Dai Hung Ngo - Academia.edu (original) (raw)

Papers by Dai Hung Ngo

Research paper thumbnail of Mechanism of Action of Mangifera indica Leaves for Anti-Diabetic Activity

Scientia Pharmaceutica

Diabetes is a major metabolic disorder whose prevalence is increasing daily. Medicinal plants hav... more Diabetes is a major metabolic disorder whose prevalence is increasing daily. Medicinal plants have played an important role in the prevention and treatment of type 2 diabetes via prophylactic and therapeutic management. In this study, Mangifera Indica leaf (MIL) extract was investigated for its promising anti-diabetic activity via an in vitro model. It was found that MIL extract possessed significant inhibition on alpha-amylase activity up to (51.4 ± 2.7)% at a concentration of 200 µg/mL. Moreover, glucose adsorption capacity of MIL was identified at (2.7 ± 0.19) mM glucose/g extract. Furthermore, the extract caused a significant increase in glucose uptake up to (143 ± 9.3)% in LO-2 liver cells. Notably, MIL extract was effective in scavenging (63.3 ± 2.1)% 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and (71.6 ± 4.3)% 2,2-azinobis-3-ethyl benzothiazoline-6-sulfonic acid (ABTS)+ radicals and inhibiting (66 ± 4.9)% NO production from RAW264.7 cells without any cytotoxicity effects. Accordin...

Research paper thumbnail of The Health Beneficial Properties of Rhodomyrtus tomentosa as Potential Functional Food

Biomolecules

Rhodomyrtus tomentosa (Aiton) Hassk. is a flowering plant belonging to the family Myrtaceae, nati... more Rhodomyrtus tomentosa (Aiton) Hassk. is a flowering plant belonging to the family Myrtaceae, native to southern and southeastern Asia. It has been used in traditional Vietnamese, Chinese, and Malaysian medicine for a long time for the treatment of diarrhea, dysentery, gynecopathy, stomachache, and wound healing. Moreover, R. tomentosa is used to make various food products such as wine, tea, and jam. Notably, R. tomentosa has been known to contain structurally diverse and biologically active metabolites, thus serving as a potential resource for exploring novel functional agents. Up to now, numerous phenolic and terpenoid compounds from the leaves, root, or fruits of R. tomentosa have been identified, and their biological activities such as antioxidant, antibacterial, anti-inflammatory, and anticancer have been evidenced. In this contribution, an overview of R. tomentosa and its health beneficial properties was focused on and emphasized.

Research paper thumbnail of The Suppressive Activity of Fucofuroeckol-A Derived from Brown Algal Ecklonia stolonifera Okamura on UVB-Induced Mast Cell Degranulation

Marine drugs, Jan 4, 2018

UV light, especially UVB, is known as a trigger of allergic reaction, leading to mast cell degran... more UV light, especially UVB, is known as a trigger of allergic reaction, leading to mast cell degranulation and histamine release. In this study, phlorotannin Fucofuroeckol-A (F-A) derived from brown algal Ecklonia stolonifera Okamura was evaluated for its protective capability against UVB-induced allergic reaction in RBL-2H3 mast cells. It was revealed that F-A significantly suppress mast cell degranulation via decreasing histamine release as well as intracellular Ca2+ elevation at the concentration of 50 μM. Moreover, the inhibitory effect of F-A on IL-1β and TNF-α productions was also evidenced. Notably, the protective activity of F-A against mast cell degranulation was found due to scavenging ROS production. Accordingly, F-A from brown algal E. stolonifera was suggested to be promising candidate for its protective capability against UVB-induced allergic reaction.

