Structure, anti-tumor activity, and potential anti-tumor mechanism of a fungus polysaccharide from Fomes officinalis.

In our ongoing process of discovering bioactive macromolecules, a homogeneous polysaccharide (FOP80-1) was first purified from Fomes officinalis. FOP80-1 with molecular weight of 4560 Da was mainly composed of →3)-d-Galp-(1→, →4)-ß-d-Manp-(1→, →6)-α-d-Glcp-(1→, →3,6)-d-Glcp-(1→, and t--d-Glcp. Besides the structure features, the anti-tumor activity and potential mechanism of FOP80-1 were also investigated. The cellular and zebrafish experiments revealed that FOP80-1 inhibited tumor proliferation, invasion, and metastasis by increasing ROS, arresting cell cycle, inducing apoptosis, and suppressing angiogenesis. Corresponding to the inhibition of angiogenesis, the surface plasmon resonance (SPR) experiments revealed that FOP80-1 had good affinity with VEGF, a crucial protein to regulate angiogenesis. Molecular docking indicated that FOP80-1 could interact with the protein VEGF.

First report of electrospun cellulose acetate nanofibers mats with chitin and chitosan nanowhiskers: Fabrication, characterization, and antibacterial activity.

Physical adsorption has shown to be facile and highly effective to deposit chitosan nanowhiskers (CsNWs, 60 % deacetylated, length: 247 nm, thickness: 4-12 nm, width:15 nm) on electrospun cellulose acetate nanofibers (CANFs, 560 nm) to effect complete surface charge reversal from negatively charged CANFs (-40 mV) to positively charged CsNWs-adsorbed CANFs (+8 mV). The CsNWs coverage did not alter the smooth and homogeneous morphology of fibers, as observed from SEM images. Biological assays showed the CsNWs covered nanofibers were effective against the Gram-negative bacterium E. coli, reducing 99 % of colony forming units (CFU) in 24 h and atoxic to healthy Vero cells. The use of CsNWs to modify cellulose fiber surfaces has been proved to be efficient and may be applied to a broad scope of fields, especially as biomaterials and biomedical applications.

Identification and assessment of residual levels of the main oxidation product of tert-butylhydroquinone in frying oils after heating and its cytotoxicity to RAW 264.7 cells.

tert-Butylhydroquinone (TBHQ) losses and the residual levels of 2-tert-butyl-1,4-benzoquinone (TBBQ) in tripalmitin at different heating temperatures with or without reflux over various time intervals were investigated. Heating at 120 °C resulted in the slowest TBHQ loss and the highest TBBQ levels (52.61-62.93 µg/mL). The highest TBBQ concentrations (111.73-164.67 µg/mL) at 5 and 8 h and residual concentrations of 10.23-46.95 µg/mL during heating at 170 °C over 24 h were observed. Furthermore, the potential cytotoxicity of TBBQ to RAW 264.7 cells was evaluated with the MTT assay, Hoechst 33258 staining test, and flow cytometry analysis. Results indicate that TBBQ dose- and time-dependently decreased the growth of cells and inhibited DNA synthesis by regulating the S/G2 transition. The TBBQ concentration giving 50% inhibition in RAW 264.7 cells was 10.71 µg/mL. This threshold value is lower than the residual level of TBBQ in oil, indicating the necessity for concerns over the safety of fried food in terms of TBBQ residues.

Synergistic effect of quercetin and pH-responsive DEAE-chitosan carriers as drug delivery system for breast cancer treatment.

Amphiphilic chitosans, which may self-assemble in aqueous solution to form nanoaggregates with different conformations depending to the environmental pH, can be used as drug transport and delivery agents, when the target pH differs from the delivery medium pH. In this study, quercetin, a bioactive flavonoid, was encapsulated in a pH-responsive system based on amphiphilic chitosan. The hydrophilic reagent 2-chloro-N,N-diethylethylamine hydrochloride (DEAE), also known to inhibit the proliferation of cancer cells, was used as a grafting agent. Drug loading experiments (DL ∼5%) showed a quercetin entrapment efficiency of 73 and 78% for the aggregates. The sizes of blank aggregates measured by dynamic light scattering (DLS) varied from 169 to 263nm and increased to ∼410nm when loaded with quercetin. The critical aggregation concentration, zeta potential and morphology of the aggregates were determined. pH had a dominant role in the release process and Fickian diffusion was the controlling factor in drug release according to the Korsmeyer-Peppas mathematical model. In vitro studies indicated that the DEAE-modified chitosan nanoaggregates showed a synergistic effect with quercetin on the control of the viability of MCF-7 cells. Therefore, DEAE-modified chitosan nanoaggregates with pH-sensibility can be used as optimized nanocarriers in cancer therapy.

