Bronchoalveolar cytokine profile differentiates Pulmonary Langerhans cell histiocytosis patients from other smoking-related interstitial lung diseases.

BACKGROUND: Pulmonary Langerhans cell histiocytosis (PLCH) is a rare interstitial lung disease (ILD) associated with smoking, whose definitive diagnosis requires the exclusion of other forms of ILD and a compatible surgical lung biopsy. Bronchoalveolar lavage (BAL) is commonly proposed for the diagnosis of ILD, including PLCH, but the diagnostic value of this technique is limited. Here, we have analyzed the levels of a panel of cytokines and chemokines in BAL from PLCH patients, in order to identify a distinct immune profile to discriminate PLCH from other smoking related-ILD (SR-ILD), and comparing the results with idiopathic pulmonary fibrosis (IPF) as another disease in which smoking is considered a risk factor. METHODS: BAL samples were collected from thirty-six patients with different ILD, including seven patients with PLCH, sixteen with SR-ILD and thirteen with IPF. Inflammatory profiles were analyzed using the Human Cytokine Membrane Antibody Array. Principal component analysis (PCA) was performed to reduce dimensionality and protein-protein interaction (PPI) network analysis using STRING 11.5 database were conducted. Finally, Random forest (RF) method was used to build a prediction model. RESULTS: We have found significant differences (p < 0.05) on thirty-two cytokines/chemokines when comparing BAL from PLCH patients with at least one of the other ILD. Four main groups of similarly regulated cytokines were established, identifying distinct sets of markers for each cluster. Exploratory analysis using PCA (principal component analysis) showed clustering and separation of patients, with the two first components capturing 69.69% of the total variance. Levels of TARC/CCL17, leptin, oncostatin M (OSM) and IP-10/CXCL10 were associated with lung function parameters, showing positive correlation with FVC. Finally, random forest (RF) algorithm demonstrates that PLCH patients can be differentiated from the other ILDs based solely on inflammatory profile (accuracy 96.25%). CONCLUSIONS: Our results show that patients with PLCH exhibit a distinct BAL immune profile to SR-ILD and IPF. PCA analysis and RF model identify a specific immune profile useful for discriminating PLCH.

Visualization of Lipid Droplets in the Alveolar Macrophage Cell Line MH-S with Live-cell Imaging by 3D Holotomographic Microscopy (Nanolive).

Lipid droplets (LD), triglycerides and sterol esters among them, are well known for their capacity as lipid storage organelles. Recently, they have emerged as critical cytoplasmic structures involved in numerous biological functions. LD storage is generated de novo by the cell and provides an energy reserve, lipid precursors, and cell protection. Moreover, LD accumulation can be observed in some pathologies as obesity, atherosclerosis, or lung diseases. Fluorescence imaging techniques are the most widely used techniques to visualize cellular compartments in live cells, including LD. Nevertheless, presence of fluorophores can damage subcellular components and induce cytotoxicity, or even alter the dynamics of the organelles. As an alternative to fluorescence microscopy, label-free techniques such as stimulated Raman scattering and coherent anti-stokes Raman scattering microscopy offer a solution to avoid the undesirable effects caused by dyes and fluorescent proteins, but are expensive and complex. Here, we describe a label-free method using live-cell imaging by 3D holotomographic microscopy (Nanolive) to visualize LD accumulation in the MH-S alveolar macrophage cell line after treatment with oleic acid, a monounsaturated fatty acid that promotes lipid accumulation.

Synthesis of Quinoline and Dihydroquinoline Embelin Derivatives as Cardioprotective Agents.

A set of new dihydroquinoline embelin derivatives was obtained from the reaction of the natural benzoquinone embelin (1) with anilines and aromatic aldehydes in the presence of AgOTf. The synthesis of these compounds involves the formation of a Knoevenagel adduct, followed by nucleophilic addition of aniline and subsequent electrocyclic ring closure. The scope of the reaction regarding the aldehydes and anilines was determined. Quinoline derivatives were also obtained from the corresponding dihydroquinolines under oxidation with DDQ. The cardioprotective activity of the synthesized compounds was screened using a doxorubicin-induced cardiotoxicity model in H9c2 cardiomyocytes. Some structure-activity relationships were outlined, and the best activities were achieved with quinoline-embelin derivatives having a 4-nitrophenyl group attached at the pyridine ring. The obtained results indicated that embelin derivatives 4i, 6a, 6d, 6k, and 6m could have potential as cardioprotective agents, as they attenuated a DOX-induced cardiotoxicity effect acting on oxidative stress and apoptosis.