Research paper thumbnail of 12 Chapter Bioprocessing of Marine products for Nutraceuticals and Functional Food products

Research paper thumbnail of Marine Algae

Trends and Applications, 2012

Research paper thumbnail of Biological effects of chitosan and its derivatives

Food Hydrocolloids, 2015

ABSTRACT Chitosan is a natural nontoxic biopolymer produced by alkaline deacetylation of chitin. ... more ABSTRACT Chitosan is a natural nontoxic biopolymer produced by alkaline deacetylation of chitin. Chitin and chitosan are insoluble in water as well as most organic solvents. Chito-oligomers (COS), depolymerized products of chitosan, has received much attention in biomedical, food, pharmaceutical, agricultural and environmental industries due to their biocompatible, biodegradable, non-toxic and non-allergenic natures. Chitosan and its derivatives have been shown to possess diverse biological activities, including antioxidant, anti-hypertensive, anti-coagulant, anti-diabetic, anti-obesity, anti-allergic, anti-inflammatory, anti-microbial, anti-cancer, neuroprotective and matrix metalloproteinases inhibitory effects. Thus, this overview mainly focuses on biological effects of chitosan and its derivatives as well as presents their potential applications as ingredients in functional foods and nutraceuticals for the prevention or treatment of chronic diseases.

Research paper thumbnail of The role of myricetin from Rhodomyrtus tomentosa (Aiton) Hassk fruits on downregulation of FcɛRI‐mediated mast cell activation

Journal of Food Biochemistry

Research paper thumbnail of An Updated Review on Pharmaceutical Properties of Gamma-Aminobutyric Acid

Molecules

Gamma-aminobutyric acid (Gaba) is a non-proteinogenic amino acid that is widely present in microo... more Gamma-aminobutyric acid (Gaba) is a non-proteinogenic amino acid that is widely present in microorganisms, plants, and vertebrates. So far, Gaba is well known as a main inhibitory neurotransmitter in the central nervous system. Its physiological roles are related to the modulation of synaptic transmission, the promotion of neuronal development and relaxation, and the prevention of sleeplessness and depression. Besides, various pharmaceutical properties of Gaba on non-neuronal peripheral tissues and organs were also reported due to anti-hypertension, anti-diabetes, anti-cancer, antioxidant, anti-inflammation, anti-microbial, anti-allergy, hepato-protection, reno-protection, and intestinal protection. Therefore, Gaba may be considered as potential alternative therapeutics for prevention and treatment of various diseases. Accordingly, this updated review was mainly focused to describe the pharmaceutical properties of Gaba as well as emphasize its important role regarding human health.

Research paper thumbnail of Investigation of Biological Activities of Wild Bitter Melon (Momordica charantia Linn. Var. Abbreviata Ser.)

Biomolecules

Wild bitter melon (Momordica charantia L. var. Abbreviata Ser.) is a wild edible variety of M. ch... more Wild bitter melon (Momordica charantia L. var. Abbreviata Ser.) is a wild edible variety of M. charantia, often used in folk medicine. In this study, the biological activities of its extract and fractions were investigated in vitro. It was found that ethyl acetate (EA) fraction exhibited high 1,1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging activity with a half maximal inhibitory concentration (IC50) value of 0.43 ± 0.04 mg/mL, while the chloroform (CF), EA, and n-butanol (Bu) fractions had strong 2,2-azinobis-3-ethyl benzothiazoline-6-sulfonic acid (ABTS)+ scavenging ability with IC50 values of 0.36 ± 0.04 mg/mL, 0.35 ± 0.02 mg/mL, and 0.35 ± 0.05 mg/mL, respectively. Moreover, the EA and Bu fractions exhibited the highest protective effect against H2O2-induced DNA damage in a concentration-dependent manner. Furthermore, the EA fraction was effective in the inhibition of enzyme α-amylase activity with an IC50 value of 0.27 ± 0.029 mg/mL. Finally, it was observed that the production...

Research paper thumbnail of Spirulina maxima peptides suppress mast cell degranulation via inactivating Akt and MAPKs phosphorylation in RBL-2H3 cells

International journal of biological macromolecules, Jan 14, 2018

In this study, the suppressive effects of peptides P1 (LDAVNR) and P2 (MMLDF) from enzymatic hydr... more In this study, the suppressive effects of peptides P1 (LDAVNR) and P2 (MMLDF) from enzymatic hydrolysate of Spirulina maxima on mast cell degranulation was elucidated. It was revealed that P1 and P2 exhibited significant inhibition on cell degranulation via decreasing β-hexosaminidase release at concentration of 200 μM. Moreover, the inhibitory effects of P1 and P2 on expression and production of interleukin (IL)-13 were evidenced. Furthermore, peptide treatment caused a remarkable inhibition on the phosphorylation of Akt and mitogen-activated protein kinases (MAPKs) including ERK, p38, and JNK. Notably, the inhibitory activity of P1 on cell degranulation was found due to blockade of FcεRI receptor. Meanwhile, the inhibitory activity of P2 was involved in alleviation of intracellular reactive oxygen species (ROS) production. Collectively, peptides P1 and P2 from S. maxima were suggested to be promising inhibitors of mast cell degranulation, contributing to the development of bioacti...

