Partition Fractions Research Articles

In Vitro Antibacterial and Antiproliferative Potential of Echinops lanceolatus Mattf. (Asteraceae) and Identification of Potential Bioactive Compounds.

Many species belonging to the genus Echinops are widely used in traditional medicine to treat infectious diseases and cancers. The present study aimed to evaluate the antibacterial and antiproliferative properties of Echinops lanceolatus Mattf. (Asteraceae). The activity of the methanolic extract and subsequent partition fractions was investigated against drug-resistant bacteria (Gram-negative and Gram-positive) and human tumor cell lines using broth microdilution and sulforhodamine B (SRB) assay, respectively. Our findings revealed weak to moderate antibacterial activities of tested extracts, with the recorded minimal inhibitory concentrations ranging from 256 to 1024 µg/mL. The ethyl acetate fraction (EL-EA) was found to be the most effective. Likewise, that fraction displayed strong antiproliferative potential with recorded IC50 of 8.27 µg/mL and 28.27 µg/mL on A549 and HeLa cells, respectively. An analysis based on the ultra-performance liquid chromatography–electrospray ionization tandem mass spectrometry (UPLC–ESI–MS/MS) of the EL-EA fraction allowed the identification of 32 compounds, of which quinic acid and derivatives, cinnamic acid derivatives, dihydrokaempferol, naringenin-7-O-glucoside, apigenin-7-O-d-glucoside, naringin, apigenin, rhoifolin, coniferyl aldehyde, and secoisolariciresinol are well-known compounds of biological importance. This study is first to report on the biological activity and phytochemical profile of E. lanceolatus. We provide a baseline to consider E. lanceolatus as a valuable source of anti-infective and antiproliferative agents.

Effects of conductive curved partition and magnetic field on natural convection and entropy generation in an inclined cavity filled with nanofluid

In this study, natural convection and entropy generation analysis of nanofluid in an inclined cavity including a curved shaped conductive partition are performed under the impact of inclined magnetic field by using Galerkin weighted residual finite element method. Numerical simulations are performed for various values of Rayleigh number (between 104 and 106), inclination angle of the cavity (between 0o and 180 o), Hartmann number (between 0 and 50), orientation angle of the magnetic field (between 0o and 90o), curvatures of the conductive partition (between 0.01 and 0.1), conductivity ratio (between 0.01 and 100) and solid nanoparticle volume fraction (between 0 and 0.03). The average Nusselt number increases with higher values of Rayleigh number, inclusion of nano sized particles whereas it is reduced with higher values of Hartmann number. When the value of Hartmann number is increased from 0 to 50, 32% and 34% of average Nusselt number reduction is obtained for water and nanofluid. The cavity inclination angle has significant effects on the convective heat transfer characteristics. When the radii of the vertical and horizontal elliptic curved partitions are increased to 0.3H, 23% and 3.8% deterioration of average Nusselt number is obtained while significant enhancement in the heat transfer is observed when the conductivity of the partition is increased. The second law analysis was included in the study and entropy generation rate was found to vary with different parameters. Contributions of solid and fluid domains to the entropy generation rate were determined.

Screening of Antibacterial and Antioxidant Activity from the Soft Corals Sinularia sp. and Sarcophyton sp. Origin Palu Bay, Central Sulawesi, Indonesia

This study aimed to evaluate the potential antibacterial and antioxidant activities of Sinulariasp. and Sarcophyton sp. from the Palu Bay, Central Sulawesi, Indonesia. Soft corals were identified as Sinulariasp. (SC1), Sinularia sp. (SC2), andSarcophytonsp. (SC3). Antibacterial activity was examined using agar diffusion well method. Antioxidant activity was measured by the DPPH radical scavenging method. The samples were macerated in MeOH: DCM. The crude extracts were partitioned with DCM, EtOAc, and BuOH. The crude extract of Sinulariasp. (SC2) showed a very strong antibacterial activity as it was able to inhibit the growth of Staphylococcus aureusand Escherichia coliup to 10 mg/mL. Sinularia sp. (SC1) crude extract showed strong activity againstS. aureus, whereas it showed moderate against E. coli.Sarcophyton sp. (SC3) crude extract showed moderate activity against S. aureus, whereas it showed weak against E. coli. The partition fractions of the three soft coral extracts had the potential to be a potent antioxidant agent.

