RESUMO
Laurencia undulata, as one of the most biologically active species in the genus Laurencia, is an edible folk herb red algae. Among them, d-isofloridoside (DIF, 940.68 Da) is isolated from Laurencia undulata, which has antioxidant and matrix metalloproteinases (MMP) inhibitory activities. However, its mechanism of action on tumor angiogenesis has not yet been reported. In this study, we have studied the mechanism of DIF on tumor metastasis and angiogenesis in HT1080 cell and human vascular endothelial cell (HUVEC). The results show that DIF can reduce the activity of MMP-2/9, and can inhibit the expression of hypoxia-inducible factor-1α (HIF-1α) by regulating the downstream PI3K/AKT and mitogen-activated protein kinases (MAPK) pathways, thereby down-regulating the production of vascular endothelial growth factor (VEGF) in CoCl2-induced HT1080 cell. In addition, DIF can inhibit the activation of VEGF receptor (VEGFR-2), regulate downstream PI3K/AKT, MAPK, nuclear factor-kappa B (NF-κB) signal pathways, activate apoptosis, and thus down-regulate the production of platelet-derived growth factor (PDGF) in VEGF-induced HUVEC. In conclusion, our research shows that DIF has the potential to develop into a tumor-preventing functional food and tumor angiogenesis inhibitor, and it can provide theoretical guidance for the high-value comprehensive utilization of edible red algae Laurencia undulata.
Assuntos
Inibidores da Angiogênese , Galactosídeos/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Laurencia , Inibidores da Angiogênese/farmacologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Fator A de Crescimento do Endotélio VascularRESUMO
Cholinergic disorder, oxidative stress, and neuroinflammation play important roles in the pathology of Alzheimer's disease. To explore the healthy potential of the edible seaweed Hizikia fusiforme on this aspect, a functional oil (HFFO) was extracted from this alga and investigated on its constituents by gas chromatography-mass spectrometry (GC/MS) in this study. Its anti-Alzheimer's related bioactivities including acetylcholinesterase (AChE) inhibition, antioxidation, and anti-neuroinflammation were evaluated, traced, and simulated by inâ vitro and in silico methods. GC/MS analysis indicated that HFFO mainly contained arachidonic acid (ARA), 11,14,17-eicosatrienoic acid (ETrA), palmitic acid, phytol, etc. HFFO showed moderate AChE inhibition and antioxidant activity. Bioactivity tracing using commercial standards verified that AChE inhibition of HFFO mainly originated from ARA and ETrA, whereas antioxidant activity mainly from ARA. Lineweaver-Burk plots showed that both ARA and ETrA are noncompetitive AChE inhibitors. A molecular docking study demonstrated low CDOCKER interaction energy of -26.33â kcal/mol for ARA and -43.70â kcal/mol for ETrA when interacting with AChE and multiple interactions in the ARA (or ETrA)-AChE complex. In the anti-neuroinflammatory evaluation, HFFO showed no toxicity toward BV-2 cells at 20â µg/mL and effectively inhibited the production of nitroxide and reduced the level of reactive oxygen species in lipopolysaccharide-induced BV-2 cells. The results indicated that HFFO could be used in functional foods for its anti-Alzheimer's disease-related activities.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Óleos de Plantas/farmacologia , Alga Marinha/química , Inibidores da Colinesterase/farmacologia , Inibidores da Colinesterase/uso terapêutico , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Cinética , Simulação de Acoplamento Molecular , Espécies Reativas de Oxigênio/metabolismoRESUMO
