Use of Dithiothreitol to Dislodge Bacteria From the Biofilm on an Aortic Valve in the Operating Theatre: A Case of Infective Endocarditis Caused by Staphylococcus aureus and Proteus mirabilis

This is the first reported case of 2 biofilm-producing bacteria, Staphylococcus aureus and Proteus mirabilis, identified from an aortic valve using an innovative device with dithiothreitol solution, able to dislodge bacterial biofilm. The method is usable in the operating theatre and recommended in infective endocarditis nonresponders to empiric therapy.

Discovery of oxybisbenzoylamides as a new class of antimalarial agents

A new antimalarial pharmacophore has been obtained starting from previously described dual inhibitors of Plasmodium falciparum.

Inhibition of metalloproteinase-9 secretion and gene expression by artemisinin derivatives

Malaria remains one of the world's most common infectious diseases, being responsible for more deaths than any other communicable disease except tuberculosis. There is strong evidence that tumour necrosis factor α and interleukin-1β are important contributors to the systemic disease caused by the infection with Plasmodium falciparum. Circulating levels of TNFα are increased after infection, as a consequence of stimulation of monocyte-macrophages by infected red blood cells or parasite products, as shown in vitro for the malaria pigment haemozoin. TNFα in turn enhances the synthesis of metalloproteinase-9 in monocytes and macrophages. Metalloproteinase-9 acts on the extracellular matrix but also on non-traditional substrates, including precursors of inflammatory cytokines, which are proteolytically activated and contribute to the amplification of the inflammatory response. The aim of the present work was to establish whether artemisinin and its derivatives artemisone, artesunate and dihydroartemisinin possess immuno-modulatory properties. In particular, it is necessary to evaluate their effects on mRNA levels and secretion of MMP-9 by the human monocytic cell line (THP-1 cells) stimulated by hemozoin or TNFα. 5μM of each derivative, although not artemisinin itself, induced significantly inhibited TNFα production. Artesunate, artemisone and DHA antagonized haemozoin-induced MMP-9 secretion by 25%, 24% and 50%, respectively. mRNA levels were also depressed by 14%, 20% and 27%, respectively, thus reflecting in part the effect observed on protein production. The derivatives significantly inhibited both TNFα-induced MMP-9 secretion and mRNA levels to a greater extent than haemozoin itself. Both haemozoin and TNFα increased NF-κB driven transcription by 11 and 7.7 fold, respectively. Artesunate, artemisone and DHA inhibited haemozoin-induced NF-κB driven transcription by 28%, 34%, and 49%, respectively. Similarly the derivatives, but not artemisinin, prevented TNFα-induced NF-κB driven transcription by 47-51%. The study indicates that artemisinins may attenuate the inflammatory potential of monocytes in vivo. Thus, in addition to direct anti-parasitic activities, the beneficial clinical effects of artemisinins for the treatment of malaria include the apparent ability to attenuate the inflammatory response, thus limiting the risk of progression to the more severe form of the disease, including the onset of cerebral malaria.

Antiplasmodial and anti-inflammatory activities of Canthium henriquesianum (K. Schum), a plant used in traditional medicine in Burkina Faso

ETHNOPHARMACOLOGICAL RELEVANCE

Canthium henriquesianum (K. Schum) is traditionally used in Burkina Faso for the treatment of malaria, but has not been properly investigated, yet. The aim of this study was to characterize in vitro the antiplasmodial and the anti-inflammatory activity of extracts from Canthium henriquesianum (K. Schum). In parallel, extracts of Gardenia sokotensis (Hutch) and Vernonia colorata (Willd), also traditionally used together in Burkina Faso and already reported with antimalarial activity, were compared.

MATERIALS AND METHODS

Plant extracts were tested in vitro for antimalarial activity against chloroquine susceptible (D10) and resistant (W2) strains of Plasmodium falciparum using the lactate dehydrogenase assay. Cell cytotoxicity was assessed on human dermal fibroblast (HDF) by the MTT assay. The selectivity index (SI) was used as the ratio of the activity against the parasites compared to the toxicity of the plant extract against HDF. In vitro cytokine production was assessed by ELISA technique.

RESULTS

Canthium henriquesianum aqueous extract had a moderate antimalarial activity (IC50<50 µg/ml) with a good selectivity index (SI=HDF/D10>7). Canthium henriquesianum diisopropyl ether extract was the most potent inhibitor of parasite growth with an IC50 9.5 µg/ml on W2 and 8.8 µg/ml on D10 and limited toxicity (SI>2). Gardenia sokotensis and Vernonia colorata aqueous extracts were shown to be significantly less active (IC50≥50 µg/ml) with substantial toxicity. In addition, when the production of IL-1β and TNFα by lipopolysaccharide (LPS) or hemozoin (malaria pigment) stimulated human THP-1 monocytes was assayed, it was found that the extract of Canthium henriquesianum induced a dose-dependent inhibition of IL-1β, but not of TNFα production, thus confirming its traditional use as antipyretic. By NMR analysis, the chromone was identified as the mostly represented compound in the diisopropyl ether extract of Canthium henriquesianum. Chromone however, was less active as antimalarial than the crude extract and it did not inhibit cytokine production at not toxic doses, indicating that other molecules in the total extracts contribute to the antiplasmodial and anti-inflammatory activity.

CONCLUSION

Canthium henriquesianum seems to possess antimalarial activity in vitro and the ability to inhibit the production of the pyrogenic cytokine IL-1β.

Correlation between catechin content and NF-κB inhibition by infusions of green and black tea

This study investigates whether infusions of green and black tea inhibit the NF-κB driven transcription in human epithelial gastric AGS cells. Water extracts were prepared from different brands of green and black tea available on the Italian market. Teas with or without caffeine were studied. An industrially prepared freeze-dried water extract of green tea was also tested. Catechin and caffeine contents were measured by HPLC analysis. The decrease in phenol and catechin content three months after the expiry date was also investigated. The NF-κB driven transcription and the free radical scavenger activity were inhibited, and this effect was related to catechin levels. The potency of epigallocatechin 3-gallate in inhibiting NF-κB driven transcription is so great that tea extracts low in epigallocatechin 3-gallate are still highly active. In one decaffeinated sample of green tea, the phenol and catechin content was very low, probably as a consequence of caffeine removal. The decrease in catechin levels after 3 months did not reduce the inhibition of NF-κB driven transcription by tea infusions. This is the first paper reporting the inhibitory effect of NF-κB of commercial green and black infusions at the gastric level, evaluating their stability as well.

