Cytosolic double-stranded DNA induces nonnecroptotic programmed cell death in trophoblasts via IFI16.

The mechanisms underlying the immune defense by trophoblasts against pathogens remain ill defined. We demonstrated that placental cell death was increased upon in vivo exposure to Listeria monocytogenes. The death of infected cells is an important host innate defense mechanism. Meanwhile, double-stranded DNA (dsDNA) derived from intracellular bacteria or dsDNA viruses is emerging as a potent pathogen-associated molecular pattern recognized by host cells. We sought to characterize trophoblast death in response to cytosolic dsDNA challenge. Our results showed that dsDNA induced caspase-dependent and -independent cell death in human trophoblasts. However, necroptosis, a cell death pathway independent of caspase, could not be induced by dsDNA treatment, even in the presence of exogenously expressed RIPK3. L. monocytogenes-derived genomic DNA triggered a similar cell death pattern. Moreover, the cell death in response to dsDNA was IFI16 dependent. These data suggest that cytosolic dsDNA induces nonnecroptotic cell death in trophoblasts via IFI16, and this could contribute to placental barrier against infection.

Liquiritigenin prevents Staphylococcus aureus-mediated lung cell injury via inhibiting the production of α-hemolysin.

Staphylococcus aureus is a significant Gram-positive bacterium that is associated with a broad spectrum of diseases ranging from minor skin infections to lethal pneumonia, endocarditis, and toxinoses. α-Hemolysin is one of the most important exotoxins that contribute to the pathogenesis of S. aureus infections. Liquiritigenin is one of the most significant active components in licorice. In this study, hemolysis, western blot, and real-time reverse transcription-PCR assays were performed to investigate the impact of liquiritigenin on the production of S. aureus α-hemolysin. The results showed that low concentrations of liquiritigenin remarkably decreased S. aureus α-hemolysin production in a dose-dependent manner. Using live/dead cell staining and lactate dehydrogenase assays, we found that liquiritigenin could protect human lung cells (A549) from α-hemolysin-mediated injury. The data indicated that this compound could potentially be useful in developing drugs aiming at staphylococcal α-hemolysin.

[Chemical constituents from the fruits of Kadsura marmorata].

OBJECTIVE: To study the chemical constituents from the fruits of Kadsura marmorata. METHODS: The chemical constituents were isolated and purified by chromatography on silica gel, Sephadex LH-20 column and HPLC. RESULTS: 9 compounds were isolated and identified as 4,5-dihydroxy-3-methoxybiphenyl (I), eriobofuran (II), 3beta, 16beta-dihydroxy urs-2-ene (III), 2alpha, 3beta, 6beta, 23-tetrahydroxy urs-12,18-dien-28-oic acid (IV), 2alpha,3beta,23-trihydroxy urs-12-en-28-oic acid (V), rutin (VI), 2-ethylhexanoic acid (VII), 2-monolaurin (VIII), glyceryl monoricinoleate (IX) on the basis of NMR and EI-MS spectroscopic analysis. CONCLUSION: All these compounds are isolated from this genus for the first time.

Immunomodulatory effects of cinobufagin isolated from Chan Su on activation and cytokines secretion of immunocyte in vitro.

The objective of this study was to evaluate the immunomodulatory effects of cinobufagin (CBG) isolated from Chan Su (Venenum Bufonis) in vitro. In this paper, our results show that CBG significantly stimulated cell proliferation of splenocytes and peritoneal macrophages (PMΦ) and markedly enhanced the phagocytic activation of PMΦ. CBG also significantly increased CD4(+)CD8(+) double-positive T-cell populations and the percentage of S-phase cells of splenic lymphocytes. The levels of several Th1 cytokines, including interferon-γ and tumor necrosis factor-α, are significantly increased after CBG treatment, whereas the levels of the Th2 cytokine interleukin-4 and interleukin-10 are significantly decreased. As a result, the ratio of Th1/Th2 also increased. Taken together, these results indicated that CBG had potential immune system regulatory effects and suggested that this compound could be developed as a novel immunotherapeutic agent to treat immune-mediated diseases such as cancer.

Allicin reduces the production of α-toxin by Staphylococcus aureus.

