Canadian Journal of Physiology and Pharmacology, 2007
Extracts of the Canadian lowbush blueberry ( Vaccinium angustifolium Ait.) have recently been dem... more Extracts of the Canadian lowbush blueberry ( Vaccinium angustifolium Ait.) have recently been demonstrated to possess significant antidiabetic potential, in accordance with the traditional use of this plant as an antidiabetic natural health product. Fermentation of blueberry juice with the Serratia vaccinii bacterium is known to modify the phenolic content and increase antioxidant activity. The present study evaluated the effects of fermented blueberry juice on glucose uptake, adipogenesis, and the signaling pathways that regulate glucose transport in muscle cells and adipocytes. A 6-hour treatment with fermented juice potentiated glucose uptake by 48% in C2C12 myotubes and by 142% in 3T3-L1 adipocytes, in the presence or absence of insulin, whereas nonfermented juice had no effect on transport. Fermented juice dramatically inhibited triglyceride content during adipogenesis of 3T3-L1 cells. Chlorogenic acid and gallic acid, both major phenolic components of fermented juice, had no e...
Fermented plant foods are gaining wide interest worldwide as healthy foods due to their unique se... more Fermented plant foods are gaining wide interest worldwide as healthy foods due to their unique sensory features and their health-promoting potentials, such as antiobesity, antidiabetic, antihypertensive, and anticarcinogenic activities. Many fermented foods are a rich source of nutrients, phytochemicals, bioactive compounds, and probiotic microbes. The excellent biological activities of these functional foods, such as anti-inflammatory and immunomodulatory functions, are widely attributable to their high antioxidant content and lactic acid-producing bacteria (LAB). LAB contribute to the maintenance of a healthy gut microbiota composition and improvement of local and systemic immunity. Besides, antioxidant compounds are involved in several functional properties of fermented plant products by neutralizing free radicals, regulating antioxidant enzyme activities, reducing oxidative stress, ameliorating inflammatory responses, and enhancing immune system performance. Therefore, these pro...
The probiotic effects ascribed to lactic acid bacteria (LAB) and their fermented dairy products a... more The probiotic effects ascribed to lactic acid bacteria (LAB) and their fermented dairy products arise not only from whole microorganisms and cell wall components but also from peptides and extracellular polysaccharides (exopolysaccharides) produced during the fermentation of milk. There is a lack of knowledge concerning the immune mechanisms induced by exopolysaccharides produced by lactic acid bacteria, which would allow a better understanding of the functional effects described to them. The aim of this study was to investigate the in vivo immunomodulating capacity of the exopolysaccharide produced by Lactobacillus kefiranofaciens by analyzing the profile of cytokines and immunoglobulins induced at the intestinal mucosa level, in the intestinal fluid and blood serum. BALB/c mice received the exopolysaccharide produced by L. kefiranofaciens for 2, 5 or 7 consecutive days. At the end of each period of administration, control and treated mice were sacrificed and the numbers of IgA+ and IgG+ cells were determined on histological slices of the small and large intestine by immunofluorescence. Cytokines (IL-4, IL-6, IL-10, IL-12, IFNgamma and TNFalpha) were also determined in the gut lamina propria as well as in the intestinal fluid and blood serum. There was an increase of IgA+ cells in the small and large intestine lamina propria, without change in the number of IgG+ cells in the small intestine. This study reports the effects of the oral administration of the exopolysaccharide produced by L. kefiranofaciens in the number of IgA+ cells in the small and large intestine, comparing simultaneously the production of cytokines by cells of the lamina propria and in the intestinal fluid and blood serum. The increase in the number of IgA+ cells was not simultaneously accompanied by an enhance of the number of IL-4+ cells in the small intestine. This finding would be in accordance with the fact that, in general, polysaccharide antigens elicit a T-independent immune response. For IL-10+, IL-6+ and IL-12+ cells, the values found were slightly increased compared to control values, while IFNgamma+ and TNFalpha+ cells did not change compared to control values. The effects observed on immunoglobulins and in all the cytokines assayed in the large intestine after kefiran administration were of greater magnitude than the ones observed in the small intestine lamina propria, which may be due to the saccharolytic action of the colonic microflora. In the intestinal fluid, only IL-4 and IL-12 increased compared to control values. In blood serum, all the cytokines assayed followed a pattern of production quite similar to the one found for them in the small intestine lamina propria. We observed that the exopolysaccharide induced a gut mucosal response and it was able to up and down regulate it for protective immunity, maintaining intestinal homeostasis, enhancing the IgA production at both the small and large intestine level and influencing the systemic immunity through the cytokines released to the circulating blood.