Chronic histological transmurality of high-intensity focused ultrasound ablation

We evaluated histologic results for surgical left maze with an high-intensity focused ultrasound (HIFU) energy source. Two patients came to our attention 6 and 48 months, respectively, after ablation concomitant to a valve procedure. Tissue specimens, obtained from the lesion site on the mitral isthmus and from the "box lesion" around the pulmonary veins were analyzed histologically. A complete transmural lesion was found in all specimens. Chronic lesions exhibited replacement of the muscular band with connective tissue. The atrial wall maintained normal thickness and vascularization. HIFU ablation represents an acceptable energy source to create transmural lesions on the beating human left atrium.

Anti-plasmodial and insecticidal activities of the essential oils of aromatic plants growing in the Mediterranean area

BACKGROUND

Sardinia is a Mediterranean area endemic for malaria up to the last century. During a screening study to evaluate the anti-plasmodial activity of some aromatic plants traditionally used in Sardinia, Myrtus communis (myrtle, Myrtaceae), Satureja thymbra (savory, Lamiaceae), and Thymus herba-barona (caraway thyme, Lamiaceae) were collected in three vegetative periods: before, during and after flowering.

METHODS

The essential oils were obtained by steam distillation, fractionated by silica gel column chromatography and analysed by GC-FID-MS. Total oil and three main fractions were tested on D10 and W2 strains of Plasmodium falciparum in vitro. Larvicidal and adulticidal activities were tested on Anopheles gambiae susceptible strains.

RESULTS

The essential oil of savory, rich in thymol, was the most effective against P. falciparum with an inhibitory activity independent from the time of collection (IC50 17-26 μg/ml on D10 and 9-11 μg/ml on W2). Upon fractionation, fraction 1 was enriched in mono-sesquiterpenoid hydrocarbons; fraction 2 in thymol (73-83%); and fraction 3 contained thymol, carvacrol and terpinen-4-ol, with a different composition depending on the time of collection. Thymol-enriched fractions were the most active on both strains (IC50 20-22 μg/ml on D10 and 8-10 μg/ml on W2) and thymol was confirmed as mainly responsible for this activity (IC50 19.7 ± 3.0 and 10.6 ± 2.0 μg/ml on D10 and W2, respectively). The essential oil of S. thymbra L. showed also larvicidal and adulticidal activities. The larvicidal activity, expressed as LC50, was 0.15 ± 0.002; 0.21 ± 0.13; and 0.15 ± 0.09 μg/ml (mean ± sd) depending on the time of collection: before, during and after flowering, respectively.

CONCLUSIONS

This study provides evidence for the use of essential oils for treating malaria and fighting the vector at both the larval and adult stages. These findings open the possibility for further investigation aimed at the isolation of natural products with anti-parasitic properties.

In-silico studies in Chinese herbal medicines' research: evaluation of in-silico methodologies and phytochemical data sources, and a review of research to date

The available databases that catalogue information on traditional Chinese medicines are reviewed in terms of their content and utility for in-silico research on Chinese herbal medicines, as too are the various protein database resources, and the software available for use in such studies. The software available for bioinformatics and 'omics studies of Chinese herbal medicines are summarised, and a critical evaluation given of the various in-silico methods applied in screening Chinese herbal medicines, including classification trees, neural networks, support vector machines, docking and inverse docking algorithms. Recommendations are made regarding any future in-silico studies of Chinese herbal medicines.

Omic techniques in systems biology approaches to traditional Chinese medicine research: present and future

Omic techniques have become key tools in the development of systems biology. As the holistic approaches underlying the practice of traditional Chinese medicine (TCM) and new tendencies in Western medicine towards personalised medicine require in-depth knowledge of mechanisms of action and active compounds, the use of omic techniques is crucial for understanding and interpretation of TCM development, especially in view of its expansion in Western countries. In this short review, omic applications in TCM research are reviewed which has allowed some speculation regarding future perspectives for these approaches in TCM modernisation and standardisation. Guidelines for good practice for the application of omics in TCM research are also proposed.

Inhibition of neutrophil elastase and metalloprotease-9 of human adenocarcinoma gastric cells by chamomile (Matricaria recutita L.) infusion

This study investigated whether the antiinflammatory effect of chamomile infusion at gastric level could be ascribed to the inhibition of metalloproteinase-9 and elastase. The infusions from capitula and sifted flowers (250-1500 µg/mL) and individual flavonoids (10 µM) were tested on phorbol 12-myristate 13-acetate-stimulated AGS cells and human neutrophil elastase. The results indicate that the antiinflammatory activity associated with chamomile infusions from both the capitula and sifted flowers is most likely due to the inhibition of neutrophil elastase and gastric metalloproteinase-9 activity and secretion; the inhibition occurring in a concentration dependent manner. The promoter activity was inhibited as well and the decrease of metalloproteinase-9 expression was found to be associated with the inhibition of NF-kB driven transcription. The results further indicate that the flavonoid-7-glycosides, major constituents of chamomile flowers, may be responsible for the antiinflammatory action of the chamomile infusion observed here.

Ellagitannins of the fruit rind of pomegranate (Punica granatum) antagonize in vitro the host inflammatory response mechanisms involved in the onset of malaria

Background

The sun-dried rind of the immature fruit of pomegranate (Punica granatum) is presently used as a herbal formulation (OMARIA, Orissa Malaria Research Indigenous Attempt) in Orissa, India, for the therapy and prophylaxis of malaria. The pathogenesis of cerebral malaria, a complication of the infection by Plasmodium falciparum, is an inflammatory cytokine-driven disease associated to an up-regulation and activity of metalloproteinase-9 and to the increase of TNF production. The in vitro anti-plasmodial activity of Punica granatum (Pg) was recently described. The aim of the present study was to explore whether the anti-malarial effect of OMARIA could also be sustained via other mechanisms among those associated to the host immune response.