Microalgae are primary producers with multiple nutrients in aquatic environments and mostly have applications in biological feed and fuel industry. There are few studies assessing the angiotensin-I-converting enzyme (ACE) inhibition potential of Isochrysis zhanjiangensis, other than its antioxidant potential. In this study, we evaluated a peptide from I. zhanjiangensis (PIZ, FEIHCC) and its vascular endothelial factors and mechanism in human umbilical vein endothelial cells (HUVEC). The results reveal that PIZ (IC50 = 61.38 µM) acts against ACE in a non-competitive binding mode. In addition, PIZ inhibits angiotensin II (Ang II)-induced vascular factor secretion and expression by blocking inflammation and apoptosis through nuclear factor κB (NF-κB), nuclear erythroid 2-related factor 2 (Nrf2), mitogen-activated protein kinases (MAPKs), and the serine/threonine kinase (Akt) signal pathways. This study reveals that PIZ has potential to be developed as a therapeutic agent for hypertension and provides a new method of high-value utilization of I. zhanjiangensis.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Haptófitas/química , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Microalgas/química , Peptídeos/farmacologia , Extratos Vegetais/farmacologia , Lesões do Sistema Vascular/metabolismo , Angiotensina II/genética , Angiotensina II/metabolismo , Inibidores da Enzima Conversora de Angiotensina/química , Apoptose/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/genética , NF-kappa B/metabolismo , Peptídeos/química , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Extratos Vegetais/química , Lesões do Sistema Vascular/tratamento farmacológico , Lesões do Sistema Vascular/genéticaRESUMO
Seahorse has been used as a traditional medicine in Southeast Asian countries for a long time. A compound, 2'-Hydroxy-5'-Methoxyacetophenone (2H5M) isolated from seahorse, Hippocampus kuda, was tested for its anti-inflammatory effect in lipopolysaccharides (LPS)-stimulated BV-2 cells and RAW264.7 cells. MTT assay indicated that 2H5M has no cytotoxicity on two kinds of cells. The concentration of nitric oxide (NO) measured by Griess Reaction System showed that 2H5M could significantly inhibit the NO concentration. The ELISA results showed that 2H5M could suppress the secretion of TNF-α in a dose-dependent manner. Moreover, western blot analysis was utilized to measure the protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways. Electrophoretic mobility shift assay (EMSA) demonstrated that 2H5M reduced NF-κB DNA binding activity. Furthermore, the molecular docking study showed that 2H5M can form active sites with NF-κB. Collectively, these results indicated that 2H5M possesses anti-inflammatory effects and may have a potential application in inflammatory disorders in the future.
Assuntos
Anti-Inflamatórios/farmacologia , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos/toxicidade , NF-kappa B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Anti-Inflamatórios/isolamento & purificação , Relação Dose-Resposta a Droga , Mediadores da Inflamação/antagonistas & inibidores , Camundongos , NF-kappa B/antagonistas & inibidores , Células RAW 264.7 , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/fisiologia , SmegmamorphaRESUMO
Hippocampus is a traditional medicine in China, which can be used for treating tumors, aging, fatigue, thrombosis, inflammation, hypertension, prostatic hyperplasia, and other diseases. 1-(5-Bromo-2-hydroxy-4-methoxyphenyl)ethanone [SE1] from seahorse (Hippocampus kuda Bleeler) has been shown to suppress proinflammatory responses. In the present study, SE1 potently inhibited gelatin digestion by MMP-9 induced by phorbol 12-myristate 13-acetate (PMA) and migration of human fibrosarcoma HT1080 cells in dose-dependent manner. Moreover, western blot analysis and immunofluorescence analysis have been studied on MAPKs (ERK1/2, p38 kinase and JNK) and NF-κB (p65 and IκB), which refer to the clear molecular mechanism. The results indicated that SE1 significantly suppressed the phosphorylation of mitogen-activated protein kinases (MAPK: p38 kinase and JNK) and NF-κB. Finally, molecular docking result showed SE1 interacts with TYR245 and HIS226 of MMP-9 by hydrogen bond and Pi-Pi bond to suppress MMP-9 activity. This data suggested that the SE1 may possess therapeutic and preventive potential for the treatment of MMP-9 related disorders.
