolites were detected and identified by UFLC-Q-TOF-MS/MS, among which 5 were reported for the first time. Furthermore, the proposed metabolic pathway revealed that naringin went through extensive phase I metabolism in human intestinal microbes. Of note, diverse metabolic profiles of naringin among human participants were obtained, which could be attributed to the distinct gut microbiota compositions of individuals.

The Modulatory Properties of Li-Ru-Kang Treatment on Hyperplasia of Mammary Glands Using an Integrated Approach

Background: Li-Ru-Kang (LRK) has been used in the treatment of hyperplasia of mammary glands (HMG) for several decades and can effectively improve clinical symptoms. This study aims to investigate the mechanism by which LRK intervenes in HMG based on an integrated approach that combines metabolomics and network pharmacology analyses.

Methods: The effects of LRK on HMG induced by estrogen-progesterone in rats were evaluated by analyzing the morphological and pathological characteristics of breast tissues. Moreover, UPLC-QTOF/MS was performed to explore specific metabolites potentially affecting the pathological process of HMG and the effects of LRK. Pathway analysis was conducted with a combination of metabolomics and network pharmacology analyses to illustrate the pathways and network of LRK-treated HMG.

Results: Li-Ru-Kang significantly improved the morphological and pathological characteristics of breast tissues. Metabolomics analyses showed that the therapeutic effect of LRK was mainly associated with the regulation of 10 metabolites, including prostaglandin E2, phosphatidylcholine, leukotriene B4, and phosphatidylserine. Pathway analysis indicated that the metabolites were related to arachidonic acid metabolism, glycerophospholipid metabolism and linoleic acid metabolism. Moreover, principal component analysis showed that the metabolites in the model group were clearly classified, whereas the metabolites in the LRK group were between those in the normal and model groups but closer to those in the normal group. This finding indicated that these metabolites may be responsible for the effects of LRK. The therapeutic effect of LRK on HMG was possibly related to the regulation of 10 specific metabolites. In addition, we further verified the expression of protein kinase C alpha (PKCα), a key target predicted by network pharmacology analysis, and showed that LRK could significantly improve the expression of PKCα.

Conclusion: Our study successfully explained the modulatory properties of LRK treatment on HMG using metabolomics and network pharmacology analyses. This systematic method can provide methodological support for further understanding the complex mechanism underlying HMG and possible traditional Chinese medicine (TCM) active ingredients for the treatment of HMG.

Angptl2 deficiency attenuates paraquat (PQ)-induced lung injury in mice by altering inflammation, oxidative stress and fibrosis through NF-κB pathway

Paraquat (PQ) is one of the most extensively used herbicides, possessing high toxicity for humans and animals. The lung is the main target organ by the poisoning of PQ resulting in acute lung injury. Nonetheless, molecular mechanisms underlying PQ-induced lung injury remain unclear. Here, we ask if angiopoietin-like protein 2 (Angptl2), a pro-inflammatory protein, contributes to inflammation that accelerates acute lung injury. The results indicated that abundant Angptl2 expression was observed in lung tissues of PQ-treated mice. Histological analysis revealed that PQ-induced histological changes were alleviated by Angptl2 knockout (Angptl2^-/-). Angptl2^-/- in PQ-treated mice attenuated acute lung injury progression by reducing the number of total cells, total leukocytes, neutrophils and macrophages in bronchoalveolar lavage fluid (BALF) and reducing inflammatory response through the inactivation of nuclear factor kappa B (NF-κB) pathway. Angptl2^-/- reduced oxidative stress in PQ-treated mice, as evidenced by the enhanced superoxide dismutase (SOD) activity and reduced malondialdehyde (MDA) levels in serum or lung tissue samples, which was accompanied with increased expressions of nuclear respiratory factor 2 (Nrf-2), heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO-1). PQ-induced fibrosis was also improved in Angptl2^-/- mice by decreasing pulmonary transforming growth factor (TGF)-β1 expressions. In vitro, we found that Angptl2 knockdown-suppressed inflammation, oxidative stress and fibrosis was restored by increasing NF-κB activation in PQ-incubated A549 cells; however, the results above were significantly reversed by inactivating NF-κB using its inhibitor, Bay 11-7085 or LY2409881. Therefore, Angptl2 could provide therapeutic effects on PQ-induced acute lung injury through inhibiting inflammation, oxidative stress and fibrosis by regulating NF-κB pathway.

Comprehensive investigation into the interconversion of C-2 diastereomers of naringin

Naringin is a flavanone that widely presents on daily diet and traditional medicinal materials. The ratios of naringin C-2 diastereomers are found different in reported samples, thus suspiciously leading to various functions. In this study, we measured the interconversion of C-2 diastereomers intensively with ultimate high-performance liquid chromatography and circular dichroism spectra. We examined the diastereomeric naringins in fresh citrus fruit, Huajuhong decoction pieces, and naringin tablet; evaluated the impact of tablet production procedures in factory; and monitored the rapid racemization in incubation. The results not only confirmed that enzyme, temperature, and pH condition could influence the interconversion but also demonstrated that diverse ratios of diastereomers showed limited influence on metabolic behaviors of naringin in the blood, which consequently cause comparable bioactivities. This study could provide comprehensive understanding of diastereomeric interconversion and provide useful reference for drug development.

Molecular targets of dietary phytochemicals for possible prevention and therapy of uterine fibroids: Focus on fibrosis

Uterine fibroids (myomas or leiomyomas) are common benign tumors of reproductive aged women. Fibroids are clinically apparent in 20-50% of women, and cause abnormal uterine bleeding, abdominal pain and discomfort, pregnancy complications and infertility. Unfortunately, limited numbers of medical treatment are available but no effective preventive strategies exist. Moreover, the benefits of medical treatments are tempered by lack of efficacy or serious adverse side effects. Fibrosis has recently been recognized as a key pathological event in leiomyoma development and growth. It is defined by the excessive deposition of extracellular matrix (ECM). ECM plays important role in making bulk structure of leiomyoma, and ECM-rich rigid structure is believed to be a cause of abnormal bleeding and pelvic pain/pressure. Dietary phytochemicals are known to regulate fibrotic process in different biological systems, and being considered as potential tool to manage human health. At present, very few dietary phytochemicals have been studied in uterine leiomyoma, and they are mostly known for their antiproliferative effects. Therefore, in this review, our aim was to introduce some dietary phytochemicals that could target fibrotic processes in leiomyoma. Thus, this review could serve as useful resource to develop antifibrotic drugs for possible prevention and treatment of uterine fibroids.

Naringin improves random skin flap survival in rats

Background

Random-pattern flap transfer is commonly used to treat soft-tissue defects. However, flap necrosis remains a serious problem. Naringin accelerates angiogenesis by activating the expression of vascular endothelial growth factor (VEGF). In the present study, we investigated whether naringin improves the survival of random skin flaps.

Results

Compared with controls, the naringin-treated groups exhibited significantly larger mean areas of flap survival, significantly increased SOD activity and VEGF expression, and significantly reduced MDA level. Hematoxylin and eosin (HE) staining revealed that naringin promoted angiogenesis and inhibited inflammation.