Phenolic and quinone methide nor-triterpenes as selective NLRP3 inflammasome inhibitors.

Dysregulated inflammasome activity, particularly of the NLRP3 inflammasome, is associated with the development of several inflammatory diseases. The study of molecules directly targeting NLRP3 is an emerging field in the discovery of new therapeutic compounds for the treatment of inflammatory disorders. Friedelane triterpenes are biologically active phytochemicals having a wide range of activities including anti-inflammatory effects. In this work, we evaluated the potential anti-inflammatory activity of phenolic and quinonemethide nor-triterpenes (1-11) isolated from Maytenus retusa and some semisynthetic derivatives (12-16) through inhibition of the NLRP3 inflammasome in macrophages. Among them, we found that triterpenes 6 and 14 were the most potent, showing markedly reduced caspase-1 activity, IL-1ß secretion (IC50 = 1.15 µM and 0.19 µM, respectively), and pyroptosis (IC50 = 2.21 µM and 0.13 µM, respectively). Further characterization confirmed their selective inhibition of NLRP3 inflammasome in both canonical and non-canonical activation pathways with no effects on AIM2 or NLRC4 inflammasome activation.

Labdane conjugates protect cardiomyocytes from doxorubicin-induced cardiotoxicity.

The cardiovascular side effects associated with doxorubicin (DOX), a wide spectrum anticancer drug, have limited its clinical application. Therefore, to explore novel strategies with cardioprotective effects, a series of new labdane conjugates were prepared (6a-6c and 8a-8d) from the natural diterpene labdanodiol (1). These hybrid compounds contain anti-inflammatory privileged structures such as naphthalimide, naphthoquinone, and furanonaphthoquinone. Biological activity of these conjugates against DOX-induced cardiotoxicity was tested in vitro and the potential molecular mechanisms of protective effects were explored in H9c2 cardiomyocytes. Three compounds 6c, 8a, and 8b significantly improved cardiomyocyte survival, via inhibition of reactive oxygen species-mediated mitogen-activated protein kinase signaling pathways (extracellular signal-regulated kinase and c-Jun N-terminal kinase) and autophagy mediated by Akt activation. Some structure-activity relationships were outlined, and the best activity was achieved with the labdane-furonaphthoquinone conjugate 8a having an N-cyclohexyl substituent. The findings of this study pave the way for further investigations to obtain more compounds with potential cardioprotective activity.

Dehydroisohispanolone as a Promising NLRP3 Inhibitor Agent: Bioevaluation and Molecular Docking.

Dehydroisohispanolone (DIH), is a labdane diterpene that has exhibited anti-inflammatory activity via inhibition of NF-κB activation, although its potential effects on inflammasome activation remain unexplored. This study aims to elucidate whether DIH modulates NLR family pyrin domain-containing protein 3 (NLRP3) inflammasome in macrophages. Our findings show that DIH inhibited NLRP3 activation triggered by Nigericin (Nig), adenosine triphosphate (ATP) and monosodium urate (MSU) crystals, indicating broad inhibitory effects. DIH significantly attenuated caspase-1 activation and secretion of the interleukin-1ß (IL-1ß) in J774A.1 cells. Interestingly, the protein expressions of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), pro-caspase-1 and pro-IL-1ß were not affected by DIH treatment. Furthermore, we found that DIH pretreatment also inhibited the lipopolysaccharide (LPS)-induced NLRP3 inflammasome priming stage. In addition, DIH alleviated pyroptosis mediated by NLRP3 inflammasome activation. Similar results on IL-1ß release were observed in Nig-activated bone marrow-derived macrophages (BMDMs). Covalent molecular docking analysis revealed that DIH fits well into the ATP-binding site of NLRP3 protein, forming a covalent bond with Cys415. In conclusion, our experiments show that DIH is an effective NLRP3 inflammasome inhibitor and provide new evidence for its application in the therapy of inflammation-related diseases.

