Summary
The immunomodulatory effects of probiotics were assessed following exposure of normal peripheral blood mononuclear cells (PBMC), cord blood cells and the spleen‐derived monocyte/macrophage ...cell line CRL‐9850 to Lactobacillus acidophilus LAVRI‐A1, Lb. rhamnosus GG, exopolysaccharides (EPS)‐producing Streptococcus thermophilus St1275, Bifidobacteriun longum BL536, B. lactis B94 and Escherichia coli TG1 strains. The production of a panel of pro‐ and anti‐inflammatory cytokines by PBMC following bacterial stimulation was measured, using live, heat‐killed or mock gastrointestinal tract (GIT)‐exposed bacteria, and results show that (i) all bacterial strains investigated induced significant secretion of pro‐ and anti‐inflammatory cytokines from PBMC‐derived monocytes/macrophages; and (ii) cytokine levels increased relative to the expansion of bacterial cell numbers over time for cells exposed to live cultures. Bifidobacteria and S. thermophilus stimulated significant concentrations of transforming growth factor (TGF)‐β, an interleukin necessary for the differentiation of regulatory T cells (Treg)/T helper type 17 (Th17) cells and, as such, the study further examined the induction of Th17 and Treg cells after PBMC exposure to selected bacteria for 96 h. Data show a significant increase in the numbers of both cell types in the exposed populations, measured by cell surface marker expression and by cytokine production. Probiotics have been shown to induce cytokines from a range of immune cells following ingestion of these organisms. These studies suggest that probiotics' interaction with immune‐competent cells produces a cytokine milieu, exerting immunomodulatory effects on local effector cells, as well as potently inducing differentiation of Th17 and Treg cells.
In this study, the in vitro angiotensin-converting enzyme (ACE)-inhibitory (ACE-I) activity of peptide fractions from different yoghurt batches was assessed. Inhibition of ACE activity resulted in an ...overall antihypertensive effect. Yoghurts were prepared either using a sole yoghurt culture including
Lactobacillus delbrueckii ssp
. bulgaricus Lb1466 and
Streptococcus thermophilus St1342, or
L. acidophilus L10,
L. casei L26 and
Bifidobacterium lactis B94 in addition to yoghurt culture. ACE-I activity was determined at weekly intervals during 28 days of cold storage. Peptide fractions showing high ACE-I activity were further purified using multiple-steps of RP-HPLC. All probiotic yoghurts showed appreciable ACE-I activity during initial stages of storage compared with the control yoghurt, with a significant (
p<0.05) decrease afterwards. The ACE-I activity ranged from IC
50 of 103.30–27.79
μg
mL
−1 with the greatest ACE inhibition achieved during first and third week of storage. The in vitro ACE-I activity could be related to the peptide liberation via degradation of caseins. In total, 8 ACE-I peptides were characterized originating from
α
s2-casein (1),
κ-casein (2) and
β-casein, of which two well-known ACE-inhibiting peptides, namely Val–Pro–Pro (VPP) and Ile–Pro–Pro (IPP), were identified. These peptides are already used in commercial products.
Cancer is the most widely recognized reason for human deaths globally. Conventional anticancer therapies, including chemotherapy and radiation, are very costly and induce severe side effects on the ...individual. The discovery of natural anticancer compounds like peptides may thus be a better alternative for cancer prevention and management. The anticancer peptides also exist in the amino acid chain of milk proteins and can be generated during proteolytic activities such as gastrointestinal digestion or food processing including fermentation. This paper presents an exhaustive overview of the contemporary literature on antitumor activities of peptides released from milk proteins. In addition, caseins and whey proteins have been evaluated for anticancer potential using the AntiCP database, a web‐based prediction server. Proline and lysine, respectively, dominate at various positions in anticancer peptides obtained from caseins and whey proteins. The remarkable number of potential anticancer peptides revealed milk proteins as favorable candidates for the development of anticancer agents or milk and milk products for reduction of cancer risks. Moreover, anticancer peptides liberated from milk proteins can be identified from fermented dairy products. Although current findings of correlation between dairy food intakes and cancer risks lack consistency, dairy‐derived peptides show promise as candidates for cancer therapy. This critical review supports the notion that milk proteins are not only a nutritious part of a normal daily diet but also have potential for prevention and/or management of cancer.
