Search

Acute lung injury (ALI) is a life-threatening syndrome which causes a high mortality rate worldwide. In traditional medicine, lots of aromatic plants—such as some Thymus species—are used for treatment of various lung diseases including pertussis, bronchitis, and asthma. Thymol, one of the primary active constituent derived from Thymus vulgaris (thyme), has been reported to exhibit potent anti-microbial, anti-oxidant, and anti-inflammatory activities in vivo and in vitro. The present study aims to investigate the protective effects of thymol in lipopolysaccharide (LPS)-induced lung injury mice model. In LPS-challenged mice, treatment with thymol (100 mg/kg) before or after LPS challenge significantly improved pathological changes in lung tissues. Thymol also inhibited the LPS-induced inflammatory cells influx, TNF-α and IL-6 releases, and protein concentration in bronchoalveolar lavage fluid (BALF). Additionally, thymol markedly inhibited LPS-induced elevation of MDA and MPO levels, as well as reduction of SOD activity. Further study demonstrated that thymol effectively inhibited the NF-κB activation in the lung. Taken together, these results suggested that thymol might be useful in the therapy of acute lung injury.

Mollugin, a kind of naphthohydroquinone, is a major constituent isolated from Rubia cordifolia L. and demonstrated to possess anti-inflammatory activity in recent reports. However, the effects and mechanism of action of mollugin in inflammation have not been fully defined. The present study was therefore designed to investigate whether mollugin suppresses the inflammatory response in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Mollugin attenuated the LPS-induced expression of nitric oxide (NO), inducible nitric oxide synthase (iNOS), interleukin (IL)-1β and IL-6 but augmented the expression of tumor necrosis factor (TNF)-α. Mollugin did not inhibit the degradation of inhibitory kappa B (IκB)-α or the nuclear translocation of p65 nuclear factor-kappa B (NF-κB) but rather enhanced the phosphorylation of p65 subunits evoked by LPS. Mollugin did not inhibit the phosphorylation of extracellular-signal-related kinase (ERK) 1/2, p38, and c-Jun N-terminal kinase (JNK) 1/2 either. Mollugin significantly reduced the LPS-mediated phosphorylation of Janus kinase (JAK) 2, signal transducers and activators of transcription (STAT) 1 and STAT3. Molecular docking analysis showed that mollugin binds to JAK2 in a manner similar to that of AG490, a specific JAK2 inhibitor. We conclude that mollugin may be a JAK2 inhibitor and inhibits LPS-induced inflammatory responses by blocking the activation of the JAK-STAT pathway.

Standardized myrtol, an essential oil containing primarily cineole, limonene and α-pinene, has been used for treating nasosinusitis, bronchitis and chronic obstructive pulmonary disease (COPD).To investigate the effects of standardized myrtol in a model of acute lung injury (ALI) induced by lipopolysaccharides (LPS).Male BALB/c mice were treated with standardized myrtol for 1.5 h prior to exposure of atomized LPS. Six hours after LPS challenge, lung injury was determined by the neutrophil recruitment, cytokine levels and total protein concentration in the bronchoalveolar lavage fluid (BALF) and myeloperoxidase (MPO) activity in the lung tissue. Additionally, pathological changes and NF-κB activation in the lung were examined by haematoxylin and eosin staining and western blot, respectively.In LPS-challenged mice, standardized myrtol at a dose of 1200 mg/kg significantly inhibited the neutrophile counts (from 820.97 ± 142.44 to 280.42 ± 65.45, 10Together, these data suggest that standardized myrtol has the potential to protect against LPS-induced airway inflammation in a model of ALI.

Praeruptorin C, D, and E (PC, PD, and PE) are three pyranocoumarins isolated from the dried root of Peucedanum praeruptorum Dunn of Umbelliferae. In the present study, we investigated the anti-inflammatory effect of these compounds in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. Pyranocoumarins significantly inhibited LPS-induced production of nitric oxide, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). The mRNA and protein expressions of inducible nitric oxide synthase, IL-6, and TNF-α were also suppressed by these compounds. Both PD and PE exhibited greater anti-inflammatory activities than PC. Further study showed that pyranocoumarins suppressed the cytoplasmic loss of inhibitor κB-α protein and inhibited the translocation of NF-κB from cytoplasm to nucleus. In addition, pyranocoumarins suppressed LPS-induced STAT3 tyrosine phosphorylation. Taken together, the results suggest that pyranocoumarins may exert anti-inflammatory effects in LPS-stimulated RAW 264.7 macrophages through the inhibition of NF-κB and STAT3 activation.

Praeruptorin A (PA) is a pyranocoumarin compound isolated from the dried root of Peucedanum praeruptorum Dunn (Umbelliferae). However, the antiinflammatory effect of PA has not been reported. The present study investigated the antiinflammatory effect of PA in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. PA significantly inhibited the LPS-induced production of nitric oxide (NO), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). The mRNA and protein expressions of inducible nitric oxide synthase (iNOS), IL-1β and TNF-α were also suppressed by this compound. Further study showed that PA decreased the cytoplasmic loss of inhibitor κB-α (IκB-α) protein and inhibited the translocation of NF-κB from cytoplasm to nucleus. Taken together, the results suggest that PA may exert antiinflammatory effects in vitro in LPS-stimulated RAW 264.7 macrophages through inhibition of NF-κB signal pathway activation.

Acute lung injury is a life-threatening syndrome characterized by overwhelming lung inflammation and increased microvascular permeability, which causes a high mortality rate worldwide. The dry root of Peucedanum praeruptorum Dunn has been long used to treat respiratory diseases in China. In the present study, Praeruptorin A, C, D and E (PA, PC, PD and PE), four pyranocoumarins extracted from this herb, have been investigated for the pharmacological effects in experimental lung injury mouse models. In lipopolysaccharide (LPS) challenged mice, PA and PC did not show protective effect against lung injury at the dose of 80 mg/kg. However, PD and PE significantly inhibited the infiltration of activated polymorphonuclear leukocytes (PMNs) and decreased the levels of TNF-α and IL-6 in bronchoalveolar lavage fluid at the same dose. There was no statistically significant difference between PD and PE group. Further study demonstrated that PD and PE suppressed protein extravasations in bronchoalveolar lavage fluid, attenuated myeloperoxidase (MPO) activity and the pathological changes in the lung. Both PD and PE suppressed LPS induced Nuclear Factor-kappa B (NF-κB) pathway activation in the lung by decreasing the cytoplasmic loss of Inhibitor κB-α (IκB-α) protein and inhibiting the translocation of p65 from cytoplasm to nucleus. We also extended our study to acid-induced acute lung injury and found that these two compounds protected mice from hydrochloric acid (HCl)-induced lung injury by inhibiting PMNs influx, IL-6 release and protein exudation. Taken together, these results suggested that PD and PE might be useful in the therapy of lung injury.

Deregulation of receptor tyrosine kinase c-Met has been reported in human cancers and is considered as an attractive target for small molecule drug discovery. In this study, a series of spiro[indoline-3, 4′-piperidine]-2-ones were designed, synthesized and evaluated as novel c-Met inhibitors. The results showed that the majority of the compounds exhibited significant inhibitory effect on c-Met with IC50 values of 0.0147–17 μM in TR-FRET-based assay and IC50 values of 1.56–1400 μM in cell-based assay. Furthermore, our docking experiments verified the results and explained the molecular mechanism of eminent activities to c-Met.