Dehydrohispanolone Derivatives Attenuate the Inflammatory Response through the Modulation of Inflammasome Activation.

The NLRP3 inflammasome plays a critical role in inflammation-mediated human diseases and represents a promising drug target for novel anti-inflammatory therapies. Hispanolone is a labdane diterpenoid isolated from the aerial parts of Ballota species. This diterpenoid and some derivatives have demonstrated anti-inflammatory effects in classical inflammatory pathways. In the present study, a series of dehydrohispanolone derivatives (1-19) was synthesized, and their anti-inflammatory activities toward NLRP3 inflammasome activation were evaluated. The structures of the dehydrohispanolone analogues produced were elucidated by NMR spectroscopy and mass spectrometry. Four derivatives significantly inhibited IL-1ß secretion, with 15 and 18 being the most active (IC50 = 18.7 and 13.8 µM, respectively). Analysis of IL-1ß and caspase-1 expression revealed that the new diterpenoids 15 and 18 are selective inhibitors of the NLRP3 inflammasome, reinforcing the previously demonstrated anti-inflammatory properties of hispanolone derivatives.

Current status of terpenoids as inflammasome inhibitors.

Increasing evidence supports NLRP3 inflammasome as a new target to control inflammation. Dysregulation of NLRP3 inflammasome has been reported to be involved in the pathogenesis of several human inflammatory diseases. However, no NLRP3 inflammasome inhibitors are available in clinic. Terpenoids are natural products with multi-target activities against inflammation. Recent studies have revealed that these compounds are capable of inhibiting the activation of NLRP3 inflammasome in several mouse models of NLRP3 inflammasome-related pathogenesis. Thus, terpenoids represent an interesting pharmacological approach for the treatment of inflammatory diseases as they are endowed with a dual mechanism of inhibition of NF-KB transcription factor and inflammasome activation, both critically involved in their anti-inflammatory effects. This work provides an overview of the current knowledge on the therapeutic potential of terpenoids as NLRP3 inflammasome inhibitors.

α-Hispanolol Induces Apoptosis and Suppresses Migration and Invasion of Glioblastoma Cells Likely via Downregulation of MMP-2/9 Expression and p38MAPK Attenuation.

α-Hispanolol (α-H) is a labdane diterpenoid that has been shown to induce apoptosis in several human cancer cells. However, the effect of α-H in human glioblastoma cells has not been described. In the present work, we have investigated the effects of α-H on apoptosis, migration, and invasion of human glioblastoma cells with the aim of identifying the molecular targets underlying its mechanism of action. The results revealed that α-H showed significant cytotoxicity against human glioma cancer cell lines U87 and U373 in a concentration- and time-dependent manner. This effect was higher in U87 cells and linked to apoptosis, as revealed the increased percentage of sub-G1 population by cell cycle analysis and acquisition of typical features of apoptotic cell morphology. Apoptosis was also confirmed by significant presence of annexin V-positive cells and caspase activation. Pretreatment with caspase inhibitors diminishes the activities of caspase 8, 9, and 3 and maintains the percentage of viable glioblastoma cells, indicating that α-H induced cell apoptosis through both the extrinsic and the intrinsic pathways. Moreover, we also found that α-H downregulated the anti-apoptotic Bcl-2 and Bcl-xL proteins and activated the pro-apoptotic Bid and Bax proteins. On the other hand, α-H exhibited inhibitory effects on the migration and invasion of U87 cells in a concentration-dependent manner. Furthermore, additional experiments showed that α-H treatment reduced the enzymatic activities and protein levels of matrix metalloproteinase MMP-2 and MMP-9 and increased the expression of TIMP-1 inhibitor, probably via p38MAPK regulation. Finally, xenograft assays confirmed the anti-glioma efficacy of α-H. Taken together, these findings suggest that α-H may exert anti-tumoral effects in vitro and in vivo through the inhibition of cell proliferation and invasion as well as by the induction of apoptosis in human glioblastoma cells. This research describes α-H as a new drug that may improve the therapeutic efficacy against glioblastoma tumors.

