Glabridin attenuates lipopolysaccharide-induced acute lung injury by inhibiting p38MAPK/ERK signaling pathway

Fabrication of sulfobutylether-β-cyclodextrin/glabridin inclusion complex for promoting bioactivities

As the main active compound of Glycyrrhiza glabra L., glabridin (GLD) has been shown to have multiple bioactivities, whereas the clinical application of GLD is restricted by its low water solubility. In this study, GLD was encapsulated into a sulfobutylether-β-cyclodextrin (SBE-β-CD)-based inclusion complex (SBE-β-CD/GLD) by the freeze-drying method. The materials characterization, antibacterial activity, stimulated cellular behavior and in vivo full-thickness diabetic wound healing ability of the hydrogels were assessed and analyzed. The successful encapsulation of the inclusion complex was confirmed by ultraviolet (UV) visible spectroscopy, Fourier transform infrared (FT-IR), X-ray diffractometer (XRD), scanning electron microscope (SEM), and nuclear magnetic resonance (NMR). SBE-β-CD as an excipient significantly enhances the water solubility of GLD, and SBE-β-CD/GLD showed excellent biocompatibility on human vascular endothelial cells (HUVECs) and erythrocytes. The SBE-β-CD/GLD inclusion complex exerted a pronounced antibacterial activity on Staphylococcus aureus and Escherichia coli in vitro. The SBE-β-CD/GLD inclusion complex markedly enhanced the antioxidant activity compared with free GLD. The SBE-β-CD/GLD inclusion complex potently accelerates the healing of full-thickness skin defects by inhibiting inflammation. The outcomes suggest that SBE-β-CD could be used as a promising drug delivery system for the clinical application of GLD.

A Comprehensive Review of Licorice: The Preparation, Chemical Composition, Bioactivities and Its Applications

Licorice (Glycyrrhiza) is a medicinal and food homologue of perennial plants derived from the dried roots and rhizomes of the genus Glycyrrhiza in the legume family. In recent years, the comprehensive utilization of licorice resources has attracted people's attention. It is widely utilized to treat diseases, health food products, food production, and other industrial applications. Furthermore, numerous bioactive components of licorice are found using advanced extraction processes, which mainly include polyphenols (flavonoids, dihydrostilbenes, benzofurans, and coumarin), triterpenoids, polysaccharides, alkaloids, and volatile oils, all of which have been reported to possess a variety of pharmacological characteristics, including anti-oxidant, anti-inflammatory, antibacterial, antiviral, anticancer, neuroprotective, antidepressive, antidiabetic, antiparasitic, antisex hormone, skin effects, anticariogenic, antitussive, and expectorant activities. Thereby, all of these compounds promote the development of novel and more effective licorice-derived products. This paper reviews the progress of research on extraction techniques, chemical composition, bioactivities, and applications of licorice to provide a reference for further development and application of licorice in different areas.

Hispidulin exerts a protective effect against oleic acid induced-ARDS in the rat via inhibition of ACE activity and MAPK pathway

This study investigates the protective role of Hispidulin on acute respiratory distress syndrome (ARDS) in rats. Rats were divided into three groups: control, ARDS, ARDS+ Hispidulin. The ARDS models were established by injecting rats with oleic acid. Hispidulin (100 mg/kg) was injected i.p. an hour before ARDS. Myeloperoxidase (MPO), Interleukin-8 (IL-8), Mitogen-activated protein kinases (MAPK), Lipid Peroxidation (LPO), Superoxide Dismutase (SOD), Glutathione (GSH), and Angiotensin-converting enzyme (ACE) were determined by ELISA. Tumor necrosis factor-alpha (TNF-α) expression was described by RT-qPCR. Caspase-3 immunostaining was performed to evaluate apoptosis. Compared with the model group, a significant decrease was observed in the MPO, IL-8, MAPK, ACE, LPO levels, and TNF-α expression in the ARDS+ Hispidulin group. Moreover, reduced caspase-3 immunoreactivity and activity of ACE were detected in the Hispidulin+ARDS group. The protective effect of Hispidulin treatment may act through inhibition of the ACE activity and then regulation of inflammatory cytokine level and alteration of apoptosis.

