Curcumin ameliorates severe influenza pneumonia via attenuating lung injury and regulating macrophage cytokines production

Curcumin, an active phenolic agent extract from the Curcuma longa, exhibits excellent anti‐cancer, anti‐inflammation, and neuroprotective effects. We aimed to investigate the anti‐influenza role of curcumin in vitro and in vivo. The effect of curcumin on replication of influenza A virus (IAV) was examined in human lung cancer cell line A549, as well as in a mouse model. Curcumin could inhibit IAV in vitro and alleviate the severity of the disease in the mouse after infection with IAV. The results also indicated that curcumin could trigger expression of Heme oxygenase‐1 in vivo and attenuate IAV‐induced injury to the lung tissue. Furthermore, curcumin could regulate immune response following IAV infection through inhibiting production of local inflammatory cytokines. In addition, curcumin was found to inhibit NF‐κB signalling in macrophages, as well as the subsequent production of cytokines/chemokines responding to IAV infection, by enhancing IκBα and AMPK. Our current study supports the potential of curcumin as a promising treatment against IAV infection, whose effect may be mediated by regulating immune response to prevent injury to the lung tissue.     

Curcumin‐loaded poly(ε‐caprolactone) nanofibres: Diabetic wound dressing with anti‐oxidant and anti‐inflammatory properties

• 1 Curcumin is a naturally occurring poly‐phenolic compound with a broad range of favourable biological functions, including anti‐cancer, anti‐oxidant and anti‐inflammatory activities. The low bioavailability and in vivo stability of curcumin require the development of suitable carrier vehicles to deliver the molecule in a sustained manner at therapeutic levels.
• 2 In the present study, we investigated the feasibility and potential of poly(caprolactone) (PCL) nanofibres as a delivery vehicle for curcumin for wound healing applications. By optimizing the electrospinning parameters, bead‐free curcumin‐loaded PCL nanofibres were developed.
• 3 The fibres showed sustained release of curcumin for 72 h and could be made to deliver a dose much lower than the reported cytotoxic concentration while remaining bioactive. Human foreskin fibroblast cells (HFF‐1) showed more than 70% viability on curcumin‐loaded nanofibres.
• 4 The anti‐oxidant activity of curcumin‐loaded nanofibres was demonstrated using an oxygen radical absorbance capacity (ORAC) assay and by the ability of the fibres to maintain the viability of HFF‐1 cells under conditions of oxidative stress.
• 5 The curcumin‐loaded nanofibres also reduced inflammatory induction, as evidenced by low levels of interleukin‐6 release from mouse monocyte–macrophages seeded onto the fibres following stimulation by Escherichia coli‐derived lipopolysaccharide.
• 6 The in vivo wound healing capability of the curcumin loaded PCL nanofibres was demonstrated by an increased rate of wound closure in a streptozotocin‐induced diabetic mice model.
• 7 These results demonstrate that the curcumin‐loaded PCL nanofibre matrix is bioactive and has potential as a wound dressing with anti‐oxidant and anti‐inflammatory properties.

     

Curcumin Inhibits 5‐Fluorouracil‐induced Up‐regulation of CXCL1 and CXCL2 of the Colon Associated with Attenuation of Diarrhoea Development

The compound 5‐fluorouracil (5‐FU) is used in cancer chemotherapy and is known to cause diarrhoea. We recently reported that chemokine (C‐X‐C motif) ligand 1 (CXCL1) and neutrophils in the colonic mucosa were markedly increased by the administration of 5‐FU in mice. Curcumin has anti‐inflammatory, antitumour and antioxidant properties. Therefore, we examined the effect of curcumin on 5‐FU‐induced diarrhoea development and CXCL1 and CXCL2 up‐regulation in the colon. Mice were given 5‐FU (50 mg/kg, i.p.) daily for 4 days. Curcumin (100 or 300 mg/kg, p.o.) was administered on the day before the first administration of 5‐FU and administered 30 min. before the administration of 5‐FU. Gene expression levels of CXCL1 and CXCL2 in the colon were examined by real‐time RT‐PCR. Curcumin reduced the 5‐FU‐induced diarrhoea development. Under this condition, the CXCL1 and CXCL2 gene up‐regulated by 5‐FU administration was inhibited by curcumin. The gene expression of CXCL1 and CXCL2 was also enhanced by 5‐FU application in vitro. The 5‐FU‐induced up‐regulated CXCL1 and CXCL2 gene expressions were inhibited by curcumin, Bay‐117082 and bortezomib, nuclear factor kappa B (NF‐κB) inhibitors, C646, a p300/cyclic adenosine monophosphate response element‐binding protein–histone acetyltransferase (HAT) inhibitor. In conclusion, these findings suggested that curcumin prevented the development of diarrhoea by inhibiting NF‐κB and HAT activation.     