NFATc3 controls tumour growth by regulating proliferation and migration of human astroglioma cells.

Calcium/Calcineurin/Nuclear Factor of Activated T cells (Ca/CN/NFAT) signalling pathway is the main calcium (Ca2+) dependent signalling pathway involved in the homeostasis of brain tissue. Here, we study the presence of NFATc members in human glioma by using U251 cells and a collection of primary human glioblastoma (hGB) cell lines. We show that NFATc3 member is the predominant member. Furthermore, by using constitutive active NFATc3 mutant and shRNA lentiviral vectors to achieve specific silencing of this NFATc member, we describe cytokines and molecules regulated by this pathway which are required for the normal biology of cancer cells. Implanting U251 in an orthotopic intracranial assay, we show that specific NFATc3 silencing has a role in tumour growth. In addition NFATc3 knock-down affects both the proliferation and migration capacities of glioma cells in vitro. Our data open the possibility of NFATc3 as a target for the treatment of glioma.

Metal Complexes of Natural Product Like-compounds with Antitumor Activity.

Cancer continues to be one of the major causes of death worldwide. Despite many advances in the understanding of this complex disease, new approaches are needed to improve the efficacy of current therapeutic treatments against aggressive tumors. Natural products are one of the most consistently successful sources of drug leads. In recent decades, research activity into the clinical potential of this class of compounds in cancer has increased. Furthermore, a highly promising field is the use of metals and their complexes in the design and development of metal-based drugs for the treatment of cancer. Metal complexes offer unique opportunities due to their ability to alter pharmacology, improving the efficacy and/or reducing the negative side effects of drug molecules. In addition, transition metals as copper, iron, and manganese, among others, can interact with active sites of enzymes, playing important roles in multiple biological processes. Thus, these complexes not only possess higher activities but also reach their targets more efficiently. This review article highlights recent advances on the emerging and expanding field of metal-based drugs. The emphasis is on new therapeutic strategies consisting of metal complexes with natural product like-compounds as a starting point for the rational design of new antitumor agents.

Semisynthesis and Inhibitory Effects of Solidagenone Derivatives on TLR-Mediated Inflammatory Responses.

A series of nine derivatives (2⁻10) were prepared from the diterpene solidagenone (1) and their structures were elucidated by means of spectroscopic studies. Their ability to inhibit inflammatory responses elicited in peritoneal macrophages by TLR ligands was investigated. Compounds 5 and 6 showed significant anti-inflammatory effects, as they inhibited the protein expression of nitric oxide synthase (NOS-2), cyclooxygenase-2 (COX-2), and cytokine production (TNF-α, IL-6, and IL-12) induced by the ligand of TLR4, lipopolysaccharide (LPS), acting at the transcriptional level. Some structure⁻activity relationships were outlined. Compound 5 was selected as a representative compound and molecular mechanisms involved in its biological activity were investigated. Inhibition of NF-κB and p38 signaling seems to be involved in the mechanism of action of compound 5. In addition, this compound also inhibited inflammatory responses mediated by ligands of TLR2 and TLR3 receptors. To rationalize the obtained results, molecular docking and molecular dynamic studies were carried out on TLR4. All these data indicate that solidagenone derivative 5 might be used for the design of new anti-inflammatory agents.

A hispanolone-derived diterpenoid inhibits M2-Macrophage polarization in vitro via JAK/STAT and attenuates chitin induced inflammation in vivo.

