Green alga Enteromorpha clathrata(E.clathrata)contains a variety of bioactive compounds,including polysaccharides,polyphenols and fat-soluble pigments etc.,among which polyphenols exhibit a wide range of medicinal pro...Green alga Enteromorpha clathrata(E.clathrata)contains a variety of bioactive compounds,including polysaccharides,polyphenols and fat-soluble pigments etc.,among which polyphenols exhibit a wide range of medicinal properties.E.clathrata polyphenols(ECPs)have shown various biological activities such as antioxidant,anti-inflammatory and antidiabetic effects;however,the potential of ECPs as an anti-cancer reagent remains unclear.The aim of this study was to investigate the anti-tumor activity and underlying mechanisms of ECPs on hepatocellular carcinoma.The cytotoxicity of Hepa1-6 cells was determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)and lactate dehydrogenase(LDH)assay.Flow cytometry and fluorescence microscope analysis of cell apoptosis after annexin V-fluorescein isothiocyanate(FITC)/propidium iodide(PI)staining.2',7'-dichlorodihydrofluorescein diacetate(DCFH-DA)assay was used for intracellular reactive oxygen species(ROS)detection.caspase-9 activity was determined using cspase-9 colorimetric assay.Mitochondrial transmembrane potential(Δψm)was measured using JC-1.Western blot and quantitative real-time PCR(qPCR)were used to assess the expressions of the apoptosis regulators Bax,Bcl-2,cytochrome c and caspase-3.It was found that ECPs showed a dose-dependent cytotoxicity against Hepa1-6 cells by inducing apoptosis.The apoptosis in ECPs-treated Hepa1-6 cells was accompanied by the loss of mitochondrial membrane potential,elevated ROS generation,increased release of mitochondrial cytochrome c,and up-regulation of caspase-9 and caspase-3.The expressions of Bax(pro-apoptotic molecule)and Bcl-2(apoptosis suppressor)were up-regulated and down-regulated,respectively,at both mRNA and protein levels.These molecular alterations revealed that ECPs caused apoptosis of cells through the mitochondrial pathway,suggesting that ECPs are potential candidates to be developed for liver cancer treatment.展开更多
[Objectives]This study was conducted to evaluate the protective effect of polysaccharides from Enteromorpha prolifera(PEP)on mice with hepatorenal syndrome induced by carbon tetrachloride.[Methods]A mouse hepatorenal ...[Objectives]This study was conducted to evaluate the protective effect of polysaccharides from Enteromorpha prolifera(PEP)on mice with hepatorenal syndrome induced by carbon tetrachloride.[Methods]A mouse hepatorenal syndrome model was induced by carbon tetrachloride.The serum levels of lipid,total antioxidant capacity,liver and kidney function,pathological changes of liver and kidney were selected to clarity the effectiveness of PEP on hepatorenal syndrome in mice.[Results]PEP effectively lowered the serum levels of lipid,increased total antioxidant capacity,improved liver and kidney injury,and alleviated pathological changes of liver and kidney of mice induced by carbon tetrachloride.[Conclusions]PEP has a potent preventive effect on hepatorenal syndrome induced by carbon tetrachloride in mice,which provides theoretical support for future clinical application of PEP.展开更多
Based on the sequence data of the nuclear ribosomal DNA internal transcribed spacer(ITS) 1,5.8 S,and ITS 2,the molecular phylogeny was analyzed on Ulvaceae species collected from Qingdao coasts in summer of 2007,inclu...Based on the sequence data of the nuclear ribosomal DNA internal transcribed spacer(ITS) 1,5.8 S,and ITS 2,the molecular phylogeny was analyzed on Ulvaceae species collected from Qingdao coasts in summer of 2007,including 15 attached Ulva and Enteromorpha samples from 10 locations and 10 free-floating Enteromorpha samples from seven locations.The result supported the monophyly of all free-floating Enteromorpha samples,implying the unialgal composition of the free-floating Enteromorpha,and the attached Ulvaceae species from Qingdao coasts were grouped into other five clades,suggesting that they were not the biogeographic origin of the free-floating Enteromorpha in that season.展开更多
