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Chinese three-striped box turtle (Cuora trifasciata), as a freshwater turtle, is used as a tonic food. The purpose of this study was to isolate peptides with cancer growth inhibition activity from trypsin-digested hydrolysates of turtle proteins. The results demonstrated that two fractions T1 and T2 exhibited good inhibition on HepG-2 and MCF-7 cancer cells, with an inhibition of 70.65–89.1%, at 500 μg/mL. Subsequently, three peptides were identified from T1 and T2, including RGVKGPR (T1–1), KLGPKGPR (T1–2), and SSPGPPVH (T2–1). By database search, T2–1 was a completely new peptide; its inhibition activity on MCF-7 cancer cells was the best, up to 70.02% at 500 μg/mL. Then, T1 and T2–1 were nanoencapsulated by chitosan. After nanoencapsulation, the inhibition percentages were 50.23% for the nanoencapsulated T1 on HepG-2 and 46.82% for the encapsulated T2–1 on MCF-7. The release experiment indicated that the encapsulated peptides could be slowly released in simulated gastrointestinal juice. [ABSTRACT FROM AUTHOR]

Plant lectins have displayed a variety of biological activities. In this study, for the first time, a 27 kDa arabinose- and mannose-specific lectin from Broccolini (Brassica oleracea Italica × Alboglabra), named as BL (Broccolini lectin), was purified by an activity-driven protocol. Mass spectrometry analysis and database search indicated that no matches with any plant lectin were found, but BL contained some peptide fragments (QQQGQQGQQLQQVISR, QQGQQQGQQGQQLQQVISR and VCNIPQVSVCPF QK). BL exhibited hemagglutinating activity against chicken erythrocytes at 4 µg/mL. BL retained full hemagglutinating activity at pH 7-8 and temperature 30-40°C, and had an optimal activity in Ca2+ solution. Bioactivity assay revealed that BL exhibited dose-dependent inhibition activity on 5 bacterial species with IC50 values of 143.95-486.33 μg/mL, and on 3 cancer cells with IC50 values of 178.82-350.93 μg/mL. Notably, 5-fold reduction in IC50 values was observed on normal L-O2 vs cancerous HepG-2 cells (924.35 vs. 178.82 μg/mL). This suggests that BL should be promising in food and medicine. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:736-743, 2015 [ABSTRACT FROM AUTHOR]

Lentinus edodeshas been valued as edible and medical resources. Polysaccharides have been known to be the most potent antitumor and immunomodulating substance inLentinus edodes. In this review, we summarize the current knowledge of the polysaccharides isolated fromLentinus edodes,including extraction and purification methods, chemical structure and chain conformation, the effects on innate and adaptive immunity and their mechanism, relationship between structure and function, and the future prospects. [ABSTRACT FROM PUBLISHER]

Spirulina platensis is a multicellular edible blue-green alga with abundant proteins (∼60%). No report is available on the antitumor polypeptides from the whole proteins of S. platensis. In this study, for the first time, an antitumor polypeptide Y2 from trypsin digest of S. platensis proteins was obtained by using freeze-thawing plus ultrasonication extraction, hydrolysis with four enzymes (trypsin, alcalase, papain, and pepsin), and gel filtration chromatography. The results showed that the degree of hydrolysis can be ordered as: trypsin (38.5%) > alcalase (31.2%) > papain (27.8%) > pepsin (7.1%). For MCF-7 and HepG2 cells, at 250 µg/mL, the maximum inhibitory rate of Y2 was 97%, while standard drug 5-FU was 55 and 97%, respectively. Furthermore, the nanoencapsulation of Y2 with chitosan (CS) was also investigated. After nanoencapsulation, the maximum encapsulation efficiency and polypeptides contents are 49 and 15%, respectively; and the antitumor activity is basically not lost. These data demonstrated the potential of nanopolypeptides (Y2-CS) in food and pharmaceutical applications. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1230-1238, 2013 [ABSTRACT FROM AUTHOR]

Chlorella pyrenoidosa is a unicellular green algae and has been a popular foodstuff worldwide. However, no reports on the antitumor peptides from such a microalgae are available in the literature. In this study, using low-temperature high-pressure extraction, enzymatic hydrolysis, ion exchange, and gel filtration chromatography, we separated a polypeptide that exhibited inhibitory activity on human liver cancer HepG2 cells, and named the polypeptide CPAP (C. pyrenoidosa antitumor polypeptide). Furthermore, the micro- and nanoencapsulation of CPAP were investigated by using two methods: complex coacervation and ionotropic gelation. The in vitro release tests revealed that CPAP was well preserved against gastric enzymatic degradation after micro/nanoencapsulation and the slowly controlled release in the intestine could be potentially achieved. These results suggest that CPAP may be a useful ingredient in food, nutraceutical, and pharmaceutical applications. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:681-687, 2013 [ABSTRACT FROM AUTHOR]

Abstract A carboxymethyl polysaccharide CMP33 (15.23 × 104 Da) was isolated from edible and pharmaceutical mushroom Poria cocos using alkaline extraction followed by DEAE-52 and Saphadex-G200 + Saphadex-G150 column chromatographies. The structure analysis showed that CMP33 was composed of glucosyl residues containing a backbone chain of (1 → 3)-linked glucose residues and side chains of (1 → 6) and (1 → 2)-linked glucose residues, and possessed triple-helix structure. Bioassay results revealed that CMP33 displayed a dose-dependent inhibition on 5 cancer cells (HepG-2, MCF-7, SGC-7901, A549) in the range of 31.25–1000 μg/mL, but low cytotoxicity on normal liver cells L-O2. Moreover, CMP33 stimulated NO release and cytokine secretion (IL-1β, IL-6 and TNF-α), and also inhibited LPS-stimulated overproduction of NO, IL-6, TNF-α and IL-1β, in RAW264.7 cells. These results suggested that CMP33 possessed anticancer, anti-inflammation and immune-stimulation activities, and potential for developing as a bioactive ingredient in functional foods. [ABSTRACT FROM AUTHOR]

Abstract: Mushrooms have been used as food or medicine for thousands of years. Due to low-fat content and absence of cholesterol, many mushrooms are excellent sources of protein. There are various mushroom proteins with interesting biological activities, such as lectins, fungal immunomodulatory proteins (FIP), ribosome inactivating proteins (RIP), ribonucleases, laccases, and other proteins, which have become popular sources of natural antitumor, antiviral, antimicrobial, antioxidative, and immunomodulatory agents. The aim of this review is to update the present status of bioactive proteins in mushrooms, and to discuss their biomedical potential and future prospectives. [Copyright &y& Elsevier]