泡叶藻聚糖低分子质量降解片段组成特征及其体外免疫诱导活性
|
摘要
目的:对从泡叶藻(Ascophyllum nodosum)中提取的泡叶藻聚糖进行化学法降解,将得到的低分子质量降解产物进行分离纯化,分析其基本组成特征和体外免疫诱导活性,为泡叶藻聚糖或其他海藻多糖的生物活性和基本结构特征研究提供参考。方法:通过酸水解法和双氧水氧化降解法制备泡叶藻聚糖低分子质量降解片段,利用超滤法和Sephadex G-50凝胶柱层析分离纯化得到4个泡叶藻聚糖低分子质量片段:HCl-F1、HCl-F2、H_2O_2-F1、H_2O_2-F2;采用对氨基苯甲酸乙酯柱前衍生样品后进行高效液相色谱及化学方法分析其单糖组成和化学组成;采用高效分子排阻色谱法测定其重均分子质量;通过小鼠巨噬细胞RAW264.7模型分析HCl-F1、HCl-F2、H_2O_2-F1、H_2O_2-F2的体外免疫诱导活性。结果:泡叶藻聚糖低分子质量片段的组成特征表明HCl-F1、HCl-F2、H_2O_2-F1、H_2O_2-F2均为杂多糖,且单糖组成存在较大差异,其重均分子质量分别为4.80、4.20、5.30、2.30 kDa。免疫活性分析细胞模型结果表明,HCl-F1、HCl-F2、H_2O_2-F2在所测定质量浓度范围(0～200μg/mL)内能明显诱导RAW264.7细胞活化,释放NO和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α),而H_2O_2-F1诱导RAW264.7细胞释放NO和TNF-α的活性明显低于HCl-F1、HCl-F2和H_2O_2-F2。结论:泡叶藻聚糖低分子质量降解片段(HCl-F1、HCl-F2和H_2O_2-F2)具有明显的免疫诱导活性,其中HCl-F1和H_2O_2-F2的免疫诱导活性明显高于泡叶藻聚糖。结合其化学组成分析的结果,提示泡叶藻聚糖低分子质量降解片段的免疫诱导活性是由单糖组成和硫酸根质量分数共同决定的。
Objective:To separate and purify low-molecular-mass fractions from the chemical degradation products of the sulfated polysaccharide ascophyllan extracted from the brown seaweed Ascophyllum nodosum and to analyze the monosaccharide composition and in vitro immunostimulatory activity of each of these fractions for the purpose of providing useful information for the studies on the biological activities and structural characteristics of ascophyllan and other seaweed polysaccharides.Methods:The degraded products of ascophyllan,prepared separately by treatment with hydrochloric acid or hydrogen peroxide,were fractionated sequentially by ultrafiltration and Sephadex G-50 gel filtration chromatography into four low-molecular-mass fractions(HCl-F1,HCl-F2,H_2O_2-F1 and H_2O_2-F2).The monosaccharide composition of each fraction was determined by high-performance liquid chromatography(HPLC)with pre-column ethyl-p-aminobenzoate(ABEE)derivatization and some of their chemical groups were analyzed.Their weight-average molecular masses were evaluated by high-performance size exclusion chromatography(HPSEC),and their in vitro immunostimulatory activities were investigated by using mouse RAW264.7 macrophages as a model.Results:All these compounds were heteropolysaccharides with significant differences in their monosaccharide composition and sulfation level The weight-average molecular masses of HCl-F1,HCl-F2,H_2O_2-F1 and H_2O_2-F2 were estimated to be 4.80,4.20,5.30 and2.30 kDa,respectively.The in vitro immunomodulatory activity revealed that HCl-F1,HCl-F2,and H_2O_2-F2 significantly induced the activation of RAW264.7 macrophages to produce immune factors such as nitric oxide(NO)and tumor necrosis factor-a(TNF-a)in the test concentration range(0–200 mg/mL),whereas the ability of H_2O_2-F1 to induce the production of NO and TNF-a in RAW264.7 cells was significantly lower than that of any other polysaccharide fraction.Conclusion:All the low-molecular-mass polysaccharide fractions(HCl-F1,HCl-F2 and H_2O_2-F2)derived from ascophyllan possessed potent immunostimulatory activity,with HCl-F1 and H_2O_2-F2 being much stronger than ascophyllan.Taken together,the immunostimulatory activity is likely determined by a combination of monosaccharide composition and sulfate content.