Materials and Methods

“McFarlane flap” models were established in 90 male Sprague-Dawley (SD) rats divided into three groups: a 40 mg/kg control group (0.5 % sodium carboxymethylcellulose), a 40 mg/kg naringin-treated group, and an 80 mg/kg naringin-treated group. The extent of necrosis was measured 7 days later, and tissue samples were subjected to histological analysis. Angiogenesis was evaluated via lead oxide–gelatin angiography, immunohistochemistry, and laser Doppler imaging. Inflammation was evaluated by measurement of serum TNF-α (tumor necrosis factor-α) and IL-6 (interleukin-6) levels. Oxidative stress was assessed by measuring superoxide dismutase (SOD) activity and the malondialdehyde (MDA) level.

Conclusion

Naringin improved random skin flap survival.

Chloroquine attenuates paraquat-induced lung injury in mice by altering inflammation, oxidative stress and fibrosis

Paraquat is one of the most extensively used herbicides and has high toxicity for humans and animals. However, there is no effective treatment for paraquat poisoning. The aim of the present study was to evaluate the effects of chloroquine on paraquat-induced lung injury in mice. Mice received a single intraperitoneal injection of paraquat and a daily intraperitoneal injection of the indicated dosages of chloroquine or dexamethasone. The histological changes, inflammation and oxidative stress in the lungs were examined at day 3, and the degree of pulmonary fibrosis was examined at day 28. H&E staining showed that chloroquine markedly attenuated lung injury induced by paraquat. In addition, the inflammatory responses induced by paraquat were inhibited after treatment with chloroquine, as indicated by the decreased number of leukocytes, the reduced levels of TNF-α, IL-1β and IL-6 in the bronchoalveolar lavage fluid, the reduced NO content, and downregulation of iNOS expression in lung tissues. No different effect was found between high-dose chloroquine and dexamethasone. Additionally, the treatment with chloroquine increased the activity of SOD and decreased the level of MDA in the lung tissues. The expressions of the anti-oxidative proteins, Nrf2, HO-1 and NQO1, were also upregulated by chloroquine treatment. The high-dose chloroquine was more effective than dexamethasone in its anti-oxidation ability. Finally, the results of Masson's staining illustrated that chloroquine markedly attenuated fibrosis in the paraquat-exposed lungs. Immunohistochemistry staining showed that the expressions of the pro-fibrotic proteins TGF-β and α-SMA were downregulated after treatment with chloroquine. In conclusion, chloroquine effectively attenuated paraquat-induced lung injury in mice.

Parecoxib reduced ventilation induced lung injury in acute respiratory distress syndrome

Background

Cyclooxygenase-2 (COX-2) contributes to ventilation induced lung injury (VILI) and acute respiratory distress syndrome (ARDS). The objective of present study was to observe the therapeutic effect of parecoxib on VILI in ARDS.

Methods

In this parallel controlled study performed at Harbin Medical University, China between January 2016 and March 2016, 24 rats were randomly allocated into sham group (S), volume ventilation group/ARDS (VA), parecoxib/volume ventilation group/ARDS (PVA). Rats in the S group only received anesthesia; rats in the VA and PVA group received intravenous injection of endotoxin to induce ARDS, and then received ventilation. Rats in the VA and PVA groups were treated with intravenous injection of saline or parecoxib. The ratio of arterial oxygen pressure to fractional inspired oxygen (PaO₂/FiO₂), the wet to dry weight ratio of lung tissue, inflammatory factors in serum and bronchoalveolar lavage fluid (BALF), and histopathologic analyses of lung tissue were examined. In addition, survival was calculated at 24 h after VILI.

Results

Compared to the VA group, in the PVA group, PaO₂/FiO₂ was significantly increased; lung tissue wet to dry weight ratio; macrophage and neutrophil counts, total protein and neutrophil elastase levels in BALF; tumor necrosis factor-α, interleukin-1β, and prostaglandin E₂ levels in BALF and serum; and myeloperoxidase (MPO) activity, malondialdehyde levels, and Bax and COX-2 protein levels in lung tissue were significantly decreased, while Bcl-2 protein levels were significantly increased. Lung histopathogical changes and apoptosis were reduced by parecpxib in the PVA group. Survival was increased in the PVA group.

Conclusions

Parecoxib improves gas exchange and epithelial permeability, decreases edema, reduces local and systemic inflammation, ameliorates lung injury and apoptosis, and increases survival in a rat model of VILI.

Traditional Chinese medicine for pulmonary fibrosis therapy: Progress and future prospects

ETHNOPHARMACOLOGICAL RELEVANCE

Pulmonary fibrosis (PF) is a chronic, debilitating and often lethal lung disorder. Despite the molecular mechanisms of PF are gradually clear with numerous researchers' efforts, few effective drugs have been developed to reverse human PF or even halt the chronic progression to respiratory failure. Traditional Chinese medicine (TCM), the main component of the medical practice used for more than 5000 years especially in China, often exerts wider action spectrum than previously attempted options in treating human diseases. Recent data have shown the anti-fibrotic benefits of the active ingredients from TCM in this field, which may represent an attractive source of the drug discovery against PF.

AIM OF THE REVIEW

This review summarizes the pre-clinical and clinical evidence on the benefits of TCM and their active ingredients, and provides a comprehensive information and reliable basis for the exploration of new treatment strategies of botanical drugs in the therapy of PF.

METHODS

The literature information was obtained from the scientific databases on ethnobotany and ethno medicines (up to Aug 2016), mainly from the Pubmed, Web of Science and CNKI databases, and was to identify the experimental studies on the anti-fibrotic role of the active agents from TCM and the involved mechanisms. The search keywords for such work included: "lung fibrosis" or "pulmonary fibrosis", and "traditional Chinese medicine", "extract" or "herb".

RESULTS

A number of studies have shown that the active agents of single herbs and TCM formulas, particularly the flavonoids, glycosides and alkaloids, exhibit potential benefits against PF, the mechanisms of which appear to involve the regulation of inflammation, oxidant stress, and pro-fibrotic signaling pathways, etc. Besides, the processing methods for discovering TCM in treating PF were prospectively discussed.

CONCLUSION

These research work have shown the therapeutic benefits of TCM in the treatment of PF. However, more continued researches should be undertaken to clarify the unconfirmed chemical composition and regulatory mechanisms, conduct standard clinical trials, and evaluate the possible side effects. The insights provided in present review will be needed for further exploration of botanical drugs in the development of PF therapy.