Activation of ALDH1A1 in MDA-MB-468 breast cancer cells that over-express CYP2J2 protects against paclitaxel-dependent cell death mediated by reactive oxygen species.

Cytochrome P450 2J2 (CYP2J2) expression is elevated in breast and other tumours, and is known to be protective against cytotoxic agents that may be used in cancer chemotherapy. This study evaluated the mechanisms by which MDA-MB-468 breast cancer cells that stably expressed CYP2J2 (MDA-2J2 cells) were protected against killing by the anti-cancer agent paclitaxel. Compared to control cells caspase-3/7 activation by paclitaxel was lower in MDA-2J2 cells, while cell proliferation and colony formation following paclitaxel treatment were increased. Basal lipid peroxidation was lower in MDA-2J2 cells than in control cells, and the paclitaxel-mediated increase in peroxidation was attenuated. The mitochondrial complex III inhibitor antimycin A modulated basal and paclitaxel-activated reactive oxygen species (ROS) formation in control cells; paclitaxel-activated ROS production was also modulated by the NADPH oxidase inhibitor diphenyleneiodonium. Paclitaxel increased the formation of protein adducts by the reactive aldehyde 4-hydroxynonenal that is produced by lipid peroxidation; adduct formation was attenuated in MDA-2J2 cells. ALDH1A1 expression and activity was strongly upregulated in MDA-2J2 cells that was attributed to CYP2J2-derived 14,15-epoxyeicosatrienoic acid (14,15-EET); the 8,9- and 11,12-EET regioisomers did not activate ALDH1A1 expression. Silencing of ALDH1A1 restored the sensitivity of MDA-2J2 cells to paclitaxel, as indicated by a more pronounced decrease in proliferation, and greater increases in caspase activity and formation of ROS to levels comparable with control cells. Similar findings were observed with doxorubicin, sorafenib and staurosporine, that also promoted ROS-mediated cell death that was attenuated in MDA-2J2 cells and reversed by ALDH1A1 gene silencing. These findings implicate ALDH1A1 as an important gene that is activated in MDA-MB-468-derived cells that contain high levels of CYP2J2. ALDH1A1 modulates the production of ROS by anti-cancer agents such as paclitaxel and diminishes their efficacy. Future approaches could adapt this information to facilitate the targeting of ALDH1A1 to promote the efficacy of ROS-generating cytotoxic agents and enhance the treatment of breast cancer.

Molecular weight and helix conformation determine intestinal anti-inflammatory effects of exopolysaccharide from Schizophyllum commune.

Intestinal anti-inflammatory activities of exopolysaccharide from S. commune were assessed using dextran sulfate sodium (DSS)-induced colitis in mice model. The changes of molecular weight (MW), atomic force microscope morphology, X-ray diffraction, particle size distribution, and viscosity were recorded after sonication treatment. The results indicated that the triple helical structure of exopolysaccharide was dissociated into single helical structure and random coiled structure by ultrasonication via breaking of inter- and intramolecular hydrogen bonds. The medium (936kDa) and high MW (1437kDa) exopolysaccharide had the mixture of triple helix and single helix conformation, while the low MW (197kDa) exopolysaccharide exhibit random coiled conformation. The intestinal anti-inflammatory activity study showed that oral administration of medium and high MW (1437kDa) exopolysaccharide significantly recovered DSS-induced colitis in inflamed tissues and reduced inflammation induced infiltration of macrophages. These results showed that medium (936kDa) and high MW (1437kDa) exopolysaccharide had intestinal anti-inflammatory activity. The intestinal anti-inflammatory activity of exopolysaccharide was related to helical structure and molecular weight.