Research paper thumbnail of 4-hydroxybenzaldehyde-chitooligomers suppresses H2O2-induced oxidative damage in microglia BV-2 cells

Carbohydrate research, Jan 22, 2017

Positive charges of chitooligomer (COS) enable COS to interact with negatively charged anionic gr... more Positive charges of chitooligomer (COS) enable COS to interact with negatively charged anionic groups on the cell surface resulting in an improvement in the biological activity of COS and its derivatives. In this study, 4-hydroxybenzaldehyde-COS (HB-COS) was synthesized and investigated for its abilities against H2O2-induced oxidative stress in microglia BV-2 cells. Under oxidative stress, HB-COS significantly attenuated reactive oxygen species (ROS) generation and DNA oxidation, and upregulated the protein levels of antioxidative enzymes. HB-COS is therefore proposed as a potential protective agent against neuronal damage.

Research paper thumbnail of The free radical scavenging and anti-inflammatory activities of gallate-chitooligosaccharides in human lung epithelial A549 cells

Process Biochemistry, 2017

Research paper thumbnail of Prevention of H2O2-induced oxidative stress in murine microglial BV-2 cells by chitin-oligomers

Process Biochemistry, 2016

Research paper thumbnail of Angiotensin- I- converting enzyme (ACE) inhibitory peptides from Pacific cod skin gelatin using ultrafiltration membranes

Process Biochemistry, 2016

Research paper thumbnail of Protective effects of peptides from skate (Okamejei kenojei) skin gelatin against endothelial dysfunction

Journal of Functional Foods, 2014

ABSTRACT Seafood processing by-product, skate (Okamejei kenojei) skin, was utilized to isolate ac... more ABSTRACT Seafood processing by-product, skate (Okamejei kenojei) skin, was utilized to isolate active peptides with antihypertensive effect. Two peptides (MVGSAPGVL, 829 Da and LGPLGHQ, 720 Da) were purified from skate skin gelatin. In human endothelial cells, nitric oxide (NO) synthesis was found to be increased and eNOS phosphorylation was upregulated by the peptides. The peptides exhibited inhibitory activities on the production and expression of IL-6. Furthermore, the peptides down-regulated the expression levels of endothelin-1. The peptides inhibited the NF-κB and the phosphorylation of MAPK pathways. In addition, the activation of the PI3K/Akt pathway by the peptides was confirmed. The present study demonstrated that the purified peptides had vasorelaxant effects via endothelium-dependent NO signaling through activation of the PI3K/Akt-eNOS pathway and inhibition of the NF-κB and MAPK pathways. The purified peptides could be used in the food industry as functional ingredients with potent benefits in reducing the risk of cardiovascular diseases.

Research paper thumbnail of Angiotensin-I converting enzyme inhibitory peptides from antihypertensive skate (Okamejei kenojei) skin gelatin hydrolysate in spontaneously hypertensive rats

Food chemistry, 2015

The aim of this study was to investigate antihypertensive effect of bioactive peptides from skate... more The aim of this study was to investigate antihypertensive effect of bioactive peptides from skate (Okamejei kenojei) skin gelatin. The Alcalase/protease gelatin hydrolysate below 1 kDa (SAP) exhibited the highest angiotensin-I converting enzyme (ACE) inhibition compared to other hydrolysates. SAP can decrease systolic blood pressure significantly in spontaneously hypertensive rats. SAP inhibited vasoconstriction via PPAR-γ expression, activation and phosphorylation of eNOS in lungs. Moreover, the expression levels of endothelin-1, RhoA, α-smooth muscle actin, cleaved caspase 3 and MAPK were decreased by SAP in lungs. Vascularity, muscularization and cellular proliferation in lungs were detected by immunohistochemical staining. Finally, two purified peptides (LGPLGHQ, 720Da and MVGSAPGVL, 829Da) showed potent ACE inhibition with IC50 values of 4.22 and 3.09 μM, respectively. These results indicate that bioactive peptides isolated from skate skin gelatin may serve as candidates agains...

