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N-acetyl-L-cysteine (NAC) is the most abundant water-soluble component of garlic. No study to date has studied the leukemia prevention ability of NAC in mouse systemic leukemia model. The current study aimed to investigate the leukemia initiation prevention potential of NAC in a mouse model. The cytotoxic concentration of NAC was determined first in HL-60 cells, and its in vivo activity was studied in a mouse acute myelocytic leukemia model with WEHI-3 leukemia cells. The results showed that a non-toxic concentration of NAC efficiently scavenged free-radicals, lowered lipid peroxidation and reduced DNA damage induced by hydrogen peroxide in a cultured HL-60 leukemia cell line. NAC also elevated the cellular antioxidant enzyme activity significantly. Furthermore, NAC prevented mouse death induced by injection of murine WEHI-3 leukemia cells and reduced organ damage, as well as activated antioxidant mechanisms. The results of this study provided strong evidence that NAC may have potential benefits in terms of elevating antioxidant activity and preventing leukemia initiation. [ABSTRACT FROM AUTHOR]

The structure, cytocompatibility, and biological activity of composites prepared from polycaprolactone (PCL) and lemon fiber (LF) blends (PCL/LF) were evaluated. Acrylic acid-grafted PCL (PCL-g-AA) was used to enhance the desirable characteristics of these composites, which had better tensile properties than the corresponding PCL/LF composites. A cytocompatibility evaluation with normal human foreskin fibroblasts of the water released from the PCL/LF and PCL-g-AA/LF composites indicated that both materials were nontoxic. Moreover, LF enhanced the flavonoid and polyphenol contents and the anti-inflammatory and antioxidant properties of the PCL-g-AA/LF and PCL/LF composites. We analyzed the effects of these composites in mushroom tyrosinase activity and B16-F10 melanoma cells; the PCL/LF and PCL-g-AA/LF membranes demonstrated reduced tyrosinase activity. Composites of PCL-g-AA or PCL containing LF had better antibacterial activity. [ABSTRACT FROM AUTHOR]

Although differentiation therapy with all-trans retinoic acid (ATRA) induces complete remission in most acute promyelocytic leukemia (APL) patients, it is associated with organ toxicity. The present study focused on investigating the effects of the natural compounds oleanolic acid (OA) and ursolic acid (UA) on proliferation and differentiation of human APL HL-60 cells in vitro and murine APL WEHI-3 cells in vivo. Results demonstrated that OA and UA significantly inhibited cellular proliferation of HL-60 in a concentration- and time-dependent manner. Non-cytotoxic concentration of OA exhibited a marked differentiation-inducing effect on HL-60 and enhanced ATRA-induced HL-60 differentiation. In contrast, UA showed only a moderate effect. Activation of MAPK/NF-κB signaling pathway was likely found to be involved in the mechanism. Moreover, OA increased survival duration of WEHI-3 transplanted BALB/c mice, and decreased leukemia cells infiltration in the liver and spleen. Thus, these results may provide new insight for developing alternative therapy in APL patients., (Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

In this study, a novel angiotensin-converting enzyme (ACE)-inhibitory tripeptide (IVR) was isolated and identified from unfertilized soft-shelled turtle egg white (SSTEW). The IC50 value of IVR was measured in vitro as low as 0.81 ± 0.03 μM, and its inhibition type was suggested as competitive according to the Lineweaver-Burk plot. This peptide can be generated from either thermolysin followed by trypsin digestion (two stages) or only trypsin digestion (one stage). Quantitative LC-MS/MS analysis indicated that two-stage digestion gave 3.14 ± 0.17 mg of IVR from 1 g of SSTEW, better than that from one-stage digestion (1.31 ± 0.12 mg). In vivo antihypertensive activity of the tripeptide IVR after single oral administration (0.1 and 1 mg/kg of body weight) led to a significant reduction in systolic blood pressure 2-4 h after administration in spontaneously hypertensive rats. In addition, the binding mechanism of IVR has been rationalized through docking simulations using the testicular ACE (tACE)-lisinopril complex at 2 Å resolution (PDB 108A ). The best docking pose was located at the tACE catalytic site resembling the mode of inhibition exerted by lisinopril, an effective hypertensive synthetic drug. The degree of inhibition of this peptide correlated with the H-bond interaction between the C-terminal of IVR and Lys511 and Tyr520 residues of tACE, a significant inhibitor registration for lisinopril. This study illustrated that IVR behaves as a transition-state analogue inhibitor and is useful in therapeutic intervention for blood pressure control. To the best of our knowledge, this is the first report of an efficient ACE-inhibitory tripeptide generated from the unfertilized egg of soft-shelled turtle.

Our previous report demonstrated that bovine ephemeral fever virus (BEFV)-infected cultured cells could induce caspase-dependent apoptosis. This study aims to further elucidate how BEFV activates the caspase cascade in bovine cells. BEFV replicated and induced apoptosis in Vero and Madin-Darby bovine kidney (MDBK) cells, and a kinetic study showed a higher efficiency of replication and a greater apoptosis induction ability of BEFV in Vero cells. Src and c-Jun N-terminal kinase (JNK) inhibitor, but not extracellular signal-regulated kinase (ERK) or p38 inhibitor, alleviated BEFV-mediated cytopathic effect and apoptosis. In BEFV-infected Vero and MDBK cells, BEFV directly induced Src tyrosine-418 phosphorylation and JNK phosphorylation and kinase activity, which was inhibited specifically by SU6656 and SP600125, respectively. The caspase cascade and its downstream effectors, Poly (ADP-ribose) polymerase (PARP) and DFF45, were also activated simultaneously upon BEFV infection. In addition, cytochrome c, but not Smac/DIABLO, was released gradually from mitochondria after BEFV infection. SU6656 suppressed Src, JNK, and caspase-3 and -9 activation, as well as PARP and DFF45 cleavage; SP600125 reduced JNK and caspase-3 and -9 activation, as well as PARP and DFF45 cleavage. Taken together, these results strongly support the hypothesis that a Src-dependent JNK signaling pathway plays a key role in BEFV-induced apoptosis. The molecular mechanism identified in our study may provide useful information for the treatment of BEFV., (INRA, EDP Sciences, 2009)

The first ORF of the ARV S1133 S1 segment encodes the nonstructural protein p10, which is responsible for the induction of cell syncytium formation. However, p10-dependent signaling during syncytium formation is fully unknown. Here, we show that dominant negative RhoA, Rho inhibitor C3 exoenzyme, ROCK/Rho-kinase inhibitor Y-27632 and Rac1 inhibitor NSC23766 inhibit p10-mediated cell fusion. p10 over-expression is concomitant with activation and membrane translocation of RhoA and Rac1, but not cdc42. RhoA and Rac1 downstream events, including JNK phosphorylation and transcription factor AP-1 and NF-kappaB activation, as well as MLC expression and phosphorylation are simultaneously activated by p10. p10 point mutant T13M possessed 20% fusion-inducing ability and four p10 fusion-deficient mutants V15M, V19M, C21S and L32A reduced or lost their ability to activate RhoA and Rac1 signaling. We conclude that p10-mediated syncytium formation proceeds by utilizing RhoA and Rac1-dependent signaling.