Phytochemical Analysis, In Vitro Anti-Inflammatory and Antimicrobial Activity of Piliostigma thonningii Leaf Extracts from Benin.

The leaves of Piliostigma thonningii are used in traditional medicine in Benin to treat inflammatory skin diseases and infections. So far, pharmacological studies of the anti-inflammatory and anti-infective effects of phytochemically characterized extracts of P. thonningii have been very limited. Therefore, we investigated the in vitro anti-inflammatory and antimicrobial effect of P. thonningii leaf extracts and analyzed the phytochemical composition of extracts of different polarities (water, 50% ethanol, and n-hexane). Quercetin-3-O-rhamnoside was confirmed as the main flavonoid in the polar extracts. GC-MS analysis identified 20 constituents of the aqueous extract and 28 lipophilic compounds of the n-hexane extract by comparison with authentic standards and spectral library data. The aqueous P. thonningii leaf extract inhibited the IL-8 and IL-6 secretion in TNF-α-stimulated HaCaT cells in a concentration-dependent manner with IC50 values of 74 µg/mL for IL-8 and 89 µg/mL for IL-6. However, an inhibitory effect of the identified quercetin-3-O-rhamnoside and its aglycone, quercetin, on the release of IL-8 and IL-6 could not be demonstrated. In the antimicrobial screening, inhibition zones for a 50% EtOH leaf extract of P. thonningii were found for Staphylococcus epidermidis, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Escherichia coli. For none of the microbial strains, however, the MIC was below 500 µg/mL, so that the antibacterial activity must be classified as low. As a result, our investigations primarily support the ethnomedical use of P. thonningii leaf extracts in topical inflammatory conditions. Further studies are required to identify the compounds responsible for the in vitro anti-inflammatory effects.

Phytochemical Characterization and In Vitro Anti-Inflammatory, Antioxidant and Antimicrobial Activity of Combretum collinum Fresen Leaves Extracts from Benin.

Leaves from Combretum collinum Fresen (Combretaceae) are commonly used for the treatment of inflammatory conditions, wound healing and bacterial infections in traditional West African medicine. This research focuses on the characterization of the phenolic profile and lipophilic compounds of leaves extracts of C. collinum. Studies of the in vitro anti-inflammatory activity were performed in TNFα stimulated HaCaT cells and antibacterial activity was evaluated with agar well diffusion and microdilution assays. Antioxidant activity was determined by DPPH and ABTS assays and compared to standards. The phytochemical studies confirmed myricetin-3-O-rhamnoside and myricetin-3-O-glucoside as major components of the leaves extracts, each contributing significantly to the antioxidant activity of the hydrophilic extracts. GC-MS analysis identified 19 substances that were confirmed by comparison with spectral library data and authentic standards. Combretum collinum aqueous leaves extract decreased pro-inflammatory mediators in TNFα stimulated HaCaT cells. Further investigations showed that myricetin-3-O-rhamnoside has an anti-inflammatory effect on IL-8 secretion. In the antimicrobial screening, the largest inhibition zones were found against S. epidermidis, MRSA and S. aureus. MIC values resulted in 275.0 µg/mL for S. epidermidis and 385.5 µg/mL for MRSA. The in vitro anti-inflammatory, antibacterial and antioxidant activity supports topical use of C. collinum leaves extracts in traditional West African medicine.

Chemical Profile and Antimicrobial Activity of the Fungus-Growing Termite Strain Macrotermes Bellicosus Used in Traditional Medicine in the Republic of Benin.