A simple and highly effective catalytic nanozyme scavenger for organophosphorus neurotoxins.

A simple and highly efficient catalytic scavenger of poisonous organophosphorus compounds, based on organophosphorus hydrolase (OPH, EC 3.1.8.1), is produced in aqueous solution by electrostatic coupling of the hexahistidine tagged OPH (His6-OPH) and poly(ethylene glycol)-b-poly(l-glutamic acid) diblock copolymer. The resulting polyion complex, termed nano-OPH, has a spherical morphology and a diameter from 25nm to 100nm. Incorporation of His6-OPH in nano-OPH preserves catalytic activity and increases stability of the enzyme allowing its storage in aqueous solution for over a year. It also decreases the immune and inflammatory responses to His6-OPH in vivo as determined by anti-OPH IgG and cytokines formation in Sprague Dawley rats and Balb/c mice, respectively. The nano-OPH pharmacokinetic parameters are improved compared to the naked enzyme suggesting longer blood circulation after intravenous (iv) administrations in rats. Moreover, nano-OPH is bioavailable after intramuscular (im), intraperitoneal (ip) and even transbuccal (tb) administration, and has shown ability to protect animals from exposure to a pesticide, paraoxon and a warfare agent, VX. In particular, a complete protection against the lethal doses of paraoxon was observed with nano-OPH administered iv and ip as much as 17h, im 5.5h and tb 2h before the intoxication. Further evaluation of nano-OPH as a catalytic bioscavenger countermeasure against organophosphorus chemical warfare agents and pesticides is warranted.

Box-Behnken design for extraction optimization, characterization and in vitro antioxidant activity of Cicer arietinum L. hull polysaccharides.

The optimal extraction conditions with a yield of 5.37±0.15% for extraction of polysaccharides from chickpea (Cicer arietinum L.) hull (CHPS) were determined as extraction temperature 99°C, extraction time 2.8h and ratio of water to raw material 24mL/g. Three fractions of CHPS-1, CHPS-2 and CHPS-3, with average molecular weight of 3.1×10(6), 1.5×10(6) and 7.8×10(5)Da, respectively, were obtained from crude CHPS by chromatography of DEAE Fast Flow and Sephadex G-100. CHPS-1 was composed of mannose, rhamnose, galactose, galacturonic acid, glucose and arabinose, CHPS-2 was composed of mannose, rhamnose, galacturonic acid, galactose, xylose and arabinose, CHPS-3 was composed of galacturonic acid, galactose and rhamnose. CHPS-3 showed the strongest reducing power and protective effect on H2O2-induced oxidative injury in PC12 cells and highest scavenging activities against DPPH and ABTS radicals, while CHPS-2 showed the highest scavenging activity against superoxide anion radical.

Regulation of cancer cell death by a novel compound, C604, in a c-Myc-overexpressing cellular environment.

The proto-oncogene c-Myc has been implicated in a variety of cellular processes, such as proliferation, differentiation and apoptosis. Several c-Myc targets have been studied; however, selective regulation of c-Myc is not easy in cancer cells. Herein, we attempt to identify chemical compounds that induce cell death in c-Myc-overexpressing cells (STF-cMyc and STF-Control) by conducting MTS assays on approximately 4000 chemical compounds. One compound, C604, induced cell death in STF-cMyc cells but not STF-Control cells. Apoptotic proteins, including caspase-3 and poly(ADP-ribose) polymerase (PARP), were cleaved in C604-treated STF-cMyc cells. In addition, SW620, HCT116 and NCI-H23 cells, which exhibit higher basal levels of c-Myc, underwent apoptotic cell death in response to C604, suggesting a role for C604 as an inducer of apoptosis in cancer cells with c-Myc amplification. C604 induced cell cycle arrest at the G2/M phase in cells, which was not affected by apoptotic inhibitors. Interestingly, C604 induced accumulation of c-Myc and Cdc25A proteins. In summary, a chemical compound was identified that may induce cell death in cancer cells with c-Myc amplification specifically through an apoptotic pathway.

Investigation of Hexadecylphosphocholine (miltefosine) usage in Pegylated liposomal doxorubicin as a synergistic ingredient: In vitro and in vivo evaluation in mice bearing C26 colon carcinoma and B16F0 melanoma.