Macrophages are highly plastic cells that adopt different functional phenotypes in response to environmental signals. Classically activated macrophages (M1) exhibit a pro-inflammatory role, mediating host defense against microorganisms or tumor cells; whereas alternatively activated macrophages (M2) perform a range of physiological processes, including inflammation, wound repair and tissue remodeling. Interestingly, M2 macrophages have been involved in pathological settings such as tumor progression, parasitic infection and respiratory disorders. Consequently, the search of new agents able to control macrophage polarization is on the basis of new therapeutic strategies. In the present study, we have evaluated the effect of the hispanolone derivative 8,9-dehydrohispanolone-15,16-lactol (DHHL) on M2 macrophage polarization. Our results reveal that DHHL significantly inhibited IL-4- or IL-13-stimulated M2 macrophage activation, as showed by reduced expression of M2 markers. In addition, DHHL suppressed IL-4-induced STAT-6 and JAK-1 tyrosine phosphorylation, suggesting that this compound inhibited M2 polarization by suppressing the JAK-STAT signaling pathway. Finally, DHHL prevented eosinophil recruitment and the presence of F4/80+-CD206+ M2-like macrophages in an in vivo model of M2 polarization via administration of chitin. Collectively, these results confirm DHHL as a novel regulator of macrophage polarization suitable to design future therapies towards M2-macrophages mediated pathologies.

Screening Assays to Characterize Novel Endothelial Regulators Involved in the Inflammatory Response.

The endothelial layer is essential for maintaining homeostasis in the body by controlling many different functions. Regulation of the inflammatory response by the endothelial layer is crucial to efficiently fight against harmful inputs and aid in the recovery of damaged areas. When the endothelial cells are exposed to an inflammatory environment, such as the outer component of gram-negative bacteria membrane, lipopolysaccharide (LPS), they express soluble pro-inflammatory cytokines, such as Ccl5, Cxcl1 and Cxcl10, and trigger the activation of circulating leukocytes. In addition, the expression of adhesion molecules E-selectin, VCAM-1 and ICAM-1 on the endothelial surface enables the interaction and adhesion of the activated leukocytes to the endothelial layer, and eventually the extravasation towards the inflamed tissue. In this scenario, the endothelial function must be tightly regulated because excessive or defective activation in the leukocyte recruitment could lead to inflammatory-related disorders. Since many of these disorders do not have an effective treatment, novel strategies with a focus on the vascular layer must be investigated. We propose comprehensive assays that are useful to the search of novel endothelial regulators that modify leukocyte function. We analyze endothelial activation by using specific expression targets involved in leukocyte recruitment (such as, cytokines, chemokines, and adhesion molecules) with several techniques, including: real-time quantitative polymerase chain reaction (RT-qPCR), western-blot, flow cytometry and adhesion assays. These approaches determine endothelial function in the inflammatory context and are very useful to perform screening assays to characterize novel endothelial inflammatory regulators that are potentially valuable for designing new therapeutic strategies.

Tumor suppressor ARF regulates tissue microenvironment and tumor growth through modulation of macrophage polarization.

Tumor microenvironment has been described to play a key role in tumor growth, progression, and metastasis. Macrophages are a major cellular constituent of the tumor stroma, and particularly tumor associated macrophages (TAMs or M2-like macrophages) exert important immunosuppressive activity and a pro-tumoral role within the tumor microenvironment. Alternative-reading frame (ARF) gene is widely inactivated in human cancer. We have previously demonstrated that ARF deficiency severely impairs inflammatory response establishing a new role for ARF in the regulation of innate immunity. On the basis of these observations, we hypothesized that ARF may also regulates tumor growth through recruitment and modulation of the macrophage phenotype in the tumor microenvironment. Xenograft assays of B16F10 melanoma cells into ARF-deficient mice resulted in increased tumor growth compared to those implanted in WT control mice. Tumors from ARF-deficient mice exhibited significantly increased number of TAMs as well as microvascular density. Transwell assays showed crosstalk between tumor cells and macrophages. On the one hand, ARF-deficient macrophages modulate migratory ability of the tumor cells. And on the other, tumor cells promote the skewing of ARF-/- macrophages toward a M2-type polarization. In conclusion, these results demonstrate that ARF deficiency facilitates the infiltration of macrophages into the tumor mass and favors their polarization towards a M2 phenotype, thus promoting tumor angiogenesis and tumor growth. This work provides novel information about the critical role of ARF in the modulation of tumor microenvironment.

8,9-Dehydrohispanolone-15,16-lactol diterpene prevents LPS-triggered inflammatory responses by inhibiting endothelial activation.