Methods

From the methanolic extract of the fruit rind, a fraction enriched in tannins (Pg-FET) was prepared. MMP-9 secretion and expression were evaluated in THP-1 cells stimulated with haemozoin or TNF. The assays were conducted in the presence of the Pg-FET and its chemical constituents ellagic acid and punicalagin. The effect of urolithins, the ellagitannin metabolites formed by human intestinal microflora, was also investigated.

Results

Pg-FET and its constituents inhibited the secretion of MMP-9 induced by haemozoin or TNF. The effect occurred at transcriptional level since MMP-9 mRNA levels were lower in the presence of the tested compounds. Urolithins as well inhibited MMP-9 secretion and expression. Pg-FET and pure compounds also inhibited MMP-9 promoter activity and NF-kB-driven transcription.

Conclusions

The beneficial effect of the fruit rind of Punica granatum for the treatment of malarial disease may be attributed to the anti-parasitic activity and the inhibition of the pro-inflammatory mechanisms involved in the onset of cerebral malaria.

Olive oil phenols modulate the expression of metalloproteinase 9 in THP-1 cells by acting on nuclear factor-kappaB signaling

In vivo studies suggest that the phenolic component contributes to the anti-inflammatory and antiatherosclerotic actions of olive oil; however, the effects in circulating cells are not fully characterized. Monocytes play a key role in inflammation-based diseases by expressing several molecules, including metalloproteinases (MMPs). In the present study, we investigated the effects of olive oil phenolic extract and individual compounds on MMP-9 in THP-1 cells, a human monocyte-like cell line. Olive oil extract prevented the stimulation of MMP-9 expression and secretion in tumor necrosis factor alpha-treated THP-1 cells. Oleuropein aglycone, a typical olive oil phenol, was active at concentrations found in the extract, although other compounds probably contribute to the biological activity. We also found that the effect of the extract and individual compounds on MMP-9 is due to impaired nuclear factor-kappaB signaling. Our findings provide further evidence on the mechanisms by which olive oil reduces the inflammatory burden associated with disorders, such as atherosclerosis.

Antiplasmodial activity of Punica granatum L. fruit rind

AIM OF THE STUDY

Sun-dried rind of the immature fruit of Punica granatum L. (Punicaceae) (Pg) is presently used as a herbal formulation (OMARIA) in Orissa, India, for the therapy and prophylaxis of malaria. The aims of this study were (i) to assess in vitro the antiplasmodial activity of the methanolic extract, of a tannin enriched fraction and of compounds/metabolites of the antimalarial plant, (ii) to estimate the curative efficacy of the Pg extracts and (iii) to explore the mechanism of action of the antiplasmodial compounds. Urolithins, the ellagitannin metabolites, were also investigated for antiplasmodial activity.

MATERIALS AND METHODS

Chloroquine-susceptible (D10) and -resistant (W2) strains of Pf were used for in vitro studies and the rodent malaria model Plasmodium berghei-BALB/c mice was used for in vivo assessments. Recombinant plasmepsins 2 and 4 were used to investigate the interference of Pg compounds with the metabolism of haemoglobin by malaria parasites.

RESULTS

The Pg methanolic extract (Pg-MeOH) inhibited parasite growth in vitro with a IC(50) of 4.5 and 2.8 microg/ml, for D10 and W2 strain, respectively. The activity was found to be associated to the fraction enriched with tannins (Pg-FET, IC(50) 2.9 and 1.5 microg/ml) in which punicalagins (29.1%), punicalins, ellagic acid (13.4%) and its glycoside could be identified. Plasmepsin 2 was inhibited by Pg-MeOH extract and by Pg-FET (IC(50) 7.3 and 3.0 microg/ml), which could partly explain the antiparasitic effect. On the contrary, urolithins were inactive. Both Pg-MeOH extract and Pg-FET did not show any in vivo efficacy in the murine model.

CONCLUSIONS

The in vitro studies support the use of Pg as antimalarial remedy. Possible explanations for the negative in vivo results are discussed.

Inhibition of NF-kB and metalloproteinase-9 expression and secretion by parthenolide derivatives

Semisynthetic derivatives of parthenolide (1) were tested on NF-kB driven transcription and metalloproteinase-9 (MMP-9) expression and secretion. The four membered ring compounds 5 and 6, obtained by acidic treatment of 1, exhibited a higher activity with respect to 1 in all the biological assays. Then an increased ability of the 5 and 6 to inhibit NF-kB driven transcription may lead to a down-regulation of MMP-9 expression and secretion. This work provides new details about the structural requisites for NF-kB inhibition.

Potent inhibition of human phosphodiesterase-5 by icariin derivatives

Plant extracts traditionally used for male impotence (Tribulus terrestris, Ferula hermonis, Epimedium brevicornum, Cinnamomum cassia), and the individual compounds cinnamaldehyde, ferutinin, and icariin, were screened against phosphodiesterase-5A1 (PDE5A1) activity. Human recombinant PDE5A1 was used as the enzyme source. Only E. brevicornum extract (80% inhibition at 50 microg/mL) and its active principle icariin (1) (IC50 5.9 microM) were active. To improve its inhibitory activity, 1 was subjected to various structural modifications. Thus, 3,7-bis(2-hydroxyethyl)icaritin (5), where both sugars in 1 were replaced with hydroxyethyl residues, potently inhibited PDE5A1 with an IC50 very close to that of sildenafil (IC50 75 vs 74 nM). Thus, 5 was 80 times more potent than 1, and its selectivity versus phosphodiesterase-6 (PDE6) and cyclic adenosine monophosphate-phosphodiesterase (cAMP-PDE) was much higher in comparison with sildenafil. The improved pharmacodynamic profile and lack of cytotoxicity on human fibroblasts make compound 5 a promising candidate for further development.