Curcumin ameliorates asthmatic airway inflammation by activating nuclear factor‐E2‐related factor 2/haem oxygenase (HO)‐1 signalling pathway

Previous studies have shown that curcumin alleviates asthma in vivo. However, the relationship between curcumin and the nuclear factor‐E2‐related factor 2 (Nrf2)/haem oxygenase (HO)‐1 pathway in asthma treatment remains unknown. The aim of the present study was to investigate the mechanisms of curcumin involved in the amelioration of airway inflammation in a mouse asthma model. Curcumin was administrated to asthmatic mice, and bronchoalveolar lavage fluid was collected. Inflammatory cell infiltration was measured by Giemsa staining. Immunoglobulin E production in bronchoalveolar lavage fluid was measured by enzyme–linked immunosorbent assay. Histological analyses were evaluated with haematoxylin‐eosin and periodic acid‐Schiff staining. Airway hyperresponsiveness was examined by whole‐body plethysmography. Nuclear factor‐E2‐related factor 2, HO‐1, nuclear factor‐κB and inhibitory κB/p‐inhibitory κB levels in lung tissues were detected by western blot, and Nrf2 activity was measured by electrophoretic mobility shift assay. Tumour necrosis factor‐α, interleukin (IL)‐1β, and IL‐6 levels in the small interfering RNA‐transfected cells were detected by enzyme–linked immunosorbent assay. Curcumin treatment significantly reduced immunoglobulin E production, attenuated inflammatory cell accumulation and goblet cell hyperplasia, and ameliorated mucus secretion and airway hyperresponsiveness. Nuclear factor‐E2‐related factor 2 and HO‐1 levels in lung tissues were significantly increased. Meanwhile, Nrf2 activity was enhanced. Nuclear factor‐κB and p‐inhibitory κB levels were elevated in the lung tissue of ovalbumin‐challenged mice. Both were restored to normal levels after curcumin treatment. Haem oxygenase‐1 and nuclear Nrf2 levels were enhanced in dose‐ and time‐dependent manners in curcumin‐treated RAW264.7 cells. Curcumin blocked lipopolysaccharide‐upregulated expression of tumour necrosis factor‐α, IL‐1β, and IL‐6. After the cells were transfected with HO‐1 or Nrf2 small interfering RNA, lipopolysaccharide‐induced pro‐inflammation cytokine expression was significantly restored. In summary, curcumin might alleviate airway inflammation in asthma through the Nrf2/HO‐1 pathway, potentially making it an effective drug in asthma treatment.     

Synthesis and Anti‐Inflammatory Evaluation of Novel C66 Analogs for the Treatment of LPS‐Induced Acute Lung Injury

We previously reported a symmetric monocarbonyl analog of curcumin (MACs), C66, which demonstrated potential anti‐inflammatory activity and low toxicity. In continuation of our ongoing research, we designed and synthesized 34 asymmetric MACs based on C66 as a lead molecule. A majority of the C66 analogs effectively inhibited LPS induction of TNF‐α and IL‐6 expression. Additionally, a preliminary SAR was conducted. Furthermore, active compounds 4a11 and 4a16 were found to effectively reduce the W/D ratio in the lungs and the protein concentration in the bronchoalveolar lavage fluid (BALF). Meanwhile, a histopathological examination indicated that these two analogs significantly attenuate tissue injury in the lungs with LPS‐induced ALI rats. 4a11 and 4a16 also inhibited mRNA expression of several inflammatory cytokines, including TNF‐α, IL‐6, IL‐1β, COX‐2, ICAM‐1 and VCAM‐1, in the Beas‐2B cells after LPS challenge. Altogether, the data exhibit a series of new C66 analogs as promising anti‐inflammatory agents for the treatment of LPS‐induced ALI.     