Combining some information from field investigation of algae along the coastal areas in China and a few pictures materialized from the western Yellow Sea in 2008,authors analyze the necessary conditions and possible w...Combining some information from field investigation of algae along the coastal areas in China and a few pictures materialized from the western Yellow Sea in 2008,authors analyze the necessary conditions and possible water area in China producing a large biomass,some reasons for firestorm,and the possibility of the reappearance of marine bloom green alga Enteromorpha prolifera.The change of habitats and the increase of nutritional levels related to the water area could be considered as direct reasons.It was transferred northward by the combination of the flow of rainwater,wind and alongshore marine current.The original region of large biomass produced is possibly located in the southwestern Yellow sea.It will possibly be appearing again in the coming years or in the future.A summary is also given referring to its reproduction,development and distribution worldwide.展开更多
Polysaccharide extracted from Enteromorpha prolifera possessed excellent biological activities,but its molecular weight was greatly high which influenced the activity.Organic Se had higher biological activities and wa...Polysaccharide extracted from Enteromorpha prolifera possessed excellent biological activities,but its molecular weight was greatly high which influenced the activity.Organic Se had higher biological activities and was safer than inorganic Se species.In the present study,Enteromorpha polysaccharide was degraded to low molecular weight by free-radical degradation method of H_2O_2 and ascorbic acid.By single factor and orthogonal experiments,the optimal degradation conditions were reaction time of 2 h,reaction temperature of 50℃,H_2O_2/ascorbic acid(n/n=1:1)concentration of 15 mmol L^(-1),and solid-liquid ratio of 1:50(g mL^(-1)).Then,the degraded polysaccharide was chemically modified to obtain its selenide derivatives by nitric acid-sodium selenite method.The selenium content was 1137.29μg g^(-1),while the content of sulfate radical had no change.IR spectra indicated that the selenite ester group was formed.Degraded polysaccharide selenide was characterized and evaluated for antioxidant,antifungal and antibacterial activities.The results showed that degraded polysaccharide selenide had strong capacity of scavenging DPPH and·OH free radical.It had significant antibacterial properties for Escherichia coli,Bacillus subtilis and Salmonella spp.,and it also had significant antifungal properties for Apple anthrax.The result ascertained degradation and selenylation modification did not change the main structure of polysaccharides.It was possible that free-radical degradation was an effective way for enhancing antioxidant activity to decrease molecular weight of polysaccharides.展开更多
From 2007 to 2009, large-scale blooms of green algae (the so-called "green tides") occurred every summer in the Yellow Sea, China. In June 2008, huge amounts of floating green algae accumulated along the coa...From 2007 to 2009, large-scale blooms of green algae (the so-called "green tides") occurred every summer in the Yellow Sea, China. In June 2008, huge amounts of floating green algae accumulated along the coast of Qingdao and led to mass mortality of cultured abalone and sea cucumber. However, the mechanism for the mass mortality of cultured animals remains undetermined. This study examined the toxic effects of Ulva (Enteromorpha) prolifera, the causative species of green tides in the Yellow Sea during the last three years. The acute toxicity of fresh culture medium and decomposing algal effluent of U. prolifera to the cultured abalone Haliotis discus hannai were tested. It was found that both fresh culture medium and decomposing algal effluent had toxic effects to abalone, and decomposing algal effluent was more toxic than fresh culture medium. The acute toxicity of decomposing algal effluent could be attributed to the ammonia and sulfide presented in the effluent, as well as the hypoxia caused by the decomposition process.展开更多