Research paper thumbnail of Antioxidant Effects of Chitin, Chitosan, and Their Derivatives

Advances in Food and Nutrition Research, 2014

Chitin, chitosan, and their derivatives are considered to promote diverse activities, including a... more Chitin, chitosan, and their derivatives are considered to promote diverse activities, including antioxidant, antihypertensive, anti-inflammatory, anticoagulant, antitumor and anticancer, antimicrobial, hypocholesterolemic, and antidiabetic effects, one of the most crucial of which is the antioxidant effect. By modulating and improving physiological functions, chitin, chitosan, and their derivatives may provide novel therapeutic applications for the prevention or treatment of chronic diseases. Antioxidant activity of chitin, chitosan, and their derivatives can be attributed to in vitro and in vivo free radical-scavenging activities. Antioxidant effect of chitin, chitosan, and their derivatives may be used as functional ingredients in food formulations to promote consumer health and to improve the shelf life of food products. This chapter presents an overview of the antioxidant activity of chitin, chitosan, and their derivatives with the potential utilization in the food and pharmaceutical industries.

Research paper thumbnail of Role of Chitosan and Its Derivatives in Cardiovascular Health

Advances in Drug Discovery and Developments, 2013

Research paper thumbnail of The role of peptides derived from Spirulina maxima in downregulation of FcεRI-mediated allergic responses

Molecular Nutrition & Food Research, 2014

Spirulina has been found suitable for use as a bioactive additive. It is an excellent source of p... more Spirulina has been found suitable for use as a bioactive additive. It is an excellent source of protein that can be hydrolyzed into bioactive peptides. Two peptides LDAVNR (P1) and MMLDF (P2) purified from enzymatic hydrolysate of Spirulina maxima have been reported to be effective against early atherosclerotic responses. In this study, the intracellular mechanism involved in the downregulation of these peptides on high-affinity IgE receptor-mediated allergic reaction was further investigated. RBL-2H3 mast cells were pretreated with P1 or P2 and sensitized with dinitrophenyl-specific IgE antibody before stimulation of antigen dinitrophenyl-BSA. It was revealed that P1 and P2 exhibited significant inhibition on mast-cell degranulation via decreasing histamine release and intracellular Ca(2+) elevation. The inhibitory activity of P1 was found due to blockade of calcium- and microtubule-dependent signaling pathways. Meanwhile, the inhibition of P2 was involved in suppression of phospholipase Cγ activation and reactive oxygen species production. Moreover, the suppressive effects of P1 and P2 on generation of IL-4 were evidenced via depression of nuclear factor-κB translocation. These findings indicate that peptides P1 and P2 from S. maxima may be promising candidates of antiallergic therapeutics, contributing to development of bioactive food ingredients for amelioration of allergic diseases.

Research paper thumbnail of The beneficial properties of marine polysaccharides in alleviation of allergic responses

Molecular Nutrition & Food Research, 2014

Marine polysaccharides have been found as the principle component in cell wall structures of seaw... more Marine polysaccharides have been found as the principle component in cell wall structures of seaweeds or exoskeletons of crustaceans. Due to numerous pharmaceutical properties of marine polysaccharides such as antioxidant, anti-inflammatory, antiallergic, antitumor, antiobesity, antidiabetes, anticoagulant, antiviral, immunomodulatory, cardioprotective, and antihepatopathy activities, they have been applied in many fields of biomaterials, food, cosmetic, and pharmacology. Recently, several marine polysaccharides such alginate, porphyran, fucoidan, and chitin and its derivatives have been evidenced as downregulators of allergic responses due to enhancement of innate immune system, alteration of Th1/Th2 balance forward to Th1 cells, inhibition of IgE production, and suppression of mast cell degranulation. This contribution, therefore, focuses on antiallergic properties of marine polysaccharides and emphasizes their potential application as bioactive food ingredients as well as nutraceuticals for prevention of allergic disorders.