Staphylococcus aureus causes a broad range of life-threatening diseases in humans. The pathogenicity of this micro-organism is largely dependent upon its virulence factors. One of the most extensively studied virulence factors is the extracellular protein α-toxin. In this study, we show that allicin, an organosulfur compound, was active against S. aureus with MICs ranged from 32 to 64 µg/mL. Haemolysis, Western blot and real-time RT-PCR assays were used to evaluate the effects of allicin on S. aureus α-toxin production and on the levels of gene expression, respectively. The results of our study indicated that sub-inhibitory concentrations of allicin decreased the production of α-toxin in both methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) in a dose-dependent manner. Furthermore, the transcriptional levels of agr (accessory gene regulator) in S. aureus were inhibited by allicin. Therefore, allicin may be useful in the treatment of α-toxin-producing S. aureus infections.

Peppermint oil decreases the production of virulence-associated exoproteins by Staphylococcus aureus.

The present study aimed to evaluate the antimicrobial activity of peppermint oil against Staphylococcus aureus, and further investigate the influence of peppermint oil on S. aureus virulence-related exoprotein production. The data show that peppermint oil, which contained high contents of menthone, isomenthone, neomenthol, menthol, and menthyl acetate, was active against S. aureus with minimal inhibitory concentrations (MICs) ranging from 64-256 µg/mL, and the production of S. aureus exotoxins was decreased by subinhibitory concentrations of peppermint oil in a dose-dependent manner. The findings suggest that peppermint oil may potentially be used to aid in the treatment of S. aureus infections.

Influence of magnolol on the secretion of alpha-toxin by Staphylococcus aureus.

In this study we investigated the antimicrobial activity of magnolol on Staphylococcus aureus. The minimal inhibitory concentrations of magnolol against 31 S. aureus strains ranged from 4-32 microg/mL. In addition, hemolysin assays, Western blotting, and real-time RT-PCR were performed to investigate the effect of magnolol on alpha-toxin secretion by both methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). The results indicated that sub-inhibitory concentrations of magnolol dose-dependently inhibited the transcription of hla (the gene encoding alpha-toxin) in S. aureus, resulting in a reduction of alpha-toxin secretion and, thus, hemolytic activities.

(E)-N'-(2,5-Dimethoxy-benzyl-idene)-2,4-dihydroxy-benzohydrazide.

In the title compound, C(16)H(16)N(2)O(5), the dihedral angle between the two benzene rings is 4.2 (2)° and an intra-molecular O-H⋯O hydrogen bond generates an S(6) ring. In the crystal, mol-ecules are linked into layers lying parallel to the bc plane by O-H⋯O and N-H⋯O hydrogen bonds.

Isolation of two new prenylflavonols from Epimedium brevicornum and their effects on cytokine production in vitro.

In an attempt to search for bioactive natural products, two new prenylflavonols, 2''-hydroxy-3''-en-anhydroicaritin (1) and 2''-hydroxy-beta-anhydroicaritin (2), were isolated from the Chinese medicinal herb Epimedium brevicornum. Their structures were determined by 1D and 2D NMR spectroscopic analysis. The effects of compounds 1 and 2 on cytokine production in vitro were investigated. Compound 1 could significantly downregulate tumor necrosis factor-alpha (TNF-alpha) production and increase interleukin-10 (IL-10) production. These results suggested that compound 1 may have anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated mouse macrophages. In addition, the biogenetic relationships among compounds 1 and 2 are discussed.

A novel threefold-interpenetrating primitive cubic network based on a dinuclear Zn2 node.

In the mixed-ligand metal-organic polymeric compound poly[[mu(2)-1,4-bis(imidazol-1-yl)benzene](mu(2)-terephthalato)dizinc(II)], [Zn(2)(C(8)H(4)O(4))(2)(C(12)H(10)N(4))](n) or [Zn(2)(bdc)(2)(bib)](n) [H(2)bdc is terephthalic acid and bib is 1,4-bis(imidazol-1-yl)benzene], the asymmetric unit contains one Zn(II) ion, with two half bdc anions and one half bib molecule lying around inversion centers. The Zn(II) ion is in a slightly distorted tetrahedral environment, coordinated by three carboxylate O atoms from three different bdc anions and by one bib N atom. The crystal structure is constructed from the secondary building unit (SBU) [Zn(2)(CO(2))(2)N(2)O(2)], in which the two metal centers are held together by two bdc linkers with bis(syn,syn-bridging bidentate) bonding modes. The SBU is connected by bdc bridges to form a two-dimensional grid-like (4,4)-layer, which is further pillared by the bib ligand. Topologically, the dinuclear SBU can be considered to be a six-connected node, and the extended structure exhibits an elongated primitive approximately cubic framework. The three-dimensional framework possesses a large cavity with dimensions of approximately 10 x 13 x 17 A in cross-section. The potential porosity is filled with mutual interpenetration of two identical equivalent frameworks, generating a novel threefold interpenetrating network with an alpha-polonium topology [Abrahams, Hoskins, Robson & Slizys (2002). CrystEngComm, 4, 478-482].