Effect of curcumin on IL-17A mediated pulmonary AMPK kinase/cyclooxygenase-2 expressions via activation of NFκB in bleomycin-induced acute lung injury in vivo

Acute lung injury (ALI) remains to be the major cause of mortality. Bleomycin (BLM) injury activates the pro-inflammatory cytokine Interleukin L-17A which regulates the expression of COX-2 and inhibits P-AMPKα in BLM/IL-17A exposed mice upon activation of NFκB and other inflammatory molecules the actual mechanism behind which remains unclear. The current investigation was carried out to assess the role of IL-17A with COX-2 and P- AMPKα and to highlight the important contribution of adjunctive use of curcumin as a promising preventive strategy for the BLM-induced ALI. Immunofluorescence analysis reveals that the natural spice curcumin blocks the expressions of COX-2, NF-κB-p65, fibronectin (FBN), and expresses P-AMPKα in vivo. Curcumin could also suppress the expressions of NF-κB-p105 in BLM/IL-17A exposed mice. mRNA expressions showed reduced expressions of PDGFA, PDGFB, CTGF, IGF1, NFκB1, NFκB2, MMP-3, MMP-9, and MMP-14 on curcumin treatment. Our study implicates a critical role of AMPKα/COX- 2 in the emergence of pulmonary fibrosis via exerting the potential role of curcumin as an adjuvant anti-inflammatory therapeutic for treating lung injury.     

Complex effect of continuous curcumin exposure on human bone marrow‐derived mesenchymal stem cell regenerative properties through matrix metalloproteinase regulation

Curcumin has been reported to be beneficial for cancers, cardiovascular and neurodegenerative diseases, based on its anti‐oxidative, anti‐inflammation, anti‐tumorigenic and neuroprotective properties. With its high‐dose application, curcumin toxicity to systemic tissues is a reasonable concern. Here, we report the responses of human bone marrow‐derived mesenchymal stem cells (hBM‐MSCs) to continuous curcumin exposure. hBM‐MSCs were treated with 0.01‐100 μmol/L curcumin continuously in vitro for 7 days. 25 μmol/L curcumin or above significantly attenuated hBM‐MSC maintenance, whereas 10 μmol/L curcumin reduced hBM‐MSC proliferation and hindered their migration with increasing cell apoptosis. Besides, 5 μmol/L curcumin treatment inhibited hBM‐MSC adipogenic differentiation, but enhanced osteogenic differentiation, which depended on matrix metalloproteinase (MMP)‐13 expression and activity. Furthermore, curcumin treatment reduced MMP1 expression but up‐regulated the immunomodulatory gene IDO1 expression. In summary, this study revealed the complex effects of continuous curcumin exposure on hBM‐MSC maintenance and regenerative properties through MMP regulation. Given the complex effects of curcumin, its use for biomedical purposes should be carefully considered in treatment length and dosage.     

Curcumin alleviates glucocorticoid‐induced osteoporosis by protecting osteoblasts from apoptosis in vivo and in vitro

Curcumin, an active component of the rhizomes of Curcumin longa L., possesses broad anti‐inflammation and anti‐cancer properties. Curcumin was previously reported to be capable of protecting ovariectomized rats against osteoporosis. However, the effect of curcumin on glucocorticoid‐induced osteoporosis (GIO) is not yet clear. The present study investigated the effects of curcumin on dexamethasone (Dex)‐induced osteoporosis in vivo and Dex‐induced osteoblast apoptosis in vivo and in vitro. The GIO rat model was induced by subcutaneous injection of Dex for 60 days and verified to be successful as evidenced by the significantly decreased bone mineral density (BMD) determined using dual X‐ray absorptiometry. Subsequently, curcumin administration (100 mg/kg) for 60 days obviously increased BMD and bone‐alkaline phosphatase, decreased carboxy‐terminal collagen cross links, enhanced bone mechanical strength, and improved trabecular microstructure, thereby alleviating Dex‐induced osteoporosis. Mechanically, curcumin remarkably reversed Dex‐induced femoral osteoblast apoptosis in vivo. In cultured primary osteoblasts, pretreatment with curcumin concentration‐dependently decreased the number of Dex‐induced apoptotic osteoblasts by down‐regulating the ratio of Bax/Bcl‐2 as well as the levels of cleaved caspase‐3 and cleaved poly ADP‐ribose polymerase (PARP). Moreover, curcumin pretreatment activated extracellular signal regulated kinase (ERK) signalling in Dex‐induced osteoblasts by up‐regulating the expression level of p‐ERK1/2. Taken together, our study demonstrated that curcumin could ameliorate GIO by protecting osteoblasts from apoptosis, which was possibly related to the activation of the ERK pathway. The results suggest that curcumin may be a promising drug for prevention and treatment of GIO.     