Research paper thumbnail of Mechanism of Action of Mangifera indica Leaves for Anti-Diabetic Activity

Scientia Pharmaceutica

Diabetes is a major metabolic disorder whose prevalence is increasing daily. Medicinal plants hav... more Diabetes is a major metabolic disorder whose prevalence is increasing daily. Medicinal plants have played an important role in the prevention and treatment of type 2 diabetes via prophylactic and therapeutic management. In this study, Mangifera Indica leaf (MIL) extract was investigated for its promising anti-diabetic activity via an in vitro model. It was found that MIL extract possessed significant inhibition on alpha-amylase activity up to (51.4 ± 2.7)% at a concentration of 200 µg/mL. Moreover, glucose adsorption capacity of MIL was identified at (2.7 ± 0.19) mM glucose/g extract. Furthermore, the extract caused a significant increase in glucose uptake up to (143 ± 9.3)% in LO-2 liver cells. Notably, MIL extract was effective in scavenging (63.3 ± 2.1)% 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and (71.6 ± 4.3)% 2,2-azinobis-3-ethyl benzothiazoline-6-sulfonic acid (ABTS)+ radicals and inhibiting (66 ± 4.9)% NO production from RAW264.7 cells without any cytotoxicity effects. Accordin...

Research paper thumbnail of The Health Beneficial Properties of Rhodomyrtus tomentosa as Potential Functional Food

Biomolecules

Rhodomyrtus tomentosa (Aiton) Hassk. is a flowering plant belonging to the family Myrtaceae, nati... more Rhodomyrtus tomentosa (Aiton) Hassk. is a flowering plant belonging to the family Myrtaceae, native to southern and southeastern Asia. It has been used in traditional Vietnamese, Chinese, and Malaysian medicine for a long time for the treatment of diarrhea, dysentery, gynecopathy, stomachache, and wound healing. Moreover, R. tomentosa is used to make various food products such as wine, tea, and jam. Notably, R. tomentosa has been known to contain structurally diverse and biologically active metabolites, thus serving as a potential resource for exploring novel functional agents. Up to now, numerous phenolic and terpenoid compounds from the leaves, root, or fruits of R. tomentosa have been identified, and their biological activities such as antioxidant, antibacterial, anti-inflammatory, and anticancer have been evidenced. In this contribution, an overview of R. tomentosa and its health beneficial properties was focused on and emphasized.

Research paper thumbnail of The Suppressive Activity of Fucofuroeckol-A Derived from Brown Algal Ecklonia stolonifera Okamura on UVB-Induced Mast Cell Degranulation

Marine drugs, Jan 4, 2018

UV light, especially UVB, is known as a trigger of allergic reaction, leading to mast cell degran... more UV light, especially UVB, is known as a trigger of allergic reaction, leading to mast cell degranulation and histamine release. In this study, phlorotannin Fucofuroeckol-A (F-A) derived from brown algal Ecklonia stolonifera Okamura was evaluated for its protective capability against UVB-induced allergic reaction in RBL-2H3 mast cells. It was revealed that F-A significantly suppress mast cell degranulation via decreasing histamine release as well as intracellular Ca2+ elevation at the concentration of 50 μM. Moreover, the inhibitory effect of F-A on IL-1β and TNF-α productions was also evidenced. Notably, the protective activity of F-A against mast cell degranulation was found due to scavenging ROS production. Accordingly, F-A from brown algal E. stolonifera was suggested to be promising candidate for its protective capability against UVB-induced allergic reaction.

Research paper thumbnail of 12 Chapter Bioprocessing of Marine products for Nutraceuticals and Functional Food products