Paraquat disrupts the anti-inflammatory action of cortisol in human macrophages in vitro: therapeutic implications for paraquat intoxications

The herbicide paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride) has been banned in Europe since 2007 due to its high toxicity in humans. However, it is still widely used in Middle/South America and in Asia where it is annually associated with a high incidence of unintentional and intentional poisoning. Human macrophage-like cell lines were used to shed more light on the inflammatory response elicited by paraquat. Paraquat (3-1000 μM) reduced cell viability in a dose- and time-dependent manner. Exposure to 50 or 200 μM paraquat for 24 h elevated the release of interleukin 8 and gene expression of tumor necrosis factor-α. Expression of the 11β-hydroxysteroid dehydrogenase 1 gene tended to increase, while cellular glutathione concentrations decreased. The anti-inflammatory effect of cortisol was significantly disrupted. The paraquat-induced cortisol resistance could not be prevented by N-acetyl-l-cysteine. However, a polyphenolic extract of grape seeds consisting of monomeric and oligomeric flavan-3-ols (MOF) reduced paraquat-induced inflammation in the presence of cortisol to baseline. In conclusion, the results suggest that an impaired cortisol response may contribute to paraquat-mediated inflammation. Agents with pleiotropic cellular and subcellular effects on redox regulation and inflammation, such as plant-derived polyphenols, may be an effective add-on to the therapy of paraquat intoxications with glucocorticoids.

Modulation of Inflammatory Response to Implanted Biomaterials Using Natural Compounds

Tissue engineering offers a promising strategy to restore injuries resulting from trauma, infection, tumor resection, or other diseases. In spite of significant progress, the field faces a significant bottleneck; the critical need to understand and exploit the interdependencies of tissue healing, angiogenesis, and inflammation. Inherently, the balance of these interacting processes is affected by a number of injury site conditions that represent a departure from physiological environment, including reduced pH, increased concentration of free radicals, hypoglycemia, and hypoxia. Efforts to harness the potential of immune response as a therapeutic strategy to promote tissue repair have led to identification of natural compounds with significant anti-inflammatory properties. This article provides a concise review of the body's inflammatory response to biomaterials and describes the role of oxygen as a physiological cue in this process. We proceed to highlight the potential of natural compounds to mediate inflammatory response and improve host-graft integration. Herein, we discuss the use of natural compounds to map signaling molecules and checkpoints that regulate the cross-linkage of immune response and skeletal repair.

Protective Effect of Astragaloside IV Against Paraquat-Induced Lung Injury in Mice by Suppressing Rho Signaling

The purpose of the present study was to evaluate the protective effects of astragaloside IV (AS IV) against paraquat (PQ)-induced pulmonary injury in vivo. Fifty BALB/C mice were randomized into five groups: (1) control, (2) PQ, (3) PQ + dexamethasone (Dex, 5 mg/kg), (4) PQ + AS IV (50 mg/kg), and (5) PQ + AS IV (100 mg/kg). A single dose of PQ (50 mg/kg, i.p.) was intraperitoneally given to induced acute lung injury. Then, mice were treated with AS IV (50 and 100 mg/kg/day, orally) for 5 days. At the end of the experiment, animals were euthanized; then, the bronchoalveolar lavage fluid (BALF) and lung tissues were collected for histological observation, biochemical assay, and Western blot analysis. Malondialdehyde (MDA), myeloperoxidase (MPO), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) in lung tissues, and interleukin-6 (IL-6), IL-1β, tumor necrosis factor-α (TNF-α) levels in BALF were determined. Histological examination indicated that AS IV attenuated lung damage caused by PQ. Biochemical results showed that AS IV treatment significantly reduced the levels of MDA, MPO, and inflammatory cytokines while increased the levels of SOD, CAT, and GSH-Px compared with those in PQ group. Western blot results revealed that AS IV attenuated the Txnip/Trx expressions and inhibited Rho/ROCK/nuclear factor kappaB (NF-κB) signaling pathway in PQ-challenged mice. These findings suggested the protective effect of AS IV as a natural product on PQ-induced pulmonary injury.

Smad2 and Smad3 Regulate Chondrocyte Proliferation and Differentiation in the Growth Plate

TGFβs act through canonical and non-canonical pathways, and canonical signals are transduced via Smad2 and Smad3. However, the contribution of canonical vs. non-canonical pathways in cartilage is unknown because the role of Smad2 in chondrogenesis has not been investigated in vivo. Therefore, we analyzed mice in which Smad2 is deleted in cartilage (Smad2^CKO), global Smad3^-/- mutants, and crosses of these strains. Growth plates at birth from all mutant strains exhibited expanded columnar and hypertrophic zones, linked to increased proliferation in resting chondrocytes. Defects were more severe in Smad2^CKO and Smad2^CKO;Smad3^-/-(Smad2/3) mutant mice than in Smad3^-/- mice, demonstrating that Smad2 plays a role in chondrogenesis. Increased levels of Ihh RNA, a key regulator of chondrocyte proliferation and differentiation, were seen in prehypertrophic chondrocytes in the three mutant strains at birth. In accordance, TGFβ treatment decreased Ihh RNA levels in primary chondrocytes from control (Smad2^fx/fx) mice, but inhibition was impaired in cells from mutants. Consistent with the skeletal phenotype, the impact on TGFβ-mediated inhibition of Ihh RNA expression was more severe in Smad2^CKO than in Smad3^-/- cells. Putative Smad2/3 binding elements (SBEs) were identified in the proximal Ihh promoter. Mutagenesis demonstrated a role for three of them. ChIP analysis suggested that Smad2 and Smad3 have different affinities for these SBEs, and that the repressors SnoN and Ski were differentially recruited by Smad2 and Smad3, respectively. Furthermore, nuclear localization of the repressor Hdac4 was decreased in growth plates of Smad2^CKO and double mutant mice. TGFβ induced association of Hdac4 with Smad2, but not with Smad3, on the Ihh promoter. Overall, these studies revealed that Smad2 plays an essential role in the development of the growth plate, that both Smads 2 and 3 inhibit Ihh expression in the neonatal growth plate, and suggested they accomplish this by binding to distinct SBEs, mediating assembly of distinct repressive complexes.

The cartilage growth plate regulates the size and shape of nearly every skeletal element in the body. TGFβs are potent inducers of cartilage formation, but the mechanisms by which they transduce their signals in cartilage during development are poorly understood. Similarly, there is strong evidence that dysregulation of the TGFβ pathway increases the risk for osteoarthritis (OA) in humans, but the underlying mechanisms are unknown. TGFβs transduce their signals through a canonical pathway involving Smad2 and Smad3, and through several non-canonical pathways. However, the roles of canonical vs. noncanonical signaling are unknown in cartilage because the combined roles of Smad2 and Smad3 have not been determined. We generated mice lacking both Smad2 and Smad3 in cartilage in order to determine the role of canonical TGFβ signaling during embryonic development. We determined that Smad2 has a more prominent role than Smad3 in non-hypertrophic chondrocytes in the growth plate, and identified elevated levels of Ihh RNA in neonatal cartilage in Smad2 and Smad3 mutants. These findings may be important because Ihh is a vital regulator of cartilage proliferation and differentiation during cartilage development. More generally, the studies identify how Smad2 and Smad3 can regulate a common target gene through distinct mechanisms.