Effect of temperature and irradiance on growth and reproduction of Enteromorpha prolifera that bloomed offshore along the Qingdao coast in summer 2008, was studied. It was showed that E. prolifera propagated mainly as...Effect of temperature and irradiance on growth and reproduction of Enteromorpha prolifera that bloomed offshore along the Qingdao coast in summer 2008, was studied. It was showed that E. prolifera propagated mainly asexually with specific growth rate （SGR） of 10.47 at 25℃/40 μmol m^-2s^-1. Under this condition, gametes with two flagellate formed and released in 5 days. At the beginning of the development, the unicell gamete divided into two cells with heteropolarity, and then the apical cell developed into thalli primordial cells, whereas the basal cell developed into rhizoid primordial cells. In 8-day culture, the monoplast gamete developed into juvenile germling of 240 μm in length. Unreleased gametes can develop directly within the alga body. E. prolifera could either reproduce through lateral branching or fragmenting except apomixis revealed by Microscopic observation. On aged tissue of E. prolifera, although the degraded pigments partially remained in faded algal filaments, numerous vegetative cells could still divide actively in the algal tissues.展开更多
In this study, a polysaccharide from Enteromorpha prolifera (EP) was extracted and its effect on maize seedlings under NaCl stress was investigated. Firstly, the components and structure of the EP were determined. We ...In this study, a polysaccharide from Enteromorpha prolifera (EP) was extracted and its effect on maize seedlings under NaCl stress was investigated. Firstly, the components and structure of the EP were determined. We found that EP is a sulfated polysaccharide of high-molecular weight (Mw, 1 840 KDa) heteropolysaccharides and the main monosaccharide is rhamnose. The polysaccharide was applied to explore its effect on the growth of maize seedlings and its defense response under a salt stress. The results show that EP could promote the growth of maize seedlings under the salt stress. In addition, EP was shown able to significantly regulate membrane permeability and adjustment of osmotic substances such as soluble protein, soluble sugar, and proline, antioxidant enzymes containing superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase. Therefore, EP is an effective salt-resistant substance for the growth of maize seedlings under NaCl stress.展开更多
Background:Enteromorpha prolifera(E.prolifera)polysaccharide has become a promising feed additive with a variety of physiological activities,such as anti-oxidant,anti-cancer,anti-diabetic,immunomodulatory,hypolipidemi...Background:Enteromorpha prolifera(E.prolifera)polysaccharide has become a promising feed additive with a variety of physiological activities,such as anti-oxidant,anti-cancer,anti-diabetic,immunomodulatory,hypolipidemic,and cation chelating ability.However,whether Enteromorpha polysaccharide-trace element complex supplementation regulates amino acid and fatty acid metabolism in chicken is largely unknown.This study was conducted to investigate the effects of E.prolifera polysaccharide(EP)-Zn supplementation on growth performance,amino acid,and fatty acid metabolism in chicken.Methods:A total of 184 one-day-old Ross-308 broiler chickens were randomly divided into two treatment groups with 8 replicates,12 chickens per replicate,and fed either the basal diet(control group)or basal diet plus E.prolifera polysaccharide-Zinc(400 mg EP-Zn/kg diet).Results:Dietary EP-Zn supplementation significantly increased(P<0.05)the body weight,average daily gain,muscle antioxidant activity,serum HDL level,and reduced serum TG and LDL concentration.In addition,dietary EPZn supplementation could modulate ileal amino acid digestibility and upregulate the mRNA expression of amino acid transporter genes in the jejunum,ileum,breast muscle,and liver tissues(P<0.05).Compared with the control group,breast meat from chickens fed EP-Zn had higher(P<0.05)Pro and Asp content,and lower(P<0.05)Val,Phe,Gly,and Cys free amino acid content.Furthermore,EP-Zn supplementation upregulated(P<0.05)the mRNA expressions of mTOR and anti-oxidant related genes,while down-regulated protein degradation related genes in the breast muscle.Breast meat from EP-Zn supplemented group had significantly lower(P<0.05)proportions ofΣn-3 PUFA,and a higher percentage ofΣn-6 PUFA and the ratio of n-6/n-3 PUFA.Besides,EP-Zn supplementation regulated lipid metabolism by inhibiting the gene expression of key enzymes involved in the fatty acid synthesis and activating genes that participated in fatty acid oxidation in the liver tissue.Conclusions:It is concluded that EP-Zn complex supplementation regulates apparent ileal amino acid digestibility,enhances amino acid metabolism,and decreases oxidative stress-associated protein breakdown,thereby improving the growth performance.Furthermore,it promotes fatty acid oxidation and restrains fat synthesis through modulating lipid metabolism-related gene expression.展开更多