Despite sequence similarity to SARS-CoV-1, SARS-CoV-2 has demonstrated greater widespread virulen... more Despite sequence similarity to SARS-CoV-1, SARS-CoV-2 has demonstrated greater widespread virulence and unique challenges to researchers aiming to study its pathogenicity in humans. The interaction of the viral receptor binding domain (RBD) with its main host cell receptor, angiotensin-converting enzyme 2 (ACE2), has emerged as a critical focal point for the development of anti-viral therapeutics and vaccines. In this study, we selectively identify and characterize the impact of mutating certain amino acid residues in the RBD of SARS-CoV-2 and in ACE2, by utilizing our recently developed NanoBiT technology-based biosensor as well as pseudotyped-virus infectivity assays. Specifically, we examine the mutational effects on RBD-ACE2 binding ability, efficacy of competitive inhibitors, as well as neutralizing antibody activity. We also look at the implications the mutations may have on virus transmissibility, host susceptibility, and the virus transmission path to humans. These critical ...
Inflammation is a biological response to the activation of the immune system by various infectiou... more Inflammation is a biological response to the activation of the immune system by various infectious or non-infectious agents, which may lead to tissue damage and various diseases. Gut commensal bacteria maintain a symbiotic relationship with the host and display a critical function in the homeostasis of the host immune system. Disturbance to the gut microbiota leads to immune dysfunction both locally and at distant sites, which causes inflammatory conditions not only in the intestine but also in the other organs such as lungs and brain, and may induce a disease state. Probiotics are well known to reinforce immunity and counteract inflammation by restoring symbiosis within the gut microbiota. As a result, probiotics protect against various diseases, including respiratory infections and neuroinflammatory disorders. A growing body of research supports the beneficial role of probiotics in lung and mental health through modulating the gut-lung and gut-brain axes. In the current paper, we ...
This review offers a systematic understanding about how polyphenols target multiple inflammatory ... more This review offers a systematic understanding about how polyphenols target multiple inflammatory components and lead to anti-inflammatory mechanisms. It provides a clear understanding of the molecular mechanisms of action of phenolic compounds. Polyphenols regulate immunity by interfering with immune cell regulation, proinflammatory cytokines’ synthesis, and gene expression. They inactivate NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) and modulate mitogen-activated protein Kinase (MAPk) and arachidonic acids pathways. Polyphenolic compounds inhibit phosphatidylinositide 3-kinases/protein kinase B (PI3K/AkT), inhibitor of kappa kinase/c-Jun amino-terminal kinases (IKK/JNK), mammalian target of rapamycin complex 1 (mTORC1) which is a protein complex that controls protein synthesis, and JAK/STAT. They can suppress toll-like receptor (TLR) and pro-inflammatory genes’ expression. Their antioxidant activity and ability to inhibit enzymes involved in the productio...