Inhibition of human cAMP-phosphodiesterase as a mechanism of the spasmolytic effect of Matricaria recutita L

Mechanisms underlying the spasmolytic activity of chamomile still remain unclear. Inhibition of cAMP- and cGMP-phosphodiesterases (PDE) is one of the mechanisms operated by spasmolytic drugs. In this study, the effect of chamomile on PDE was investigated. Human platelet cAMP-PDE and recombinant PDE5A1 were assayed in the presence of infusions prepared from sifted flowers and capitula. LC-ESI-MS/MS analysis showed different compositions in infusions made with sifted flowers and capitula. Chamomile inhibited cAMP-PDE activity (IC50 = 17.9-40.5 microg/mL), while cGMP-PDE5 was less affected (-15% at 50 microg/mL). Among the individual compounds tested, only flavonoids showed an inhibitory effect (IC50 = 1.3-14.9 microM), contributing to around 39% of the infusion inhibition; other compounds responsible for cAMP-PDE inhibition still remain unknown. Although experimental evidence supporting the use of chamomile for gastrointestinal minor spasms dates back to the fifties, cAMP-PDE inhibition as a likely mechanism underlying the spasmolytic activity is reported for the first time.

Old and new targets for innovative antimalarial compounds: the different strategies of the Italian Malaria Network

Clinical treatment-failures to affordable drugs encouraged new investigation for discovery and development of new prophylactic and therapeutic interventions against malaria. The Drug Discovery Cluster (DDcl) of the Italian Malaria Network gathers several highly integrated and complementary laboratories from different Italian Institutions to identify, synthesise, screen in vitro and in vivo new antimalarial molecules directed against the intraerythrocytic stage of P. falciparum parasites and/or with transmission blocking activity to select lead compounds for further development. Complementary research activities, both in vitro and in the clinics, aim at investigating the pathogenetic mechanisms of severe malaria anaemia and the different manifestations of the disease in malaria-HIV co-infected patients to identify new therapies and improve survival.

Determination of aloesin and aloeresin A for the detection of aloe in beverages

This work describes a sensitive high-performance liquid chromatography (HPLC) method for the quantification of aloesin and aloeresin A in alcoholic beverages containing aloe as a flavoring agent. The compounds were prepared from Aloe ferox juice. Sephadex LH20 and ion-exchange resin AG1X2 column chromatography were used for aloesin. Aloeresin A was obtained by Sephadex LH20 and silica gel column chromatography followed by purification on Discovery DSC-18 solid-phase extraction tubes. A 98 mg amount of aloesin (>99% purity) and 34 mg of aloeresin A (>98% purity) were recovered from 2.5 g of aloe juice. The HPLC method was validated, and intra- and interday performances were established. In-house validation was carried out by analyzing samples of beverages with and without aloe as a flavoring agent.

High antiplasmodial activity of novel plasmepsins I and II inhibitors

The aim of this study was to develop new antiplasmodial compounds acting through distinct mechanisms during both the liver and the blood stages of the parasite life cycle. Compounds were designed on the basis of the "double-drug" approach: primaquine, which has been linked to statine-based inhibitors of plasmepsins (PLMs), the plasmodial aspartic proteases involved in degradation of hemeoglobin. The compounds were tested in vitro for anti-PLM I/PLM II activities and against chloroquine-sensitive (D10) and chloroquine-resistant (W2) strains of P. falciparum. An antiplasmodial activity (IC(50)) as low as 0.1 microM was obtained, an excellent improvement in comparison with inhibitors previously reported (IC(50) = 2-20 microM). The killing activity was equally directed against both P. falciparum strains and was correlated to lipophilicity (calculated as ALogP), for all compounds but one (9). All compounds inhibited PLM I and PLM II in the nanomolar range (K(i) = 1-700 nM). The most promising compounds (2, 6, 10) were not cytotoxic against human fibroblasts at 100 microM and were highly selective for PLMs vs human cathepsin D.

Minor components of olive oil modulate proatherogenic adhesion molecules involved in endothelial activation

The Mediterranean diet reduces the risk of coronary artery disease as a consequence of its high content of antioxidants, namely, hydroxytyrosol (HT) and oleuropein aglycone (OleA), typical of virgin olive oil. Because intercellular and vascular cell adhesion molecules (ICAM-1 and VCAM-1) and E-selectin are crucial for endothelial activation, the role of the phenolic extract from extra virgin olive oil (OPE), OleA, HT, and homovanillyl alcohol (HVA) on cell surface and mRNA expression in human umbilical vascular endothelial cells (HUVEC) was evaluated. OPE strongly reduced cell surface expression of ICAM-1 and VCAM-1 at concentrations physiologically relevant (IC50 < 1 microM), linked to a reduction in mRNA levels. OleA and HT were the main components responsible for these effects. HVA inhibited cell surface expression of all the adhesion molecules, whereas the effect on mRNA expression was weaker. These results supply new insights on the protective role of olive oil against vascular risk through the down-regulation of adhesion molecules involved in early atherogenesis.

Inhibition of cGMP-phosphodiesterase-5 by biflavones of Ginkgo biloba

Ginkgo biloba dimeric flavonoids (GBDF) were shown to inhibit cAMP phosphodiesterase activity and to promote vasorelaxation. In particular, amentoflavone exhibited endothelium-dependent relaxation of rat aorta rings via enhanced generation and/or increased biological activity of nitric oxide, leading to elevated cGMP levels. The aim of this study was to investigate whether GBDF were able to inhibit cGMP-specific phosphodiesterase-5 (PDE5) as well. Human recombinant PDE5A1 was prepared by expression of the full-length cDNA of PDE5A1 in COS-7 cells. The PDE activity was determined in the presence of biflavones at 0.1-100 microM. All biflavones inhibited PDE5A1 in a concentration-dependent fashion, ginkgetin being the most potent (IC50 = 0.59 microM). The ability to inhibit the enzyme followed this order: ginkgetin > bilobetin > sciadopitysin > amentoflavone > sequoiaflavone. These data suggest that GBDF could exert a vasodilating effect through a mechanism independent of NO release.