RESUMO
Fermented microalgae Pavlova lutheri (P. lutheri), the product of Hansenula polymorpha fermentation, exhibited an increase in alkaline phosphatase (ALP) activity in MG63 osteoblastic cells when compared to that of nonfermented P. lutheri. Fractionation of the fermented P. lutheri resulted in identification of the active peptide [peptide of P. lutheri fermentation (PPLF)] with the sequence of EPQWFL. PPLF significantly increased ALP release from MG63 cells and mineralization in a dosedependent manner. In addition, the intracellular levels of ALP and osteocalcin (OCN) proteins were augmented by PPLF treatment. To identify the molecular mechanism underlying the effect of PPLF on osteoblastic differentiation, the phosphorylation levels of the mitogenactivated protein kinases, p38, extracellular signalregulated kinases 1/2 and Jun, and nuclear factor (NF)κB were determined following PPLF treatment and the differences in expression were analyzed using p38 and NFκB selective inhibitors. These results concluded that PPLF from fermented P. lutheri induced osteoblastic differentiation by increasing ALP and OCN release in MG63 cells via the p38/p65 signaling pathway, indicating that PPLF supplement may be effective for therapeutic application in the field of bone health.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Haptófitas/química , Microalgas/química , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Peptídeos/farmacologia , Fosfatase Alcalina/metabolismo , Calcificação Fisiológica/efeitos dos fármacos , Linhagem Celular , Fermentação , Humanos , Osteoblastos/citologia , Osteocalcina/metabolismo , Peptídeos/químicaRESUMO
Ultraviolet-B (UV-B) irradiation has been known to generate oxidative stress by increasing reactive oxygen species (ROS) in skin cells. Several naturally occurring antioxidant compounds isolated from marine algae are believed to protect against ROS. In this study, we assessed the antioxidative effect of eckstolonol isolated from Ecklonia cava against UV-B-induced ROS in human keratinocytes (HaCaTs). We investigated the effects of photo-oxidative stress by UV-B (50 mJ/cm(2)) and the antioxidative effects of eckstolonol using fluorometry, flow cytometry, microscopy, and cell viability and comet assays. UV-B irradiation decreased cell viability, which was restored in a dose-dependent manner with eckstolonol treatment (0, 5, 50, 100, and 200 µM). Moreover, eckstolonol reduced UV-B-induced ROS, lipid peroxidation, damaged DNA levels, and cell death. These antioxidative effects seem to be due to the enzymatic activities of catalase (CAT) and superoxide dismutase (SOD). Collectively, these results indicate that eckstolonol is capable of protecting keratinocytes from photo-oxidative stress.
Assuntos
Antioxidantes/farmacologia , Dioxanos/farmacologia , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Raios Ultravioleta , Catalase/metabolismo , Linhagem Celular , Sobrevivência Celular , Ensaio Cometa , Humanos , Queratinócitos , Peroxidação de Lipídeos/efeitos dos fármacos , Phaeophyceae , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismoRESUMO
Marine microalgae have been reported as valuable new sources of pharmacologically active compounds and there are now numerous commercial applications of microalgae. Hence, in this study we evaluated the protective effects of peptides purified from marine microalgae, Navicula incerta, against alcohol-induced damage in HepG2/CYP2E1 cells. To obtain bioactive peptides from microalgae, N. incerta was hydrolysed using various enzymes (alcalase, α-chymotrypsin, neutrase, papain, pepsin, pronase-E and trypsin), and the hydrolysates were evaluated for cytoprotective activity. Among them, papain-derived hydrolysate exhibited higher antioxidant activities than those of other enzymes. Therefore, papain hydrolysate was purified in order to obtain potent antihepatotoxic and antioxidative peptides. The amino acid sequences of the purified peptides were analysed as; NIPP-1 (Pro-Gly-Trp-Asn-Gln-Trp-Phe-Leu) with molecular mass 1 171 Da, and NIPP-2 (Val-Glu-Val-Leu-Pro-Pro-Ala-Glu-Leu) with molecular mass 1108 Da. Furthermore, this study demonstrated that NIPP-1 and NIPP-2 peptides inhibited ethanol-induced cytotoxicity in HepG2/CYP2E1 cells.
