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Tenebrio molitor is an excellent source of high-quality protein that produces various bioactive peptides. It is a traditional Chinese herbal medicine which has the effect of “activating blood and dissolving stasis”. It aimed to obtain antithrombotic peptides from the Tenebrio molitor larvae hydrolysate generated by treatment with pepsin and trypsin. The hydrolysate was subjected to ion exchange chromatography and gel filtration chromatography; the obtained antithrombotic activity values of the fractions were 40.87% and 65.61% at 8.0 mg/mL, respectively. After further preparation by reverse-phase liquid chromatography, the peptides with antithrombotic activity of 28.66% at 0.2 mg/mL were identified by liquid chromatography tandem mass spectrometry as SLVDAIGMGP and AGFAGDDAPR. Both of the peptides were shown to be nontoxic and could interact with thrombin exosite 1 by molecular docking. These results indicate that peptides from Tenebrio molitor might be used as potential antithrombotic components in the future.

For the high-value utilization of tuna liver, the effects of acid-aided (Acid-pH) and alkali-aided pH-shifting (Alkali-pH) on the physicochemical and functional properties of the protein powder prepared by pH-shifting and freeze-drying were studied. As expected, the protein powder with high purity could be obtained through Acid-pH or Alkali-pH followed by freeze drying, while the Alkali-pH led to a higher protein yield, higher protein ratio, lower lipid ratio and lower heavy metal content than Acid-pH. The amino acid profile of the protein powder prepared by Alkali-pH (Alkali-PP) was similar with that prepared by Acid-pH (Acid-PP). In addition, compared with Acid-PP, the Alkali-PP possessed the greater capacities in emulsion activity, foaming capacity and fat absorption capacity. Furthermore, the foaming capacity, foam stability and fat absorption capacity of Alkali-PP was better than soy protein powder. Therefore, Alkali-pH followed by freeze-drying would be a better alternative to prepare high-quality protein powder from tuna liver in the food industry.

Bacteriocins are bioactive antimicrobial peptides synthesized in the ribosome of numerous bacteria and released extracellularly. Bacteriocins have the ability to kill or inhibit the growth of prokaryotes and could potentially be useful against pathogens and antibiotic-resistant strains of bacteria. The antimicrobial mechanisms and relatively narrow killing spectrums of bacteriocins distinguish them from traditional broad-spectrum antibiotics, making them possible candidates to replace antibiotics in the future. In recent years, researchers have discovered many new bacteriocins from different sources. However, the discovery of new bacteriocins involves complicated screening, identification, purification, and characterization processes. This review describes the strategies currently employed for screening, identification, purification, and characterization of bacteriocins. Approximately 40 novel bacteriocins are reviewed in this paper. Our conclusions about the research process will guide the development of novel methods and allow for the faster, easier, and more efficient discovery of novel bacteriocins.

Alaska Pollock is rich in resource. And during its processing, skin is peeled as byproducts. The skin of Alaska Pollock contains lots of collagen or gelatin, promising materials, which can be used in food, cosmetics, biomedical and pharmaceutical industries. Extracting collagen from the dry skin of Alaska Pollock is studied in this study to provide a better basement for fully using this renewable resource. Three kinds of gelatin were extracted by using acid, pepsin-assisted acid and hot water, respectively. The productivity of Acid Soluble Gelatin (ASG), Pepsin Soluble Gelatin (PSG) and hot Water Soluble Gelatin (WSG) were 7.33, 30.89 and 12.67%, respectively. Their UV absorption spectrum were similar and match with the absorption of dilute protein solution. The protein contents of ASG, PSG and WSG were 84-90%, with no significantly difference between them. The characters of SDS-PAGE and the circular dichroism spectrum shown that the PSG is broken into small fragment and has less secondary structure. In conclusion, the hot water extraction is the best way to extract the gelatin from the dry skin of Alaska Pollock.

The physicochemical and functional properties of covalently modified whey protein isolate (WPI) by (−)-epigallocatechin-3-gallate (EGCG) were investigated. WPI was chemically modified by EGCG under alkaline conditions. The effect of modification on foaming and emulsifying properties was evaluated. The results of SDS-PAGE and size exclusion chromatography indicated that modification by EGCG induced cross-linking on proteins of WPI. Fourier transform infrared spectroscopy (FT-IR) analysis illustrated the incorporation of phenolic groups into the modified WPI and the changes in protein secondary structure. Intrinsic fluorescence spectra revealed that modified WPI had a more compact tertiary structure compared to unmodified WPI. The modified WPI exhibited better foaming and emulsifying properties than unmodified WPI. These results suggest that EGCG modification is a potential method for improving the functional properties of WPI.