Protective effect of Diosmin against benzo(a)pyrene‐induced lung injury in Swiss Albino Mice

Diosmin, a naturally occurring flavonoid commonly present in citrus fruit, is known to exhibit anti‐inflammatory, antimutagenic, antioxidant, and free radical scavenging as well as blood lipid lowering activities among others. Diosmin has also been used for the treatment of various diseases including diabetes mellitus and Alzheimer's disease. Our study explores the role of Diosmin in pulmonary toxicity (lung injury) induced by environmental contaminant benzo(a)pyrene [B(a)P]. Swiss Albino Mice (SAM) were administered with either Diosmin 100 or 200 mg/kg body weight daily for 14 days and then challenged with a single dose of B(a)P. On the 15th day, animals were sacrificed; lung tissues and blood were collected for molecular analysis. B(a)P administration in mice induced the thickening of lung epithelium, damaged alveolar architecture, and promoted inflammatory cell infiltration in the lung tissues. Also, B[a]P significantly increased the expression of NF‐kB, COX‐2, IL‐6, Bax, cleaved caspase 3, and cleaved PARP proteins and decreased antioxidant enzyme levels. Diosmin‐100 and Diosmin‐200 significantly attenuated the damage to lung epithelium, alveolar architecture, and reduced inflammatory cell infiltration in the lung tissues of mice. Diosmin significantly (P < .05) attenuated the levels of oxidative stress markers: lactate dehydrogenase and xanthine oxidase. A decrease in expression of NF‐kB, COX‐2, IL‐6, Bax, cleaved caspase 3, and cleaved PARP proteins in mice was challenged with B[a]P. Diosmin thus could be a promising therapeutic adjuvant against B[a]P‐induced oxidative stress and lung damage.     

Rutin improves endotoxin‐induced acute lung injury via inhibition of iNOS and VCAM‐1 expression

Endotoxins exist anywhere including in water pools, dust, humidifier systems, and machining fluids. The major causal factor is endotoxins in many serious diseases, such as fever, sepsis, multi‐organ failure, meningococcemia, and severe morbidities like neurologic disability, or hearing loss. Endotoxins are also called lipopolysaccharide (LPS) and are important pathogens of acute lung injury (ALI). Rutin has potential beneficial effects including anti‐inflammation, antioxidation, anti‐hyperlipidemia, and anti‐platelet aggregation. Pre‐treatment with rutin inhibited LPS‐induced neutrophil infiltration in the lungs. LPS‐induced expression of vascular cell adhesion molecule (VCAM)‐1 and inducible nitric oxide synthase (iNOS) was suppressed by rutin, but there was no influence on expression of intercellular adhesion molecule‐1 and cyclooxygenase‐2. In addition, activation of the nuclear factor (NF)κB was reduced by rutin. Furthermore, we found that the inhibitory concentration of rutin on expression of VCAM‐1 and iNOS was similar to NFκB activation. In conclusion, rutin is a potential protective agent for ALI via inhibition of neutrophil infiltration, expression of VCAM‐1 and iNOS, and NFκB activation. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 185–191, 2016.     

Endotoxin‐induced acute lung injury in mice is protected by 5,7‐dihydroxy‐8‐methoxyflavone via inhibition of oxidative stress and HIF‐1α