Assuntos
Antioxidantes/farmacologia , Microalgas/química , Substâncias Protetoras/farmacologia , Hidrolisados de Proteína/farmacologia , Sobrevivência Celular , Diatomáceas/química , Etanol/efeitos adversos , Células Hep G2 , Humanos , Peptídeos/farmacologiaRESUMO
Alcohol-induced liver injury progresses from fatty infiltration followed by a harmful cause of inflammation leading to an irreversible damage. In this study, two compounds (emodin and chrysophanol) isolated from marine fungus Aspergillus sp. were examined for their protective effects against ethanol-induced toxicity in vitro. Ethanol-induced HepG2/CYP2E1 cells were treated with the compounds at various concentrations, and the results showed that there was a dose-dependent decrease of gamma-glutamyl transpeptidase (GGT) activity and increase of glutathione (GSH) in the culture media with an increase in cell viability. Furthermore, the protective effects of the compounds were evaluated by protein expression levels of GGT, GSH, and CYP2E1 using Western blot. Among the compounds, emodin addressed to the ethanol-induced cytotoxicity more effectively compared to the chrysophanol. It could be suggested that emodin isolated from this genus would be a potential candidate for attenuating ethanol induced liver damage for further industrial applications such as functional food and pharmaceutical developments.
RESUMO
The matrix metalloproteinase (MMP) family is involved in the breakdown of extracellular matrix in normal physiological processes, as well as in the disease processes such as arthritis and cancer metastasis. In the present study, dieckol was obtained with high yield from marine brown alga Ecklonia cava (EC), and its effect was assessed on the expression of MMP-2 and -9 and morphological changes in human fibrosarcoma cell line (HT1080). Dieckol inhibited the expression of MMP-2 and -9 in a dose-dependent manner and also suppressed the cell invasion and the cytomorphology in 3D culture system on HT1080 cells. Moreover, dieckol may influence nuclear factor kappa B (NF-κB) pathway without obvious influence on activator protein-1 (AP-1) pathway and tissue inhibitor of metalloproteinases (TIMPs). In conclusion, dieckol could significantly suppress MMP-2 and -9 expression and alter cytomorphology of HT1080 cell line via NF-κB pathway.
RESUMO
The sea cucumber Stichopus japonicus is an important food and traditional medicine in Asian countries. However, ethyl acetate solvent fraction of S. japonicus (SCEA-F) is largely unknown for its anti-inflammatory activity and related molecular mechanisms. In this study, effect of SCEA-F on inflammation was investigated in LPS stimulated RAW264.7 cells. SCEA-F significantly inhibited the productions of NO and PGE(2) by inhibiting iNOS and COX-2 at their protein and gene levels. The production and the gene transcription of pro-inflammatory cytokines are also inhibited. The responsible molecular signaling for these inhibitory actions was found to be through suppression of the phosphorylation of MAPK molecules; ERK and p38 MAPK. These results indicate that SCEA-F inhibits LPS-induced inflammatory response via blocking of MAPK signaling pathway in murine macrophages, thus demonstrated its in vitro anti-inflammatory potential. Therefore it could be suggested that SCEA-F could be effectively used in functional food preparations.
RESUMO
In the exploration of abundant marine biological resources, edible red alga Laurencia undulata led to two bioactive isolates: floridoside (1) and D-isofloridoside (2). For the first time, the antioxidant properties of both derivatives (1 and 2) were characterized via free radical scavenging using the ESR technique, reactive oxygen species (ROS) inhibition, membrane protein oxidation, myeloperoxidase (MPO) inhibition, gene expression levels of glutathione (GSH) and superoxide dismutase (SOD), and protein expression of MMP-2 and MMP-9. The results demonstrate that floridoside and D-isofloridoside possess significant antioxidant capacity and are potential inhibitors of MMP-2 and MMP-9. These results clarified that these components may be responsible for the relative activities of crude extract from this genus, which is used as folk medicine. Furthermore, the structure-activity relationships were also suggested. Both isomers could be effective candidates for applications in food and pharmaceutical fields as natural marine antioxidants.