The fungus growing termite species Macrotermes bellicosus (M. bellicosus) is used in nutrition and traditional medicine in the Republic of Benin for the treatment of infectious and inflammatory diseases. Previous findings demonstrated evidence of anti-inflammatory and spasmolytic properties of M. bellicosus. The aim of the present study was to evaluate the antimicrobial potential of different extracts of M. bellicosus samples and determine the chemical profile of an ethanolic M. bellicosus extract. Chemical profiling was conducted using centrifugal partition chromatography and 13C-NMR, followed by MALDI-TOF MS. Major identified compounds include hydroquinone (HQ), methylhydroquinone (MHQ), 3,4-dihydroxyphenethyl glycol (DHPG), N-acetyldopamine (NADA) and niacinamide. The fatty acid mixture of the extract was mainly composed of linoleic and oleic acid and highlights the nutritional purpose of M. bellicosus. Using the Kirby-Bauer disc diffusion and broth microdilution assay, an antibacterial activity of M. bellicosus samples was observed against various clinical strains with a highest growth inhibition of S. aureus. In addition, HQ and MHQ as well as fractions containing DHPG, niacinamide and NADA inhibited S. aureus growth. The reported antimicrobial activity of M. bellicosus and identified active substances provide a rationale for the traditional medicinal use of M. bellicosus.

IgY antibodies in human nutrition for disease prevention.

Oral administration of preformed specific antibodies is an attractive approach against infections of the digestive system in humans and animals in times of increasing antibiotic resistances. Previous studies showed a positive effect of egg yolk IgY antibodies on bacterial intoxications in animals and humans. Immunization of chickens with specific antigens offers the possibility to create various forms of antibodies. Research shows that orally applied IgY's isolated from egg yolks can passively cure or prevent diseases of the digestive system. The use of these alternative therapeutic drugs provides further advantages: (1) The production of IgY's is a non-invasive alternative to current methods; (2) The keeping of chickens is inexpensive; (3) The animals are easy to handle; (4) It avoids repetitive bleeding of laboratory animals; (5) It is also very cost effective regarding the high IgY concentration within the egg yolk. Novel targets of these antigen specific antibodies are Helicobacter pylori and also molecules involved in signaling pathways in gastric cancer. Furthermore, also dental caries causing bacteria like Streptococcus mutans or opportunistic Pseudomonas aeruginosa in cystic fibrosis patients are possible targets. Therefore, IgY's included in food for human consumption may be able to prevent or cure human diseases.

Finite Element Analysis of Plastic Deformation in Ultrasonic Vibration Superimposed Face Milling of Steel X46Cr13.

Ultrasonic vibration superimposed face milling enables the generation of predefined surface microstructures by an appropriate setting of the process parameters. The geometrical reproducibility of the surface characteristics depends strongly on the plastic material deformation. Thus, the precise prediction of the emerging surface microstructures using kinematic simulation models is limited, because they ignore the influence of material flow. Consequently, the effects of plastic as well as elastic deformation are investigated in depth by finite element analysis. Microstructured surfaces resulting from these numerical models are characterized quantitatively by areal surface parameters and compared to those from a kinematical simulation and a real machined surface. A high degree of conformity between the values of the simulated surfaces and the measured values is achieved, particularly with regard to material distribution. Deficits in predictability exist primarily due to deviations in plastic deformation. Future research can address this, either by implementing a temperature consideration or adapting specific modeling aspects like an adjusted depth of cut or experimental validated material parameters.

Pin-Shaped Surface Structures Generated by Laser Single Pulse Drilling for High-Strength Interfaces in Thermally Joined Polymer-Metal Hybrids.

Laser structuring is by far the most investigated metal surface-pretreatment method for creating adhesion in polymer-metal hybrids. Especially, cone-like protrusions show excellent wetting behaviour as well as high compound strength. However, the processing time is extremely high. Therefore, this paper assesses a process strategy for creating pin structures with scalable height by single pulse drilling with an Nd/YVO4 nanosecond laser system on EN AW-6082 aluminium alloy. The strength testing is carried out by butt-bonded hollow cylinder torsion. The samples are manufactured by heat-conduction thermal joining with polyamide 6. Ten different surface structures with two different ablation diameters are investigated and compared to cone-like protrusions in terms of processing time, wetting behaviour, shear strength and fracture behaviour. The experimental results show that pulse drilling pins structures with high aspect ratio reach-strength values close to cone-like protrusions but with 31 times higher processing rate.