BMC complementary and alternative medicine, Jan 4, 2017
We recently reported that blueberry juice fermented (FJ) with Serratia vaccinii bacterium has ant... more We recently reported that blueberry juice fermented (FJ) with Serratia vaccinii bacterium has antidiabetic activities both in vivo and in vitro. The purpose of this project was to elucidate the effect of FJ on glucose homeostasis in liver and skeletal muscle cells and to identify active fractions/compounds responsible for this effect. FJ was fractionated using standard chromatography procedures. Hepatic (H4IIE, HepG2) and skeletal muscle cells (C2C12) were treated with maximum non-toxic concentrations of FJ, fractions and isolated compounds thereof. Glucose-6-phosphatase (G6Pase) activity was measured using glucose oxidase method. To measure glucose uptake and glycogen synthase (GS) activity, radioactive assays were used. Fractionation of FJ yielded seven fractions. FJ and its phenolic fractions F2, F3-1 and F3-2 respectively inhibited G-6Pase by 31, 45, 51 and 26%; activated GS by 2.3-, 2.3-, 2.2- and 2-fold; and stimulated glucose uptake by 19, 25, 18 and 15%, as compared to DMSO ...
Puberty is an important developmental event that is marked by the reorganizing and remodeling of ... more Puberty is an important developmental event that is marked by the reorganizing and remodeling of the brain. Exposure to stress during this critical period of development can have enduring effects on both reproductive and non-reproductive behaviors. The purpose of this study was to investigate age and sex differences in immune response by examining sickness behavior, body temperature changes, and serum cytokine levels following an immune challenge. The effects of circulating gonadal hormones on age and sex differences in immune response were also examined. Results showed that male mice display more sickness behavior and greater fluctuations in body temperature following LPS treatment than female mice. Moreover, adult male mice display more sickness behavior and a greater drop in body temperature following LPS treatment compared to pubertal male mice. Following gonadectomy, pubertal and adult males displayed steeper and prolonged drops in body temperature compared to sham-operated counterparts. Gonadectomy did not eliminate sex differences in LPS-induced body temperature changes, suggesting that additional factors contribute to the observed differences. LPS treatment increased cytokine levels in all mice. However, the increase in pro-inflammatory cytokines was higher in adult compared to pubertal mice, while the increase in anti-inflammatory cytokines was greater in pubertal than in adult mice. Our findings contribute to a better understanding of age and sex differences in acute immune response following LPS treatment and possible mechanisms involved in the enduring alterations in behavior and brain function following pubertal exposure to LPS.
Administration of kefir and a kefir cell-free fraction (KF) to mice injected with breast tumor ce... more Administration of kefir and a kefir cell-free fraction (KF) to mice injected with breast tumor cells produced, locally in the mammary gland, different profiles of cells secreting cytokines. Here, the immune cell populations in mammary glands affected by the cyclic consumption of kefir or KF for 2 or 7 d were evaluated using a breast tumor model. Apoptosis was also assayed as another mechanism involved in tumor growth delay. The rate development of tumor cells, IgA(+) cells, and CD4+ and CD8+ T lymphocytes was monitored in mammary gland tissues. The number of Bcl-2(+) cells in the mammary gland was compared with the apoptosis observed in the tumor. Two-day cyclical administration of both products delayed tumor growth and increased the number of IgA(+) cells in the mammary gland. Changes in the balance between CD4+ and CD8+ cells in the mammary gland were observed in mice from the group fed KF cyclically for 2 d, such that the number of CD4+ cells increased when the number of CD8+ cel...
The antimutagenic effects of whey, acetone extracts, and protein fractions isolated from milk tha... more The antimutagenic effects of whey, acetone extracts, and protein fractions isolated from milk that had been fermented by Lactobacillus helveticus L89 were investigated using the mutagen 4-nitroquinoline-N'-oxide in the Ames test (Salmonella typhimurium TA 100). Fermented milk significantly inhibited mutagenesis induced by 4-nitroquinoline-N'-oxide. However, milk fermented by a nonproteolytic variant of the same strain showed no inhibitory effects. Results were similar for the whey fractions and acetone extracts of the fermented milks. After fermentation, milk proteins were fractionated by size-exclusion HPLC and were tested for antimutagenicity. The fraction showing the greatest activity was further analyzed by reverse-phase HPLC. Our results indicate that antimutagenic compounds are produced in milk during fermentation by L. helveticus, and the release of peptides is one possible contributing mechanism.