Up to date, the morbidity and mortality rates of acute lung injury (ALI) still rank high among clinical illnesses. Endotoxin, also called lipopolysaccharide (LPS), induced sepsis is the major cause for ALI. Beneficial biological effects, such as antioxidation, anti‐inflammation, and neuroprotection was found to express by 5,7‐dihydroxy‐8‐methoxyflavone (DHMF). The purpose of present study was to investigate the potential protective effects of DHMF and the possibile mechanisms involved in LPS‐induced ALI. In our experimental model, ALI was induced in mice by intratracheal injection of LPS, and DHMF at various concentrations was injected intraperitoneally for 30 min prior to LPS administration. Pretreatment with DHMF inhibited not only the histolopatholgical changes occurred in lungs but also leukocytes infiltration in LPS‐induced ALI. Decreased activity of antioxidative enzymes (AOE) such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) caused by LPS was reversed by DHMF. LPS‐induced lipid peroxidation HIF‐1α accumulation, NF‐κB phosphorylation, and IκBα degradation were all inhibited by DHMF. In addition, LPS‐induced expression of proinflammatory mediators such as TNF‐α and IL‐1β were also inhibited by 5,7‐dihydroxy‐8‐methoxyflavone. These results suggested that the protective mechanisms of DHMF on endotoxin‐induced ALI might be via up‐regulation of antioxidative enzymes, inhibition of NFκB phosphorylation, and HIF‐1α accumulation. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1700–1709, 2016.     

Placental Growth Factor Triggers Epithelial‐to‐Mesenchymal Transition‐like Changes in Rat Type II Alveolar Epithelial Cells: Activation of Nuclear Factor κB Signalling Pathway

Epithelial‐to‐mesenchymal transition (EMT) occurs frequently in lung epithelium in response to damage stimuli, such as inflammation and oxidative stress. Our group has already found an excessive release of placental growth factor (PLGF) in hyperoxic lung injury in newborn rodents. Nonetheless, whether this increased PLGF plays a role in mediating EMT process of alveolar epithelial cells (AECs) is unclear and requires further investigation. In this study, primary type II AECs were first isolated for neonatal Sprague Dawley (SD) rats and treated with different doses (25 or 100 ng/ml) of recombinant PLGF for 48 hr. As compared to the untreated AECs, exogenous PLGF induced a reduction in E‐cadherin (a critical epithelial maker) and increases in vimentin and fibronectin (mesenchymal markers) in a dose‐dependent manner. The higher dose was more potent in promoting the EMT‐like changes in AECs. We also found that PLGF promoted the degradation of nuclear factor κB (NFκB) inhibitor (IκBα), induced phosphorylation of NFκB p65 at Ser 536 and enhanced p65 nuclear translocation in primary AECs. In addition, the NFκB inhibitor BAY 11‐7082 partly counteracted PLGF‐induced alterations in EMT‐related proteins in rat AECs. In summary, our study demonstrates that exogenous PLGF can induce EMT‐like changes in type II AECs at least partly by activating NFκB signalling transduction in vitro. PLGF may play a role in driving fibrotic lesions and thus can be a promising target for lung diseases.     

α‐Lipoic acid prolongs survival and attenuates acute kidney injury in a rat model of sepsis

Acute kidney injury is a frequent and serious complication in patients with severe sepsis. α‐Lipoic acid (ALA), a naturally occurring dithiol compound, has been shown to possess anti‐inflammatory and anti‐oxidative properties. In the present study we investigated whether ALA could attenuate acute kidney injury and improve survival in a rat model of sepsis. Rats were subjected to caecal ligation and puncture (CLP) to induce sepsis. α‐Lipoic acid (200 mg/kg) was administered by oral gavage either immediately (early treatment) or 12 h after the surgical procedure (delayed treatment). Both early and delayed ALA treatment effectively prolonged survival, improved pathological damage in kidney tissues and reduced serum blood urea nitrogen and creatinine levels in CLP‐induced septic rats. Furthermore, early treatment with ALA markedly inhibited the release of tumour necrosis factor‐α, interleukin (IL)‐6 and IL‐1β into the serum and reduced mRNA and protein expression of inducible nitric oxide synthase and high mobility group box 1 in kidney tissues from CLP‐induced rats. Finally, CLP‐induced nuclear factor‐κB activation in kidney tissues was significantly suppressed by early ALA treatment. Together, the results indicate that ALA is able to reduce mortality and attenuate acute kidney injury associated with sepsis, possibly by anti‐inflammatory actions. α‐Lipoic acid may be a promising novel agent for the treatment of conditions associated with septic shock.     