基金the National Key R&D Program of China(No.2018YFD0901105)the Ningbo Natural Science Foundation(No.202003N4128)the Scientific Research Foundation of Graduate School of Ningbo University(No.IF2021085)。
文摘Green alga Enteromorpha clathrata(E.clathrata)contains a variety of bioactive compounds,including polysaccharides,polyphenols and fat-soluble pigments etc.,among which polyphenols exhibit a wide range of medicinal properties.E.clathrata polyphenols(ECPs)have shown various biological activities such as antioxidant,anti-inflammatory and antidiabetic effects;however,the potential of ECPs as an anti-cancer reagent remains unclear.The aim of this study was to investigate the anti-tumor activity and underlying mechanisms of ECPs on hepatocellular carcinoma.The cytotoxicity of Hepa1-6 cells was determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)and lactate dehydrogenase(LDH)assay.Flow cytometry and fluorescence microscope analysis of cell apoptosis after annexin V-fluorescein isothiocyanate(FITC)/propidium iodide(PI)staining.2',7'-dichlorodihydrofluorescein diacetate(DCFH-DA)assay was used for intracellular reactive oxygen species(ROS)detection.caspase-9 activity was determined using cspase-9 colorimetric assay.Mitochondrial transmembrane potential(Δψm)was measured using JC-1.Western blot and quantitative real-time PCR(qPCR)were used to assess the expressions of the apoptosis regulators Bax,Bcl-2,cytochrome c and caspase-3.It was found that ECPs showed a dose-dependent cytotoxicity against Hepa1-6 cells by inducing apoptosis.The apoptosis in ECPs-treated Hepa1-6 cells was accompanied by the loss of mitochondrial membrane potential,elevated ROS generation,increased release of mitochondrial cytochrome c,and up-regulation of caspase-9 and caspase-3.The expressions of Bax(pro-apoptotic molecule)and Bcl-2(apoptosis suppressor)were up-regulated and down-regulated,respectively,at both mRNA and protein levels.These molecular alterations revealed that ECPs caused apoptosis of cells through the mitochondrial pathway,suggesting that ECPs are potential candidates to be developed for liver cancer treatment.
基金Supported by Natural Science Research Fund for Colleges and Universities in Jiangsu Province(No.20KJB310026)Provincial General Project of Undergraduate Innovation and Entrepreneurship Training Program(202010324055Y).
文摘[Objectives]This study was conducted to evaluate the protective effect of polysaccharides from Enteromorpha prolifera(PEP)on mice with hepatorenal syndrome induced by carbon tetrachloride.[Methods]A mouse hepatorenal syndrome model was induced by carbon tetrachloride.The serum levels of lipid,total antioxidant capacity,liver and kidney function,pathological changes of liver and kidney were selected to clarity the effectiveness of PEP on hepatorenal syndrome in mice.[Results]PEP effectively lowered the serum levels of lipid,increased total antioxidant capacity,improved liver and kidney injury,and alleviated pathological changes of liver and kidney of mice induced by carbon tetrachloride.[Conclusions]PEP has a potent preventive effect on hepatorenal syndrome induced by carbon tetrachloride in mice,which provides theoretical support for future clinical application of PEP.
基金Supported by NSFC (40506030)the Innovative Key Project of the Chinese Academy of Sciences (KZCX2-YW-209)Science & Technology Project of Qingdao City (06-2-2-12-JCH)
文摘Based on the sequence data of the nuclear ribosomal DNA internal transcribed spacer(ITS) 1,5.8 S,and ITS 2,the molecular phylogeny was analyzed on Ulvaceae species collected from Qingdao coasts in summer of 2007,including 15 attached Ulva and Enteromorpha samples from 10 locations and 10 free-floating Enteromorpha samples from seven locations.The result supported the monophyly of all free-floating Enteromorpha samples,implying the unialgal composition of the free-floating Enteromorpha,and the attached Ulvaceae species from Qingdao coasts were grouped into other five clades,suggesting that they were not the biogeographic origin of the free-floating Enteromorpha in that season.