Leishmanicidal and antimicrobial activity of primin and primin-containing extracts from Miconia willdenowii

As a part of an ongoing bioprospective project, searching for potential medicinal plants from the Brazilian Atlantic Forest, Miconia willdenowii was selected for its potential leishmanicidal and antimicrobial activities. The crude ethanolic extract of M. willdenowii showed an inhibition of 99.7% of the promastigote forms of Leishmania amazonensis at the concentration of 80 μg/mL. Further investigation of its antimicrobial activity against pathogenic fungi and Gram positive and negative bacteria, revealed a significant antimicrobial activity. A bioguided study with its liquid-liquid partition fractions revealed the hexane fraction (Hex) as the most active against Leishmania, inhibiting 99.2% and 46.9% of the protozoan at concentrations of 40 and 20 μg/mL, respectively. Hex also showed significant antimicrobial activity against Staphylococcus aureus and Candida krusei with IC50 of 15.6 and 62.5 μg/mL, respectively. Purification of Hex led to the isolation of 2-methoxy-6-pentyl-benzoquinone (1, also known as primin) as the active metabolite, probably responsible for the observed antimicrobial and anti-leishmania effects. Primin (1) disclosed leishmanicidal activity (IC50 = 1.25 μM), showing higher potency than the standard drug amphotericin B (IC50 = 5.08 μM), with additional antifungal effects against all tested fungi species. Compound 1 also showed significant activity against S. aureus (IC50 = 8.94 μM), showing a comparable potency with the reference drug chloramphenicol (IC50 = 6.19 μM), but with a potential cytotoxicity towards peripheral human blood mononuclear cells (CC50 = 255.15 μM). Here in, the antimicrobial and anti-L. amazonensis effects of M. willdenowii are reported for the first time, as well as Primin (1) as its probable bioactive metabolite.

Anti-hyperglycaemic and anti-oxidant activities of five Nigerian antidiabetic plants

Leaves of Olax subscorpioidea, Hoslundia opposita, Cleistopholis patens, Plumbago zeylanica and Dioscoreophyllum cumminsii that are used as anti-diabetics were evaluated for hyperglycaemic-lowering and antioxidant activities to justify their Nigerian ethnomedicinal usage. Leaf methanolic extracts (100, 200 and 400 mg/kg, p.o.) were assayed in normal, glucose- and alloxan-induced diabetic rats, while 1,1,-diphenyl-2-picrylhydrazyl, total antioxidant capacity, ferric reducing antioxidant power and hydroxyl radical scavenging tests were used for their antioxidant activity. Effects of n-hexane, dichloromethane, ethylacetate and aqueous partition fractions of the three most active anti-hyperglycaemic extracts were also tested in glucose-loaded rats. In normoglycaemic rats, all extracts generally lacked activity, while with glucose-loaded rats, only O. subscorpioidea (200mg/kg) and C. patens (400 mg/kg) at 1 h and O. subscorpioidea (200, 400 mg/kg) and C. patens (400 mg/kg) at 2-4 hours gave lowered (p < 0.05) blood glucose levels than glibenclamide (5 mg/kg), while activity of H. opposita and P. zeylanica (200 mg/kg) were only comparable to glibenclamide. When daily fed for fourteen days to alloxan-induced diabetic rats, all extracts, at their most active doses, gave significantly higher activity than glibenclamide. Olax subscorpioidea leaf extract had the highest hyperglycaemic-lowering and least antioxidant activities. Highest antioxidant activity of H. opposita may suggest some contribution of antioxidant property to its hyperglycaemic-lowering activity. The glucose-lowering and insulinotropic constituents of O. subscorpioidea, H. opposita and C. patens should be concentrated in their aqueous, aqueous and dichloromethane fractions, respectively. Anti-hyperglycaemic ethnomedicinal use of these plants was justified and H. opposita has additional antioxidant property. Keywords: Antioxidant activity; Diabetes mellitus; Nigerian anti-diabetic plants

Conjugate mixed convection of nanofluid in a cubic enclosure separated with a conductive plate and having an inner rotating cylinder