Assuntos
Inibidores Enzimáticos/química , Galactosídeos/química , Glicerol/análogos & derivados , Laurencia/química , Inibidores de Metaloproteinases de Matriz , Proteínas de Membrana/metabolismo , Animais , Antioxidantes/química , Antioxidantes/metabolismo , Linhagem Celular , Inibidores Enzimáticos/metabolismo , Galactosídeos/metabolismo , Glicerol/química , Glicerol/metabolismo , Humanos , Laurencia/metabolismo , Metaloproteinases da Matriz/metabolismo , Camundongos , Oxirredução , Ligação ProteicaRESUMO
Marine red algae of genus Laurencia are becoming the most important resources to produce unique natural metabolites with wide bioactivities. However, reports related to Laurencia undulata, an edible species used as folk herb, are rarely found to date. In this research, 5-hydroxymethyl- 2-furfural (5-HMF) was isolated and characterized by nuclear magnetic resonance (NMR) from Laurencia undulata as well as other marine algae. The following characteristics of 5-HMF were systematically evaluated: its antioxidant activities, such as typical free-radicals scavenging in vitro by electron spin resonance spectrometry (ESR) and intracellular reactive oxygen species (ROS) scavenging; membrane protein oxidation; oxidative enzyme myeloperoxidase (MPO) inhibition; as well as expressions of antioxidative enzymes glutathione (GSH) and superoxide dismutase (SOD) on the gene level, using the polymerase chain reaction (PCR) method. The results demonstrated that 5-HMF could be developed as a novel marine natural antioxidant or potential precursor for practical applications in the food, cosmetic, and pharmaceutical fields.
Assuntos
Antioxidantes/química , Furaldeído/análogos & derivados , Furaldeído/química , Laurencia/química , Oxirredução , Animais , Antioxidantes/isolamento & purificação , Antioxidantes/metabolismo , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Espectroscopia de Ressonância de Spin Eletrônica , Radicais Livres , Furaldeído/isolamento & purificação , Furaldeído/metabolismo , Regulação da Expressão Gênica , Glutationa/biossíntese , Glutationa/genética , Humanos , Microbiologia Industrial , Laurencia/metabolismo , Espectroscopia de Ressonância Magnética , Proteínas de Membrana/metabolismo , Camundongos , Estresse Oxidativo , Peroxidase/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/biossíntese , Superóxido Dismutase/genéticaRESUMO
Arthritis is one of the most prevalent chronic inflammatory diseases, and it is characterized by structural and biochemical changes in major tissues of the joint, including degradation of the cartilage matrix, insufficient synthesis of extracellular matrix (ECM). Ecklonia cava (EC) is a member of the family of Laminariaceae, which is an edible marine brown alga with various bioactivities. In this study of the methanol extract of brown alga EC, the dieckol (1) and 1-(3',5'-dihydroxyphenoxy)-7-(2'',4'',6''-trihydroxyphenoxy) 2,4,9-trihydroxydibenzo-1,4,-dioxin (2) were isolated and characterized by NMR techniques with high yield. Phlorotannin derivatives (1, 2) promoted osteosarcoma differentiation by increasing alkaline phosphatase (ALP) activity, mineralization, total protein and collagen synthesis in human osteosarcoma cell (MG-63 cells), respectively. Furthermore, these phlorotannin derivatives (1, 2) inhibited mRNA gene and protein levels of matrix metalloproteinase (MMP-1, MMP-3, and MMP-13), iNOS and COX-2 in casein zymography, Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR) assays. In addition, it was observed that the phlorotannins inhibited phosphorylation of JNK and p38 MAPK in human osteosarcoma cell. These results suggested the phlorotannin derivatives (1, 2) could promote cell differentiation, attenuate MMP-1, MMP-3, MMP-13 expressions, and inflammatory response via MAPK pathway in chronic articular diseases.