Carvedilol attenuates paraquat-induced lung injury by inhibition of proinflammatory cytokines, chemokine MCP-1, NF-κB activation and oxidative stress mediators

Paraquat is a highly toxic herbicide that selectively accumulates in the lungs and causes pulmonary damage through the oxidative and inflammatory processes. Carvedilol is a nonselective beta and alpha-adrenergic blocking agent that has been shown to possess powerful antioxidant and anti-inflammatory properties. In the present study, we evaluated the protective effects and the underlying mechanisms of carvedilol on paraquat-induced lung injury in a mouse model. Mice were injected with a single dose of paraquat (20mg/kg, ip), and treated with carvedilol (10 and 20mg/kg/day, orally) for eight days. At the end of the experiment, lung tissue and blood samples were collected for histological and biochemical analysis. The results showed that carvedilol treatment improved the histopathological changes in the lung tissue of mice exposed to paraquat. Carvedilol significantly decreased the levels of malondialdehyde (MDA), carbonyl protein, myeloperoxidase (MPO), and nitric oxide (NO), while increased the levels of glutathione (GSH), superoxide dismutase (SOD), catalase and glutathione reductase compared with paraquat group. Carvedilol treatment also significantly reduced the levels of proinflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, transforming growth factor (TGF)-β1 and monocyte chemoattractant protein (MCP)-1 in the lung tissue. Treatment of mice with carvedilol decreased paraquat-induced expression of nuclear factor kappa B (NF-κB). In addition the plasma levels of matrix metalloproteinase (MMP)-9 and the lung hydroxyproline content significantly reduced by carvedilol treatment. Taken together, these results indicate that carvedilol is able to decrease the severity of paraquat-induced lung injury through inhibition of inflammation and oxidative stress.

Protective effect of naringin against ankylosing spondylitis via ossification, inflammation and oxidative stress in mice

Naringin is an abundant flavanone in pomelo, grapefruit as well as lime and its variants, has been shown to exhibit certain antioxidative, anti-inflammatory, anti-cancer and hypoglycemic effects. The aim of the current study was to evaluate the protective effects of naringin against ankylosing spondylitis (AS) and to elucidate the potential underlying mechanism. Firstly, a mouse model of ankylosing spondylitis (AS) was established. Next, osteocalcin (OC), alkaline phosphatase (ALP) and triglyceride (TG) activity values, inflammatory factor and oxidative stress were evaluated in the AS mice. Then, the Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) protein expression levels in the AS mice were investigated using western blot analysis. The results showed that naringin increased OC, ALP and TG activity values in the AS mouse model. Furthermore, inflammatory factor and oxidative stress levels in the AS mice were restrained by treatment with naringin. Furthermore, JAK2 and STAT3 protein expression levels were reduced by treatment with naringin. In conclusion, the present results indicated that the protective effects of naringin against AS are exerted via the induction of ossification, suppression of inflammation and oxidative stress and the downregulation of JAK2/STAT3 in mice.

Protective Effects of Arachidonic Acid Against Paraquat-Induced Pulmonary Injury

In this study, we aimed to study the effects of arachidonic acid (AA) on acute lung injury (ALI) caused by paraquat (PQ) in mice. Male Kunming mice were randomly divided into three groups: control group, PQ group, and PQ + AA group (n = 24). The mice in the PQ and PQ + AA groups received a single oral dose of 20 mg/kg bodyweight PQ, and the mice of the PQ + AA group were challenged by 500 mg/kg bodyweight AA posttreatment 2 h after PQ administration. The results indicated that the administration of AA significantly increased the activity of superoxide dismutase (SOD), decreased the activity of myeloperoxidase (MPO), the content of malondialdehyde (MDA), and the level of lactate dehydrogenase (LDH). Pathological examination also revealed that AA effectively alleviated PQ-induced histological damage. Furthermore, AA significantly reduced PQ-induced upregulations of inflammatory mediators such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-8. These results demonstrated that AA had effective protection against PQ-induced ALI.

Naringin suppresses the metabolism of A375 cells by inhibiting the phosphorylation of c-Src

Elevation of glycolysis, increase in lactic acid production, and enhancement of mitochondrial biogenesis are all the changes of energy metabolism of melanoma cells. Melanoma cells' metabolism and energy production networks play an important role in cancer proliferation, survival, motility, invasiveness, metastasis, and angiogenesis. Since the Warburg theory was put forward in the 1930s, more researchers focus on finding new ways for effectively eliminating cancer cells by targeting their energy metabolism. In this study, we found naringin has the inhibitory effects on the glucose metabolism of A375 cells, a melanoma cell line, in a concentration-dependent manner. We also found that naringin could significantly reduce the phosphorylation of c-Src. In summary, we demonstrated that naringin inhibits the malignant phenotype of A375 cells by suppressing c-Src and its downstream signaling pathway. More importantly, we provide the novel mechanism that, as a natural inhibitor of c-Src, naringin could be an effective candidate for the treatment of melanoma.

Perfluorocarbon attenuates inflammatory cytokines, oxidative stress and histopathologic changes in paraquat-induced acute lung injury in rats

The effects of perfluorocarbon (PFC) on paraquat (PQ) induced acute lung injury (ALI) was evaluated among rats. Twenty four Wistar rats were divided into 4 groups: control group injected by saline physiologic 0.9%, PFC group injected by Perfluorocarbon, PQ group injected by PQ and PQ+PFC group injected by PFC one hour after receiving paraquat. Bronchoalveular fluid content, inflammatory cytokines, oxidative and histopathologic changes were measured after 72 h. The levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and transforming growth factor-β1(TGF-β1) in the PQ group were increased compared to either control or PFC groups, but their levels decreased in PQ+PFC group significantly (p<0.05). Also, histopathologic evaluation revealed an increase in malondialdehyde (MDA) and hydroxyproline (HP) in the PQ group but a decrease in PQ+PFC group significantly (p<0.01). PFC emulsion by its anti-inflammatory, anti-oxidative and anti-fibrotic properties can reduce the inflammatory and fibrotic alterations, pulmonary oedema, and pulmonary histopathologic changes created by PQ.

SIRT3 Mediates the Antioxidant Effect of Hydrogen Sulfide in Endothelial Cells

AIM

Oxidative stress is a key contributor to endothelial dysfunction and associated cardiovascular pathogenesis. Hydrogen sulfide (H2S) is an antioxidant gasotransmitter that protects endothelial cells against oxidative stress. Sirtuin3 (SIRT3), which belongs to the silent information regulator 2 (SIR2) family, is an important deacetylase under oxidative stress. H2S is able to regulate the activity of several sirtuins. The present study aims to investigate the role of SIRT3 in the antioxidant effect of H2S in endothelial cells.

RESULTS

Cultured EA.hy926 endothelial cells were exposed to hydrogen peroxide (H2O2) as a model of oxidative stress-induced cell injury. GYY4137, a slow-releasing H2S donor, improved cell viability, reduced oxidative stress and apoptosis, and improved mitochondrial function following H2O2 treatment. H2S reversed the stimulation of MAPK phosphorylation, downregulation of SIRT3 mRNA and reduction of the superoxide dismutase 2 and isocitrate dehydrogenase 2 expression which were induced by H2O2. H2S also increased activator protein 1 (AP-1) binding activity with SIRT3 promoter and this effect was absent in the presence of the specific AP-1 inhibitor, SR11302 or curcumin. Paraquat administration to mice induced a defected endothelium-dependent aortic vasodilatation and increased oxidative stress in both mouse aorta and small mesenteric artery, which were alleviated by GYY4137 treatment. This vasoprotective effect of H2S was absent in SIRT3 knockout mice.