In this study, convective heat transfer features of CNT-water nanofluid in a three dimensional cubic enclosure which is separated by a conductive partition and having an inner rotating adiabatic circular cylinder were examined. Numerical simulations were performed with Galerkin weighted residual finite element method. Various values of Richardson number of the left cavity (between 0.01 and 100), angular rotational speed of the inner cylinder (between −34724 and 34724), vertical (between 0.25 and 0.75) and horizontal (between 0.1 and 0.3) locations of the cylinder, thickness (between 0.01 and 0.2) and thermal conductivity ratio (between 0.1 and 100) of the conductive partition and nanoparticle volume fraction (between 0 and 0.03) on the fluid flow and heat transfer were analyzed. It was observed that the average heat transfer enhances for higher values of Richardson number, angular rotational speed of the cylinder (generally in both directions), solid particle volume fraction of nanofluid and thermal conductivity of the partition. The rate of enhancement are in the range of 11–14% when configurations with the lowest and highest values of Richardson number are considered whereas 18% of enhancement is attained at the highest rotational speed of the cylinder as compared to motionless cylinder configuration. The enhancements in the average Nusselt numbers with the inclusion of the CNT-nanoparticle at the highest solid volume fraction are in the range of 82% and 90% as compared to water. The average heat transfer coefficient is estimated by using POD and interpolation among POD modes and modal coefficients which is found to be computationally inexpensive and the method produces accurate results as compared to high fidelity three dimensional intensive computational fluid dynamics simulations.

Three-dimensional analytical modeling of cutting temperature for round insert considering semi-infinite boundary and non-uniform heat partition

Temperature distribution is a vital factor in cutting process for its significant effects on tool wear and tool life as well as the optimization of cutting parameters. With the gradually wide application of round insert in high-efficiency machining, the precise prediction of cutting temperature distribution for this kind of insert becomes critical. However, the irregular contact geometry between round insert and the workpiece leads to great challenges in thermal modeling. This study focuses on the thermal mechanism of dry turning operation with round insert based on analytical method. A three-dimensional temperature prediction model is proposed based on semi-infinite boundary theory and non-uniform heat partition model. Firstly, a novel discretization approach is utilized to determine the spatial distributions of shear and frictional heat source in a unified three-dimensional coordinate system. Secondly, a new method is developed to determine the intensity of frictional heat source in the presence of sticking-sliding zone at the tool-chip interface. Thirdly, a modified heat partition model is proposed to determine the non-uniformly distributed heat partition fractions on both sides of the tool-chip interface. The predicted temperature isotherms on tool rake face indicate that the area with maximum interface temperature is at a certain distance from the cutting edge. Finally, the proposed model is verified from three aspects including finite-element (FE) simulations using AdvanEdge, comparisons with recent literatures and experiments. Satisfactory agreement between the predictions and the measurements as well as the simulations has been reached. The overall results validate the effectiveness and reasonableness of the proposed model.

Rock Strength and Texture Evolution During Deformation in the Earth's Ductile Lithosphere: A Two‐Phase Thermodynamics Model

AbstractBuilding upon the two‐phase and grain damage theory, we propose a new formulation allowing to track the evolution of phase mixing/segregation during ductile deformation of a two‐phased aggregate. Our model is based on a set of variables characterizing a rock texture: the mean grain sizes and the phase proportion. During ductile deformation, activation of different micromechanical processes impacts the aggregate texture. Dislocation and diffusion creep are the two main deformation processes considered. We only account for the effect of Zener pinning in slowing down grain growth and allow for active grain‐size reduction mechanisms in the diffusion creep domain. For this purpose, an equation is proposed to track the phase mixing evolution during ductile deformation. Numerical application using anorthite rheology shows that any grain reduction mechanisms that could be active in the diffusion creep regime requires a very high partition fraction in order to reach the grain size predicted by the feldspar piezometer. Application of this model to gabbroic composition, relevant for the ductile crust, demonstrates that the strong coupling between phases grain sizes and interface evolution results in steady‐state grain sizes far below the field boundary. This effect is coeval with an important increase of mixing between the two phases. In addition, accounting for the phase mixing results in a drop of the global aggregate stress during deformation. This model allows for further comparison of mylonitized textures evolution with natural shear zones at the local and regional scales.

Terminalia fagifolia Mart. & Zucc. elicits vasorelaxation of rat thoracic aorta through nitric oxide and K+ channels dependent mechanism.