Total 24 isolates with antimicrobial activity against Staphylococcus aureus, Escherichia coli, Bacillus cereus and Shigella castellani, out of 259 strains, were isolated from the internal of seven marine fishes. The extracellular metabolites of strain S14, isolated from the internal of shark, showed stronger inhibition against the four tested bacteria, including G- and G+ bacteria. Based on the 16S rDNA the sequencing analysis, the strain S14 belonged to a member of Staphylococcus epidermidis with 99% DNA similarity and named to Staphylococcus epidermidis S14. The Staphylococcus epidermidis S14 secreted rarely antibacterial substance in the stabilization period and the antibacterial active substances might be the secondary metabolites. The antibacterial metabolites were not hydrolyzed by pepsin, trypsin and lysozyme. The antibacterial metabolites were stable for 30 min to high temperature treatment at 100°C and had higher antibacterial activity at neutral pH.

Glypican-3 (GPC3) is a membrane of heparan sulfate proteoglycan family involved in cell proliferation, adhesion, migration, invasion, and differentiation during the development of the majority of mesodermal tissues and organs. GPC3 is explored as a potential biomarker for hepatocellular carcinoma screening. However, as a tumor-associated antigen, its role in ovarian cancer remains elusive. In this report, the expression levels of GPC3 in the various ovarian cancer cells were determined with quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and GPC3 expression in ovarian cancer UCI 101 and A2780 cells was knocked down by siRNA transfection, and the effects of GPC3 knockdown on in vitro cell proliferation, migration, and invasion were respectively analyzed by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay and Transwell migration assay. Additionally, the effect of GPC3 knockdown on in vivo tumorigenesis were investigated in athymic nude mice. The results indicated that GPC3 knockdown significantly promoted cell proliferation and increased cell migration and invasion by upregulation of matrix metalloproteinase (MMP)-2 and MMP-9 expression and downregulation of tissue inhibitor of metalloproteinase-1 expression. Additionally, GPC3 knockdown also increased in vivo tumorigenicity of UCI 101 and A2780 cells and final tumor weights and volumes after subcutaneous cell injection in the nude mice. The results of immunohistochemical staining and Western blotting both demonstrated a lower expression of GPC3 antigen in the tumors of GPC3 knockdown groups than that of negative control groups. Moreover, transforming growth factor-β2 protein expression in the tumors of GPC3 knockdown groups was significantly increased, which at least contributed to tumor growth in the nude mice. Taken together, these findings suggest that GPC3 knockdown promotes the progression of human ovarian cancer cells by increasing their migration, invasion, and tumorigenicity, and suggest that GPC3 is a potential therapeutic target for ovarian cancer patients.

Staphylococcus aureus and its drug-resistant strains, which threaten public health and food safety, are in need of effective control by biopreservatives. A novel bacteriocin, pentocin JL-1, produced by Lactobacillus pentosus that was isolated from the intestinal tract of Chiloscyllium punctatum, was purified by a four-step chromatographic process. Mass spectrometry based on MALDI-TOF indicated that pentocin JL-1 has a molecular mass of 2987.23 Da. Only six of the twenty-five amino acids could be identified by Edman degradation. This bacteriocin is thermostable and tolerates a pH range of 5–7. Also, it is sensitive to proteinase K, trypsin, pepsin, and alkaline protease. This bacteriocin has a broad inhibitory spectrum against both Gram-positive and Gram-negative strains and in particular is effective against multidrug-resistant S. aureus. Additionally, we showed that the cell membrane is the target of pentocin JL-1 against methicillin-resistant S. aureus (MRSA), causing a loss of proton motive force. Furthermore, pentocin JL-1 has a drastic impact on the structure and integrity of MRSA cells. These results suggest that pentocin JL-1 has potential as a biopreservative in the food industry.

Rare earth element pollution and elevated ultraviolet-B (UV-B) radiation occur simultaneously in some regions, but the combined effects of these two factors on plants have not attracted enough attention. Nitrogen nutrient is vital to plant growth. In this study, the combined effects of lanthanum(III) and elevated UV-B radiation on nitrate reduction and ammonia assimilation in soybean (Glycine max L.) roots were investigated. Treatment with 0.08 mmol L(-1) La(III) did not change the effects of elevated UV-B radiation on nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), glutamate synthase (GOGAT), glutamate dehydrogenase (GDH), nitrate, ammonium, amino acids, or soluble protein in the roots. Treatment with 0.24 mmol L(-1) La(III) and elevated UV-B radiation synergistically decreased the NR, NiR, GS, and GOGAT activities as well as the nitrate, amino acid, and soluble protein levels, except for the GDH activity and ammonium content. Combined treatment with 1.20 mmol L(-1) La(III) and elevated UV-B radiation produced severely deleterious effects on all test indices, and these effects were stronger than those induced by La(III) or elevated UV-B radiation treatment alone. Following the withdrawal of La(III) and elevated UV-B radiation, all test indices for the combined treatments with 0.08/0.24 mmol L(-1) La(III) and elevated UV-B radiation recovered to a certain extent, but they could not recover for treatments with 1.20 mmol L(-1) La(III) and elevated UV-B radiation. In summary, combined treatment with La(III) and elevated UV-B radiation seriously affected nitrogen nutrition in soybean roots through the inhibition of nitrate reduction and ammonia assimilation.