INNOVATION

The present results highlight a novel role for SIRT3 in the protective effect of H2S against oxidant damage in the endothelium both in vitro and in vivo.

CONCLUSION

H2S enhances AP-1 binding activity with the SIRT3 promoter, thereby upregulating SIRT3 expression and ultimately reducing oxidant-provoked vascular endothelial dysfunction. Antioxid. Redox Signal. 24, 329-343.

The Protective Effect of Naringin against Bleomycin-Induced Pulmonary Fibrosis in Wistar Rats

The aim of the current study was to investigate the protective effect of naringin on bleomycin-induced pulmonary fibrosis in rats. Twenty-four Wistar rats randomly divided into four groups (control, bleomycin alone, bleomycin + naringin 40, and bleomycin + naringin 80) were used. Rats were administered a single dose of bleomycin (5 mg/kg; via the tracheal cannula) alone or followed by either naringin 40 mg/kg (orally) or naringin 80 mg/kg (orally) or water (1 mL, orally) for 14 days. Rats and lung tissue were weighed to determine the lung index. TNF-α and IL-1β levels, hydroxyproline content, and malondialdehyde (MDA) levels were assayed. Glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities were determined. Tissue sections were stained with hematoxylin-eosin, Masson's trichrome, and 0.1% toluidine blue. TNF-α, IL-1β, and MDA levels and hydroxyproline content significantly increased (p < 0.01) and GPx and SOD activities significantly decreased in bleomycin group (p < 0.01). Naringin at a dose of 80 mg/kg body weight significantly decreased TNF-α and IL-1β activity, hydroxyproline content, and MDA level (p < 0.01) and increased GPx and SOD activities (p < 0.05). Histological evidence supported the results. These results show that naringin has the potential of reducing the toxic effects of bleomycin and may provide supportive therapy for conventional treatment methods for idiopathic pulmonary fibrosis.

Wound healing potential of naringin ointment formulation via regulating the expression of inflammatory, apoptotic and growth mediators in experimental rats

CONTEXT

Wound healing is a consequence of a complex process involving inflammatory, proliferative, and remodeling phases. Naringin, a flavanone glycoside, is associated with modulation of various oxido-inflammatory and growth factors.

AIM

The aim of this study is to evaluate the wound-healing activity of naringin ointment formulation (NOF) on experimental wound models.

MATERIALS AND METHODS

A soft paraffin-based cream containing 1, 2, and 4% (w/w) naringin was formulated and evaluated for physicochemical characters. Excision wounds and incisions wounds were used to study the topical effect of NOF for 20 d (once a day) on various biochemical, molecular, and histological parameters.

RESULTS

NOF (2 and 4%, w/w) treatment showed a significant decrease (p < 0.05) in wound area and epithelization period whereas the rate of wound contraction increased significantly (p < 0.05). The altered levels of oxido-nitrosative stress (SOD, GSH, MDA, MPO, and NO) were significantly (p < 0.05) restored by NOF. Treatment produced a significant increase (p < 0.05) in tensile strength, hydroxyproline content, and protein content. TNF-α, IL-1β, IL-6, IL-8, NF-κB, smad-7, and Bax mRNA expression were significantly down-regulated (p < 0.05) by NOF, whereas polymerase gamma (pol-γ), smad-3, VEGF and TGF-β, and collagen-1 mRNA expressions were significantly up-regulated (p < 0.05) by NOF. Histological alterations in wound skin were also restored by NOF.

CONCLUSION

NOF exerts wound healing potential via down-regulated expression of inflammatory (NF-κB, TNF-α, and ILs), apoptotic (pol-γ and Bax), and up-regulated growth factor (VEGF and TGF-β) expression, thus modulating collagen-1 expression to induce angiogenesis leading to wound healing.

Effects of rapamycin against paraquat-induced pulmonary fibrosis in mice

BACKGROUND AND AIMS

Ingestion of paraquat (PQ), a widely used herbicide, can cause severe toxicity in humans, leading to a poor survival rate and prognosis. One of the main causes of death by PQ is PQ-induced pulmonary fibrosis, for which there are no effective therapies. The aim of this study was to evaluate the effects of rapamycin (RAPA) on inhibiting PQ-induced pulmonary fibrosis in mice and to explore its possible mechanisms.

METHODS

Male C57BL/6J mice were exposed to either saline (control group) or PQ (10 mg/kg body weight, intraperitoneally; test group). The test group was divided into four subgroups: a PQ group (PQ-exposed, non-treated), a PQ+RAPA group (PQ-exposed, treated with RAPA at 1 mg/kg intragastrically), a PQ+MP group (PQ-exposed, treated with methylprednisolone (MP) at 30 mg/kg intraperitoneally), and a PQ+MP+RAPA group (PQ-exposed, treated with MP at 30 mg/kg intraperitoneally and with RAPA at 1 mg/kg intragastrically). The survival rate and body weight of all the mice were recorded every day. Three mice in each group were sacrificed at 14 d and the rest at 28 d after intoxication. Lung tissues were excised and stained with hematoxylin-eosin (H&E) and Masson's trichrome stain for histopathological analysis. The hydroxyproline (HYP) content in lung tissues was detected using an enzyme-linked immunosorbent assay (ELISA) kit. The expression of transforming growth factor-β1 (TGF-β1) and α-smooth muscle actin (α-SMA) in lung tissues was detected by immunohistochemical staining and Western blotting.

RESULTS

A mice model of PQ-induced pulmonary fibrosis was established. Histological examination of lung tissues showed that RAPA treatment moderated the pathological changes of pulmonary fibrosis, including alveolar collapse and interstitial collagen deposition. HYP content in lung tissues increased soon after PQ intoxication but had decreased significantly by the 28th day after RAPA treatment. Immunohistochemical staining and Western blotting showed that RAPA treatment significantly down-regulated the enhanced levels of TGF-β1 and α-SMA in lung tissues caused by PQ exposure. However, RAPA treatment alone could not significantly ameliorate the lower survival rate and weight loss of treated mice. MP treatment enhanced the survival rate, but had no significant effects on attenuating PQ-induced pulmonary fibrosis or reducing the expression of TGF-β1 and α-SMA.

CONCLUSIONS

This study demonstrates that RAPA treatment effectively suppresses PQ-induced alveolar collapse and collagen deposition in lung tissues through reducing the expression of TGF-β1 and α-SMA. Thus, RAPA has potential value in the treatment of PQ-induced pulmonary fibrosis.