ABSTRACTTerminalia fagifolia Mart. & Zucc. (Combretaceae) is a plant commonly found in the regions of the Brazilian cerrado, popularly used for the treatment of gastrointestinal disorders. There are no reports in the literature on the use of T. fagifolia for the treatment of the cardiovascular system conditions. Nevertheless, plants of the same genus, such as Terminalia arjuna (Roxb.) Wight & Arn and Terminalia superba Engler & Diels, present cardioprotective, hypotensive and vasodilatating effects. In light of this, the aim of the study was to investigate the effect of the ethanolic extract (Tf-EE) and of its aqueous (Tf-AQF), hexanic (Tf-HEXF) and hydroethanolic (Tf-HAF) partition fractions obtained from the stem bark of T. fagifolia Mart. & Zucc. The effects of the extract and partition fractions of T. fagifolia were evaluated on isometric tensions in the thoracic aorta rings of Wistar rats (250–300 g). Tf-EE, Tf-HEXF and Tf-HAF presented a concentration-dependent vasorelaxant effect, and Tf-AQF presented a vasorelaxant effect that was more potent in the presence of endothelium. The relaxation curves of the aorta promoted by the fraction investigated were attenuated in the presence of the following pharmacological tools: L-NAME, ODQ or PTIO. The vasorelaxant effect of the aorta promoted by Tf-AQF was attenuated in the presence of TEA and 4-AP. Tf-EE induced a concentration-dependent and endothelium-independent vasorelaxation. Tf-HAF and Tf-HEXF presented concentration-dependent and vascular-endothelium-independent vasorelaxation, but did not obtain 100% of relaxation. On the other hand, Tf-AQF presented concentration-dependent vasorelaxation that was more potent in aorta rings with vascular endothelium. The relaxant mechanism induced by the Tf-AQF involves the NO/sGC/cGMP pathway and channels Kv.

Free Radical Scavenging and Anticollagenase Properties of Sargachromanol I from Myagropsis myagroides

The present study investigated the free radical scavenging activity and antiwrinkle properties of methanol extract, hexane, chloroform, ethyl acetate, and butanol partition fractions of Myagropsis myagroides. The methanol extract showed higher free radical scavenging (65.46 % at 0.5 mg/ml) and collagenase inhibitory activity (29.64 % at 1000 μg/ml) than the water extract (16.68 % at 0.5 mg/ml and < 5 % at 1000 μg/ml). The hexane fraction exhibited strong free radical scavenging activity (96.36 % at 0.5 mg/ml) and collagenase inhibitory activity (IC50 of 712.21 μg/ml). The hexane fraction was subjected to silica gel column chromatography, Sephadex LH-20 column chromatography, octadecyl silica Sepak cartridge, and preparative high performance liquid chromatography. Sargachromaol I was isolated, which showed strong free radical scavenging activity (95.82 % at 0.1 mg/ml) and collagenase inhibitory activity (IC50 value of 54.01 μg/ml). The potential value in preventing skin aging could be confirmed through effects of extract from Myagropsis myagroides on free radical scavenging activity and collagenase inhibitory properties.

A novel approach to thermal modeling based on three-dimensional analysis in turning Inconel 718 with round insert

The sharp increase of heat generated when processing difficult-to-machine materials is the main reason of short tool life and poor surface integrity. Temperature modeling plays a significant role in the mechanism of metal cutting, which can guide the optimization of cutting parameters. This paper proposes a modified three-dimensional analytical model of temperature prediction for oblique turning Inconel 718 with round carbide insert. The discretization of heat sources is indispensable to analyze the temperature rise due to the complicated geometry of uncut chip area. In this study, primary heat source (shear band) and secondary heat source (tool-chip interface) that divided into many increments through different discretization methods are considered to analyze thermal effects. For each increment of secondary heat source, the local contact length is calculated through a modified function considering global chip flow angle in oblique cutting. The local heat liberation intensities of primary and secondary heat sources are determined through analytical force prediction model. The variation of heat partition fraction with respect to immersion angle is given to study the characteristics of secondary heat source. Finally, a modified three-dimensional expression of temperature rises when turning with round insert considering semi-infinite medium is proposed based on classical thermal theory. The temperature distributions in chip, tool and workpiece can be determined through the proposed model. The results calculated through predictive model show good agreement with that given by finite element method (FEM) and experiments, which validates the correctness of the proposed model.