Effects of Papaverine and Glycerilnitrate-Verapamil Solution as Topical and Intraluminal Vasodilators for Internal Thoracic Artery

BACKGROUND

Arterial spasm is described as an event occurring after left internal thoracic artery (LITA) harvesting. Many vasodilators have been used to treat or prevent LITA spasm. The aim of this study is to compare the effects between glyceril-trinitrate/verapamil (GV) solution and papaverine to treat LITA spasm and to determine the best delivery method.

METHODS

One hundred consecutive ischemic patients were randomly assigned to three groups: group GV (n = 34, GV solution), group P (n = 33, papaverine), or group C (n = 33, normal saline). In each patient, pedicled LITA was harvested, thereafter sprayed with the randomized solution, and covered with a sponge. Fifteen minutes after heparin administration, LITA was distally divided; flow per minute was calculated after measuring the free flow for over 15 seconds; this is named "topical free flow." Then, the vasodilator was injected intraluminally and free flow per minute was measured; this is called "intraluminal free flow."

RESULTS

Analysis of variance was applied to detect differences among groups; paired-sample t test was used for LITA topical free flow versus intraluminal free flow within single groups. Mean LITA free flows were as follows: group GV, topical free flow = 38.6 +/- 25.2 mL/min versus intraluminal free flow = 58.8 +/- 29 mL/min (p < 0.0001); group P, topical free flow = 45.4 +/- 38.9 mL/min versus intraluminal free flow mL/min (p < 0.0001); group C, topical free flow = 31.6 +/- 19.9 mL/min versus intraluminal free flow = 34 +/- 19.8 mL/min (p = 0.14). Topical free flow difference among the three groups was not statistically significant (p = 0.1); intraluminal free flow difference was statistically significant (p = 0.001). Intraluminal free flow in group GV and in group P were higher than intraluminal free flow in group C (p = 0.004 and 0.001, respectively). Intraluminal free flow of group P was higher than that of group GV; this difference did not reach statistical significance (p = 1.00).

CONCLUSIONS

Glyceril-trinitrate/verapamil solution and papaverine are able to treat the spasm and increase the flow of the LITA, when they are used intraluminally. When used topically, these vasodilator agents do not ensure an optimal free flow.

A structure-activity study for the inhibition of metalloproteinase-9 activity and gene expression by analogues of gallocatechin-3-gallate

Catechins are able to modulate the gelatinolytic activity of matrix metalloproteinase-9 (MMP-9) by reducing its release from macrophages. Gallocatechins decrease MMP-9 secretion by lowering MMP-9 promoter activity and mRNA levels. The effect appears to be dependent on some structural and stereochemical requirements. In this study, the relationship between chemical structure and activity was studied by testing the effect of analogues of (+/-)-gallocatechin-3-gallate (+/-)-GCG, selectively deprived of hydroxyl groups, on MMP-9 activity, transcription, and secretion. Our results indicate that (+/-)-GCG and (+/-)-catechin-3-gallate are characterized by a substitution pattern compatible with direct inhibition of MMP-9 activity. Conversely, when transcription was the target, (+/-)-trans-3-flavanol-3-benzoate, lacking all the hydroxyl groups, was the most effective both in lowering MMP-9 promoter activity and consequently protein secretion, and in inhibiting nuclear-factor-kappaB-driven transcription. Our results suggest that the structural requirements for enzyme inhibition are different from those necessary for targeting gene expression.

In vitro inhibition of human cGMP-specific phosphodiesterase-5 by polyphenols from red grapes

A moderate consumption of red wine may reduce the risk of cardiovascular diseases via wine-derived phenolic compounds. A variety of biological mechanisms have been proposed for wine-derived phenolic compounds including nitric oxide-mediated vasorelaxation. This study examined whether the vasodilating effect of wine-derived phenolic compounds was associated with the inhibition of phosphodiesterases (PDEs) and, in particular, PDE5. For this purpose, human recombinant PDE5A1 isoform was prepared by expression of the full-length cDNA of PDE5A1 into COS-7 cells. Red wine and the extracts from grape skin inhibited PDE5A1 activity, whereas the seed extracts had a negligible effect. The mixture of anthocyanins inhibited the enzyme activity (IC50 = 11.6 microM), with malvidin-3-O-beta-glucoside (IC50 = 35.4 microM) and malvidin (IC50 = 24.9 microM) the most potent among the monoglucosides and aglycons, respectively. trans-Resveratrol and trans-piceid exhibited negligible effects, whereas hydroxycinnamates were completely inactive. These results indicate that polyphenols-induced vasorelaxation may also be sustained by smooth muscle PDE inhibition by anthocyanins present in red wines and grapes.

Plasmepsin II inhibition and antiplasmodial activity of Primaquine-Statine 'double-drugs'

Statine-based inhibitors of Plasmepsin II (PLMII) coupled with Primaquine have been designed using the 'double-drug' approach. The IC50 values for PLMII inhibition ranged from 0.59 to 400 nM and the best IC50 value for inhibition of Plasmodium falciparum growth in vitro was 0.4 microM, which represent a remarkable improvement compared to other statine-based PLMII inhibitors.

Analysis by high-performance liquid chromatography of teucrin A in beverages flavoured with an extract of Teucrium chamaedrys L

Due to its liver toxicity, the medicinal use of germander (Teucrium chamaedrys L.) was banned in some countries. Nevertheless, alcoholic extracts are still permitted as flavour ingredients since they are fundamental in providing a bitter aromatic taste. Teucrin A represents the substance of major concern regarding the potential toxicity of germander. Hence, teucrin A represents the best analytical and toxicological marker of alcoholic extracts of T. chamaedrys. A sensitive high-performance liquid chromatography method to detect teucrin A in beverages is reported. Teucrin A was prepared by isolation from the plant extract using column chromatography and crystallization. The identity and purity (99%) were established by melting point, nuclear magnetic resonance and liquid chromatography-mass spectrometry. The high-performance liquid chromatography procedure was validated and its intra- and interday performance was established (relative standard deviation < or = 13% and error < or = 10%). In-house validation was carried out by analysing samples of beverages not containing T. chamaedrys spiked with a range of concentrations of teucrin A. The limit of detection was 0.1 ppm and the limit of quantification was 0.3 ppm. Teucrin A accounted for about 70% of the neo-clerodane diterpenoids found in the total extract of a specimen of T. chamaedrys. The content (+/- standard deviation) in 18 batches of different geographical origin was 2338 +/- 740 ppm, per cent coefficient of variation = 32, minimum-maximum = 999 - 3445 ppm. The mean level of teucrin A in 10 bottles of the same brand was 6.1 +/- 0.8 ppm, per cent coefficient of variation = 12. In 10 different brands found on the Italian market, the content of teucrin A ranged from not detectable to 10 ppm.