Endothelial activation contributes to lung inflammatory disorders by inducing leucocyte recruitment to pulmonary parenchyma. Consequently, vascular-targeted therapies constitute promising strategies for the treatment of inflammatory pathologies. In the present study, we evaluated the effect of 8,9-dehydrohispanolone-15,16-lactol diterpene (DT) on lung endothelium during inflammation. Lung endothelial cells pre-treated with DT and activated with lipopolysaccharide (LPS) or tumour necrosis factor-α (TNF-α) exhibited reduced expression of the pro-inflammatory cytokines Cxcl10, Ccl5 and Cxcl1, whereas the anti-inflammatory molecules IL1r2 and IL-10 were induced. Consistent with this result, DT pre-treatment inhibited nuclear factor κB (NF-κB) nuclear translocation, by interfering with IκBα phosphorylation, and consequently NF-κB transcriptional activity in endothelium activated by LPS or TNF-α. Furthermore, DT, probably through p38 signalling, induced transcriptional activation of genes containing activator protein 1 (AP-1)-binding elements. Inhibition of p38 prevented IL1r2 mRNA expression in endothelium incubated with DT alone or in combination with LPS or TNF-α. Accordingly, conditioned medium (CM) from these cells failed to stimulate leucocytes as measured by a reduction in adhesive ability of the leucocyte cell line J774 to fibronectin (FN). Additionally, DT reduced the expression of the endothelial adhesion molecules E-selectin, vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1) after activation. Similarly, expression of VCAM-1 and ICAM-1 molecules on the lung endothelial layer of C57/BL6 mice pre-treated with DT and challenged with LPS were unchanged. Finally, inhibition of vascular adhesion molecule expression by DT decreased the interaction of J774 cells with lung endothelial cells in an inflammatory environment. Our findings establish DT as a novel endothelial inhibitor for the treatment of inflammatory-related diseases triggered by Gram-negative bacteria or by the associated cytokine TNF-α.

Biological evaluation of angular disubstituted naphthoimidazoles as anti-inflammatory agents.

A series of naphthoimidazoles derivatives (3a-3f) were tested for potential anti-inflammatory activity on lipopolysaccharide (LPS)-treated macrophages. Naphthoimidazole 3e exhibited significant inhibitory effects on nitric oxide (NO) production (IC50 <10µM) and decreased the expression of nitric oxide synthase-2 (NOS-2) and cycloxygenase-2 (COX-2) enzymes. It also inhibited the activation of transcription factor NF-κB. Naphthoimidazole 3e might represent a starting point for the synthesis of new anti-inflammatory naphthoimidazoles derivatives.

Chemokines and relapses in childhood acute lymphoblastic leukemia: A role in migration and in resistance to antileukemic drugs.

We studied whether chemokines may have a role in relapses in childhood acute lymphoblastic leukemia (ALL). We compared the levels of chemokine receptors in marrow samples from 82 children with ALL at diagnosis versus 15 at relapses, and quantified the levels of chemokines in central system fluid (CSF) samples. The functional role of specific chemokines was studied in vitro and in vivo. The expression of some chemokine receptors was upregulated upon leukemic relapse, both in B- and in T-ALL, and in cases of medullary and extramedullary involvement. CXCL10 induced chemotaxis in leukemic cell lines and in primary leukemic cells, depending upon the levels of CXCR3 expression. CXCL10 specifically diminished chemotherapy-induced apoptosis on ALL cells expressing CXCR3, partially inhibiting caspase activation and maintaining the levels of the antiapoptotic protein Bcl-2. Finally, immunodeficient mice engrafted with CXCR3-expressing human leukemic cells showed decreased infiltration of marrow, spleen, and CNS after receiving a CXCR3-antagonist molecule. CXCR3 signaling in ALL may have a dual function: chemotactic for the localisation of leukemic blasts in specific niches, and it may also confer resistance to chemotherapy, enhancing the chances for relapses.

α-Hispanolol sensitizes hepatocellular carcinoma cells to TRAIL-induced apoptosis via death receptor up-regulation.