This study evaluated the effect of protein hydrolysis by lactic acid bacteria during milk ferment... more This study evaluated the effect of protein hydrolysis by lactic acid bacteria during milk fermentation on the release of amino acids and peptides duing subsequently simulated peptic and pancreatic digestion. After digestion with trypsin, we compared the elution patterns of proteins and peptides obtained from unfermented milk and from milk fermented by Lactobacillus helveticus under pH control, using HPLC gel filtration and reverse-phase HPLC. The results indicate that milk fermentation affects the release of some amino acids during simulated gastrointestinal digestion and has a major impact on the modification of protein elution profiles obtained after digestion with trypsin. We conclude that proteolysis during fermentation may lead to the formation of novel peptides during gastrointestinal digestion.
Active Hexose Correlated Compound (AHCC(®)) is a cultured mushroom extract that is commercially a... more Active Hexose Correlated Compound (AHCC(®)) is a cultured mushroom extract that is commercially available and promoted for immune support. Available data suggest that AHCC supplementation affects immune cell populations and immune outcomes, including natural killer cell response to infection. The mechanism by which AHCC exerts its effects is not well understood. The present work aimed to characterize the immunomodulatory activity of AHCC in the gut and to study the effects of AHCC on toll-like receptor (TLR) signaling in intestinal epithelial cells (IECs). BALB/c mice were fed AHCC by gavage. In vivo activities were assessed by immunohistochemistry and cytokine production. The effects of AHCC on ex vivo primary cell culture from IECs were examined after challenge with LPS or E. coli alone or in the presence of anti-TLR-2 and TLR-4 blocking antibodies. Feeding AHCC resulted in increased IgA+ cells in the intestine and increased sIgA, IL-10, and IFN-γ in the intestinal fluid. In IECs,...
Lactic acid bacteria (LAB) are present in many foods such as yoghurt and are frequently used as p... more Lactic acid bacteria (LAB) are present in many foods such as yoghurt and are frequently used as probiotics to favour some biological functions in the host. Many investigators have evaluated the therapeutic effects of yoghurt and LAB commonly used in yoghurt production against diseases such as cancer, infection, and gastrointestinal disorders. The increase of immune cell activity in the prevention of cancer by LAB consumption has also been described. Another possible explanation for the preventive effect of probiotics on carcinogenesis is their effect on other bacteria in the intestine. Probiotics may suppress the growth of bacteria that convert procarcinogens into carcinogens, thereby reducing the amount of carcinogens in the intestine. The present review is focused on two types of cancer in which milk fermented by LAB may show a beneficial effect: colon cancer and breast cancer
A growing body of evidence supports the therapeutic effects of blueberry in neurodegenerative dis... more A growing body of evidence supports the therapeutic effects of blueberry in neurodegenerative disorders. Biotransformation of blueberry juice by Serratia vaccinii bacteria increases its phenolic content and antioxidant activity. In neuronal cell culture, biotransformed blueberry juice (BJ) significantly increased the activity of antioxidant enzymes, namely catalase and superoxide dismutase. Moreover, BJ protected neurons against H2O2-induced cell death in a dose-dependent manner. This associated with the upregulation of mitogen-activated protein kinase (MAPK) family enzymes p38 and c-Jun N-terminal kinase (JNK) activation, as well as with the protection of extracellular signal-regulated kinase (ERK1/2) and MAPK/ERK kinase (MEK1/2) activity loss induced by H2O2. The present studies demonstrate that BJ can protect neurons against oxidative stress possibly by increasing antioxidant enzyme activities and activating p38- and JNK-dependent survival pathways while blocking MEK1/2- and ERK1...