Hippophae rhamnoides Prevents Oleic Acid-Induced Acute Respiratory Distress Syndrome by Releasing Acetylcholinesterase Activity and Mitigation of Angiotensin-Converting Enzyme Level

Hippophae rhamnoides exhibit a wide variety of medicinal and pharmacological effects. The present study aims to determine the role of ethanol extract of H. rhamnoides on oleic acid (OA)-induced acute respiratory distress syndrome (ARDS) in rats. Male rats were randomly divided into the following groups: (I) Control, (II) OA, and (III) OA+H. rhamnoides. H. rhamnoides extract (500 mg/kg) was given orally for 2 weeks before OA in Group III. Levels of total antioxidant capacity, total oxidant status (TOS), myeloperoxidase (MPO), mitogen-activated protein kinase (MAPK), acetylcholinesterase (AChE), and angiotensin-converting enzyme (ACE) were quantified by enzyme-linked immunosorbent assay (ELISA). Real time quantitative polymerase chain reaction was utilized to evaluate the expression of nuclear factor kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, and matrix metalloproteinase 2 (MMP2). Also, Caspase-3 immunostaining and expression were performed to evaluate apoptosis. Compared with the OA group, there was a significantly decrease in the levels of MPO, TOS, MAPK, and ACE and in the expression of NF-κB, TNF-α, IL-6, MMP2, and Caspase-3 in the H. rhamnoides administration group. Moreover, the activity of AChE and level of TAS were substantially higher in the H. rhamnoides administration compared with the OA group. The findings in the study suggest that the protective effect of H. rhamnoides pretreatment may act through inhibition of the ACE activity, releasing AChE, regulation of inflammatory cytokine levels, and suppression of apoptotic process in ARDS.

Immunomodulatory effect of glabridin in ovalbumin induced allergic asthma and its comparison with methylprednisolone in a preclinical rodent model

Glabridin, a polyphenolic flavonoid derived from Glycyrrhiza glabra (licorice) roots, has shown anti-inflammatory and antioxidant properties. The current study sought to investigate glabridin's immunomodulatory effect in ovalbumin induced allergic asthma. Healthy male Wistar rats were divided into five groups. Group I served as a control group. Asthma was induced in groups II- IV. Groups III and IV were treated with glabridin (40 mg/kg) and methylprednisolone (15 mg/kg), respectively. Inflammatory cells counts were determined in blood and bronchoalveolar lavage fluid (BALF). Serum IgE levels and levels of catalase, superoxide dismutase and glutathione peroxidase in lung homogenate were measured. The levels of mRNA expression of pro-inflammatory, anti-inflammatory and oxidative stress markers were analysed. Delayed type hypersensitivity (DTH) and acute toxicity of glabridin were also checked. Glabridin significantly decreased inflammatory cells in the blood and BALF. It increased the concentration of antioxidant enzymes catalase, superoxide dismutase and glutathione peroxidase. Glabridin markedly decreased serum IgE levels and DTH when compared to asthmatic rats. It significantly alleviated the expression of TNF-α, IL-4, IL-5, CXCL1, iNOS, and NF-κB. Administering 10 times the therapeutic dose of glabridin did not show any signs of acute toxicity. Findings suggest that glabridin has the potential to ameliorate allergic asthma and its effects are comparable to those of methylprednisolone. The immunomodulatory effect of glabridin might be contributed by the suppression of pro-inflammatory cytokines, oxidative stress markers, IgE antibodies, and elevation of antioxidant enzymes, suggesting future study and clinical trials to propose it as a candidate to treat allergic asthma.