(E)-N'-(3,4-Dimethoxy-benzyl-idene)-2,4-dihydroxy-benzohydrazide methanol solvate.

The title compound, C(16)H(16)N(2)O(5)·CH(3)OH, was obtained from a condensation reaction of 3,4-dimethoxy-benzaldehyde and 2,4-dihydroxy-benzohydrazide. The non-H atoms of the Schiff base mol-ecule are approximately coplanar (r.m.s. deviation = 0.043 Å) and the dihedral angle between the two benzene rings is 1.6 (1)°. The mol-ecule adopts an E configuration with respect to the C=N double bond. An intra-molecular O-H⋯O hydrogen bond is observed. The Schiff base and methanol mol-ecules are linked into a two-dimensional network parallel to (10) by inter-molecular N-H⋯O, O-H⋯N and O-H⋯O hydrogen bonds.

(E)-4-Bromo-N'-(2-nitro-benzyl-idene)benzohydrazide.

The title compound, C(14)H(10)BrN(3)O(3), was obtained by a condensation reaction between 2-nitro-benzaldehyde and 4-bromo-benzohydrazide. The dihedral angle between the two benzene rings is 4.1 (2)°. The mol-ecule displays an E configuration about the C=N bond. In the crystal, mol-ecules are linked into a chain along [100] by inter-molecular N-H⋯O hydrogen bonds.

Purine-containing cucurbitane triterpenoids from Cucurbita pepo cv dayangua.

Phytochemical investigation of the fruits of Cucurbita pepo cv dayangua led to the isolation of cucurbitaglycosides A (1) and B (2). This is the first report of cucurbitane triterpenoids with a purine unit. Their structures were elucidated mainly based on interpretation of HRESIMS results, as well as 1D and 2D NMR spectra. Cucurbitaglycosides A and B showed cytotoxic activity against the human epithelial carcinoma cell line HeLa with IC50 of 17.2 and 28.4 microg/mL, respectively.

Acute electrical stimulation of nucleus ambiguus enhances immune function in rats.

BACKGROUND: Up to now, many "immunoactive" brain areas have been identified, such as hypothalamic nuclei, brain reward system; but the nucleus ambiguous (Amb), a nucleus nervi vagis of medulla oblongata, was less well studied in neuroimmunomodulation. METHODS: In order to obtain more profound comprehension and more knowledge on Amb, we studied the effect of acute electrical stimulation of Amb on thymus and spleen activity in rat. A stimulator was applied to stimulate the Amb of the anaesthetic rats using the parameter at 100 microgA x 5 ms x 100 Hz every 1 s for 1 min. The levels of TGF-13 and thymosin-beta4 mRNA in thymus, the release of IL-2 and IL-6 at splenocyte in vitro and splenic lymphocyte proliferation were measured at hour 0.5, 1, 2, 3 following the electrical stimulation. RESULTS: The results showed that concanavalin A (Con A)-induced splenic lymphocyte proliferation and the release of IL-2 and IL-6 were all significantly enhanced at 0.5, 1, and 2 h following effective Amb stimulation as compared to in the control group. However, as compared to in the control group, the levels of TGF-beta and thymosin-beta4 mRNA in the thymus were both remarkably reduced at 0.5, 1, and 2 h following effective Amb stimulation. CONCLUSIONS: These findings reveal that the Amb participates in the modulation of animal immune functions.

Three new caffeoyl glycosides from the roots of Picrorhiza scrophulariiflora.

From the underground parts of Picrorhiza scrophulariiflora, three new caffeoyl glycosides, scrocaffeside A-C (1-3), together with two caffeic acid derivates, 4-O-beta-D-glucopyranosyl caffeic acid (4) and 4-methoxy caffeic acid (5) and a phenylethanoid glycoside, scroside D (6), were isolated. Their structures were elucidated on the basis of chemical and spectroscopic evidence and comparisons with literature data of related compounds.