Slowing down of alpha particles in ICF DT plasmas

With the effects of the projectile recoil and plasma polarization considered, the slowing down of 3.54 MeV alpha particles is studied in inertial confinement fusion DT plasmas within the plasma density range from 1024 to 1026 cm−3 and the temperature range from 100 eV to 200 keV. It includes the rate of the energy change and range of the projectile, and the partition fraction of its energy deposition to the deuteron and triton. The comparison with other models is made and the reason for their difference is explored. It is found that the plasmas will not be heated by the alpha particle in its slowing down the process once the projectile energy becomes close to or less than the temperature of the electron or the deuteron and triton in the plasmas. This leads to less energy deposition to the deuteron and triton than that if the recoil of the projectile is neglected when the temperature is close to or higher than 100 keV. Our model is found to be able to provide relevant, reliable data in the large range of the density and temperature mentioned above, even if the density is around 1026 cm−3 while the deuteron and triton temperature is below 500 eV. Meanwhile, the two important models [Phys. Rev. 126, 1 (1962) and Phys. Rev. E 86, 016406 (2012)] are found not to work in this case. Some unreliable data are found in the last model, which include the range of alpha particles and the electron-ion energy partition fraction when the electron is much hotter than the deuteron and triton in the plasmas.

Sorption of p-Nitrophenol by Biochars of Corncob Prepared at Different Pyrolysis Temperatures

Sorption of p-nitrophenol (PNP) on biochars prepared from pyrolysis of corncob in the temperature range of 200-600℃ (CC200-CC600) was investigated. Sorption mechanisms were discussed. Pyrolysis temperature showed a pronounced effect on properties of biochars. Decreases in molar H/C, O/C and (O+N)/C ratios were resulted from removal of H- and O-containing functional groups with increasing pyrolysis temperature, and produced biochars with low polarity and high aromaticity. The isotherms data were well described by the Freundlich model. Batch sorption experiments showed that the PNP sorption was strongly dependent on the properties of biochars. A linear relationship was observed between sorption parameters (n and KF) and properties of biochars such as molar elemental ratios[H/C, O/C, and (O+N)/C]. The sorption and partition fractions were quantified by isotherm separation method. PNP sorption on biochar produced at 200℃ was linear due to partition on uncarbonized organic matter in biochar, while PNP sorption on biochars produced at 300-600℃ was nonlinear and adsorption-dominant for all the biochars via π-π electron donor-acceptor interaction and pore-filling.

Antinociceptive effect of extracts of Marrubium astracanicum Jacq. aerial parts.

The genus Marrubium is used for treatment of joint pain, gout, stomach-ache and colic in Iranian Traditional Medicine. Marrubium astracanicum Jacq. (M. astracanicum) is a native species in the flora of Iran. The aim of this study was to evaluate the antinociceptive properties of various extracts of aerial parts of M. astracanicum. Antinociceptive activities of total hydroalcoholic extract (THE) and its n-hexane (non-polar) and residual partition (polar) fractions were analyzed using formalin test in mice. Morphine (5 mg/kg) and normal saline were used as positive and negative controls, respectively. Intraperitoneal administration of THE (50, 100 and 200 mg/kg), non-polar fraction (200 mg/kg) and polar fraction (100 and 200 mg/kg), 30 min before formalin injection, caused significant analgesic activity in acute phase (0-5 min after formalin injection) of formalin test (p<0.05 as compared to control and p>0.05 in comparison with morphine). In chronic phase (15-60 min after formalin injection), non-polar and polar fractions (50, 100 and 200 mg/kg) showed significant analgesic activity (p<0.001 as compared to control and p>0.05 in comparison with morphine). Different extracts of M. astracanicum demonstrated antinociceptive activity that support the traditional usage of Marrubium genus for the treatment of arthritis, gout and other inflammatory diseases.