Synthetic Glabridin Derivatives Inhibit LPS-Induced Inflammation via MAPKs and NF-κB Pathways in RAW264.7 Macrophages

Glabridin is a polyphenolic compound with reported anti-inflammatory and anti-oxidative effects. In the previous study, we synthesized glabridin derivatives-HSG4112, (S)-HSG4112, and HGR4113-based on the structure-activity relationship study of glabridin to improve its biological efficacy and chemical stability. In the present study, we investigated the anti-inflammatory effects of the glabridin derivatives in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. We found that the synthetic glabridin derivatives significantly and dose-dependently suppressed the production of nitric oxide (NO) and prostaglandin E2 (PGE2), and decreased the level of inducible nitric oxygen synthase (iNOS) and cyclooxygenase-2 (COX-2) and the expression of pro-inflammatory cytokines interleukin-1β (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α). The synthetic glabridin derivatives inhibited the nuclear translocation of the NF-κB by inhibiting phosphorylation of the inhibitor of κB alpha (IκB-α), and distinctively inhibited the phosphorylation of ERK, JNK, and p38 MAPKs. In addition, the compounds increased the expression of antioxidant protein heme oxygenase (HO-1) by inducing nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) through ERK and p38 MAPKs. Taken together, these results indicate that the synthetic glabridin derivatives exert strong anti-inflammatory effects in LPS-stimulated macrophages through MAPKs and NF-κB pathways, and support their development as potential therapeutics against inflammatory diseases.

Review on the Diverse Biological Effects of Glabridin

Glabridin is a prenylated isoflavan from the roots of Glycyrrhiza glabra Linne and has posed great impact on the areas of drug development and medicine, due to various biological properties such as anti-inflammation, anti-oxidation, anti-tumor, anti-microorganism, bone protection, cardiovascular protection, neuroprotection, hepatoprotection, anti-obesity, and anti-diabetes. Many signaling pathways, including NF-κB, MAPK, Wnt/β-catenin, ERα/SRC-1, PI3K/AKT, and AMPK, have been implicated in the regulatory activities of glabridin. Interestingly, glabridin has been considered as an inhibitor of tyrosinase, P-glycoprotein (P-gp), and CYP2E1 and an activator of peroxisome proliferator-activated receptor γ (PPARγ), although their molecular regulating mechanisms still need further investigation. However, poor water solubility and low bioavailability have greatly limited the clinical applications of glabridin. Hopefully, several effective strategies, such as nanoemulsions, microneedles, and smartPearls formulation, have been developed for improvement.

Glabridin Plays Dual Action to Augment the Efficacy and Attenuate the Hepatotoxicity of Methotrexate in Arthritic Rats

Glabridin is chemically an isoflavane class of natural phenols and is found mainly in the roots of Glycyrrhiza glabra. It has several beneficial pharmacological actions for the management of inflammatory disorders as well as can counteract drug-induced toxic effects. On the other hand, methotrexate (MTX) is the first-line disease-modifying antirheumatic drug for the treatment of rheumatoid arthritis. However, its treatment is associated with major side effects like hepatotoxicity. In the quest to explore a suitable combination therapy that can improve the efficacy and reduce the hepatotoxicity of MTX, we hypothesized that glabridin might serve the purpose for which there is no literature precedent to date. We explored the antiarthritic efficacy of MTX in the presence or the absence of glabridin using Mycobacterium-induced arthritic model in rats. The results of reduction in paw swelling, inhibition of serum cytokines (TNF-α, IL-6, and IL-1β), and improvement in the bone joints from radiological and histopathological findings suggest that glabridin can substantially augment the antiarthritic efficacy of MTX. Further, results of concomitant glabridin treatment with MTX in the experimental time frame demonstrate that glabridin could considerably prevent the MTX-induced hepatic alteration in serum biochemical markers (SGPT and SGOT) and oxidative stress markers (malondialdehyde (MDA) and glutathione reduced (GSH)). Moreover, glabridin showed a marked effect in impeding the regulation of NF-κB/IκBα and Nrf2/Keap1 pathways in the hepatic tissues. The results of simultaneous administration of glabridin with MTX in the rat model indicate that glabridin had no pronounced effect of causing severe alteration in the pharmacokinetic behavior of MTX. In summary, glabridin can significantly potentiate the antiarthritic efficacy of MTX and can also minimize its hepatotoxicity via the inhibition of inflammation and oxidative stress. Further research should be performed to develop glabridin as a phytotherapeutics for the improved efficacy and better tolerability of MTX at the reduced dose level of MTX.