基金Supported by general and major projects of National Natural Science Foundation of China (Nos 40876081,30570125,and 30499340(partly)the National High Technology Research and Development Program of China (863 Program)(No 2008BAC49B01)Knowledge Innovation Project of Chinese Academy of Sciences (No KSCX2-YW-Z-018)
文摘Combining some information from field investigation of algae along the coastal areas in China and a few pictures materialized from the western Yellow Sea in 2008,authors analyze the necessary conditions and possible water area in China producing a large biomass,some reasons for firestorm,and the possibility of the reappearance of marine bloom green alga Enteromorpha prolifera.The change of habitats and the increase of nutritional levels related to the water area could be considered as direct reasons.It was transferred northward by the combination of the flow of rainwater,wind and alongshore marine current.The original region of large biomass produced is possibly located in the southwestern Yellow sea.It will possibly be appearing again in the coming years or in the future.A summary is also given referring to its reproduction,development and distribution worldwide.
基金financially supported by the National Key R&D Program of China (No.2017YFD0501500)the National Key Technology R & D Program of China (No.2015BAD11B01-04)
文摘Polysaccharide extracted from Enteromorpha prolifera possessed excellent biological activities,but its molecular weight was greatly high which influenced the activity.Organic Se had higher biological activities and was safer than inorganic Se species.In the present study,Enteromorpha polysaccharide was degraded to low molecular weight by free-radical degradation method of H_2O_2 and ascorbic acid.By single factor and orthogonal experiments,the optimal degradation conditions were reaction time of 2 h,reaction temperature of 50℃,H_2O_2/ascorbic acid(n/n=1:1)concentration of 15 mmol L^(-1),and solid-liquid ratio of 1:50(g mL^(-1)).Then,the degraded polysaccharide was chemically modified to obtain its selenide derivatives by nitric acid-sodium selenite method.The selenium content was 1137.29μg g^(-1),while the content of sulfate radical had no change.IR spectra indicated that the selenite ester group was formed.Degraded polysaccharide selenide was characterized and evaluated for antioxidant,antifungal and antibacterial activities.The results showed that degraded polysaccharide selenide had strong capacity of scavenging DPPH and·OH free radical.It had significant antibacterial properties for Escherichia coli,Bacillus subtilis and Salmonella spp.,and it also had significant antifungal properties for Apple anthrax.The result ascertained degradation and selenylation modification did not change the main structure of polysaccharides.It was possible that free-radical degradation was an effective way for enhancing antioxidant activity to decrease molecular weight of polysaccharides.
基金Supported by the National Key Technology R&D Program (No. 2008BAC49B01)the National Basic Research Program of China (973 Program) (No. 2010CB428705)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No. 40821004)
文摘From 2007 to 2009, large-scale blooms of green algae (the so-called "green tides") occurred every summer in the Yellow Sea, China. In June 2008, huge amounts of floating green algae accumulated along the coast of Qingdao and led to mass mortality of cultured abalone and sea cucumber. However, the mechanism for the mass mortality of cultured animals remains undetermined. This study examined the toxic effects of Ulva (Enteromorpha) prolifera, the causative species of green tides in the Yellow Sea during the last three years. The acute toxicity of fresh culture medium and decomposing algal effluent of U. prolifera to the cultured abalone Haliotis discus hannai were tested. It was found that both fresh culture medium and decomposing algal effluent had toxic effects to abalone, and decomposing algal effluent was more toxic than fresh culture medium. The acute toxicity of decomposing algal effluent could be attributed to the ammonia and sulfide presented in the effluent, as well as the hypoxia caused by the decomposition process.
基金Supported by the National Key Technology Support Program,Qingdao Sci & Tech Bureau and National High Technology Research and Development Program of China (No.2006AA09Z21)
文摘Effect of temperature and irradiance on growth and reproduction of Enteromorpha prolifera that bloomed offshore along the Qingdao coast in summer 2008, was studied. It was showed that E. prolifera propagated mainly asexually with specific growth rate （SGR） of 10.47 at 25℃/40 μmol m^-2s^-1. Under this condition, gametes with two flagellate formed and released in 5 days. At the beginning of the development, the unicell gamete divided into two cells with heteropolarity, and then the apical cell developed into thalli primordial cells, whereas the basal cell developed into rhizoid primordial cells. In 8-day culture, the monoplast gamete developed into juvenile germling of 240 μm in length. Unreleased gametes can develop directly within the alga body. E. prolifera could either reproduce through lateral branching or fragmenting except apomixis revealed by Microscopic observation. On aged tissue of E. prolifera, although the degraded pigments partially remained in faded algal filaments, numerous vegetative cells could still divide actively in the algal tissues.