Research paper thumbnail of Marine Algae

Trends and Applications, 2012

Research paper thumbnail of Biological effects of chitosan and its derivatives

Food Hydrocolloids, 2015

ABSTRACT Chitosan is a natural nontoxic biopolymer produced by alkaline deacetylation of chitin. ... more ABSTRACT Chitosan is a natural nontoxic biopolymer produced by alkaline deacetylation of chitin. Chitin and chitosan are insoluble in water as well as most organic solvents. Chito-oligomers (COS), depolymerized products of chitosan, has received much attention in biomedical, food, pharmaceutical, agricultural and environmental industries due to their biocompatible, biodegradable, non-toxic and non-allergenic natures. Chitosan and its derivatives have been shown to possess diverse biological activities, including antioxidant, anti-hypertensive, anti-coagulant, anti-diabetic, anti-obesity, anti-allergic, anti-inflammatory, anti-microbial, anti-cancer, neuroprotective and matrix metalloproteinases inhibitory effects. Thus, this overview mainly focuses on biological effects of chitosan and its derivatives as well as presents their potential applications as ingredients in functional foods and nutraceuticals for the prevention or treatment of chronic diseases.

Research paper thumbnail of The role of myricetin from Rhodomyrtus tomentosa (Aiton) Hassk fruits on downregulation of FcɛRI‐mediated mast cell activation

Journal of Food Biochemistry

Research paper thumbnail of An Updated Review on Pharmaceutical Properties of Gamma-Aminobutyric Acid

Molecules

Gamma-aminobutyric acid (Gaba) is a non-proteinogenic amino acid that is widely present in microo... more Gamma-aminobutyric acid (Gaba) is a non-proteinogenic amino acid that is widely present in microorganisms, plants, and vertebrates. So far, Gaba is well known as a main inhibitory neurotransmitter in the central nervous system. Its physiological roles are related to the modulation of synaptic transmission, the promotion of neuronal development and relaxation, and the prevention of sleeplessness and depression. Besides, various pharmaceutical properties of Gaba on non-neuronal peripheral tissues and organs were also reported due to anti-hypertension, anti-diabetes, anti-cancer, antioxidant, anti-inflammation, anti-microbial, anti-allergy, hepato-protection, reno-protection, and intestinal protection. Therefore, Gaba may be considered as potential alternative therapeutics for prevention and treatment of various diseases. Accordingly, this updated review was mainly focused to describe the pharmaceutical properties of Gaba as well as emphasize its important role regarding human health.

Research paper thumbnail of Investigation of Biological Activities of Wild Bitter Melon (Momordica charantia Linn. Var. Abbreviata Ser.)

Biomolecules

Wild bitter melon (Momordica charantia L. var. Abbreviata Ser.) is a wild edible variety of M. ch... more Wild bitter melon (Momordica charantia L. var. Abbreviata Ser.) is a wild edible variety of M. charantia, often used in folk medicine. In this study, the biological activities of its extract and fractions were investigated in vitro. It was found that ethyl acetate (EA) fraction exhibited high 1,1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging activity with a half maximal inhibitory concentration (IC50) value of 0.43 ± 0.04 mg/mL, while the chloroform (CF), EA, and n-butanol (Bu) fractions had strong 2,2-azinobis-3-ethyl benzothiazoline-6-sulfonic acid (ABTS)+ scavenging ability with IC50 values of 0.36 ± 0.04 mg/mL, 0.35 ± 0.02 mg/mL, and 0.35 ± 0.05 mg/mL, respectively. Moreover, the EA and Bu fractions exhibited the highest protective effect against H2O2-induced DNA damage in a concentration-dependent manner. Furthermore, the EA fraction was effective in the inhibition of enzyme α-amylase activity with an IC50 value of 0.27 ± 0.029 mg/mL. Finally, it was observed that the production...

Research paper thumbnail of Spirulina maxima peptides suppress mast cell degranulation via inactivating Akt and MAPKs phosphorylation in RBL-2H3 cells

International journal of biological macromolecules, Jan 14, 2018

In this study, the suppressive effects of peptides P1 (LDAVNR) and P2 (MMLDF) from enzymatic hydr... more In this study, the suppressive effects of peptides P1 (LDAVNR) and P2 (MMLDF) from enzymatic hydrolysate of Spirulina maxima on mast cell degranulation was elucidated. It was revealed that P1 and P2 exhibited significant inhibition on cell degranulation via decreasing β-hexosaminidase release at concentration of 200 μM. Moreover, the inhibitory effects of P1 and P2 on expression and production of interleukin (IL)-13 were evidenced. Furthermore, peptide treatment caused a remarkable inhibition on the phosphorylation of Akt and mitogen-activated protein kinases (MAPKs) including ERK, p38, and JNK. Notably, the inhibitory activity of P1 on cell degranulation was found due to blockade of FcεRI receptor. Meanwhile, the inhibitory activity of P2 was involved in alleviation of intracellular reactive oxygen species (ROS) production. Collectively, peptides P1 and P2 from S. maxima were suggested to be promising inhibitors of mast cell degranulation, contributing to the development of bioacti...