COVID-19 patient with B Cell Lymphoma co-morbidity managed with co-administration of Ayurvedic formulation

‘Renaissance took place in Chaos and plague’. It was COVID-19 pandemic, when world realized ayurveda co-interventions are praiseworthy even in acute, infective and fatal conditions like COVID-19. We report perhaps first case of COVID-19 patient with cancer managed with poly-herbal ayurvedic formulation and integrated approach. In the first wave of COVID-19 (June 2020), a 47 year old male with history of Chronic kidney disease and active B Cell Lymphoma complained of fever, malaise, cattarah and ageusia. He was found positive on RT-PCR which was done promptly and was later treated in home quarantine with antipyretics, Vitamin C and Madhav rasayan a polyherbal preparation containing Piper longum, Glycyrrhiza glabra, Eclipta alba, Achyranthes aspera, Embelia ribes and Aloe vera designed to modulate host response. It was challenging to treat a patient with cancer with immunocompromised status as he had recently finished his chemotherapy cycle (R–CHOP regimen). Patient well tolerated the intervention and recovered symptomatically. He did not developed any respiratory complications and oxygen saturation remained maintained. On 7th day RT-PCR was found to be negative. Plethora of literature is available on anti-viral and immunomodulatory efficacies of Ayurveda herbs based on in vitro studies. Such efficacies can be replicated at patient's level if supported with wisdom of Ayurveda epistemology. Early diagnosis on RT-PCR and early inception of ayurveda medicine and diet interventions might be crucial element for better recovery.

Potential therapeutic interventions of plant-derived isoflavones against acute lung injury

Acute lung injury (ALI) is a life-threatening syndrome that possibly leads to high morbidity and mortality as no therapy exists. Several natural ingredients with negligible adverse effects have recently been investigated to possibly inhibit the inflammatory pathways associated with ALI at the molecular level. Isoflavones, as phytoestrogenic compounds, are naturally occurring bioactive compounds that represent the most abundant category of plant polyphenols (Leguminosae family). A broad range of therapeutic activities of isoflavones, including antioxidants, chemopreventive, anti-inflammatory, antiallergic and antibacterial potentials, have been extensively documented in the literature. Our review exclusively focuses on the possible anti-inflammatory, antioxidant role of botanicals'-derived isoflavones against ALI and their immunomodulatory effect in experimentally induced ALI. Despite the limited scope covering their molecular mechanisms, isoflavones substantially contributed to protecting from ALI via inhibiting toll-like receptor 4 (TLR4)/Myd88/NF-κB pathway and subsequent cytokines, chemokines, and adherent proteins. Nonetheless, future research is suggested to fill the gap in elucidating the protective roles of isoflavones to alleviate ALI concerning antioxidant potentials, inhibition of the inflammatory pathways, and associated molecular mechanisms.