Canadian Journal of Physiology and Pharmacology, 2007
Extracts of the Canadian lowbush blueberry ( Vaccinium angustifolium Ait.) have recently been dem... more Extracts of the Canadian lowbush blueberry ( Vaccinium angustifolium Ait.) have recently been demonstrated to possess significant antidiabetic potential, in accordance with the traditional use of this plant as an antidiabetic natural health product. Fermentation of blueberry juice with the Serratia vaccinii bacterium is known to modify the phenolic content and increase antioxidant activity. The present study evaluated the effects of fermented blueberry juice on glucose uptake, adipogenesis, and the signaling pathways that regulate glucose transport in muscle cells and adipocytes. A 6-hour treatment with fermented juice potentiated glucose uptake by 48% in C2C12 myotubes and by 142% in 3T3-L1 adipocytes, in the presence or absence of insulin, whereas nonfermented juice had no effect on transport. Fermented juice dramatically inhibited triglyceride content during adipogenesis of 3T3-L1 cells. Chlorogenic acid and gallic acid, both major phenolic components of fermented juice, had no e...
Fermented plant foods are gaining wide interest worldwide as healthy foods due to their unique se... more Fermented plant foods are gaining wide interest worldwide as healthy foods due to their unique sensory features and their health-promoting potentials, such as antiobesity, antidiabetic, antihypertensive, and anticarcinogenic activities. Many fermented foods are a rich source of nutrients, phytochemicals, bioactive compounds, and probiotic microbes. The excellent biological activities of these functional foods, such as anti-inflammatory and immunomodulatory functions, are widely attributable to their high antioxidant content and lactic acid-producing bacteria (LAB). LAB contribute to the maintenance of a healthy gut microbiota composition and improvement of local and systemic immunity. Besides, antioxidant compounds are involved in several functional properties of fermented plant products by neutralizing free radicals, regulating antioxidant enzyme activities, reducing oxidative stress, ameliorating inflammatory responses, and enhancing immune system performance. Therefore, these pro...
The probiotic effects ascribed to lactic acid bacteria (LAB) and their fermented dairy products a... more The probiotic effects ascribed to lactic acid bacteria (LAB) and their fermented dairy products arise not only from whole microorganisms and cell wall components but also from peptides and extracellular polysaccharides (exopolysaccharides) produced during the fermentation of milk. There is a lack of knowledge concerning the immune mechanisms induced by exopolysaccharides produced by lactic acid bacteria, which would allow a better understanding of the functional effects described to them. The aim of this study was to investigate the in vivo immunomodulating capacity of the exopolysaccharide produced by Lactobacillus kefiranofaciens by analyzing the profile of cytokines and immunoglobulins induced at the intestinal mucosa level, in the intestinal fluid and blood serum. BALB/c mice received the exopolysaccharide produced by L. kefiranofaciens for 2, 5 or 7 consecutive days. At the end of each period of administration, control and treated mice were sacrificed and the numbers of IgA+ and IgG+ cells were determined on histological slices of the small and large intestine by immunofluorescence. Cytokines (IL-4, IL-6, IL-10, IL-12, IFNgamma and TNFalpha) were also determined in the gut lamina propria as well as in the intestinal fluid and blood serum. There was an increase of IgA+ cells in the small and large intestine lamina propria, without change in the number of IgG+ cells in the small intestine. This study reports the effects of the oral administration of the exopolysaccharide produced by L. kefiranofaciens in the number of IgA+ cells in the small and large intestine, comparing simultaneously the production of cytokines by cells of the lamina propria and in the intestinal fluid and blood serum. The increase in the number of IgA+ cells was not simultaneously accompanied by an enhance of the number of IL-4+ cells in the small intestine. This finding would be in accordance with the fact that, in general, polysaccharide antigens elicit a T-independent immune response. For IL-10+, IL-6+ and IL-12+ cells, the values found were slightly increased compared to control values, while IFNgamma+ and TNFalpha+ cells did not change compared to control values. The effects observed on immunoglobulins and in all the cytokines assayed in the large intestine after kefiran administration were of greater magnitude than the ones observed in the small intestine lamina propria, which may be due to the saccharolytic action of the colonic microflora. In the intestinal fluid, only IL-4 and IL-12 increased compared to control values. In blood serum, all the cytokines assayed followed a pattern of production quite similar to the one found for them in the small intestine lamina propria. We observed that the exopolysaccharide induced a gut mucosal response and it was able to up and down regulate it for protective immunity, maintaining intestinal homeostasis, enhancing the IgA production at both the small and large intestine level and influencing the systemic immunity through the cytokines released to the circulating blood.