Research paper thumbnail of 4-hydroxybenzaldehyde-chitooligomers suppresses H2O2-induced oxidative damage in microglia BV-2 cells

Carbohydrate research, Jan 22, 2017

Positive charges of chitooligomer (COS) enable COS to interact with negatively charged anionic gr... more Positive charges of chitooligomer (COS) enable COS to interact with negatively charged anionic groups on the cell surface resulting in an improvement in the biological activity of COS and its derivatives. In this study, 4-hydroxybenzaldehyde-COS (HB-COS) was synthesized and investigated for its abilities against H2O2-induced oxidative stress in microglia BV-2 cells. Under oxidative stress, HB-COS significantly attenuated reactive oxygen species (ROS) generation and DNA oxidation, and upregulated the protein levels of antioxidative enzymes. HB-COS is therefore proposed as a potential protective agent against neuronal damage.

Research paper thumbnail of The free radical scavenging and anti-inflammatory activities of gallate-chitooligosaccharides in human lung epithelial A549 cells

Process Biochemistry, 2017

Research paper thumbnail of Prevention of H2O2-induced oxidative stress in murine microglial BV-2 cells by chitin-oligomers

Process Biochemistry, 2016

Research paper thumbnail of Angiotensin- I- converting enzyme (ACE) inhibitory peptides from Pacific cod skin gelatin using ultrafiltration membranes

Process Biochemistry, 2016

Research paper thumbnail of Protective effects of peptides from skate (Okamejei kenojei) skin gelatin against endothelial dysfunction

Journal of Functional Foods, 2014

ABSTRACT Seafood processing by-product, skate (Okamejei kenojei) skin, was utilized to isolate ac... more ABSTRACT Seafood processing by-product, skate (Okamejei kenojei) skin, was utilized to isolate active peptides with antihypertensive effect. Two peptides (MVGSAPGVL, 829 Da and LGPLGHQ, 720 Da) were purified from skate skin gelatin. In human endothelial cells, nitric oxide (NO) synthesis was found to be increased and eNOS phosphorylation was upregulated by the peptides. The peptides exhibited inhibitory activities on the production and expression of IL-6. Furthermore, the peptides down-regulated the expression levels of endothelin-1. The peptides inhibited the NF-κB and the phosphorylation of MAPK pathways. In addition, the activation of the PI3K/Akt pathway by the peptides was confirmed. The present study demonstrated that the purified peptides had vasorelaxant effects via endothelium-dependent NO signaling through activation of the PI3K/Akt-eNOS pathway and inhibition of the NF-κB and MAPK pathways. The purified peptides could be used in the food industry as functional ingredients with potent benefits in reducing the risk of cardiovascular diseases.

Research paper thumbnail of Angiotensin-I converting enzyme inhibitory peptides from antihypertensive skate (Okamejei kenojei) skin gelatin hydrolysate in spontaneously hypertensive rats

Food chemistry, 2015

The aim of this study was to investigate antihypertensive effect of bioactive peptides from skate... more The aim of this study was to investigate antihypertensive effect of bioactive peptides from skate (Okamejei kenojei) skin gelatin. The Alcalase/protease gelatin hydrolysate below 1 kDa (SAP) exhibited the highest angiotensin-I converting enzyme (ACE) inhibition compared to other hydrolysates. SAP can decrease systolic blood pressure significantly in spontaneously hypertensive rats. SAP inhibited vasoconstriction via PPAR-γ expression, activation and phosphorylation of eNOS in lungs. Moreover, the expression levels of endothelin-1, RhoA, α-smooth muscle actin, cleaved caspase 3 and MAPK were decreased by SAP in lungs. Vascularity, muscularization and cellular proliferation in lungs were detected by immunohistochemical staining. Finally, two purified peptides (LGPLGHQ, 720Da and MVGSAPGVL, 829Da) showed potent ACE inhibition with IC50 values of 4.22 and 3.09 μM, respectively. These results indicate that bioactive peptides isolated from skate skin gelatin may serve as candidates agains...

