Background: Pseudorabies virus (PRV) infection induces apoptosis in swine cells both in vitro and in vivo; however, the mechanism associated with host-cell signaling has not been studied. This study investigated the role of free radicals caused by cellular oxidative stress after viral infection and examined whether the DNA damage response plays an important role in PRV-induced apoptosis. Methods: Several apoptosis assays and western blotting confirmed PRV-induced apoptosis. PRV-mediated oxidative stress was evaluated by reactive oxygen species (ROS) assay. Results: Our results showed that PRV caused apoptosis in a porcine kidney cell line, PK15, and induced expressions of proapoptotic Bcl family proteins in a dose- and time-dependent manner. Expressions of specific DNA damage sensors and phosphorylation of histone H2AX were also significantly increased, which subsequently activated the expressions of checkpoint kinase 1/2 and proapoptotic p53. Caffeine, a known DNA damage inhibitor, was found to inhibit caspase-3 activation and protect cells from PRV-induced apoptosis. Additionally, the antioxidant N-acetyl-L-cysteine was shown to prevent the production of cellular ROS, protecting DNA from cleavage. Conclusions: Our results confirmed that oxidative stress and free radicals arising from PRV infection cause DNA damage, which consequently triggers apoptosis.
Five novel peptides (LPLF, WLQL, LPSW, VPGLAL, and LVGLPL) bearing dipeptidyl peptidase IV (DPP-IV) inhibitory activities were identified from the gastrointestinal enzymatic hydrolysate of soft-shelled turtle yolk (SSTY) proteins. Peptides were isolated separately using reversed-phase (RP) chromatography in parallel with off-line strong cation exchange (SCX) chromatography followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis to determine sequences. Among these peptides, LPSW showed the highest DPP-IV inhibitory activity with an IC50 value of 269.7 ± 15.91 µM. The results of the pre-incubation experiment and the kinetic study of these peptides indicated that WLQL is a true inhibitor and its inhibition toward DPP-IV is of an uncompetitive model, while LPLF, LPSW, and VPGLAL are real-substrates and competitive inhibitors against DPP-IV. The DPP-IV inhibitory peptides derived from SSTY hydrolysate in study are promising in the management of hyperglycemia in Type 2 diabetes.
The green alga Caulerpa microphysa, which is native to Taiwan, has a relatively high economic value and a well-developed culture technique, and is used mainly as a foodstuff. Its extract has been shown to exhibit antitumor properties, but the polysaccharide content of the extract and its anti-inflammatory and wound-healing effects and moisture-absorption and -retention capacity remain unknown. Hence, the objective of this study was to evaluate the potential of the polysaccharides in C. microphysa extract (CME) for use in cosmetics. The overall polysaccharide yield from the CME was 73.93% w/w, with four molecular weight fractions. The polysaccharides comprised 59.36 mol% mannose, 27.16 mol% glucose, and 13.48 mol% galactose. In addition, the CME exhibited strong antiallergic, wound-healing, transdermal-delivery, and moisture-absorption and -retention effects. In conclusion, the results suggested that CME potentially has anti-inflammatory and wound-healing effects and a good moisture capacity, which can be used in cosmetic applications.
Background/Aim: The clinical course of acute leukemia is complicated, and it is often necessary to combine or change treatment methods due to the rapid increase and spread of malignant cells. In this study, the potential anti-leukemia activities of prepared garlic essential oil (GEO) and some organosulfur compounds contained therein were examined. Materials and Methods: Garlic essential oil component identification by gas chromatography-mass spectrometry (GC-MS). MTT assay evaluated cytotoxicity of tested samples. Leukemia cell differentiation was determined by NBT assay. Apoptosis and related mechanisms were investigated by western blotting. Results: GC-MS analysis confirmed that the two most abundant constituents, diallyl disulfide (DADS) and diallyl trisulfide (DATriS), constituted 80% of the composition. GEO and DADS exhibited the best effects in terms of significant production of intracellular reactive oxygen species (ROS), induction apoptosis and potentiation differentiation of human promyelocytic leukemia cell line HL-60 cells. The GEO-mediated apoptosis was alleviated by the free radical scavenger N-acetyl-L-cysteine (NAC). Conclusion: The anti-leukemia activity of GEO and organosulfur compound DADS through the action of ROS elevation was herein confirmed.
5 July 2014 in Journal of the American Oil Chemists' Society