Preparation of Antioxidant Peptide by Microwave- Assisted Hydrolysis of Collagen and Its Protective Effect Against H2O2-Induced Damage of RAW264.7 Cells.

Antioxidant peptides have elicited interest for the versatility of their use in the food and pharmaceutical industry. In the current study, antioxidant peptides were prepared by microwave-assisted alkaline protease hydrolysis of collagen from sea cucumber (Acaudina molpadioides). The results showed that microwave irradiation significantly improved the degree of hydrolysis of collagen and the hydroxyl radical (OH⋅) scavenging activity of hydrolysate. The content and OH⋅ scavenging activity of collagen peptides with molecular weight ≤ 1 kDa (CPS) in the hydrolysate obtained at 250 W increased significantly compared with the non-microwave-assisted control. CPS could scavenge OH⋅ and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical in a dose-dependent manner. The scavenging activity of OH⋅ and DPPH radical was 93.1% and 41.2%, respectively, at CPS concentration of 1 mg/mL. CPS could significantly promote RAW264.7 cell proliferation and reduce the Reactive Oxygen Species (ROS) level of H2O2-induced damage in RAW264.7 cells in a dose-dependent manner. Furthermore, all CPS-treated groups exhibited an increase in superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and a decrease in malondialdehyde (MDA) level compared with the control. These results showed that CPS could effectively protect RAW264.7 cells from H2O2-induced damage, implying the potential utilization of CPS as a natural antioxidant for food and pharmaceutical applications.

Anticancer Activity of Anthopleura anjunae Oligopeptides in Prostate Cancer DU-145 Cells.

Anthopleura anjunae anti-tumor peptide (AAP-H) is a pentapeptide from the sea anemone Anthopleura anjunae with an amino acid sequence of Tyr-Val-Pro-Gly-Pro that is obtained by alkaline protease enzymatic hydrolysis extraction. In this study, we investigated the inhibitory effects of AAP-H on prostate cancer DU-145 cell proliferation using a methylthiazolyldiphenyl-tetrazolium bromide assay. Cell morphology was analyzed by hematoxylin-eosin staining, acridine orange/ethidium bromide fluorescence staining, Hoechst 33258 fluorescence staining, and scanning electron microscopy. The mitochondrial membrane potential was determined by flow cytometry following JC-1 staining. The cell apoptosis rate was measured by Annexin V-fluorescein isothiocyanate and propidium iodide staining followed by flow cytometric analysis, and the expression of apoptosis-associated proteins was assayed by Western blotting. The results demonstrated that AAP-H induced significant reductions in the number of viable cells and increased cell death in both a dose-dependent and time-dependent manner, with an IC50 of approximately 9.605 mM, 7.910 mM, and 2.298 mM at 24 h, 48 h, and 72 h, respectively. The morphologic characteristics of apoptotic cells were observed after treatment with AAP-H. The mitochondrial membrane potential was markedly decreased, and apoptosis increased after AAP-H treatment. Pro-apoptotic proteins, such as Bax, cytochrome-C, caspase-3, and caspase-9 were increased, but Bcl-2 was decreased. These findings suggest that AAP-H has moderate inhibitory effects on prostate cancer DU-145 cells, and the mechanism might involve the mitochondria-mediated apoptotic pathway. Therefore, AAP-H is a candidate anti-prostate cancer drug or health-care food.

Anti-Fatigue Effect by Peptide Fraction from Protein Hydrolysate of Croceine Croaker (Pseudosciaena crocea) Swim Bladder through Inhibiting the Oxidative Reactions including DNA Damage.