The polyphenolic flavonoid silymarin that is the milk thistle extract has been found to possess an anti-cancer effect against various human epithelial cancers. In this study, to explore the regulative effect of silymarin on human ovarian cancer line A2780s and PA-1 cells, 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide assay and flow cytometry were respectively used to determine the inhibitory effect of silymarin on the both cell lines, and to measure their cell cycle progression. Apoptosis induction and mitochondrial membrane potential damage were separately detected by terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end labeling assay and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide staining. Additionally, western blotting was applied to determine cytochrome C release and expression levels of p53, p21, p27, p16, CDK2, Bax, Bcl-2, procaspase-9, procaspase-3, cleaved caspase-9 and caspase-3 proteins. The activity of caspase-9 and caspase-3 was measured using Caspase-Glo-9 and Caspase-Glo-3 assay. The results indicated that silymarin effectively suppressed cell growth in a dose- and time-dependent manner, and arrested cell cycle progression at G1/S phase in A2780s and PA-1 cells via up-regulation of p53, p21, and p27 protein expression, and down-regulation of CDK2 protein expression. Additionally, silymarin treatment for 24h at 50 and 100µg/ml resulted in a reduction of mitochondrial membrane potential and cytochrome C release, and significantly induced apoptosis in A2780s and PA-1 cells by increasing Bax and decreasing Bcl-2 protein expression, and activation of caspase-9 and caspase-3. Therefore, silymarin is a possible potential candidate for the prevention and treatment of ovarian cancer.

Ultraviolet-B (UV-B, 280-320 nm) radiation has seriously affected the growth of plants. Finding the technology/method to alleviate the damage of UV-B radiation has become a frontal topic in the field of environmental science. The pretreatment with rare earth elements (REEs) is an effective method, but the regulation mechanism of REEs is unknown. Here, the regulation effects of lanthanum (La(III)) on nitrogen assimilation in soybean seedlings (Glycine max L.) under ultraviolet-B radiation were investigated to elucidate the regulation mechanism of REEs on plants under UV-B radiation. UV-B radiation led to the inhibition in the activities of the key enzymes (nitrate reductase, glutamine synthetase, glutamate synthase) in the nitrogen assimilation, the decrease in the contents of nitrate and soluble proteins, as well as the increase in the content of amino acid in soybean seedlings. The change degree of UV-B radiation at the high level (0.45 W m(-2)) was higher than that of UV-B radiation at the low level (0.15 W m(-2)). The pretreatment with 20 mg L(-1) La(III) could alleviate the effects of UV-B radiation on the activities of nitrate reductase, glutamine synthetase, glutamate synthase, and glutamate dehydrogenase, promoting amino acid conversion and protein synthesis in soybean seedlings. The regulation effect of La(III) under UV-B radiation at the low level was better than that of UV-B radiation at the high level. The results indicated that the pretreatment with 20 mg L(-1) La(III) could alleviate the inhibition of UV-B radiation on nitrogen assimilation in soybean seedlings.

Silver nanoparticles (Ag NPs) previously classified as antimicrobial agents have been widely used in consumers and industrial products, especially food storage material. Ag NPs used as antimicrobial agents may be found in liver. Thus, examination of the ability of Ag NPs to penetrate the liver is warranted. The aim of the study was to determine the optimal viability assay for using with Ag NPs in order to assess their toxicity to liver cells. For toxicity evaluations, cellular morphology, mitochondrial function (3-(4, 5-dimethylazol-2-yl)-2, 5-diphenyl-tetrazolium bromide, MTT assay), membrane leakage of lactate dehydrogenase (lactate dehydrogenase, LDH release assay), Oxidative stress markers (malonaldehyde (MDA), glutathione (GSH) and superoxide dismutase (SOD)), DNA damage (single cell gel eletrophoresis, SCGE assay), and protein damage were assessed under control and exposed conditions (24 h of exposure). The results showed that mitochondrial function decreased significantly in cells exposed to Ag NPs at 25 μgmL−1. LDH leakage significantly increased in cells exposed to Ag NPs (≥ 25 μg mL−1) while micro-sized silver particles tested displayed LDH leakage only at higher doses (100 μgmL−1). The microscopic studies demonstrated that nanoparticle-exposed cells at higher doses became abnormal in size, displaying cellular shrinkage, and an acquisition of an irregular shape. Due to toxicity of silver, further study conducted with reference to its oxidative stress. The results exhibited significant depletion of GSH level, increase in SOD levels and lead to lipid peroxidation, which suggested that cytotoxicity of Ag NPs in liver cells might be mediated through oxidative stress. The results demonstrates that Ag NPs lead to cellular morphological modifications, LDH leakage, mitochondrial dysfunction, and cause increased generation of ROS, depletion of GSH, lipid peroxidation, oxidative DNA damage and protein damage. Though the exact mechanism behind Ag NPs toxicity is suggested oxidative stress and lipid peroxidation playing an important role in Ag NPs elicited cell membrane disruption, DNA damage, protein damage and subsequent cell death. Our preliminary data suggest that oxidative stress might contribute to Ag NPs cytotoxicity. To reveal whether apoptosis involved in Ag NPs toxicity, further studies are underway.