Effects of 20-hydroxyecdysone, Leuzea carthamoides extracts, dexamethasone and their combinations on the NF-κB activation in HeLa cells

Objectives The plant steroid 20‐hydroxyecdysterone (20E) and 20E‐containing extracts from Leuzea carthamoides (Willd.) DC are sold with claims of anabolic and immunomodulatory effects. Yet their effect on the activation of nuclear factor kappa B (NF‐κB), a key player in immune response and cell fate, and their influence on the NF‐κB‐inhibiting activity of steroidal anti‐inflammatory drugs is still unknown. Methods The ability of 20E, Leuzea extracts and selected steroidal/non‐steroidal anti‐inflammatory drugs to influence the activation of NF‐κB was explored using, as the experimental model, human cervical cancer HeLa‐IL‐6 cells stably transfected with an IL‐6‐bound reporter gene. Effects on cell viability and proliferation were monitored (MTT assay). HPLC‐DAD was used to establish links between chemical patterns of Leuzea extracts and their bioactivities. Key findings 20E inhibited NF‐κB activation (IC50 31.8 µm ) but was less active than other plant metabolites (xanthohumol 3.8 µm , withaferin A 1.4 µm ). Leuzea extracts with high content in 20E had a fair activating effect, but in contrast, some extracts with low 20E content significantly inhibited NF‐κB activation at IC50s ranging from 3.5 to 6.2 µg/ml. Combination tests confirmed that 20E does not explain the NF‐κB modulation achieved by Leuzea extracts. The extracts but not 20E itself showed a significant modulation of the NF‐κB inhibitory effect of dexamethasone. Conclusions 20E is unlikely a major player in the NF‐κB inhibitory effects displayed by some Leuzea extracts in vitro. If confirmed in vivo, caution should prevail towards marketed Leuzea extracts that are non‐standardised or standardised on 20E only, since different starting materials and extracts may even cause opposite effects. More importantly, our results indicate the interaction potential of Leuzea with steroidal anti‐inflammatory drugs.     

Anti‐inflammatory properties of resveratrol in the retinas of type 2 diabetic rats

Resveratrol (trans‐3,5,4′‐trihydroxystilbene) is a nutritional supplement with anti‐inflammatory properties. The present study investigated the long‐term anti‐inflammatory property of resveratrol in the retinas of type 2 diabetic rats. Male Wistar rats were divided into four groups: normal control, diabetic control, resveratrol‐treated normal rats and resveratrol‐treated diabetic rats. Type 2 diabetes was induced by a single dose injection of streptozotocin (50 mg/kg; i.p.) 15 min after the administration of nicotinamide (110 mg/kg; i.p.) in 12‐h fasted rats (the streptozotocin–nicotinamide type 2 diabetic model). Oral resveratrol administration (5 mg/kg per day for 4 months) significantly improved glucose tolerance, and alleviated hyperglycemia and weight loss in diabetic rats. Furthermore, resveratrol administration significantly decreased the elevated levels of nuclear factor‐κB activity, and mRNA expression, tumour necrosis factor alpha level and apoptotic cells in the retinas of the diabetic rats. Furthermore, resveratrol did not significantly affect plasma insulin levels. Long‐term resveratrol administration has beneficial anti‐inflammatory properties in a rat model of diabetes. However, whether resveratrol exerts its effects directly or through reducing blood glucose levels requires further investigation.     

Resveratrol attenuates hyperoxia‐induced oxidative stress,inflammation and fibrosis and suppresses Wnt/β‐catenin signalling in lungs of neonatal rats

Although survival rate of infants born prematurely has been raised by supplemental oxygen treatment, it is followed by high morbidity of hyperoxia‐induced bronchopulmonary dysplasia. In this study, the effect of resveratrol on the lung injury was evaluated in hyperoxia‐exposed rats of preterm birth. The results demonstrated that hyperoxia led to thickened alveolar wall, simplified alveolar architecture and fibrosis. In addition, elevated methane dicarboxylic aldehyde level, decreased glutathione level and superoxide dismutase activity were also found in hyperoxic lungs, as well as the increased tumor necrosis factor‐α, interleukin‐1β and interleukin‐6 in the bronchoalveolar lavage fluid. Fibrotic‐associated proteins transforming growth factor‐β1, α‐smooth muscle actin, collagen I and fibronectin deposition were also found in interstitial substance of lungs. Furthermore, Wnt/β‐catenin signalling was found to be active in hyperoxia‐induced lungs. In addition, expression of SP‐C was increased and T1α was decreased in hyperoxia‐exposed lungs. Resveratrol intraperitoneal administration alleviated hyperoxia‐induced histological injury of lungs, regulated redox balance, decreased pro‐inflammatory cytokine release, and down‐regulated expression of fibrotic‐associated proteins. Furthermore, Wnt/β‐catenin signalling was also suppressed by resveratrol, as represented by diminished expression of lymphoid enhancer factor‐1, Wnt induced signalling protein‐1 and cyclin D1. In addition, the increase of SP‐C and decrease of T1α expression was prevented as well. The present study showed that resveratrol could protect lungs from hyperoxia‐induced injury through its antioxidant, anti‐inflammatory and anti‐fibrotic effects. The transdifferentiation of alveolar epithelial type II cells to alveolar epithelial type I cells promotion and Wnt/β‐catenin signalling suppression are also involved in the protective effect.     