The inhibition of Mpro, the primary protease of COVID-19, by Poria cocos and its active compounds: a network pharmacology and molecular docking study

Poria cocos is a traditional Chinese medicine (TCM) that can clear dampness, promote diuresis, and strengthen the spleen and stomach. Poria cocos has been detected in many TCM compounds that are used for COVID-19 intervention. However, the active ingredients and mechanisms associated with the effect of Poria cocos on COVID-19 remain unclear. In this paper, the active ingredients of Poria cocos, along with their potential targets related to COVID-19, were screened using TCMSP, GeneCards, and other databases, by means of network pharmacology. We then investigated the active components, potential targets, and interactions, that are associated with COVID-19 intervention. The primary protease of COVID-19, Mpro, is currently a key target in the design of potential inhibitors. Molecular docking techniques and molecular dynamics simulations demonstrated that the active components of Poria cocos could bind stably to the active site of Mpro with high levels of binding activity. Pachymic acid is based on a triterpene structure and was identified as the main component of Poria cocos; its triterpene active component has low binding energy with Mpro. The pachymic acid of Mpro activity was further characterized and the IC₅₀ was determined to be 18.607 μmol L⁻¹. Our results indicate that pachymic acid exhibits a certain inhibitory effect on the Mpro protease.

The inhibition of Mpro, the primary protease of COVID-19, by Poria cocos.

The role of phytochemicals in sepsis: A mechanistic and therapeutic perspective

Sepsis and septic shock are still a leading cause of mortality and morbidity in intensive care units worldwide. Sepsis is an uncontrolled and excessive response of the innate immune system toward the invading infectious microbes, characterized by the hyper-production of pro-inflammatory mediators such as interleukin (IL)-1β, IL-6, tumor-necrosis factor (TNF)-α, and high-mobility group box 1 (HMGB1). In severe sepsis, the overwhelming production of pro-inflammatory cytokines and reactive oxygen species may compromise organ function and lead to the induction of abnormal apoptosis in different organs, resulting in multiple organ dysfunction syndrome and death. Hence, compounds that are able to attenuate inflammatory responses may have therapeutic potential for sepsis treatment. Understanding the pathophysiology and underlying molecular mechanisms of sepsis may provide useful insights in the discovery and development of new effective therapeutics. Therefore, numerous studies have invested much effort into elucidating the mechanisms involved with the onset and development of sepsis. The present review mainly focuses on the molecules and signaling pathways involved in the pathogenicity of sepsis. Additionally, several well-known natural bioactive herbal compounds and phytochemicals, which have shown protective and therapeutic effects with regard to sepsis, as well as their mechanisms of action, are presented. This review suggests that these phytochemicals are able to attenuate the overwhelming inflammatory responses developed during sepsis by modulating different signaling pathways. Moreover, the anti-inflammatory and cytoprotective activities of phytochemicals make them potent compounds to be included as complementary therapeutic agents in the diets of patients suffering from sepsis in an effort to alleviate sepsis and its life-threatening complications, such as multi-organ failure.

Glabridin Attenuates the Retinal Degeneration Induced by Sodium Iodate In Vitro and In Vivo

Background

Age-related macular degeneration (AMD) is one of the major causes of blindness in the elderly over the age of 60. AMD is divided into dry AMD and wet AMD. Although there are certain treatment methods for wet age-related macular degeneration (AMD), there are no effective treatments for dry AMD yet, and finding new drugs or treatment methods for dry AMD has become a priority. For this purpose, this study explored Glabridin (Glab), an isoflavane found in the root extract of licorice, which has never been investigated in relation to eye diseases.

Purpose

To investigate the effect of Glab on the sodium iodate (NaIO₃) induced retinal degeneration in vitro and in vivo.

Methods

In vitro, cell viability and cytotoxicity were tested with methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay among the groups of ARPE-19 cells. The cell apoptosis was tested with Hoechst 33342 staining and flow cytometry. The level of Reactive oxygen species (ROS) was measured to check the effect on oxidative stress. The protein expressions of phosphorylation of ERK1/2 and p38 were detected by Western blotting. In vivo, C57BL/6J mice were pretreated with Glab intraperitoneally for one week and continued for 4 weeks. NaIO₃ was given to mice through tail vein intravenous injection after 1 week of Glab administration. The retinas of mice were monitored by Optical coherence tomography (OCT) and electroretinography (ERG) at 1w, 2w, 3w, and 4w, respectively, followed by H&E staining.