Vascular effects of wine polyphenols

Moderate consumption of red wine has been putatively associated with lowering the risk of developing coronary heart disease. This beneficial effect is mainly attributed to the occurrence of polyphenol compounds such as anthocyanosides (ACs), catechins, proanthocyanidins (PAs), stilbenes and other phenolics in red wine. This review focuses on the vascular effects of red wine polyphenols (RWPs), with emphasis on anthocyanosides and proanthocyanidins. From in vitro studies, the effect of red wine polyphenols on the vascular tone is thought to be due to short- and long-term mechanisms. NO-mediated vasorelaxation represents the short-term response to wine polyphenols, which exert the effect by increasing the influx of extracellular Ca(2+), and the mobilization of intracellular Ca(2+) in endothelial cells. Polyphenolic compounds may also have long-term properties, as they increase endothelial NO synthase expression acting on the promoter activity. In addition, they decrease the expression of adhesion molecules and growth factors, involved in migration and proliferation of vascular smooth muscle cells. Moreover, they inhibit platelet aggregation. However, a paucity of data as regards the bioavailability and metabolism of these compounds in human studies is a limiting factor to proving their efficacy in vivo.

Inhibition of metalloproteinase-9 activity and gene expression by polyphenolic compounds isolated from the bark of Tristaniopsis calobuxus (Myrtaceae)

Excessive breakdown of extracellular matrix by metalloproteinases (MMPs) occurs in many pathological conditions, and thus inhibition of MMP activity might have therapeutic potential. The methanolic extract and the identified compounds from the bark of Tristaniopsis calobuxus Brongniart & Gris (Myrtaceae) were tested on the activity, production, and gene expression of MMP-9. The extract produced a concentration-dependent inhibition (50-95% at 10-50 microg/ml) of MMP-9 activity. The inhibitory activity was retained in the ethyl acetate-soluble fraction (50-95% inhibition at 10-50 microg/ml) which also reduced the release of MMP-9 by mouse peritoneal macrophages up to 80%. In the ethyl acetate-soluble fraction, two active fractions, 5A and 5B were identified. HPLC-MS and NMR analyses of these fractions indicated the presence of gallocatechin, ellagic acid, and its glycoside derivatives. Since the absolute configuration of gallocatechin was not determined, in the next experiments both (+)-gallocatechin (2R,3S) and (-)-gallocatechin (2S,3R) were tested, and (-)-epigallocatechin (2R,3R) was included for comparison. 5A and 5B inhibited MMP-9 secretion, an observation which correlated with the decrease of MMP-9 promoter activity and the downregulation of mRNA levels. All compounds decreased MMP-9 mRNA levels and secretion. Ellagic acid, (+)-gallocatechin and (-)-epigallocatechin, but not (-)gallocatechin inhibited promoter-driven transcription. Thus configuration at C2 (R) of the flavanol seem to be critical for the interaction with the promoter.

In vitro studies on the mechanism of action of two compounds with antiplasmodial activity: ellagic acid and 3,4,5-trimethoxyphenyl(6'-O-aalloyl)-beta-D-glucopyranoside

To investigate the mechanism of action of two antiplasmodial compounds, ellagic acid and 3,4,5-trimethoxyphenyl (6'-O-galloyl)-beta-D-glucopyranoside (TMPGG), we studied in vitro two metabolic reactions of intraerythrocytic parasites: the activity of recombinant plasmepsin II, one of the haemoglobin proteases, and the detoxification of haematin into beta-haematin. Both compounds inhibited plasmepsin II activity, but at concentrations ten-fold higher than those needed for inhibiting parasite growth. Moreover, ellagic acid inhibited the formation of beta-haematin, with an IC50 only 3-fold higher than that of chloroquine. These data suggest that the antiplasmodial activity of ellagic acid could be related to the inhibition of beta-haematin formation, whereas plasmepsin II does not represent the main target of the two compounds.

Biflavones of Ginkgo biloba stimulate lipolysis in 3T3-L1 adipocytes

Ginkgo biloba L. biflavones were shown to increase cAMP phosphodiesterase activity and to stimulate skin microcirculation. The aim of this study was to investigate whether biflavones were able to stimulate lipolysis in adipocytes. Lipolysis was assayed in fully differentiated 3T3-L1 fat cells in the presence of biflavones at 0.005 - 100 microM. Cell viability was evaluated at 0.5 -100 microM. Theophylline and caffeine were used as reference compounds. Lipolytic activity in untreated cells was 0.62 +/- 0.15 micromoles glycerol/mg DNA/h. All biflavones except sciadopitysin stimulated lipolysis in a concentration-dependent fashion. Maximal stimulation was observed at 0.1 - 0.5 microM. At higher concentrations the effect diminished progressively and was lost at 100 microM. Only a partial loss of cell viability was observed with biflavones at 10 - 100 microM.

In vitro antiplasmodial activity of extracts of Tristaniopsis species and identification of the active constituents: ellagic acid and 3,4,5-trimethoxyphenyl-(6'-O-galloyl)-O-beta-D-glucopyranoside

Screening of plants from New Caledonia for antiplasmodial activity against Plasmodium falciparum revealed that methanolic extracts of the leaves and bark of Tristaniopsis calobuxus, T. yateensis, and T.glauca inhibited the growth of chloroquine-sensitive and -resistant clones. Ellagic acid and the new compound 3,4,5-trimethoxyphenyl-(6'-O-galloyl)-O-beta-D-glucopyranoside were identified as the active constituents (IC50 0.5 and 3.2 microM, respectively). The growth inhibition of both clones was comparable. The compounds showed negligible or very low cytotoxicity to human skin fibroblasts and Hep G2 cells when tested at concentrations ranging from 0.5 to 100 microM.