New secoiridoid glycosides from the roots of Picrorhiza scrophulariiflora.

Three new secoiridoid glycosides, named picrogentiosides A (1), B (2) and C (3), have been isolated from the underground parts of Picrorhiza Scrophulariiflora, together with the two known compounds plantamajoside (4) and plantainoside D (5). Their structures were established by spectroscopic analyses and comparisons with data from related compounds. A pilot pharmacological study showed that picrogentiosides A (1) and B (2) have an immunomodulatory effect in vitro.

(E)-4-Bromo-N'-(2-hydr-oxy-1-naphthyl-methyl-ene)benzohydrazide.

The title compound, C(18)H(13)BrN(2)O(2), was synthesized by the reaction of 2-hydr-oxy-1-naphthaldehyde with 4-bromo-benzohydrazide. This Schiff base mol-ecule has an E configuration about the C=N bond and is almost planar, the dihedral angle between the mean planes through the substituted benzene ring and the naphthyl system being 6.6 (2)°. There is an intra-molecular O-H⋯N hydrogen bond involving the naphthyl hydr-oxy substituent and the N' atom of the hydrazide group. In the crystal structure, mol-ecules are linked through inter-molecular N--H⋯O hydrogen bonds to form chains extending along the b direction.

[Studies on chemical constituents of Syringa veutina].

OBJECTIVE: To study the chemical constituents of Syringa veutina Kom. METHODS: The constituents were isolated and repeatedly purified on silica and Sephadex LH-20 column chromatography. They were dentified and structurally elucidated by spectral analysis. RESULTS: Seven compounds were obtained. They were identified as Syningin(1), Liriodendrin(2), (+) -Medioresinol di-O-beta-D-glucopyranosied (3), Rutin(4), Quercetin 3-O-beta-D-glucopyranoside (5), Kaempferol-3-O-beta-D-glucopyranosied (6), D-mannitol (7). CONCLUSION: Compound 2 and 3 were isolated from this genus for the first time. Compound 4, 5, 6 and 7 were isolated from this plant for the first time.

Non-Hematopoietic MLKL Protects Against Salmonella Mucosal Infection by Enhancing Inflammasome Activation.

The intestinal mucosal barrier is critical for host defense against pathogens infection. Here, we demonstrate that the mixed lineage kinase-like protein (MLKL), a necroptosis effector, promotes intestinal epithelial barrier function by enhancing inflammasome activation. MLKL-/- mice were more susceptible to Salmonella infection compared with wild-type counterparts, with higher mortality rates, increased body weight loss, exacerbated intestinal inflammation, more bacterial colonization, and severe epithelial barrier disruption. MLKL deficiency promoted early epithelial colonization of Salmonella prior to developing apparent intestinal pathology. Active MLKL was predominantly expressed in crypt epithelial cells, and experiments using bone marrow chimeras found that the protective effects of MLKL were dependent on its expression in non-hematopoietic cells. Intestinal mucosa of MLKL-/- mice had impaired caspase-1 and gasdermin D cleavages and decreased interleukin (IL)-18 release. Moreover, administration of exogenous recombinant IL-18 rescued the phenotype of increased bacterial colonization in MLKL-/- mice. Thus, our results uncover the role of MLKL in enhancing inflammasome activation in intestinal epithelial cells to inhibit early bacterial colonization.

[Determination of the cucurbitacins from Cucubita pepo cv dayangua by HPLC].

OBJECTIVE: To establish an HPLC method for the simultaneous determination of four bioactive cucurbitacins in Cucubita pepo cv Dayangua. METHODS: The HPLC chromatography was carried out with a lineal gradient programming and detection wavelength at 215 nm. Kromasil C8 column (150 mm x 4.6 mm ID, 5 microm)was used. The mobile phase was acetonitrile-water (containing 2.0% HAc) and the flow rate was 1.0 ml/min. RESULTS: The linear range of 23, 24-dihydrocucurbitacin F was 0.28-5.6 microg/ml (r = 0.9978), 23, 24-dihydrocucurbitacin D 0.39-7.8 microg/ml (r = 0.9986), cucurbitacin B 0.304-6.08 microg/ml (r = 0.9983), cucurbitacin E 2. 52 -50. 4 microg/ml (r = 0.9998). The method was accurate with variation less than 5% and recovery more than 95%. CONCLUSION: The method is successfully applied to determination of the four cucurbitacins from Cucubita pepo cv dayangua.