Research paper thumbnail of Antioxidant Effects of Chitin, Chitosan, and Their Derivatives

Advances in Food and Nutrition Research, 2014

Chitin, chitosan, and their derivatives are considered to promote diverse activities, including a... more Chitin, chitosan, and their derivatives are considered to promote diverse activities, including antioxidant, antihypertensive, anti-inflammatory, anticoagulant, antitumor and anticancer, antimicrobial, hypocholesterolemic, and antidiabetic effects, one of the most crucial of which is the antioxidant effect. By modulating and improving physiological functions, chitin, chitosan, and their derivatives may provide novel therapeutic applications for the prevention or treatment of chronic diseases. Antioxidant activity of chitin, chitosan, and their derivatives can be attributed to in vitro and in vivo free radical-scavenging activities. Antioxidant effect of chitin, chitosan, and their derivatives may be used as functional ingredients in food formulations to promote consumer health and to improve the shelf life of food products. This chapter presents an overview of the antioxidant activity of chitin, chitosan, and their derivatives with the potential utilization in the food and pharmaceutical industries.

Research paper thumbnail of Role of Chitosan and Its Derivatives in Cardiovascular Health

Advances in Drug Discovery and Developments, 2013

Research paper thumbnail of The role of peptides derived from Spirulina maxima in downregulation of FcεRI-mediated allergic responses

Molecular Nutrition & Food Research, 2014

Spirulina has been found suitable for use as a bioactive additive. It is an excellent source of p... more Spirulina has been found suitable for use as a bioactive additive. It is an excellent source of protein that can be hydrolyzed into bioactive peptides. Two peptides LDAVNR (P1) and MMLDF (P2) purified from enzymatic hydrolysate of Spirulina maxima have been reported to be effective against early atherosclerotic responses. In this study, the intracellular mechanism involved in the downregulation of these peptides on high-affinity IgE receptor-mediated allergic reaction was further investigated. RBL-2H3 mast cells were pretreated with P1 or P2 and sensitized with dinitrophenyl-specific IgE antibody before stimulation of antigen dinitrophenyl-BSA. It was revealed that P1 and P2 exhibited significant inhibition on mast-cell degranulation via decreasing histamine release and intracellular Ca(2+) elevation. The inhibitory activity of P1 was found due to blockade of calcium- and microtubule-dependent signaling pathways. Meanwhile, the inhibition of P2 was involved in suppression of phospholipase Cγ activation and reactive oxygen species production. Moreover, the suppressive effects of P1 and P2 on generation of IL-4 were evidenced via depression of nuclear factor-κB translocation. These findings indicate that peptides P1 and P2 from S. maxima may be promising candidates of antiallergic therapeutics, contributing to development of bioactive food ingredients for amelioration of allergic diseases.

Research paper thumbnail of The beneficial properties of marine polysaccharides in alleviation of allergic responses

Molecular Nutrition & Food Research, 2014

Marine polysaccharides have been found as the principle component in cell wall structures of seaw... more Marine polysaccharides have been found as the principle component in cell wall structures of seaweeds or exoskeletons of crustaceans. Due to numerous pharmaceutical properties of marine polysaccharides such as antioxidant, anti-inflammatory, antiallergic, antitumor, antiobesity, antidiabetes, anticoagulant, antiviral, immunomodulatory, cardioprotective, and antihepatopathy activities, they have been applied in many fields of biomaterials, food, cosmetic, and pharmacology. Recently, several marine polysaccharides such alginate, porphyran, fucoidan, and chitin and its derivatives have been evidenced as downregulators of allergic responses due to enhancement of innate immune system, alteration of Th1/Th2 balance forward to Th1 cells, inhibition of IgE production, and suppression of mast cell degranulation. This contribution, therefore, focuses on antiallergic properties of marine polysaccharides and emphasizes their potential application as bioactive food ingredients as well as nutraceuticals for prevention of allergic disorders.