Simulation-Assisted Process Design and Experimental Verification of Laterally Confined Oxide Areas Generated with Continuous Electrolytic Free Jet on EN AW-7075 Aluminum Alloy.

Local anodization with a free electrolyte jet is a suitable solution for locally confined surface functionalization without additionally required preparation of the parts. However, the geometrical formation of the anodic oxide layer in jet-based anodization is not yet sufficiently understood. In this study, numerical calculations based on physical descriptions are used to describe the lateral and vertical oxide formation on aluminum alloy EN AW-7075. The required electrical resistance and capacitance were determined by immersion-based anodization and implemented into the numerical simulation model to evaluate the electrical conductivity of the porous layer. The simulation results showed an electrical conductivity of 2.6 × 10-6 S/m for the porous layer. Subsequently, a model for jet-based anodization was developed and the previous results were implemented to calculate the oxide formation. The simulation results showed decreasing oxide layer thickness at increasing radial distance from the center of the jet, which corresponds to experimental results. The simulation model was validated by varying the current efficiency from 5% to 90%, where similar developments of the anodic oxide layer thickness compared with experimental results were determined at 5%.

Investigation of the Tribological Behaviour of Various AMC Surfaces against Brake Lining Material.

AlSi7Mg/SiCp aluminium matrix composites (AMCs) with a high ceramic content (35 vol.%) that were produced by using the field-assisted sintering technique (FAST) were subjected to tribological preconditioning and evaluated as a potential lightweight material to substitute grey cast iron brake discs. However, since an uncontrolled running-in process of the AMC surface can lead to severe wear and thus to failure of the friction system, AMC surfaces cannot be used directly after finishing and have to be preconditioned. A defined generation of a tribologically conditioned surface (tribosurface) is necessary, as was the aim in this study. To simulate tribological conditions in automotive brake systems, the prepared AMC samples were tested in a pin-on-disc configuration against conventional brake lining material under dry sliding conditions. The influence of the surface topography generated by face turning using different indexable inserts and feeds or an additional plasma electrolytic treatment was investigated at varied test pressures and sliding distances. The results showed that the coefficient of friction remained nearly constant when the set pressure was reached, whereas the initial topography of the samples studied by SEM varied substantially. A novel approach based on analysing the material ratio determined by 3D surface measurement was developed in order to obtain quantitative findings for industrial application.

Cytotoxicity of Medicinal Plant Species Used by Traditional Healers in Treating People Suffering From HIV/AIDS in Uganda.

Introduction: Many people living with HIV/AIDS (PLHIV) in Uganda widely use herbal medicines. However, their toxicity and safety have not been investigated. The use of these plants can potentially cause harmful effects to the health of patients. The purpose of this study was to determine the cytotoxicity of some commonly used medicinal plant species used by PLHIV. Methods: The cytotoxicity of the plant extracts was determined with the AlamarBlue cell viability assay using the human glioblastoma cell line U87.CD4.CXCR4. The cells were treated with varying concentrations of extracts of Warburgia ugandensis, Erythrina abyssinica, Cryptolepis sanguinolenta, Albizia coriaria, Psorospermum febrifugium, Gymnosporia senegalensis, Zanthoxylum chalybeum, Securidaca longipendunculata, Vachellia hockii, Gardenia ternifolia, and Bridelia micrantha reconstituted with ethanol and dimethyl sulfoxide (DMSO). Using regression analysis, the half maximal cytotoxic concentration (CC50) of the plant extracts were calculated from exponential curve fits, since they provided the highest coefficient of determination, R2. Results: The ethanol extracts of W. ugandensis (CC50 = 7.6 µg/ml) and A. coriaria (CC50 = 1.5 µg/ml) as well as the DMSO-reconstituted extracts of W. ugandensis (CC50 = 6.4 µg/ml) and A. coriria (CC50 = < 4 µg/ml) were highly cytotoxic. The cytotoxicity of W. ugandensis and A. coriaria compared well with the indigenous traditional knowledge of the toxic effects experienced when the plants were not used correctly. However, the cytotoxicity of most of the plant extracts (15/22) was low to moderate (CC50 = 21-200 µg/ml). Conclusion: Most of the plant species tested in this study had low to moderate cytotoxicity against U87.CD4.CXCR4 cells, except W. ugandensis and A. coriria which were highly cytotoxic.