The search for alternative preservatives is on the rise due to safety issues linked with the application of synthetic antioxidants and the extensive increase in bacterial resistance to several ...conventional antibiotics. Therefore, the quest for finding suitable alternatives including bioactive peptides has received attention. This article reports a comprehensive insight concerning antioxidative and antibacterial peptides derived from milk proteins, a prolific source of peptides having various bioactivities. Caseins and whey proteins have also been evaluated for antioxidative and antibacterial potential using the BIOPEP database. A notable number of potentially active peptides are present in milk proteins. Technological approaches are here reported for the production of these peptides. The findings of this review show potentiality of utilizing dairy derived antioxidative and antibacterial peptides in the development of a superior alternative to the current generation of preservatives and therapeutic agents, as well as a functional ingredient in dietetic or pharmaceutical applications.
Although many fruit by-products are good sources of nutrients, little is known about their prebiotic potential. This research was aimed at establishing the prebiotic effect of pineapple wastes on ...probiotics including
Lactobacillus
(
L
.)
acidophilus
(ATCC® 4356™),
L
.
casei
(ATCC® 393™) and
L
.
paracasei
spp.
paracasei
(ATCC® BAA52™) and the subsequent release of antioxidant and antimutagenic peptides in yogurt during their growth. Oven- and freeze- dried peel and pomace were milled separately into powders and tested for prebiotic activities. The net probiotic growth (1.28–2.14 log cfu/g) in customized MRS broth containing the pineapple powders as a direct carbohydrate source was comparable to MRS broth containing glucose. The powders were also separately added to milk during the manufacturing of yogurt with or without probiotics. An increase (by 0.3–1.4 log cycle) in probiotic populations was observed in the yogurts as a consequence of pineapple powder supplementation. Crude water-soluble peptide extracts, prepared by high-speed centrifugation of the yogurts, displayed remarkable antioxidant activities assessed through in vitro assays, namely scavenging activity of 1,1-diphenyl-2-picrylhydrazyl radicals (IC
50
= 0.37–0.19 mg/ml) and hydroxyl radicals (58.52–73.55 %). The peptide extracts also exhibited antimutagenic activities (18.60–32.72 %) as sodium azide inhibitor in the
Salmonella
mutagenicity test. Together, these results suggest that pineapple by-products exhibited prebiotic properties and could possibly be commercially applied in new functional food formulations.
The growth and metabolism of two probiotic organisms (
L. acidophilus LAFTI
® L10 and
Lactobacillus casei LAFTI
® L26) and a regular yoghurt culture (
L. delbrueckii ssp.
bulgaricus Lb1466 and
...Streptococcus thermophilus St1342) were studied in yoghurt containing 0.5%, 1.0%, and 1.5% (w/v) of high amylose corn starch powder (Hi-maize
®) or inulin. Viable cell counts of probiotic organisms, their metabolites and proteolytic activities, and viscosity of the yoghurts were determined during refrigerated storage for 28
d at 4
oC. In the presence of inulin, cultures showed better retention of viability (8.0
log
cfu
g
−1) in comparison with that of Hi-maize, which had a reduction by one log cycle. Lower concentrations of 0.5–1.0% Hi-maize improved (
P<0.05) the production of propionic acid and also increased proteolytic activity of probiotic organisms substantially. A greater release of free amino acids may have sustained better growth of the organisms in yoghurts. Supplementation with either Hi-maize or inulin increased the viscosity of probiotic yoghurts significantly (
P<0.05).
Suitability of soy yogurt as a system for delivering probiotics and other bioactive compounds was assessed by fermenting soy milk using starter culture containing Lactobacillus delbrueckii ssp. ...bulgaricus Lb1466, Streptococcus thermophilus St1342, and probiotic organisms (Lactobacillus acidophilus LAFTI L10, Bifidobacterium lactis LAFTI B94, and Lactobacillus paracasei LAFTI L26). Fermentations were terminated at different pH of 4.50, 4.55, and 4.60 and metabolic patterns of cultures (viability, proteolytic activity, organic acids production, angiotensin-converting enzyme (ACE) inhibitory activity) were investigated during 28 d of storage at 4 degrees C. The presence of probiotics enhanced the growth of L. delbrueckii ssp. bulgaricus Lb1466 and S. thermophilus St134 in soy yogurt in comparison to the control produced by sole yogurt culture. In general, different termination pH had no effect (P > 0.05) on the viability of probiotic organisms that maintained good viability in soy yogurt during cold storage. Higher levels of essential growth factors in the form of peptides and amino acids in soy yogurts may have promoted the growth of L. acidophilus LAFTI L10, B. lactis LAFTI B94, and L. paracasei LAFTI L26. The use of probiotic strains as a part of starter culture in soy yogurt resulted in a substantial increase in in vitro ACE inhibitory activity compared with the control produced by yogurt culture only. This improvement of ACE inhibition in soy yogurt is partly due to higher proteolytic activity of probiotics.