Naringin ameliorates sodium arsenite-induced renal and hepatic toxicity in rats: decisive role of KIM-1, Caspase-3, TGF-β, and TNF-α

Chronic exposure of a naturally occurring metal arsenic leads to renal and hepatic diseases. Naringin, a flavanone glycoside, possesses anti-inflammatory and anti-oxidant potential. The aim of this investigation was to evaluate the protective effect of naringin against arsenic-induced renal and hepatic toxicity in rats. Renal and hepatic toxicity was induced in rats by sodium arsenite (5 mg/kg, p.o.). Rats were treated orally with either vehicle or naringin (20, 40, and 80 mg/kg) or Coenzyme Q10 (10 mg/kg) for 28 days. Various biochemical, histological, and molecular biomarkers were assessed in kidney and liver. Treatment with naringin (40 and 80 mg/kg) significantly and dose-dependently restored (p < 0.01 and p < 0.001) altered levels of kidney (serum creatinine, urine creatinine, BUN, uric acid, and creatinine clearance) and liver function test (AST and ALT) induced by sodium arsenite. Elevated levels of oxido-nitrosative stress in renal and hepatic tissue was significantly and dose-dependently decreased (p < 0.01 and p < 0.001) by naringin (40 and 80 mg/kg) treatment. It significantly and dose-dependently down-regulated (p < 0.01 and p < 0.001) renal KIM-1, Caspase-3, TGF-β, and TNF-α mRNA expression. Histopathological alteration induced in kidney and liver by sodium arsenite was reduced by naringin (40 and 80 mg/kg) treatment. In conclusion, naringin treatment ameliorates arsenic-induced renal and hepatic damage in rats due its antioxidant and anti-inflammatory properties via down-regulation of elevated oxido-nitrosative stress, KIM-1, Caspase-3, TGF-β, and TNF-α levels.

Neuroprotective efficacy of naringin on 3-nitropropionic acid-induced mitochondrial dysfunction through the modulation of Nrf2 signaling pathway in PC12 cells

Oxidative stress and mitochondrial dysfunction are implicated in neuronal apoptosis associated with Huntington's disease. Naringin is the flavanone present in grapefruit and related citrus species possess diverse pharmacological and therapeutic properties including antioxidant, anti-apoptotic, and neuroprotective properties. The aim of this study was to investigate the protective effect of naringin on 3-nitropropionic acid (3-NP)-induced neurotoxicity in pheochromocytoma cells (PC12) cells and to explore its mechanism of action. Naringin protects PC12 cells from 3-NP neurotoxicity, as evaluated the by cell viability assays. The lactate dehydrogenase release was decreased upon naringin treatment in 3-NP-induced PC12 cells. Naringin treatment enhances the antioxidant defense by increasing the activities of enzymatic antioxidants and the level of reduced glutathione. The increase in levels of reactive oxygen species and lipid peroxidation induced by 3-NP were significantly decreased by naringin. PC12 cells induced with 3-NP showed decrease in the mitochondrial membrane potential and mitochondrial respiratory complex enzymes, succinate dehydrogenase and cytochrome c oxidase activities, and it was significantly altered to near normal upon naringin treatment. Naringin reduced the 3-NP-induced apoptosis through the modulation in expressions of B-cell lymphoma 2 and Bcl-2-associated X protein. Further, naringin enhances the nuclear translocation of Nrf2 and induces the

NAD(P)H

quinone oxidoreductase-1 and Heme oxygenase-1 expressions through the phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway. Taken together, the above findings suggest that naringin augments cellular antioxidant defense capacity and reduces the 3-NP-induced neurotoxicity in PC12 cells through the PI-3K/Akt-dependent Nrf2 activation in PC12 cells.

Effect of glycosides based standardized fenugreek seed extract in bleomycin-induced pulmonary fibrosis in rats: Decisive role of Bax, Nrf2, NF-κB, Muc5ac, TNF-α and IL-1β

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive multifactorial disease with limited therapeutic options. Glycosides based standardized fenugreek seed extract (SFSE-G) possesses potent anti-inflammatory and anti-oxidant property.

AIM

To evaluate the efficacy of SFSE-G against bleomycin (BLM) induced pulmonary fibrosis by assessing behavioral, biochemical, molecular and ultrastructural changes in the laboratory rats.

MATERIALS AND METHODS

IPF was induced in male Sprague-Dawley rats by single intratracheal BLM (6IU/kg) injection followed by SFSE-G (5, 10, 20 and 40mg/kg, p.o.) or methylprednisolone (10mg/kg, p.o.) treatment for 28day. Various parameters were analyzed in lung and bronchoalveolar lavage fluid (BALF) after 14 and 28days of the drug treatment.

RESULTS

SFSE-G (20 and 40mg/kg, p.o.) administration significantly prevented the BLM induced alteration in body weight, lung index, lung function test and hematology. The altered total and differential cell count in BALF and blood was significantly prevented by SFSE-G treatment. The decreased peripheral blood oxygen content after BLM instillation was significantly increased by SFSE-G treatment. SFSE-G significantly enhanced the BALF and lung antioxidant status, through modulating the SOD, GSH, T-AOC, MDA, NO level and Nrf2, HO-1 mRNA expression. There was a significant reduction in lung 5-HT level by SFSE-G treatment. The altered mRNA expression of biomarkers of lung inflammation (TNF-α, IL-1β, IL-6 and IL-8), fibrosis (TGF-β, collagen-1, ET-1, Muc5ac, NF-κB, VEGF, Smad-3) and apoptosis (Bax, Bcl-2 and Caspase-3) were significantly prevented by SFSE-G treatment. BLM induced histological inflammatory and fibrotic insult in the lung were reduced by SFSE-G treatment. It also ameliorated BLM induced lung ultrastructural changes as observed by transmission electron microscopic studies. However, administration of SFSE-G (5mg/kg, p.o.) failed to show any protective effect against BLM-induced PF whereas SFSE-G (10mg/kg, p.o.) showed significant amelioration in BLM-induced PF except lung function test, BALF and lung antioxidant level.

CONCLUSION

SFSE-G showed anti-fibrotic efficacy executed through induction of Nrf2, which in turn may modulate anti-inflammatory molecules, inhibit fibrogenic molecules and decreased apoptosis to ameliorate BLM induced pulmonary fibrosis.

Effects of noninvasive positive pressure ventilation on oxygenation status and prognosis in patients with acute paraquat-induced lung injury

PURPOSE

The aim of this study was to evaluate the effects of noninvasive positive pressure ventilation (NIPPV) on oxygenation status and prognosis in patients with acute lung injury induced by paraquat (PQ) poisoning.

METHODS

Patients with acute PQ-induced lung injury treated with NIPPV were admitted to an emergency intensive care unit. Changes in oxygenation status (respiratory rate and the partial pressure of alveolar O2 and CO2 [PaO2 and PaCO2, respectively]) after initial NIPPV were observed. Differences in inspiratory pressure (PI) between nonsurvivors and survivors were compared. The relationship between PI and the prognosis of patients with acute PQ-induced lung injury was evaluated.