Warburgia ugandensis Leaf and Bark Extracts: An Alternative to Copper as Fungicide against Downy Mildew in Organic Viticulture?

In organic viticulture, copper-based fungicides are commonly used to suppress Downy Mildew infection, caused by the oomycete Plasmopara viticola. However, the frequent and intensive use of such fungicides leads to accumulation of the heavy metal in soil and nearby waters with adverse effects on the ecosystem. Therefore, alternative, organic fungicides against Downy Mildew are urgently needed to reduce the copper load in vineyards. In this study, the use of Warburgia ugandensis Sprague (Family Canellacea) leaf and bark extracts as potential fungicides against Downy Mildew were evaluated. In vitro (microtiter) and in vivo (leaf discs, seedlings) tests were conducted, as well as field trials to determine the efficacy of the extracts against Downy Mildew. The results revealed an MIC100 of 500 µg/mL for the leaf extract and 5 µg/mL for the bark extract. Furthermore, experiments with leaf discs and seedlings demonstrated a strong protective effect of the extracts for up to 48 h under (semi-) controlled conditions. However, in field trials the efficacy of the extracts distinctly declined, regardless of the extracts' origin and concentration.

Introducing Fractal Dimension for Interlaminar Shear and Tensile Strength Assessment of Mechanically Interlocked Polymer-Metal Interfaces.

The interlaminar strength of mechanically interlocked polymer-metal interfaces is strongly dependent on the surface structure of the metal component. Therefore, this contribution assesses the suitability of the fractal dimension for quantification of the surface structure, as well as interlaminar strength prediction of aluminum/polyamide 6 polymer-metal hybrids. Seven different surface structures, manufactured by mechanical blasting, combined mechanical blasting and etching, thermal spraying, and laser ablation, are investigated. The experiments are carried out on a butt-bonded hollow cylinder testing method that allows shear and tensile strength determination with one specific specimen geometry. The fractal dimension of the metal surfaces is derived from cross-sectional images. For comparison, the surface roughness slope is determined and related to the interlaminar strength. Finally, a fracture analysis is conducted. For the investigated material combination, the experimental results indicate that the fractal dimension is an appropriate measure for predicting the interlaminar strength.

Data on medicinal plants used by herbalists for boosting immunity in people living with HIV/AIDS in Uganda.

This Data in Brief article provides supplementary information to or earlier Ethnobotanical survey on medicinal plants used by traditional medicine practitioners to boost the immune system in people living with HIV/AIDS in Uganda [1]. We identified 71 medicinal plant species from 37 families and 64 genera. The data were analysed using descriptive statistics such as frequencies and percentages. Most of the plant species used were trees (27) and herbs (25) from the Fabaceae (15.7%) Asteraceae Phyllanthaceae (8.6%), Rubiaceae (5.7%) and Rubiaceae (5.7%) families. Additionally, we conducted a detailed literature review of the documented species to justify their use as immunostimulants. This data is derived from a larger survey to document the use of medicinal plant species in treating opportunistic infections in Uganda by Anywar et al. [2].

Lightweight UV-C disinfection system.

UV-C exposure is an effective disinfectant for a range of bacteria and viruses. As such, UV-C treatment, in combination with a chemical wipe, is a common cleaning protocol in medical facilities. Given the increase in severe bacterial and viral agents in society, having access to environmentally friendly disinfectant methods is of increasing interest. In response, we designed, constructed, and validated a UV-C disinfection system from readily accessible components. To improve the UV-C intensity, the enclosure interior was coated with chrome paint. The system is validated using Bacillus cereus, a gram-positive endospore-forming bacteria.

Secretory products from human adipocytes stimulate proinflammatory cytokine secretion from human endothelial cells.