Results

In vitro, the Glab protected the retinal pigment epithelial (RPE) cells against oxidative stress and apoptosis by inhibiting phosphorylation of ERK1/2 and the p38 MAPK pathway. In vivo, Glab significantly prevented retinal damage by stopping the progression of retinal degeneration and reducing the formation of deposits on the RPE layer induced by NaIO₃. According to the findings of electroretinogram (ERG), Glab helped to maintain the normal function of the retina.

Conclusion

Glabridin has a protective effect against retinal degeneration. It is suggested that Glab be further investigated for the treatment of retinal degeneration diseases.

Calreticulin Blockade Attenuates Murine Acute Lung Injury by Inducing Polarization of M2 Subtype Macrophages

Calreticulin (CALR) has anti-tumor effects by increasing dendritic cell maturation and tumor antigen presentation. However, whether CALR affects macrophages and modulates progression of acute respiratory distress syndrome/acute lung injury (ARDS/ALI) remains unknown. In this study, we discovered that CALR protein was highly expressed in the mice with LPS-induced ALI and CALR expression level was positively correlated to the severity of ALI. Commercial anti-CALR antibody (aCALR) can neutralize recombinant CALR (rCALR) and suppress the expression of TNF-alpha and IL-6 in the rCALR-treated macrophages. Blocking CALR activity by intraperitoneal (i.p.) administration of aCALR significantly suppressed ALI, accompanied with lower total cell counts, neutrophil and T cell infiltration in bronchoalveolar lavage (BAL) and lung tissues. The expression of CXCL15, IL-6, IL-1beta, TNF-alpha, and CALR were significantly reduced, in association with more polarization of Siglec F+CD206+M2 subtype macrophages in the aCALR-treated mice. Pre-depletion of circulating monocytes did not abolish the aCALR-mediated suppression of ALI. Further analysis in bone marrow-derived macrophages (BMDMs) showed that aCALR suppressed the expression of CD80, IL-6, IL-1beta, IL-18, NLRP3, and p-p38 MAPK; but enhanced the expression of CD206 and IL-10. In addition, we observed more expression and phosphorylation of STAT6 in the aCALR-treated BMDM. Lack of STAT6 resulted in comparable and slightly higher expression of CALR, TNF-alpha and IL-6 in the aCALR-treated STAT6-/- BMDMs than the untreated cells. Therefore, we conclude that CALR is a novel biomarker in the evaluation of ALI. Blocking CALR activity by aCALR effectively suppressed ALI independent of circulating monocytes. Siglec F+CD206+M2 subtype macrophages and p38 MAPK/STAT6 signaling pathway played important role in the immune regulation of aCALR. Blocking CALR activity is a promising therapeutic approach in the treatment of ARDS/ALI.

Exosomal miR-451 from human umbilical cord mesenchymal stem cells attenuates burn-induced acute lung injury

BACKGROUND

The aim of this study was to investigate the molecular mechanism of human umbilical cord mesenchymal stem cells (MSCs)-derived exosomes (hUCMSC-Exos) in regulating burn-induced acute lung injury (ALI).

METHODS

In this study, we initially isolated exosomes from hUCMSCs and identified them by transmission electron microscopy. The expression of the protein markers CD9 and CD63 in the exosomes was determined by western blot analysis. The expression of miR-451 in the hUCMSC-Exos was determined by qRT-PCR. The levels of TNF-α, IL-1β, and IL-6 in lung tissues and serum as well as the levels of malondialdehyde, myeloperoxidase, superoxide dismutase in lung tissues were detected by ELISA. Hematoxylin-eosin stain was used to observe the morphological changes of lung tissues after burn. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assays were performed to detect apoptosis in lung tissues after burn. The expression of proteins related to the Toll-like receptor 4 (TLR4)/NF-κB signaling pathway in lung tissues after burn was analyzed by western blotting.