FINDINGS

A total of 86 patients (47 women, 39 men; mean age, 33.5 [24.5] years [range, 22-61 years]) were included. There were significant differences in respiratory rate, PaO2, and PaCO2 from before to after initial NIPPV (respiratory rate, 35 [14] vs 26 [16] min(-1) [P = 0.037]; PaO2, 61.8 [19.6] vs 73.5 [26.8] mm Hg [P = 0.046]; and PaCO2, 27.7 [16.4] vs 34.6 [19.2] mm Hg [P = 0.039]). The overall mortality rate was 75.6% (65/86) during a 28-day follow-up period. We observed a significant difference in initial PI (PIinit) between nonsurvivors and survivors (8.2 [4.3] vs 6.6 [3.8] cm H2O; P = 0.043). Furthermore, nonsurvivors had a greater maximal PI (PImax) than did survivors (21.6 [9.8] vs 15.4 [8.5] cm H2O; P = 0.022). Correlation analysis revealed that both PIinit and PImax were associated with a poor prognosis in patients with acute PQ-induced lung injury (PIinit, r = -0.29 [P = 0.038]; PImax, r = -0.31 [P = 0.042]).

IMPLICATIONS

NIPPV may effectively improve oxygenation status in patients with acute PQ-induced lung injury, thereby relieving dyspnea and promoting the recovery of pulmonary function. PIinit and PImax may be important determinants of prognosis in acute PQ-induced lung injury. These findings need further verification in a large-scale, multicenter, randomized controlled study that combines other factors with a relatively long-term follow-up.

Protective effects of intranasal curcumin on paraquot induced acute lung injury (ALI) in mice

Paraquot (PQ) is widely and commonly used as herbicide and has been reported to be hazardous as it causes lung injury. However, molecular mechanism underlying lung toxicity caused by PQ has not been elucidated. Curcumin, a known anti-inflammatory molecule derived from rhizomes of Curcuma longa has variety of pharmacological activities including free-radical scavenging properties but the protective effects of curcumin on PQ-induced acute lung injury (ALI) have not been studied. In this study, we aimed to study the effects of curcumin on ALI caused by PQ in male parke's strain mice which were challenged acutely by PQ (50mg/kg, i.p.) with or without curcumin an hour before (5mg/kg, i.n.) PQ intoxication. Lung specimens and the bronchoalveolar lavage fluid (BALF) were isolated for pathological and biochemical analysis after 48h of PQ exposure. Curcumin administration has significantly enhanced superoxide dismutase (SOD) and catalase activities. Lung wet/dry weight ratio, malondialdehyde (MDA) and lactate dehydrogenase (LDH) content, total cell number and myeloperoxidase (MPO) levels in BALF as well as neutrophil infiltration were attenuated by curcumin. Pathological studies also revealed that intranasal curcumin alleviate PQ-induced pulmonary damage and pro-inflammatory cytokine levels like tumor necrosis factor-α (TNF-α) and nitric oxide (NO). These results suggest that intranasal curcumin may directly target lungs and curcumin inhalers may prove to be effective in PQ-induced ALI treatment in near future.

Metallothioneins attenuate paraquat-induced acute lung injury in mice through the mechanisms of anti-oxidation and anti-apoptosis

Paraquat (PQ) is a widely used herbicide, and lung is the primary target of PQ poisoning. Metallothionein (MT) is a potent antioxidant and free radical scavenger, and has been shown to play a protective role in lung injury induced by different stressors. This study was undertaken to evaluate the protective potential of MT against PQ-induced acute lung injury using MT-I/II null (MT(-/-)) mice. Wild-type (MT(+/+)) mice and MT(-/-) mice were given one intragastric administration of 50mg/kg PQ for 24h, and it was revealed that MT(-/-) mice were more susceptible to PQ-induced acute lung injury than MT(+/+) mice evidenced by the following findings. As compared with MT(+/+) mice, MT(-/-) mice presented more severe histopathological lesions in the lung, higher pulmonary malondialdehyde content, and more reduced pulmonary antioxidative enzymes activities. PQ also induced more apoptosis in pneumocytes from MT(-/-) mice, and the expressions of apoptosis-related proteins Bax, Bcl-2, cleaved-caspase-3, and the ratio of Bax/Bcl-2 were all more significantly increased in PQ-treated MT(-/-) mice. Our results clearly demonstrate that endogenous MT can attenuate PQ-induced acute lung injury, possibly through the mechanisms of anti-oxidation and anti-apoptosis.

Effect of citrus flavonoids, naringin and naringenin, on metabolic syndrome and their mechanisms of action

Flavonoids are important natural compounds with diverse biologic activities. Citrus flavonoids constitute an important series of flavonoids. Naringin and its aglycone naringenin belong to this series of flavonoids and were found to display strong anti-inflammatory and antioxidant activities. Several lines of investigation suggest that naringin supplementation is beneficial for the treatment of obesity, diabetes, hypertension, and metabolic syndrome. A number of molecular mechanisms underlying its beneficial activities have been elucidated. However, their effect on obesity and metabolic disorder remains to be fully established. Moreover, the therapeutic uses of these flavonoids are significantly limited by the lack of adequate clinical evidence. This review aims to explore the biologic activities of these compounds, particularly on lipid metabolism in obesity, oxidative stress, and inflammation in context of metabolic syndrome.

Transforming growth factor-Beta inhibits heme oxygenase-1 expression in lung fibroblast through nuclear factor-kappa-B-dependent pathway

BACKGROUND

Heme oxygenase-1 (HO-1) contributes to the pathogenesis of pulmonary fibrosis. However, the expression of HO-1 in fibroblasts under fibrotic conditions has not been studied.

METHODS

This study was conducted to investigate the expression of HO-1 in lung fibroblasts from mice and humans under fibrotic conditions by Western blot.

RESULTS

We found that the expression of HO-1 was significantly decreased in lung fibroblasts isolated from bleomycin-challenged mice in comparison with control mice. Transforming growth factor-β (TGF-β) inhibited HO-1 expression and induced differentiation in human lung fibroblasts. Pretreatment with nuclear factor-κB (NF-κB) activation inhibitor or knockdown of the NF-κB p65 subunit attenuated TGF-β-induced inhibition of HO-1 expression and differentiation in human lung fibroblasts. Similarly, lysophosphatidic acid (LPA) induced TGF-β expression and decreased HO-1 expression in human lung fibroblasts. Interestingly, pretreatment with neutralized anti-TGF-β antibody attenuated LPA effects in human lung fibroblasts.

CONCLUSION

These data suggested that TGF-β inhibited HO-1 expression in human lung fibroblasts through activation of NF-κB.