Hyperplasia and hypertrophy of fat cells can be found in obesity and increased adiposity is associated with endothelial dysfunction as an early event of atherosclerosis. However, it is unclear whether human adipocytes directly influence endothelial protein secretion. To study the crosstalk between fat and endothelial cells, human umbilical venous endothelial cells (HUVECs) were cultured in infranatants (Adipo) of primary differentiated human adipocytes. Interestingly, significantly increased secretion of 23 cytokines and chemokines from HUVECs was detected in four independent experiments after Adipo stimulation by protein array analysis detecting a total of 174 different proteins. Among those, time-dependent Adipo-induced upregulation of cytokine secretion in HUVECs was confirmed by ELISA for interleukin (IL)-8, monokine induced by gamma interferon, macrophage inflammatory protein (MIP)-1beta, MIP-3alpha, monocyte chemoattractant protein-1, and IL-6. Factors besides adiponectin, leptin, resistin, and tumor necrosis factor alpha appear to mediate these stimulatory effects. Our findings suggest that endothelial cell secretion is significantly influenced towards a proinflammatory pattern by adipocyte-secreted factors.

Process Understanding of Plasma Electrolytic Polishing through Multiphysics Simulation and Inline Metrology.

Currently, the demand for surface treatment methods like plasma electrolytic polishing (PeP)-a special case of electrochemical machining-is increasing. This paper provides a literature review on the fundamental mechanisms of the plasma electrolytic polishing process and discusses simulated and experimental results. The simulation shows and describes a modelling approach of the polishing effect during the PeP process. Based on the simulation results, it can be assumed that PeP can be simulated as an electrochemical machining process and that the simulation can be used for roughness and processing time predictions. The simulation results exhibit correlations with the experimentally-achieved approximation for roughness decrease. The experimental part demonstrates the results of the PeP processing for different times. The results for different types of roughness show that roughness decreases exponentially. Additionally, a current efficiency calculation was made. Based on the experimental results, it can be assumed that PeP is a special electrochemical machining process with low passivation.

Process Control in Jet Electrochemical Machining of Stainless Steel through Inline Metrology of Current Density.

Jet electrochemical machining (Jet-ECM) is a flexible method for machining complex microstructures in high-strength and hard-to-machine materials. Contrary to mechanical machining, in Jet-ECM there is no mechanical contact between tool and workpiece. This enables Jet-ECM, like other electrochemical machining processes, to realize surface layers free of mechanical residual stresses, cracks, and thermal distortions. Besides, it causes no burrs and offers long tool life. This paper presents selected features of Jet-ECM, with special focus on the analysis of the current density during the machining of single grooves in stainless steel EN 1.4301. Especially, the development of the current density resulting from machining grooves intersecting previous machining steps was monitored in order to derive systematic influences. The resulting removal geometry is analyzed by measuring the depth and the roughness of the machined grooves. The correlation between the measured product features and the monitored current density is investigated. This correlation shows that grooves with the desired depth and surface roughness can be machined by controlling current density through the adjustment of process parameters. On the other hand, current density is sensitive to the changes of working gap. As a consequence of the changes of workpiece form and size for the grooves intersecting premachined grooves as well as the grooves with a lateral gap, working gap, and current density change. By analyzing monitoring data and removal geometry results, the suitability of current density inline monitoring to enable process control is shown, especially with regards to manufacture products that should comply with tight predefined specifications.

Effect of Metal Surface Topography on the Interlaminar Shear and Tensile Strength of Aluminum/Polyamide 6 Polymer-Metal-Hybrids.

Mechanical interlocking has been proven to be an effective bonding mechanism for dissimilar material groups like polymers and metals. Therefore, this contribution assesses several surface pretreatments for the metallic adherent. Blasting, etching, combined blasting and etching, thermal spraying, and laser structuring processes are investigated with regard to the achievable interlaminar strength and the corresponding surface roughness parameters. The experiments are carried out on EN AW-6082/polyamide 6 polymer-metal-hybrids, utilizing a novel butt-bonded hollow cylinder specimen geometry for determining the shear and tensile strength. The experimental results indicate that the surface roughness slope has a major impact on the interlaminar strength. A laser-generated pin structure is found to provide the best mechanical performance as well as the highest surface slope of all investigated structuring methods.