基金Supported by the Commonweal Item of State Oceanic Administration of the People’s Republic of China(No.201505033)the Shandong Province Key Research and Development Project(No.2017GHY215008)the Qingdao Science and Technology Project(No.17-3-3-60-nsh)
文摘In this study, a polysaccharide from Enteromorpha prolifera (EP) was extracted and its effect on maize seedlings under NaCl stress was investigated. Firstly, the components and structure of the EP were determined. We found that EP is a sulfated polysaccharide of high-molecular weight (Mw, 1 840 KDa) heteropolysaccharides and the main monosaccharide is rhamnose. The polysaccharide was applied to explore its effect on the growth of maize seedlings and its defense response under a salt stress. The results show that EP could promote the growth of maize seedlings under the salt stress. In addition, EP was shown able to significantly regulate membrane permeability and adjustment of osmotic substances such as soluble protein, soluble sugar, and proline, antioxidant enzymes containing superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase. Therefore, EP is an effective salt-resistant substance for the growth of maize seedlings under NaCl stress.
基金financially supported by the earmarked fund for NSFC(31902196)Key Collaborative Research Program of the Alliance of International Science Organizations(ANSO-CR-KP-2021-10)+2 种基金China Agriculture Research System(CARS-35)China Postdoctoral Science Foundation-funded project(2021 M693383,2019 M662273)Taishan industry leading talent blue talent project。
文摘Background:Enteromorpha prolifera(E.prolifera)polysaccharide has become a promising feed additive with a variety of physiological activities,such as anti-oxidant,anti-cancer,anti-diabetic,immunomodulatory,hypolipidemic,and cation chelating ability.However,whether Enteromorpha polysaccharide-trace element complex supplementation regulates amino acid and fatty acid metabolism in chicken is largely unknown.This study was conducted to investigate the effects of E.prolifera polysaccharide(EP)-Zn supplementation on growth performance,amino acid,and fatty acid metabolism in chicken.Methods:A total of 184 one-day-old Ross-308 broiler chickens were randomly divided into two treatment groups with 8 replicates,12 chickens per replicate,and fed either the basal diet(control group)or basal diet plus E.prolifera polysaccharide-Zinc(400 mg EP-Zn/kg diet).Results:Dietary EP-Zn supplementation significantly increased(P<0.05)the body weight,average daily gain,muscle antioxidant activity,serum HDL level,and reduced serum TG and LDL concentration.In addition,dietary EPZn supplementation could modulate ileal amino acid digestibility and upregulate the mRNA expression of amino acid transporter genes in the jejunum,ileum,breast muscle,and liver tissues(P<0.05).Compared with the control group,breast meat from chickens fed EP-Zn had higher(P<0.05)Pro and Asp content,and lower(P<0.05)Val,Phe,Gly,and Cys free amino acid content.Furthermore,EP-Zn supplementation upregulated(P<0.05)the mRNA expressions of mTOR and anti-oxidant related genes,while down-regulated protein degradation related genes in the breast muscle.Breast meat from EP-Zn supplemented group had significantly lower(P<0.05)proportions ofΣn-3 PUFA,and a higher percentage ofΣn-6 PUFA and the ratio of n-6/n-3 PUFA.Besides,EP-Zn supplementation regulated lipid metabolism by inhibiting the gene expression of key enzymes involved in the fatty acid synthesis and activating genes that participated in fatty acid oxidation in the liver tissue.Conclusions:It is concluded that EP-Zn complex supplementation regulates apparent ileal amino acid digestibility,enhances amino acid metabolism,and decreases oxidative stress-associated protein breakdown,thereby improving the growth performance.Furthermore,it promotes fatty acid oxidation and restrains fat synthesis through modulating lipid metabolism-related gene expression.