Despite sequence similarity to SARS-CoV-1, SARS-CoV-2 has demonstrated greater widespread virulen... more Despite sequence similarity to SARS-CoV-1, SARS-CoV-2 has demonstrated greater widespread virulence and unique challenges to researchers aiming to study its pathogenicity in humans. The interaction of the viral receptor binding domain (RBD) with its main host cell receptor, angiotensin-converting enzyme 2 (ACE2), has emerged as a critical focal point for the development of anti-viral therapeutics and vaccines. In this study, we selectively identify and characterize the impact of mutating certain amino acid residues in the RBD of SARS-CoV-2 and in ACE2, by utilizing our recently developed NanoBiT technology-based biosensor as well as pseudotyped-virus infectivity assays. Specifically, we examine the mutational effects on RBD-ACE2 binding ability, efficacy of competitive inhibitors, as well as neutralizing antibody activity. We also look at the implications the mutations may have on virus transmissibility, host susceptibility, and the virus transmission path to humans. These critical ...
Inflammation is a biological response to the activation of the immune system by various infectiou... more Inflammation is a biological response to the activation of the immune system by various infectious or non-infectious agents, which may lead to tissue damage and various diseases. Gut commensal bacteria maintain a symbiotic relationship with the host and display a critical function in the homeostasis of the host immune system. Disturbance to the gut microbiota leads to immune dysfunction both locally and at distant sites, which causes inflammatory conditions not only in the intestine but also in the other organs such as lungs and brain, and may induce a disease state. Probiotics are well known to reinforce immunity and counteract inflammation by restoring symbiosis within the gut microbiota. As a result, probiotics protect against various diseases, including respiratory infections and neuroinflammatory disorders. A growing body of research supports the beneficial role of probiotics in lung and mental health through modulating the gut-lung and gut-brain axes. In the current paper, we ...
This review offers a systematic understanding about how polyphenols target multiple inflammatory ... more This review offers a systematic understanding about how polyphenols target multiple inflammatory components and lead to anti-inflammatory mechanisms. It provides a clear understanding of the molecular mechanisms of action of phenolic compounds. Polyphenols regulate immunity by interfering with immune cell regulation, proinflammatory cytokines’ synthesis, and gene expression. They inactivate NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) and modulate mitogen-activated protein Kinase (MAPk) and arachidonic acids pathways. Polyphenolic compounds inhibit phosphatidylinositide 3-kinases/protein kinase B (PI3K/AkT), inhibitor of kappa kinase/c-Jun amino-terminal kinases (IKK/JNK), mammalian target of rapamycin complex 1 (mTORC1) which is a protein complex that controls protein synthesis, and JAK/STAT. They can suppress toll-like receptor (TLR) and pro-inflammatory genes’ expression. Their antioxidant activity and ability to inhibit enzymes involved in the productio...