RESULTS

Our results showed that hUCMSC-Exos successfully decreased TNF-α, IL-1β, and IL-6 levels in rats after burn, and this reduction was reversed when the miR-451 expression in the hUCMSC-Exo group was inhibited. HUCMSC-Exo-derived miR-451 improves ALI via the TLR4/NF-κB pathway.

CONCLUSION

We demonstrated that exosomes derived from hUCMSCs mediate miR-451 to attenuate burn-induced ALI.

Protective Effect and Mechanism of Alprostadil in Acute Respiratory Distress Syndrome Induced by Oleic Acid in Rats

BACKGROUND This study investigated the role and mechanism of alprostadil in acute respiratory distress syndrome (ARDS) induced by oleic acid (OA) in rats. MATERIAL AND METHODS Sprague-Dawley rats were randomly divided into control, OA model, and OA + Alprostadil (2.5, 5, and 10 μg/kg, respectively) groups. The ARDS model was induced by femoral vein injection of OA, and alprostadil was administrated immediately. Lung injury was evaluated by lung wet-dry weight ratio (W/D) and histological analyses. Expressions of ACE, inflammatory mediators, apoptotic-related proteins, and proteins in the MAPKs and NF-κB signaling pathways were determined by Western blot or immunohistochemical staining. RESULTS Compared with the control group, the OA model group had significantly increased W/D, lung injury score, and collagen deposition at 3 h after OA injection. However, alprostadil (10 μg/kg) treatment significantly reduced OA-induced elevation of these indicators. Additionally, OA-induced expression of TNF-α and IL-1β were suppressed by alprostadil. The OA-induced activation of nuclear factor (NF) κB p65 was also reduced by alprostadil. Furthermore, we found that Alprostadil had an inhibitory effect on the phosphorylation of JNK, ERK1/2, and p38 MAPKs. Alprostadil inhibited Bax but increased Bcl-2, indicating a suppressive role in apoptosis. Remarkably increased expression of ACE in the OA model group was observed, which was decreased by alprostadil. CONCLUSIONS Alprostadil has a protective effect on ARDS induced by OA in rats, possibly through inhibiting apoptosis, suppressing the activation of MAPKs and NF-κB signaling pathways, and decreasing ACE protein expression. Therefore, the use of alprostadil in clinical ARDS treatment is promising.

Geraniol alleviates LPS-induced acute lung injury in mice via inhibiting inflammation and apoptosis

Geraniol (GOH), a special type of acyclic monoterpene alcohol, has been widely used to treat many diseases associated with inflammation and apoptosis. Acute lung injury (ALI) is a common clinical disease in humans characterized by pulmonary inflammation and apoptosis. In the present study, we investigated the protective effects of GOH in a mouse model of ALI induced by the intranasal administration of lipopolysaccharide (LPS) and elucidated the underlying molecular mechanisms in RAW 264.7 cells. In vivo, GOH treatment markedly ameliorated pathological injury and pulmonary cell apoptosis and reduced the wet/dry (W/D) weight ratio of lungs, myeloperoxidase (MPO) activity and the production of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α). In vitro, the levels of pro-inflammatory cytokines, iNOS and COX-2 were significantly increased in LPS-stimulated RAW 264.7 cells, an effect that was decreased by GOH treatment. Moreover, GOH treatment dramatically reduced the expression of Toll-like receptor 4 (TLR4) and then prevented the nuclear factor-κB (NF-κB) activation. GOH treatment also promoted anti-apoptotic Bcl-2 expression and inhibited pro-apoptotic Bax and Caspase-3 expression. Furthermore, knockdown of TLR4 expression exerted a similar effect and inhibited the phosphorylation of p65, as well as the Bax and Caspase-3 expression. Taken together, these results suggest that GOH treatment alleviates LPS-induced ALI via inhibiting pulmonary inflammation and apoptosis, a finding that might be associated with the inhibition of TLR4-mediated NF-κB and Bcl-2/Bax signalling pathways.