Anti-inflammatory potential of Phaseolus calcaratus Roxburgh, a oriental medicine, on LPS-stimulated RAW 264.7 macrophages

Objectives The seed of Phaseolus calcaratus Roxburgh (PHCR) has traditionally been used as a herbal medicine, considered to have anti‐inflammatory potential. Here we examined the ability of PHCR seed extract to inhibit inflammatory responses of macrophages to bacterial toxin and the mechanism involved. Methods In the present study, we prepared four fractions from an ethanol extract of PHCR seed and investigated their effects on the production of nitric oxide and cytokines, and the expression of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)‐stimulated RAW 264.7 macrophage cells. Key findings The fractions inhibited LPS‐induced nitric oxide production and cyclooxygenase‐2 (COX‐2) expression in the cells. The ethyl acetate fraction at 100 µg/ml almost completely suppressed NO production, iNOS and COX‐2 expression, and TNF‐α and IL‐6 secretion in cells stimulated with LPS. The fraction also inhibited phosphorylation of extracellular signal‐regulated kinase (ERK) and p38 in LPS‐stimulated cells with the attendant suppression of IκBα nuclear translocation and nuclear factor (NF)‐κB activation. Furthermore, PHCR seed extracts contained a large number of phenolic compounds having antioxidant potentials against 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radicals and hydroxyl radicals. We identified catechin‐7‐O‐β‐d ‐glucopyranoside as one of the active compounds responsible for the biological activity of PHCR seed extract. Conclusions These results suggest for the first time that ethanol extracts from PHCR seed have anti‐inflammatory potential on LPS‐stimulated macrophages through the down‐regulation of ERK/p38‐ and NF‐κB‐mediated signalling pathways.     

Comprehensive lipid profiling of bleomycin‐induced lung injury

Drug‐induced lung injury is an adverse effect of drug treatment that can result in respiratory failure. Because lipid profiling could provide cutting‐edge understanding of the pathophysiology of toxicological responses, we performed lipidomic analyses of drug‐induced lung injury. We used a mouse model of bleomycin‐induced lung injury and followed the physiological responses at the acute inflammatory (day 2), inflammatory‐to‐fibrosis (day 7) and fibrosis (day 21) phases. The overall lipid profiles of plasma, lung and bronchoalveolar lavage fluid (BALF) revealed that drastic changes in lipids occurred in the lung and BALF, but not in the plasma, after 7 and 21 days of bleomycin treatment. In the lung, the levels of ether‐type phosphatidylethanolamines decreased, while those of phosphatidylcholines, bismonophosphatidic acids and cholesterol esters increased on days 7 and 21. In BALF, the global lipid levels increased on days 7 and 21, but only those of some lipids, such as phosphatidylglycerols/bismonophosphatidic acids and phosphatidylinositols, increased from day 2. The lung levels of prostaglandins, such as prostaglandin D₂, were elevated on day 2, and those of 5‐ and 15‐lipoxygenase metabolites of docosahexaenoic acid were elevated on day 7. In BALF, the levels of 12‐lipoxygenase metabolites of polyunsaturated fatty acids were elevated on day 7. Our comprehensive lipidomics approach suggested anti‐inflammatory responses in the inflammatory phase, phospholipidosis and anti‐inflammatory responses in the inflammatory‐to‐fibrosis phase, and increased oxidative stress and/or cell phenotypic transitions in the fibrosis phase. Understanding these molecular changes and potential mechanisms will help develop novel drugs to prevent or treat drug‐induced lung injury.