Assuntos
Artrite Reumatoide/metabolismo , Benzofuranos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/metabolismo , Dioxanos/farmacologia , Metaloproteinases da Matriz/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Osteossarcoma/metabolismo , Floroglucinol/análogos & derivados , Fosfatase Alcalina/metabolismo , Artrite Reumatoide/genética , Benzofuranos/química , Benzofuranos/isolamento & purificação , Western Blotting , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/efeitos dos fármacos , Ciclo-Oxigenase 2/genética , Dioxanos/química , Dioxanos/isolamento & purificação , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Inibidores de Metaloproteinases de Matriz , Metaloproteinases da Matriz/genética , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/genética , Osteossarcoma/patologia , Phaeophyceae/química , Floroglucinol/química , Floroglucinol/isolamento & purificação , Floroglucinol/farmacologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Células Tumorais CultivadasRESUMO
Seven phlorotannins were isolated and characterized from an edible marine brown alga Ecklonia cava (EC), along with three common sterol derivatives (fucosterol, ergosterol, and cholesterol) according to the comprehensive spectral analysis of MS and NMR data. Compounds 5 (7-phloro eckol) and 7 (6,6'-bieckoll) of phlorotannin derivatives were obtained for the first time with the high yields. No reports of compound 3 (Fucodiphloroethol G) was published up to date. The antioxidant properties of all phlorotannins were assessed by total antioxidant activity in a linoleic acid model, free radicals scavenging assay using electron spin resonance spectrometry (ESR) technique, cellular reactive oxygen species (ROS) assay by DCFH-DA, membrane protein oxidation assay; measurement of cellular glutathione (GSH) level in RAW264.7 cell line, and myeloperoxidase (MPO) assay in HL-60 cell line. The results revealed that all phlorotannins had antioxidant properties in vitro, especially, compounds 7 (6,6'-bieckol), 6, and 3 showed the significant activities compared to the other phlorotannins. Furthermore, the structure-activity relationship (SAR) was discussed based on the structural differences of the tested phlorotannins which have polymeriged phloroglucinal units with diverse skeletons and linkages. It could be suggested that phlorotaninns from this genus would be more potential candidates for the development of unique natural antioxidants for further industrial applications as functional foods, cosmetics and pharmaceuticals. As well as our results makes it clear to understand the reason behind the use of EC as traditional folk herb for a long history.
Assuntos
Antioxidantes/farmacologia , Sequestradores de Radicais Livres/farmacologia , Phaeophyceae/química , Taninos/farmacologia , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Linhagem Celular , Dioxinas/química , Dioxinas/isolamento & purificação , Dioxinas/farmacologia , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/isolamento & purificação , Células HL-60 , Humanos , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Esteróis/isolamento & purificação , Relação Estrutura-Atividade , Taninos/química , Taninos/isolamento & purificaçãoRESUMO
To produce bioactive peptides from by-products of fish processing, bigeye tuna dark muscle was hydrolyzed using various enzymes (alcalase, alpha-chymotrypsin, neutrase, papain, pepsin, and trypsin), and the hydrolysates were evaluated for antioxidant activity. Considering the results of degree of hydrolysis and antioxidant activities, peptic hydrolysate was used for further studies to identify a potent antioxidant peptide. Antioxidant peptide was purified using consecutive chromatographic methods and was identified as being H-Leu-Asn-Leu-Pro-Thr-Ala-Val-Tyr-Met-Val-Thr-OH (MW 1,222 Da) by quantitative time-of-flight electrospray ionization mass spectrometry. Purified antioxidant peptide from bigeye tuna dark muscle (APTDM) was investigated for its antioxidant activities using both free radical scavenging effects and polyunsaturated fatty acid (PUFA) peroxidation inhibitory activity. The results showed that APTDM effectively quenched with low 50% inhibitory concentration values compared to vitamin C as a positive control against four different free radicals: 1,1-diphenyl-2-picrylhydrazyl, hydroxyl, superoxide, and alkyl radical. APTDM also inhibited PUFA peroxidation in a linoleic acid emulsion system, and the activity was similar to that of alpha-tocopherol. We further investigated its antioxidant activities on cellular systems, and the results showed that APTDM significantly scavenged cellular radicals and enhanced the viability of tert-butyl hydroperoxide-induced cytotoxicity. These results indicate that APTDM or a peptide fraction containing APTDM would be a beneficial ingredient for functional food and/or pharmaceuticals.