In this investigation, Hexadecylphosphocholine (HePC, miltefosine) was being used as a new ingredient in Pegylated liposomal doxorubicin (PLD) and different aspects of this integration such as its effect on doxorubicin (Dox) release and cell uptake, cytotoxicity of liposomes, in vivo distribution and half-life clearance time of Dox as well as median survival time were illustrated. The liposomal formulations were Pegylated liposomal doxorubicin containing 0, 0.5, 1, 2 and 4% mole ratios of HePC (HePC-PLD) and their respective Dox-free liposomes (HePC-PLs). The cells used were colon carcinoma (C26), adriamycin-resistant breast cancer (MCF-7-ADR), and B16F0 melanoma cell lines, of which C26 and B16F0 cells were exploited for tumoring in BALB/c and C57Bl/6 mice, respectively. In most cases, increase in miltefosine percentage resulted in physically liposomal instability, increased Dox delivery and toxicity and reduced blood half-life of Dox. Overall, HePC 4% -PLD and PLD differed significantly in many respects and it was considered too toxic to be injected at the same dose (15mg Dox/ kg) as PLD. Although HePC 2% -PLD could extend the median survival time marginally in comparison to PLD, the concept of HePC- containing liposomes merits further investigation.

Effects of 3-styrylchromones on metabolic profiles and cell death in oral squamous cell carcinoma cells.

4H-1-benzopyran-4-ones (chromones) are important naturally-distributing compounds. As compared with flavones, isoflavones and 2-styrylchromones, there are only few papers of 3-styrylchromones that have been published. We have previously reported that among fifteen 3-styrylchromone derivatives, three new synthetic compounds that have OCH3 group at the C-6 position of chromone ring, (E)-3-(4-hydroxystyryl)-6-methoxy-4H-chromen-4-one (compound 11), (E)-6-methoxy-3-(4-methoxystyryl)-4H-chromen-4-one (compound 4), (E)-6-methoxy-3-(3,4,5-trimethoxystyryl)-4H-chromen-4-one (compound 6) showed much higher cytotoxicities against four epithelial human oral squamous cell carcinoma (OSCC) lines than human normal oral mesenchymal cells. In order to further confirm the tumor specificities of these compounds, we compared their cytotoxicities against both human epithelial malignant and non-malignant cells, and then investigated their effects on fine cell structures and metabolic profiles and cell death in human OSCC cell line HSC-2. Cytotoxicities of compounds 4, 6, 11 were assayed with MTT method. Fine cell structures were observed under transmission electron microscope. Cellular metabolites were extracted with methanol and subjected to CE-TOFMS analysis. Compounds 4, 6, 11 showed much weaker cytotoxicity against human oral keratinocyte and primary human gingival epithelial cells, as compared with HSC-2, confirming their tumor-specificity, whereas doxorubicin and 5-FU were highly cytotoxic to these normal epithelial cells, giving unexpectedly lower tumor-specificity. The most cytotoxic compound 11, induced the mitochondrial vacuolization, autophagy suppression followed by apoptosis induction, and changes in the metabolites involved in amino acid and glycerophospholipid metabolisms. Chemical modification of lead compound 11 may be a potential choice for designing new type of anticancer drugs.

Cytotoxic effect of triterpenoids from the root bark of Hibiscus syriacus.

In this study, 4 new triterpenoids-3ß- acetoxy-olean-11-en,28,13ß-olide (1), 3ß- acetoxy-11α,12α-epoxy-olean-28,13ß-olide (2), 19α-epi-betulin (3), and 20, 28-epoxy-17ß,19ß-lupan-3ß-ol (4)-and 12 known compounds, were isolated from the root bark of Hibiscus syriacus L. by using acetone extraction. Their structures were characterized by extensive spectroscopic analysis. To investigate cytotoxicity, A549 human lung cancer cells were exposed to the extract and the compounds identified from it. Significantly reduced cell viability was observed with betulin-3-caffeate (12) (IC50, 4.3 µM). The results of this study indicate that betulin-3-caffeate (12) identified from H. syriacus L. may warrant further investigation for potential as anticancer therapies.