The search for alternative therapeutics is on the rise due to the extensive increase in bacterial resistance to various conventional antibiotics and side effects of conventional cancer therapies. ...Bioactive peptides released from natural sources such as dairy foods by lactic acid bacteria have received attention as a potential source of biotherapeutic peptides. However, liberation of peptides in yogurt depends on proteolytic activities of the cultures used. Thus, this research was conducted to establish generation of inhibitory peptides in yogurt against pathogenic bacteria and cancer cells during storage at 4°C for 28d. Water-soluble crude peptide extracts were prepared by high-speed centrifugation of plain and probiotic yogurts supplemented with or without pineapple peel powder (PPP). The inhibition zones against Escherichia coli and Staphylococcus aureus by PPP-fortified probiotic yogurt at 28d of storage were, respectively, 25.89 and 11.72mm in diameter, significantly higher than that of nonsupplemented control yogurts. Antiproliferative activity against HT29 colon cancer cells was also significantly higher in probiotic yogurt with PPP than in nonsupplemented probiotic yogurt. Overall, crude water-soluble peptide extracts of the probiotic yogurt with PPP possessed stronger inhibitory activities against bacteria and cancer cells than controls, and these activities were maintained during storage. However, activities were lowered substantially during in vitro gastrointestinal digestion. These findings support the possibility of utilizing dairy-derived bioactive peptides in the development of a superior alternative to the current generation of antibacterial and anticancer agents, as well as a functional ingredient in foods, nutraceuticals, and pharmaceuticals.
Short chain fatty acids (SCFAs) are major products of prebiotic fermentation and confer human health benefits such as immune-regulation. In this study, reconstituted skim milk supplemented with ...prebiotics (RSMP) including inulin, hi-maize or β-glucan was fermented by probiotic strains of Lactobacillus spp. and Bifidobacteria spp. After 24 h of fermentation, probiotics growth and SCFAs production were investigated and the produced SCFAs were extracted. Inulin and Lactobacillus rhamnosus GG ATCC 53013 (LGG) combination released highest concentrations of SCFAs compared to LGG and hi-maize or β-glucan. Extracted SCFAs were then used for in vitro immune modulation study in human peripheral blood mononuclear cells (PBMCs). In lipopolysaccharide (LPS)-stimulated PBMCs, SCFAs particularly butyrate down-regulated tumor necrosis factor alpha, interleukin (IL)-12, interferon gamma (IFN-γ) and transforming growth factor beta-1 (TGF-β1), and up-regulated IL-4, IL-10, while no significant effect was noted in non-LPS-stimulated PBMCs. The results indicate that SCFAs regulated cytokine milieu in LPS-stimulated PBMCs to anti-inflammatory cytokines.
Short-chain fatty acids (SCFAs) including acetate, propionate and butyrate play an important role in the physiological functions of epithelial cells and colonocytes, such as immune response ...regulation. Human intestinal epithelial cells (IECs) contribute in intestinal immune response via different ways, such as production of different immune factors including Interleukin (IL) IL-8, which act as chemoattractant for neutrophils, and subsequently enhance inflammation. Therefore, we aimed to evaluate the effects of SCFAs on IECs viability and production of IL-8 in vitro. SCFAs were co-cultured with either normal intestinal epithelial (T4056) or adenocarcinoma derived (HT-29) cell lines for 24-96 h in the presence of E.coli lipopolysaccharides (LPS). Cell viability, proliferation, production of IL-8 and expression of IL-8 mRNA were determined in the cell cultures. The result showed that 20 mM of SCFAs was non-cytotoxic to T4056 and enhanced their growth, whereas the growth of HT-29 was inhibited. The SCFAs down regulated LPS-stimulated IL-8 secretion with different response patterns, but no obvious effects on the release of IL-8 from non LPS- stimulated cells. In conclusion, SCFAs showed regulatory effect on release of LPS-stimulated IL-8 as well as the expression of mRNA of IL-8; these might explain the anti-inflammatory and anti-carcinogenic mechanism of SCFAs.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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