Screening of plants from new caledonia and vanuatu for inhibitory activity of xanthine oxidase and elastase

A series of 38 plants (55 plant extracts) from New Caledonia and 22 plants (40 plant extracts) from Vanuatu (Efate and Erromango islands) were screened for xan-thine oxidase (XOD) and elastase inhibitory activity. Of the crude extracts 82% were found to possess xanthine oxidase inhibitory activity, and 23% were active against elastase, at a concentration of 50 µg/ml. The methanol extracts of Cunonia montana Schlechter (Cunoniaceae) and Amyema scandens Danser (Loranthaceae), bark and leaves, respectively, exhibited the highest activity in both the assays. C. montana bark extract at 50 µg/ml exhibited 85 and 84% inhibition of XOD and elastase, respectively. IC 50 values were 23 ± 0.82 and 41 ± 3 µg/ml, respectively, for XOD and elastase. A. scandens leaf extract, at 50 µg/ml, exhibited 88 and 71% inhibition of XOD and elastase, respectively. IC 50 values were 13 ± 0.48 and 44 ± 2.2 µg/ml respectively, for XOD and elastase.

Inhibition of cAMP-phosphodiesterase by biflavones of Ginkgo biloba in rat adipose tissue

This work compares the inhibition of cAMP-phosphodiesterase in rat adipose tissue by a mixture of Ginkgo biloba biflavones with the effect of individual dimeric flavonoids. The degree of enzyme inhibition by G. biloba biflavones was amentoflavone > bilobetin > sequoiaflavone > ginkgetin = isoginkgetin. Sciadopitysin was almost inactive.

LC-UV-electrospray-MS-MS mass spectrometry analysis of plant constituents inhibiting xanthine oxidase

PURPOSE

A previous screening showed that Amyema scandensi [corrected] Danser (Loranthaceae) efficiently inhibited XOD. The aim of this study was to identify the compounds with anti-XOD properties. For this purpose, Electrospray Tandem Mass Spectrometry (ESI-MS-MS) coupled with UV and Diode Array LC techniques were employed.

METHODS

Leaves were delipidized with petroleum ether and extracted with acetone:water 70:30, v:v. The extract was fractionated into the ethyl acetate and water soluble phases. Chemical investigation was performed following the bioactivity guided fractionation. Two fractions with anti-XOD activity were isolated by silica gel column chromatography of the ethyl acetate phase and analyzed by LC-UV-ESI-MS-MS.

RESULTS

The compounds identified with authentic standards were: catechin, epicatechin, epicatechin-3-gallate, quercetin-3-O-glucoside, quercetin-3-O-rhamnoside, and isorhamnetin-3-O-glucoside. Other constituents, only partially characterized, were a procyanidin dimer, a procyanidin trimer, three dimers epi/catechine-epi/catechine gallate and isorhamnetin-O-deoxyhexose. The anti-XOD activity was mainly due to galloyl-containing oligomeric proanthocyanidins.

CONCLUSIONS

The coupling of UV Diode Array-HPLC with ESI-MS-MS represents a versatile tool for the rapid characterization of compounds in complex mixtures, avoiding time-consuming previous isolation.

Effects of aging and of chronic obstructive pulmonary disease on RR interval variability

Clinical and experimental investigations suggest that spectral analysis of RR interval variability might be employed to assess changes in autonomic regulation of the SA node occurring in various chronic, cardiac or respiratory conditions. We studied three groups of subjects: young healthy, older healthy, and old patients with chronic obstructive pulmonary disease (COPD), considering RR interval and breathing, i.e. tidal volume, variability in the frequency domain (AR algorithms), in order to obtain markers of the sympathetic and vagal modulation of the SA node [by way, respectively, of the low (LF) and high frequency (HF) spectral components]. The gain of the relationship between tidal volume and heart period variation (index beta) was also examined. COPD patients demonstrated a reduced resting RR variance with maintained spectral power distribution; upon tilting they did not manifest the usual increase of LF (and attendant decrease of HF) component. Additionally, we observed that the index beta at rest was significantly reduced in older as opposed to younger subjects. This index was also reduced by tilt, in both groups. In patients the index beta was reduced as compared to the group of similar age and younger subjects, and did not diminish further with tilt. This study indicates that in patients with COPD, sympathetic excitatory modulation of the SA node is depressed. Furthermore, the index beta, which provides an assessment of the gain of respiratory modulation of RR interval variability is significantly reduced in patients, as compared to healthy subjects of similar age. These abnormalities of autonomic control, may represent a functional correlation of the hyperinflated state present in this clinical condition which can be assessed non-invasively with spectral analysis of RR interval and respiration.

Pharmacological activities of Chelidonium majus L. (Papaveraceae)

Chelidonium majus L. (Papaveraceae) has a long history as being useful for the treatment of many diseases in European countries. This plant is of great interest for its use also in Chinese herbal medicine. The plant contains, as major secondary metabolites, isoquinoline alkaloids, such as sanguinarine, chelidonine, chelerythrine, berberine and coptisine. Other compounds structurally unrelated to the alkaloids have been isolated from the aerial parts: several flavonoids and phenolic acids. C. majus extracts and its purified compounds exhibit interesting antiviral, antitumour and antimicrobial properties both in vitro and in vivo.