Conjugate natural convection in a nanofluid filled partitioned horizontal annulus formed by two isothermal cylinder surfaces under magnetic field

Natural convection in a CuO-water nanofluid filled horizontal partitioned annulus formed by two isothermal surfaces under the influence of an inclined magnetic field was numerically investigated. A conductive partition with varying thickness and thermal conductivity was placed within the annulus. Finite element method was utilized to solve the governing equations. The influence of the Rayleigh number (between 104 and 106), Hartmann number (between 0 and 40), magnetic inclination angle (between 0° and 90°), thermal conductivity of the partition (between 0.06 and 60) and solid volume fraction of the nanoparticle (between 0 and 0.04) on the fluid flow and heat transfer characteristics were studied for various thickness values of the partition. Local and average Nusselt number along the inner surface enhance as the value of the thickness of the partition and Rayleigh number and magnetic inclination angle (up 45°) increase and as the value of Hartmann number decreases. The influence of the thickness of the conductive partition is more pronounced in the conduction dominated regime when Rayleigh number is low and Hartmann number is high. Average heat transfer enhances with thermal conductivity of the partition and this is more effective for a thicker partition. Almost a linearly varying relation exists between the average Nusselt number and solid nanoparticle volume fraction and the slope of the curve is slightly higher for a thick partition.

Oleanonic acid from Lippia lupulina (Verbenaceae) shows strong in vitro antileishmanial and antitrypanosomal activity

ABSTRACT Leishmaniasis and Chagas disease affect millions of people in tropical and subtropical regions. Drugs used currently to treat such diseases often present undesirable side effects and low efficiency. The aim of this work was to identify extracts and isolated compounds from the genus Lippia with leishmanicidal and trypanocidal activity. Fifteen extracts from different plant parts of Lippia species with partially known chemical compositions, four partition fractions, six compounds and a mixture of four interconverting flavanones previously isolated from Lippia salviaefolia and Lippia lupulina were assayed in vitro towards epimastigote forms of Trypanosoma cruzi and promastigote forms of Leishmania amazonensis. The root extract of L. lupulina had potent activity against T. cruzi and L. amazonensis (IC50 of 20.0 and 54.5 µg mL-1, respectively). The triterpenoid oleanonic acid showed the strongest activity against these protozoans (IC50 of 18.5 and 29.9 µM, respectively). Our results indicate that Lippia plants and their derivatives deserve further investigation in the search for new antiprotozoal drugs, particularly for the treatment of leishmaniasis and Chagas disease.

&lt;em&gt;In Vitro&lt;/em&gt; Evaluation of Extracts of Solanum torvum (Solanaceae) Fruits for Anti-Trichomonal Activity

Trichomonasis is curable when treated. However there is increasing incidence of resistance to therapeutic drugs. <em>Solanum torvum</em> has several ethnomedicinal applications and therefore a potential source of antiparasitic drugs. The objective of this study was to assess the therapeutic potentials of extracts of fruits of <em>Solanum torvum</em> against <em>Trichomonas gallinarum</em>. Crude methanol extract of Solanum torvum was partitioned into petroleum ether (STF₁), chloroform (STF₂), ethyl acetate (STF₃), aqueous (STF₄) and STF₅ (_precipitate) fractions. STF₁, STF₂ and STF₃ were each subjected to vacuum liquid chromatography to obtain STF_{11- 17}, STF_{21- 28} and STF_{31- 37}. The crude extract STF₀, partition fractions STF_1-5 and sub fractions STF_{11- 17}, STF_{21- 28} STF_{31- 37} were assayed for anti-trichomonal activity. The crude extract, STF₀, at 24 h and 48 h showed LC₅₀ and LC₉₀ of 386.34±17.96, 2168.31±119.43, 85.81±20.10, 324.72±17.73 (μg/mL), respectively. STF₅ (_precipitate) had LD₅₀ and LD₉₀ at 24 and 48 h as 25.84±5.12, 70.36±15.64 and 13.87±1.61, 42.94±6.20 (μg/mL), respectively. STF₁, STF₂ and STF₃ had LD₉₀ at 48h as 72.76±1.72, 119.39±3.90 and 114.54±36.08 (μg/mL) while STF₁₃, STF₁₄, STF₂₃ and STF₃₄ had corresponding values of LD₉₀ at 48h as 67.18±14.90, 88.07±4.78, 89.95±7.99 and 84.03±8.03 (μg/mL). The partition fractions STF₁, STF₂ and STF₃, the VLC sub fractions STF₁₃, STF₁₄, STF₂₃, STF₃₄ and the standard drug did not show significant difference (p>0.05) in their bioactivities. It is concluded that methanol extracts of the fruits of Solanum torvum are a potential source of drug (s) for the treatment of trichomoniasis.