BMC complementary and alternative medicine, Jan 4, 2017
We recently reported that blueberry juice fermented (FJ) with Serratia vaccinii bacterium has ant... more We recently reported that blueberry juice fermented (FJ) with Serratia vaccinii bacterium has antidiabetic activities both in vivo and in vitro. The purpose of this project was to elucidate the effect of FJ on glucose homeostasis in liver and skeletal muscle cells and to identify active fractions/compounds responsible for this effect. FJ was fractionated using standard chromatography procedures. Hepatic (H4IIE, HepG2) and skeletal muscle cells (C2C12) were treated with maximum non-toxic concentrations of FJ, fractions and isolated compounds thereof. Glucose-6-phosphatase (G6Pase) activity was measured using glucose oxidase method. To measure glucose uptake and glycogen synthase (GS) activity, radioactive assays were used. Fractionation of FJ yielded seven fractions. FJ and its phenolic fractions F2, F3-1 and F3-2 respectively inhibited G-6Pase by 31, 45, 51 and 26%; activated GS by 2.3-, 2.3-, 2.2- and 2-fold; and stimulated glucose uptake by 19, 25, 18 and 15%, as compared to DMSO ...
Puberty is an important developmental event that is marked by the reorganizing and remodeling of ... more Puberty is an important developmental event that is marked by the reorganizing and remodeling of the brain. Exposure to stress during this critical period of development can have enduring effects on both reproductive and non-reproductive behaviors. The purpose of this study was to investigate age and sex differences in immune response by examining sickness behavior, body temperature changes, and serum cytokine levels following an immune challenge. The effects of circulating gonadal hormones on age and sex differences in immune response were also examined. Results showed that male mice display more sickness behavior and greater fluctuations in body temperature following LPS treatment than female mice. Moreover, adult male mice display more sickness behavior and a greater drop in body temperature following LPS treatment compared to pubertal male mice. Following gonadectomy, pubertal and adult males displayed steeper and prolonged drops in body temperature compared to sham-operated counterparts. Gonadectomy did not eliminate sex differences in LPS-induced body temperature changes, suggesting that additional factors contribute to the observed differences. LPS treatment increased cytokine levels in all mice. However, the increase in pro-inflammatory cytokines was higher in adult compared to pubertal mice, while the increase in anti-inflammatory cytokines was greater in pubertal than in adult mice. Our findings contribute to a better understanding of age and sex differences in acute immune response following LPS treatment and possible mechanisms involved in the enduring alterations in behavior and brain function following pubertal exposure to LPS.
Administration of kefir and a kefir cell-free fraction (KF) to mice injected with breast tumor ce... more Administration of kefir and a kefir cell-free fraction (KF) to mice injected with breast tumor cells produced, locally in the mammary gland, different profiles of cells secreting cytokines. Here, the immune cell populations in mammary glands affected by the cyclic consumption of kefir or KF for 2 or 7 d were evaluated using a breast tumor model. Apoptosis was also assayed as another mechanism involved in tumor growth delay. The rate development of tumor cells, IgA(+) cells, and CD4+ and CD8+ T lymphocytes was monitored in mammary gland tissues. The number of Bcl-2(+) cells in the mammary gland was compared with the apoptosis observed in the tumor. Two-day cyclical administration of both products delayed tumor growth and increased the number of IgA(+) cells in the mammary gland. Changes in the balance between CD4+ and CD8+ cells in the mammary gland were observed in mice from the group fed KF cyclically for 2 d, such that the number of CD4+ cells increased when the number of CD8+ cel...
The antimutagenic effects of whey, acetone extracts, and protein fractions isolated from milk tha... more The antimutagenic effects of whey, acetone extracts, and protein fractions isolated from milk that had been fermented by Lactobacillus helveticus L89 were investigated using the mutagen 4-nitroquinoline-N'-oxide in the Ames test (Salmonella typhimurium TA 100). Fermented milk significantly inhibited mutagenesis induced by 4-nitroquinoline-N'-oxide. However, milk fermented by a nonproteolytic variant of the same strain showed no inhibitory effects. Results were similar for the whey fractions and acetone extracts of the fermented milks. After fermentation, milk proteins were fractionated by size-exclusion HPLC and were tested for antimutagenicity. The fraction showing the greatest activity was further analyzed by reverse-phase HPLC. Our results indicate that antimutagenic compounds are produced in milk during fermentation by L. helveticus, and the release of peptides is one possible contributing mechanism.