Effect of the flavanolignans of Silybum marianum L. on lipid peroxidation in rat liver microsomes and freshly isolated hepatocytes

The effect of several flavanolignans (silicristin, silidianin, silybin and isosilybin) present in silymarin, the extract of Silybum marianum fruits, was tested on lipid peroxidation in rat liver microsomes and freshly isolated hepatocytes. In microsomes lipid peroxidation was generated by ADP/Fe2+ and NADPH. All flavanolignans inhibited peroxidation in a concentration dependent manner. In hepatocytes lipid peroxidation was induced by ADP/Fe3+ complex and cell damage was evaluated as LDH activity released in the medium. The inhibition of the peroxidative process by flavanolignans was also evident in this model, even if with a potency order different from that found in microsomes. In contrast, the effect on LDH release was significant only for silybin and isosilybin, the other compounds being inactive on this parameter.

Plasma lipoproteins and cholesterol metabolism in Yoshida rats: an animal model of spontaneous hyperlipemia

The purpose of this study was to characterize the lipoprotein profile and cholesterol metabolism in Yoshida rats, a strain of inbred genetically hyperlipemic animals. For comparison, Brown Norway rats were used as control animals. Plasma cholesterol and triglycerides were higher in Yoshida as compared to Brown Norway, the elevation of cholesterol being due to a rise in HDL fraction. Triglyceride distribution among lipoproteins showed an increase in VLDL fraction. Hyperlipemia was not related to diabetes, hypothyroidism or nephropathy. Plasma triglycerides production was increased in Yoshida rats, while lipoprotein and hepatic lipases were similar in the two groups. Hypercholesterolemia was associated with a defect of lipoprotein receptor activity and with elevated HMG-CoA reductase and cholesterol 7 alpha - hydroxylase; conversely ACAT activity was lower in Yoshida as compared to Brown Norway rats. Sterol fecal excretion was comparable in the two groups and hypercholesterolemia in Yoshida rats was not associated to an increase of cholesterol saturation of the bile. We suggest that lipoprotein overproduction is the main cause for hyperlipidemia in this strain of rats.

Effect of natural and structurally modified bile acids on cholesterol metabolizing enzymes in rat liver microsomes. II

The effect of ursodeoxycholic acid analogues bearing modifications at the side-chain moiety of the molecule was tested on cholesterol 7 alpha-hydroxylase and HMG-CoA reductase in rat liver microsomes. The compounds included 23 R,S mixture and the single isomers 23R and 23S of 23 methylursodeoxycholic acid (23-methyl UDCA), the isomeric mixture (cis + trans) of 3 alpha,7 beta-dihydroxy-20,22-methylen-5 beta-cholan-23-oic acid (norcypro-UDCA) and the corresponding single isomers. Each steroid was added to liver microsomes as the sodium salt, at concentrations ranging from 25 to 200 microM. Isomers 23R and 23S of 23-methyl-UDCA inhibited cholesterol 7 alpha-hydroxylase in a concentration-dependent manner. The inhibitory capacity was similar for the two isomers. The extent of inhibition of the analogues was greater than that of the parent compound UDCA. Shortening of the side-chain in norcypro-UDCA resulted in a partial loss of the inhibitory effect, as compared to cypro-UDCA (3 alpha,7 beta-dihydroxy-22,23-methylen-5 beta-cholan-24-oic acid). None of these bile acid derivatives affected the activity of the enzyme HMG-CoA reductase.

Phytochemical characterization and radical scavenger activity of flavonoids from Helichrysum italicum G. Don (Compositae)

The glycosidic fraction of the flavonoids extracted from the flowering tops of the Helichrysum italicum G. Don was isolated, purified and characterized. This fraction was constituted by three compounds, which were assigned the structure of 4,2',4',6'-tetrahydroxychalcone-2'-glucoside, kaempferol-3-glucoside and naringenin-glycoside. Radical scavenger properties of the single glycosyl-flavonoids and of the in toto glycosidic fraction were tested with in vitro systems where different reactive oxygen species are generated (superoxide ions, hydroxyl radicals) and on lipid peroxidation induced by ADP/Fe2+ and NADPH or CCl4 in rat liver microsomes. The formation of reactive oxygen species was detected by cytochrome c reduction, salicylic acid hydroxylation and hyaluronic acid depolymerization. The action of the glycosidic fraction on the release of TXB2 and 12-HETE in human platelets, after collagen stimulation, was also evaluated. The glycosidic fraction inhibited in a dose dependent fashion lipid peroxidation in rat liver microsomes treated with ADP/Fe2+ or CCl4. This effect is due to the ability of flavonoids to scavenge free radicals at different stages of the process (superoxide ions, hydroxyl and lipid peroxide radicals). The single glycosyl-flavonoids exhibited a different scavenger activity, depending on the oxygen species and the chemical structure of the compounds. No effect of the fraction was observed on TXB2 and 12-HETE formation at 100 microns concentration.

Effect of natural and structurally modified bile acids on cholesterol metabolizing enzymes in rat liver microsomes

The effect of chenodeoxycholic (CDCA), ursodeoxycholic (UDCA), tauroursodeoxycholic (TUDCA), cholic (CA), ursocholic (UCA) acids, analogues of CDCA and UDCA with a cyclopropyl ring at C22, C23 (cypro-CDCA and cypro-UDCA) and 23-methylursodeoxycholic acid (MUDCA) on cholesterol 7 alpha-hydroxylase was studied in rat liver microsomes. Cypro-analogues consisted of a mixture of four diasteroisomers, while MUDCA was the racemic mixture of two enantiomers. Each steroid was added to liver microsomes at concentrations ranging from 10 to 200 microM. With the exception of UCA and CA, all the bile acids inhibited cholesterol 7 alpha-hydroxylase activity. The inhibition shown by cypro-CDCA and cypro-UDCA was stronger than that observed with the corresponding natural compounds. 22S,23S cypro-UDCA exhibited an inhibitory effect which was more pronounced than that of the diasteroisomer mixture. The isomer 22R,23S was less effective and decreased cholesterol 7 alpha-hydroxylase activity in a manner comparable to that of UDCA. The effect of CDCA, UDCA and the cyclopropyl analogues was also tested with respect to HMG-CoA reductase and acylCoA cholesterol acyltransferase (ACAT) activities. ACAT was stimulated by the isomer 22S,23S cypro-UDCA but not affected by the other bile acids. No effect was observed as regards HMG-CoA reductase.