The swim bladder of the croceine croaker (Pseudosciaena crocea) was believed to have good curative effects in various diseases, including amnesia, insomnia, dizziness, anepithymia, and weakness after giving birth, in traditional Chinese medicine. However, there is no research focusing on the antioxidant and anti-fatigue peptides from croceine croaker swim bladders at present. Therefore, the purpose of this study was to investigate the bioactivities of peptide fractions from the protein hydrolysate of croceine croaker related to antioxidant and anti-fatigue effects. In the study, swim bladder peptide fraction (SBP-III-3) was isolated from the protein hydrolysate of the croceine croaker, and its antioxidant and anti-fatigue activities were measured using in vitro and in vivo methods. The results indicated that SBP-III-3 exhibited good scavenging activities on hydroxyl radicals (HO•) (EC50 (the concentration where a sample caused a 50% decrease of the initial concentration of HO•) = 0.867 mg/mL), 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH•) (EC50 = 0.895 mg/mL), superoxide anion radical ( O 2 - •) (EC50 = 0.871 mg/mL), and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical (ABTS⁺•) (EC50 = 0.346 mg/mL). SBP-III-3 also showed protective effects on DNA damage in a concentration-effect manner and prolonged the swimming time to exhaustion of Institute of Cancer Research (ICR) mice by 57.9%-107.5% greater than that of the control. SBP-III-3 could increase the levels of muscle glucose (9.4%-115.2% increase) and liver glycogen (35.7%-157.3%), and decrease the levels of blood urea nitrogen (BUN), lactic acid (LA), and malondialdehyde (MDA) by 16.4%-22.4%, 13.9%-20.1%, and 28.0%-53.6%, respectively. SBP-III-3 also enhanced the activity of lactic dehydrogenase to scavenge excessive LA for slowing the development of fatigue. In addition, SBP-III-3 increased the activities superoxide dismutase, catalase, and glutathione peroxidase to reduce the reactive oxygen species (ROS) damage in mice. In conclusion, SBP-III-3 possessed good anti-fatigue capacities on mice by inhibiting the oxidative reactions and provided an important basis for developing the swim bladder peptide functional food.

Associations of nm23H1, VEGF-C, and VEGF-3 receptor in human prostate cancer.

We studied the expression of the non-metastatic clone 23 type 1 (nm23H1) gene, vascular endothelial growth factor (VEGF)-C, and its receptor VEGFR-3 using an in situ hybridization technique and immunohistochemical analyses with prostate cancer tissues and adjacent benign tissues of 52 human archival cases. The association between VEGF-C expression, microlymphatic count (MLC), and staining intensity for nm23H1 and VEGFR-3 was used to evaluate tumor metastasis and survival rate. MLC values were significantly higher in tumorous tissue than in non-cancerous tissue. VEGF-C mRNA, VEGFR-3, and nm23H1 were highly expressed in tumorous tissue. VEGFR-3 expression was greater in VEGF-C mRNA-positive tumors than in VEGF-C mRNA-negative tumors. The association of VEGFR-3 expression with VEGF-C mRNA and MLC suggested that the poor prognosis and tumor metastasis associated with VEGFR-3 expression may be due, in part, to its role in promoting angiogenesis. VEGF-C expression was significantly associated with tumor lymphangiogenesis, angiogenesis, and immune response as a potent multifunctional stimulating factor in prostate cancer. Expression of nm23H1 was significantly inversely correlated with lymph node metastasis. Furthermore, there was a strong negative correlation between the expression of nm23H1, VEGF-C mRNA, and MLC. These findings provide important information for prophylactic, diagnostic, and therapeutic strategies for prostate cancer.

Coexpression of the mutated BRCA1 mRNA and p53 mRNA and its association in Chinese prostate cancer.

The mutations of BRCA1 and p53 genes have been simultaneously characterized in many tumors. However, their coexpression and associations have not been investigated quantitatively in prostate cancer. In the present study, the expressions of the mutated BRCA1 mRNA and p53 mRNA were examined in 48 Chinese prostate cancer cases and 10 corresponding adjacent benign tissues with in situ hybridization. The 5-year survival rates of the corresponding patients after operation were investigated. The results showed that the positive expressions of the mutated BCRA1 mRNA and p53 mRNA are involved in prostate cancer (P < 0.05). Moreover, there is a closed negative association between the expressions of the mutated BRCA1 gene and p53 gene in the mRNA level with the progression, angiogenesis, metastasis, and survival rate of prostate cancer. Their coexpression and negative association suggest that the two altered tumor suppressor genes might interact functionally in prostate cancer to provide a potential signal determining a prognosis of the tumor metastasis and survival rate. Further work will be done to elucidate the interaction mechanisms in prostate cancer.

[Development of a mobile digital hydraulic extracorporeal heart compression machine].

This article introduces the working principle, the structural design of a mobile digital hydraulic extracorporeal heart compression machine and its trial result on the human model. The result shows that the machine which has the advantages of easy operation, fast effectiveness, safety, line display and agile adjustment, is an ideal medical device for patients with cardiac arrest and is of great social benefit and great market expectations.