Endothelial Protection, AT1 blockade and Cholesterol-Dependent Oxidative Stress: the EPAS trial.

BACKGROUND: Statins and angiotensin type 1 (AT1) receptor blockers reduce cardiovascular mortality and morbidity. In the Endothelial Protection, AT1 blockade and Cholesterol-Dependent Oxidative Stress (EPAS) trial, impact of independent or combined statin and AT1 receptor blocker therapy on endothelial expression of anti-atherosclerotic and proatherosclerotic genes and endothelial function in arteries of patients with coronary artery disease were tested. METHODS AND RESULTS: Sixty patients with stable coronary artery disease undergoing elective coronary artery bypass grafting (CABG) surgery were randomized 4 weeks before surgery to: (A) control without inhibition of renin-angiotensin system or statin; (B) statin (pravastatin 40 mg/d); (C) AT1 blockade (irbesartan 150 mg/d); or (D) combination of statin and AT1 blocker in same dosages. Primary end point was a priori therapy-dependent regulation of an anti-atherosclerotic endothelial expression quotient Q including mRNA expression (in arbitrary units measured by real-time polymerase chain reaction) of endothelial nitric oxide synthase and C-type natriuretic peptide, divided by expression of oxidized low-density lipoprotein receptor LOX-1 and NAD(P)H oxidase subunit gp91phox in left internal mammary arteries biopsies obtained by CABG surgery; 49 patients completed the study. Statin therapy increased lnQ from 3.2+/-0.4 to 4.4+/-0.4 significantly versus control. AT(1) blockade showed a trend to increase lnQ to 4.2+/-0.5. Combination of statin and AT1 blocker further increased lnQ to 5.1+/-0.6, but a putative interaction of both therapies in lnQ was not significant. Furthermore, preoperative therapy with statin, AT1 blocker and their combination improved endothelial function in internal mammary artery rings. CONCLUSIONS: Statin and AT1 blocker therapy independently and in combination improve an anti-atherosclerotic endothelial expression quotient and endothelial function.

Antioxidative effects of exercise training in patients with chronic heart failure: increase in radical scavenger enzyme activity in skeletal muscle.

BACKGROUND: In chronic heart failure (CHF), cross-talk between inflammatory activation and oxidative stress has been anticipated in skeletal muscle (SM). The role of the radical scavenger enzymes superoxide dismutase (SOD), catalase (Cat), and glutathione peroxidase (GPX), which remove oxygen radicals, has never been assessed in the SM in this context. Moreover, it remains unknown whether exercise training augments the activity of these enzymes in CHF. METHODS AND RESULTS: Twenty-three patients with CHF were randomized to either 6 months of exercise training (T) or a sedentary lifestyle (C); 12 age-matched healthy subjects (HS) were studied in parallel. Activity of Cat, SOD, and GPX was assessed in SM biopsies before and after 6 months (6 months). Oxidative stress was determined by measuring nitrotyrosine formation. SOD, Cat, and GPX activity was reduced by 31%, 57%, and 51%, respectively, whereas nitrotyrosine formation was increased by 107% in SM in CHF (P<0.05 versus HS). In CHF, exercise training augmented GPX and Cat activity in SM by 41% (P<0.05 versus before and group C) and 42% (P<0.05 versus before and group C), respectively, and decreased nitrotyrosine production by 35% (from 3.8+/-0.4% tissue area before to 2.5+/-0.3% after 6 months; P<0.05 versus before). CONCLUSIONS: The reduced activity of major antioxidative enzymes in the SM of CHF patients is associated with increased local oxidative stress. Exercise training exerts antioxidative effects in the SM in CHF, in particular, due to an augmentation in activity of radical scavenger enzymes.