This study evaluated the effect of protein hydrolysis by lactic acid bacteria during milk ferment... more This study evaluated the effect of protein hydrolysis by lactic acid bacteria during milk fermentation on the release of amino acids and peptides duing subsequently simulated peptic and pancreatic digestion. After digestion with trypsin, we compared the elution patterns of proteins and peptides obtained from unfermented milk and from milk fermented by Lactobacillus helveticus under pH control, using HPLC gel filtration and reverse-phase HPLC. The results indicate that milk fermentation affects the release of some amino acids during simulated gastrointestinal digestion and has a major impact on the modification of protein elution profiles obtained after digestion with trypsin. We conclude that proteolysis during fermentation may lead to the formation of novel peptides during gastrointestinal digestion.
Active Hexose Correlated Compound (AHCC(®)) is a cultured mushroom extract that is commercially a... more Active Hexose Correlated Compound (AHCC(®)) is a cultured mushroom extract that is commercially available and promoted for immune support. Available data suggest that AHCC supplementation affects immune cell populations and immune outcomes, including natural killer cell response to infection. The mechanism by which AHCC exerts its effects is not well understood. The present work aimed to characterize the immunomodulatory activity of AHCC in the gut and to study the effects of AHCC on toll-like receptor (TLR) signaling in intestinal epithelial cells (IECs). BALB/c mice were fed AHCC by gavage. In vivo activities were assessed by immunohistochemistry and cytokine production. The effects of AHCC on ex vivo primary cell culture from IECs were examined after challenge with LPS or E. coli alone or in the presence of anti-TLR-2 and TLR-4 blocking antibodies. Feeding AHCC resulted in increased IgA+ cells in the intestine and increased sIgA, IL-10, and IFN-γ in the intestinal fluid. In IECs,...
Lactic acid bacteria (LAB) are present in many foods such as yoghurt and are frequently used as p... more Lactic acid bacteria (LAB) are present in many foods such as yoghurt and are frequently used as probiotics to favour some biological functions in the host. Many investigators have evaluated the therapeutic effects of yoghurt and LAB commonly used in yoghurt production against diseases such as cancer, infection, and gastrointestinal disorders. The increase of immune cell activity in the prevention of cancer by LAB consumption has also been described. Another possible explanation for the preventive effect of probiotics on carcinogenesis is their effect on other bacteria in the intestine. Probiotics may suppress the growth of bacteria that convert procarcinogens into carcinogens, thereby reducing the amount of carcinogens in the intestine. The present review is focused on two types of cancer in which milk fermented by LAB may show a beneficial effect: colon cancer and breast cancer
A growing body of evidence supports the therapeutic effects of blueberry in neurodegenerative dis... more A growing body of evidence supports the therapeutic effects of blueberry in neurodegenerative disorders. Biotransformation of blueberry juice by Serratia vaccinii bacteria increases its phenolic content and antioxidant activity. In neuronal cell culture, biotransformed blueberry juice (BJ) significantly increased the activity of antioxidant enzymes, namely catalase and superoxide dismutase. Moreover, BJ protected neurons against H2O2-induced cell death in a dose-dependent manner. This associated with the upregulation of mitogen-activated protein kinase (MAPK) family enzymes p38 and c-Jun N-terminal kinase (JNK) activation, as well as with the protection of extracellular signal-regulated kinase (ERK1/2) and MAPK/ERK kinase (MEK1/2) activity loss induced by H2O2. The present studies demonstrate that BJ can protect neurons against oxidative stress possibly by increasing antioxidant enzyme activities and activating p38- and JNK-dependent survival pathways while blocking MEK1/2- and ERK1...
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Papers by Chantal Matar