Hispanolone derivatives have been previously described as anti-inflammatory and antitumoral agents. However, their effects on overcoming Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance remain to be elucidated. In this study, we analyzed the cytotoxic effects of the synthetic hispanolone derivative α-hispanolol (α-H) in several tumor cell lines, and we evaluated the induction of apoptosis, as well as the TRAIL-sensitizing potential of α-H in the hepatocellular carcinoma cell line HepG2. Our data show that α-H decreased cell viability in a dose-dependent manner in HeLa, MDA-MB231, U87 and HepG2 cell lines, with a more prominent effect in HepG2 cells. Interestingly, α-H had no effect on non-tumoral cells. α-H induced activation of caspase-8 and caspase-9 and also increased levels of the proapoptotic protein Bax, decreasing antiapoptotic proteins (Bcl-2, X-IAP and IAP-1) in HepG2 cells. Specific inhibition of caspase-8 abrogated the cascade of caspase activation, suggesting that the extrinsic pathway has a critical role in the apoptotic events induced by α-H. Furthermore, combined treatment of α-H with TRAIL enhanced apoptosis in HepG2 cells, activating caspase-8 and caspase-9. This correlated with up-regulation of both the TRAIL death receptor DR4 and DR5. DR4 or DR5 neutralizing antibodies abolished the effect of α-H on TRAIL-induced apoptosis, suggesting that sensitization was mediated through the death receptor pathway. Our results demonstrate that α-H induced apoptosis in the human hepatocellular carcinoma cell line HepG2 through activation of caspases and induction of the death receptor pathway. In addition, we describe a novel function of α-H as a sensitizer on TRAIL-induced apoptotic cell death in HepG2 cells.

Anti-inflammatory activity and phenolic profile of propolis from two locations in Región Metropolitana de Santiago, Chile.

ETHNOPHARMACOLOGICAL RELEVANCE: Propolis has long been used as a popular folk medicine due to its wide spectrum of alleged biological and pharmaceutical properties. In Chile, propolis is widely used by folklore medicine as an anti-inflammatory agent; however, this property has not been demonstrated by scientific methods. AIM OF THE STUDY: The objective of this study was to determine the anti-inflammatory activity in vivo and in vitro and to establish the phenolic profile of propolis collected in two localities in Región Metropolitana de Santiago (RM), Chile. MATERIALS AND METHODS: Propolis was collected in the areas of Caleu and Buin, RM Chile. Following that, the samples were unwaxed to obtain the global ethanolic extracts of propolis (EEPs) and, from these, the serial extracts of dichloromethane (EEP-DCMs) and ethanol (EEP-EtOHs). The topic anti-inflammatory effect was evaluated through mice ear edema induced by arachidonic acid (AA) and 12-O-tetradecanoylphorbol-13-acetate (TPA) at a dose of 3 mg/ear. Nitric oxide (NO) measurements were determined spectrophotometrically (Greiss reagent) by the accumulation of nitrite in the medium of macrophages RAW 264.7 stimulated with the lipopolysaccharide (LPS, 1 µg/mL) for 20 h at different concentrations of the EEPs, EEP-DCMs and EEP-EtOHs (6.25-50.00 µg/mL). The content of total phenols and flavonoids were determined through the methods of Folin-Ciocalteau and AlCl3, respectively. The profile of phenolic compounds was determined by HPLC-UV-ESI-MS/MS. RESULTS: The EEP-EtOH (64%) and EEP (59%) of Buin were the most active in the inflammation induced by TPA and AA respectively, being the anti-inflammatory effect stronger than the same Caleu extracts. Regarding the release of NO, all the extracts from the Buin propolis inhibited significantly its release in a concentration-dependent manner, this inhibition was stronger than the extracts from Caleu propolis. CONCLUSIONS: Our research shows for the first time a comparative study of the topical in vivo activity of two Chilean propolis. Both propolis showed in vivo topical anti-inflammatory activity against AA and TPA, the most active was Buin propolis and this difference is due in part to the variations in total phenols and flavonoids content and the phenolic profile. The phenols and flavonoids content of Buin propolis was higher than Caleu propolis. The extracts from Buin propolis result in a lower release of NO.