Anti-adipogenic activity of Carduus crispus and its constituent apigenin in 3T3-L1 adipocytes by downregulating PPARγ and C/EBPα

Carduus crispus, native to Europe and Asia, is a traditional herbal medicine used for treating inflammatory disorders in Korea. Obesity is characterized by a state of chronic inflammation with increased inflammatory markers along with the expression and release of inflammation-related adipokines. Most anti-obesity drugs have been developed based on this concept. Our research for anti-obesity agents derived from C. crispus utilized the 3T3-L1 cell line. The methanol extract was initially screened and exhibited significant inhibition of adipogenesis in 3T3-L1 adipocytes. Among five liquid–liquid partition fractions, the ethyl acetate (EA) fraction showed the most potent suppressive effect compared with hexane, chloroform, n-butanol, and water. The EA fraction was considered for further study because of the presence of abundant polyphenols, including flavonoids. To isolate the active components from the EA fraction, elution–extrusion countercurrent chromatography was used. Among the seven fractions from the EA layer, fraction 6 inhibited lipid accumulation as well as CCAAT/enhancer-binding protein alpha and peroxisome proliferator-activated receptor gamma protein expression levels. The active component apigenin (fraction 6) was confirmed using high-performance liquid chromatography, electrospray ionization mass spectrometry, and one-dimensional nuclear magnetic resonance spectroscopy. The present data suggest that apigenin is one of the main bioactive compounds from C. crispus for inhibiting adipogenesis in 3T3-L1 adipocytes via the activation of AMP-activated protein kinase.

PCDD/F and PCB water column partitioning examination using natural organic matter and black carbon partition coefficient models

A 9-year water dataset from the Houston Ship Channel (HSC) was analyzed to understand partitioning in polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs). Total PCBs had more mass as dissolved (74%) whereas total PCDD/Fs did not (11%). Generally, the limited number of PCDD/Fs (only 2378 substituted) explained these differences though differences in chemical behavior beyond log K ow also likely influence partitioning. The particular fractionation seen in the HSC also seemed related to a wide variation in particulate organic carbon (POC)/dissolved organic carbon (DOC) ratio (0.42-180%). Published and unaltered linear free energy and linear solvation energy relationships for DOC, POC, and particulate black carbon (BC) resulted in predictions that were at best 27% (PCB) and 25% root-mean-square error (RMSE) (PCDD/F) partition fraction compared to observed (using estimated BC/POC fractions of 10 and 25%, respectively). These results show, at least in light of the uncertainties in this data (e.g., precise fraction of BC), that a 25% accuracy in model prediction of operationally dissolved or suspended fraction for any one PCB or PCDD/F congener is the best prediction that may be expected. It is therefore recommended that site-specific data be used to calibrate most any water column-partitioning model if it is to be expected to describe what actually occurs in field conditions.

In vitro anti-Neisseria gonorrhoeae activity of Senna podocarpa root extracts

Senna podocarpa (Guill. & Perr.) Lock leaf and root are used in African countries to treat sexually transmitted diseases, namely gonorrhoea.A bioguided fractionation study was performed to evaluate the antibacterial activity of a S. podocarpa root hydro-ethanol extract (Spr).Spr, its major compounds and liquid–liquid partition fractions (Spr-1, diethyl ether; Spr-2, ethyl acetate; Spr-3, water) as well as chromatographically isolated main compounds of Spr-1, were tested against nine Neisseria gonorrhoeae reference and clinical strains, including strains with diminished susceptibility to penicillin, tetracycline, and ciprofloxacin. Spr showed anti-N. gonorrhoeae activity against all tested strains with minimum inhibitory concentrations (MIC) ranging from 100 to 400mg/L.The main compounds isolated from the most active fraction, Spr-1 (MIC: 50–100mg/L) were identified as rhein (1), emodin (2), chrysophanol (3) and physcione (4) by LC-UV/DAD co-chromatography with reference standards. Rhein (MIC: 3.13mg/L against all test strains) proved to be the most active of the isolates, while 2–4 and sennosides A and B (5–6), the major compounds of the total extract, were inactive in the range of tested concentrations (MIC>75mg/L).Rhein was shown to be responsible for the anti-N. gonorrhoeae activity of S. podocarpa root and it can be used as a marker compound to assess the antibacterial activity of this medicinal plant.