New insights into antioxidant strategies against paraquat toxicity

Paraquat (PQ, 1,1'-dimethyl-4-4'-bipyridinium dichloride) is a highly toxic quaternary ammonium herbicide widely used in agriculture, it exerts its toxic effects mainly because of its redox cycle through the production of superoxide anions in organisms, leading to an imbalance in the redox state of the cell causing oxidative damage and finally cell death. The contribution of mitochondrial dysfunction including increased production of reactive oxygen species besides the reduction in oxygen consumption as well as in the activity of some respiratory complexes has emerged as a key component in the mechanisms through which PQ induces cell death. Although several aspects of PQ-mitochondria interaction remain to be clarified, recent advances have been conducted with reproducible results. Currently, there is no treatment for PQ poisoning; however, several studies taking into account oxidative stress as the main mechanism of PQ-induced toxicity suggest an antioxidant therapy as a viable alternative. In fact, it has been shown that the antioxidants naringin, sylimarin, edaravone, Bathysa cuspidata extracts, alpha-lipoic acid, pirfenidone, lysine acetylsalicylate, selenium, quercetin, C-phycocyanin, bacosides, and vitamin C may be useful in the treatment against PQ toxicity. The main mechanisms involved in the protective effect of these antioxidants include the reduction of oxidative stress and inflammation and the induction of antioxidant defenses. Interestingly, recent findings suggest that the induction of nuclear factor erythroid like-2 (Nrf2), a major regulator of the antioxidant response, by some of the above-mentioned antioxidants, has been involved in the protective effect against PQ-induced toxicity.

Structure-activity association of flavonoids in lung diseases

Flavonoids are polyphenolic compounds classified into flavonols, flavones, flavanones, isoflavones, catechins, anthocyanidins, and chalcones according to their chemical structures. They are abundantly found in Nature and over 8,000 flavonoids have from different sources, mainly plant materials, have been described. Recently reports have shown the valuable effects of flavonoids as antiviral, anti-allergic, antiplatelet, antitumor, antioxidant, and anti-inflammatory agents and interest in these compounds has been increasing since they can be helpful to human health. Several mechanisms of action are involved in the biological properties of flavonoids such as free radical scavenging, transition metal ion chelation, activation of survival genes and signaling pathways, regulation of mitochondrial function and modulation of inflammatory responses. The anti-inflammatory effects of flavonoids have been described in a number of studies in the literature, but not frequently associated to respiratory disease. Thus, this review aims to discuss the effects of different flavonoids in the control of lung inflammation in some disorders such as asthma, lung emphysema and acute respiratory distress syndrome and the possible mechanisms of action, as well as establish some structure-activity relationships between this biological potential and chemical profile of these compounds.

Six months chronic toxicological evaluation of naringin in Sprague-Dawley rats

Naringin is a flavonoid showing variable pharmacological properties and is distributed ubiquitously in plant foods. There is a paucity of reported data regarding its safety profile. In the present study, chronic toxicity studies of naringin was designed and conducted by oral gavage at doses of 0, 50, 250 and 1250 mg/kg in Sprague-Dawley (SD) rats for six months followed by 1-month recovery period. During the 6-month treatment period and one month recovery period, no mortality and toxicologically significant changes in clinical signs, opthalmoscopic examination, hematology, clinical biochemistry, serumsexhormone, macroscopic findings, organ weights and histopathological examination were noted and attributed to naringin administration. Although consecutive and/or isolated periods of significant body weights and food consumption decreases were relevant to naringin administration, they were not considered toxicologically significant. In addition, slight, non-pathological and reversible hair loss was noted during the 6-month treatment period and considered as a kind of change possibly relevant to naringin administration; however, it was not considered adverse change and to be of toxicological significance. Based on the results of this study, the no-observed-adverse-effect-level (NOAEL) of naringin in rats is greater than 1250 mg/kg/day when administered orally for 6 consecutive months.

Pharmacological Activities of Sijunzi Decoction Which Are Related to Its Antioxidant Properties

This paper introduces the antioxidant constituents and pharmacological effects of Sijunzi decoction by looking up literatures in recent years. Sijunzi decoction is composed of Ginseng, Atractylodes, Tuckahoe, and Glycyrrhiza. The antioxidant ingredients of Sijunzi decoction include paeonol, dauricine, naringin, and isoliquiritigenin. The study has proved that it possesses wide pharmacological effects of anticardiovascular diseases, antinervous system disease, antidiabetes, antimetabolic syndrome, and antitumor. Research on the antioxidant components of Sijunzi decoction and their targets is a promising study area in the future.

Protective role of andrographolide in bleomycin-induced pulmonary fibrosis in mice

Idiopathic pulmonary fibrosis (IPF) is a chronic devastating disease with poor prognosis. Multiple pathological processes, including inflammation, epithelial mesenchymal transition (EMT), apoptosis, and oxidative stress, are involved in the pathogenesis of IPF. Recent findings suggested that nuclear factor-κB (NF-κB) is constitutively activated in IPF and acts as a central regulator in the pathogenesis of IPF. The aim of our study was to reveal the value of andrographolide on bleomycin-induced inflammation and fibrosis in mice. The indicated dosages of andrographolide were administered in mice with bleomycin-induced pulmonary fibrosis. On day 21, cell counts of total cells, macrophages, neutrophils and lymphocytes, alone with TNF-α in bronchoalveolar lavage fluid (BALF) were measured. HE staining and Masson’s trichrome (MT) staining were used to observe the histological alterations of lungs. The Ashcroft score and hydroxyproline content of lungs were also measured. TGF-β1 and α-SMA mRNA and protein were analyzed. Activation of NF-κB was determined by western blotting and electrophoretic mobility shift assay (EMSA). On day 21 after bleomycin stimulation, andrographolide dose-dependently inhibited the inflammatory cells and TNF-α in BALF. Meanwhile, our data demonstrated that the Ashcroft score and hydroxyproline content of the bleomycin-stimulated lung were reduced by andrographolide administration. Furthermore, andrographloide suppressed TGF-β1 and α-SMA mRNA and protein expression in bleomycin-induced pulmonary fibrosis. Meanwhile, andrographolide significantly dose-dependently inhibited the ratio of phospho-NF-κB p65/total NF-κB p65 and NF-κB p65 DNA binding activities. Our findings indicate that andrographolide compromised bleomycin-induced pulmonary inflammation and fibrosis possibly through inactivation of NF-κB. Andrographolide holds promise as a novel drug to treat the devastating disease of pulmonary fibrosis.

Potential effects of medicinal plants and secondary metabolites on acute lung injury

Acute lung injury (ALI) is a life-threatening syndrome that causes high morbidity and mortality worldwide. ALI is characterized by increased permeability of the alveolar-capillary membrane, edema, uncontrolled neutrophils migration to the lung, and diffuse alveolar damage, leading to acute hypoxemic respiratory failure. Although corticosteroids remain the mainstay of ALI treatment, they cause significant side effects. Agents of natural origin, such as medicinal plants and their secondary metabolites, mainly those with very few side effects, could be excellent alternatives for ALI treatment. Several studies, including our own, have demonstrated that plant extracts and/or secondary metabolites isolated from them reduce most ALI phenotypes in experimental animal models, including neutrophil recruitment to the lung, the production of pro-inflammatory cytokines and chemokines, edema, and vascular permeability. In this review, we summarized these studies and described the anti-inflammatory activity of various plant extracts, such as Ginkgo biloba and Punica granatum, and such secondary metabolites as epigallocatechin-3-gallate and ellagic acid. In addition, we highlight the medical potential of these extracts and plant-derived compounds for treating of ALI.