Assuntos
Antioxidantes/farmacologia , Peptídeos/farmacologia , Atum , Animais , Antioxidantes/isolamento & purificação , Células Cultivadas , Sequestradores de Radicais Livres/isolamento & purificação , Sequestradores de Radicais Livres/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Músculo Esquelético , Peptídeos/isolamento & purificação , Hidrolisados de Proteína/isolamento & purificação , Hidrolisados de Proteína/farmacologia , terc-Butil Hidroperóxido/toxicidadeRESUMO
Bullfrog (Rana catesbeiana Shaw) muscle protein was enzymatically hydrolyzed for extraction of an antioxidant peptide. Antioxidant peptide from bullfrog muscle protein hydrolysate (APBMH) was purified using consecutive chromatographic methods, and the amino acid sequence was identified as being Leu-Glu-Gln-Gln-Val-Asp-Asp-Leu-Glu-Gly-Ser-Leu-Glu-Gln-Glu-Lys-Lys (molecular mass of 1,988 Da) by quantitative time-of-flight electrospray ionization mass spectroscopy. To assess antioxidant activities of APBMH, two different in vitro systems were employed: free radical scavenging activity by electron spin resonance (ESR) spectroscopy and polyunsaturated fatty acid (PUFA) peroxidation inhibition assay. ESR revealed that APBMH is an effective free radial scavenger with activity similar to that of vitamin C against 1,1-diphenyl-2-picrylhydrazyl, hydroxyl, and superoxide radicals, and its 50% inhibitory concentration values were 179.4 microM, 162.7 microM, and 176.1 microM, respectively. APBMH also significantly retarded PUFA oxidation, and more potently than did alpha-tocopherol, which was used as a positive control. In addition, the ability of APBMH to inhibit the oxidative damage of DNA was assessed, in vitro, by measuring the conversion of supercoiled pBR322 plasmid DNA to the open circular form. It was found that APBMH significantly protected hydroxyl radical-induced DNA damage dose-dependently.
Assuntos
Antioxidantes/isolamento & purificação , Proteínas Musculares/química , Peptídeos/isolamento & purificação , Rana catesbeiana , Sequência de Aminoácidos , Animais , Antioxidantes/farmacologia , Cromatografia Líquida de Alta Pressão , Dano ao DNA/efeitos dos fármacos , Espectroscopia de Ressonância de Spin Eletrônica , Hidrólise , Radical Hidroxila/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Peptídeo Hidrolases/metabolismo , Peptídeos/química , Peptídeos/farmacologia , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
A low-molecular-weight peptide with potent antioxidative activity was obtained from Mytilus coruscus muscle protein using an in vitro gastrointestinal digestion system. The potent antioxidant peptide, which was identified as Leu-Val-Gly-Asp-Glu-Gln-Ala-Val-Pro-Ala-Val-Cys-Val-Pro (1.59 kDa), exhibited higher protective activity against polyunsaturated fatty acid (PUFA) peroxidation than the native antioxidants, ascorbic acid and alpha-tocopherol. In a free radical scavenging assay using electron spin resonance spectroscopy, hydroxyl radical formation was quenched by 75.04% in the presence of M. coruscus peptide (50 microg/mL), which was similar to ascorbic acid. In addition, the purified peptide could also quench super-oxide and carbon-centered radicals, but those activities were weaker than for ascorbic acid. This study showed that the low-molecular-weight peptide released from in vitro gastrointestinal digestion of mussel exhibited potent antioxidant potential by inhibiting the formation of reactive oxygen species formed by the peroxidation of PUFAs.