Objective:To separate and purify low-molecular-mass fractions from the chemical degradation products of the sulfated polysaccharide ascophyllan extracted from the brown seaweed Ascophyllum nodosum and to analyze the monosaccharide composition and in vitro immunostimulatory activity of each of these fractions for the purpose of providing useful information for the studies on the biological activities and structural characteristics of ascophyllan and other seaweed polysaccharides.Methods:The degraded products of ascophyllan,prepared separately by treatment with hydrochloric acid or hydrogen peroxide,were fractionated sequentially by ultrafiltration and Sephadex G-50 gel filtration chromatography into four low-molecular-mass fractions(HCl-F1,HCl-F2,H_2O_2-F1 and H_2O_2-F2).The monosaccharide composition of each fraction was determined by high-performance liquid chromatography(HPLC)with pre-column ethyl-p-aminobenzoate(ABEE)derivatization and some of their chemical groups were analyzed.Their weight-average molecular masses were evaluated by high-performance size exclusion chromatography(HPSEC),and their in vitro immunostimulatory activities were investigated by using mouse RAW264.7 macrophages as a model.Results:All these compounds were heteropolysaccharides with significant differences in their monosaccharide composition and sulfation level The weight-average molecular masses of HCl-F1,HCl-F2,H_2O_2-F1 and H_2O_2-F2 were estimated to be 4.80,4.20,5.30 and2.30 kDa,respectively.The in vitro immunomodulatory activity revealed that HCl-F1,HCl-F2,and H_2O_2-F2 significantly induced the activation of RAW264.7 macrophages to produce immune factors such as nitric oxide(NO)and tumor necrosis factor-a(TNF-a)in the test concentration range(0–200 mg/mL),whereas the ability of H_2O_2-F1 to induce the production of NO and TNF-a in RAW264.7 cells was significantly lower than that of any other polysaccharide fraction.Conclusion:All the low-molecular-mass polysaccharide fractions(HCl-F1,HCl-F2 and H_2O_2-F2)derived from ascophyllan possessed potent immunostimulatory activity,with HCl-F1 and H_2O_2-F2 being much stronger than ascophyllan.Taken together,the immunostimulatory activity is likely determined by a combination of monosaccharide composition and sulfate content.
引文
[1]KADAM S U,ALVAREZ C,TIWARI B K,et al.Extraction and characterization of protein from Irish brown seaweed Ascophyllum nodosum[J].Food Research International,2017,99:1021-1027.DOI:10.1016/j.foodres.2016.07.018.
[2]曲桂燕.五种褐藻岩藻聚糖硫酸酯提取纯化及其功能活性的比较研究[D].青岛:中国海洋大学,2013:3-5.DOI:10.7666/d.D326849.
[3]NAKAYASU S,SOEGIMA R,YAMAGUCHI K,et al.Biological activities of fucose-containing polysaccharide ascophyllan isolated from the brown aalga Ascophyllum nodosum[J].Bioscience Biotechnology&Biochemistry,2009,73(4):961-964.DOI:10.1271/bbb.80845.
[4]LARSEN B,HAUG A,PAINTER T,et al.Sulphated polysaccharides in brown algae.I.isolation and preliminary characterisation of three sulphated polysaccharides from Ascophyllum nodosum(L.)Le Jol[J].Acta Chemica Scandinavica,1966,20:219-230.DOI:10.3891/acta.chem.scand.20-0219.
[5]王晶.海带褐藻多糖硫酸酯的结构、化学修饰与生物活性研究[D].青岛:中国科学院研究生院(海洋研究所),2010:15.
[6]LARSEN B,HAUG A,PAINTER T J.Sulphated polysaccharides in brown algae.3.the native state of dfucoidan in Ascophyllum nodosum and fucus vesiculosus[J].Acta Chemica Scandinavica,1970,24(9):3339-3352.DOI:10.3891/acta.chem.scand.24-3339.
[7]K L O A R E G B,D E M A R T Y M,M A B E A U S.P o l y a n i o n i c characteristics of purified sulphated homofucans from brown algae[J].International Journal of Biological Macromolecules,1986,8(6):380-386.DOI:10.1016/0141-8130(86)90060-7.
[8]MEDCALF D G,LARSEN B.Structural studies on ascophyllan and the fucose-containing complexes from the brown alga Ascophyllum nodosum[J].Carbohydrate Research,1977,59(2):539-546.DOI:10.1016/S0008-6215(00)83191-2.
[9]JIANG Z D,OKIMURA T,KENICH Y,et al.The potent activity of sulfated polysaccharide,ascophyllan,isolated from Ascophyllum nodosum to induce nitric oxide and cytokine production from mouse macrophage RAW264.7 cells:comparison between ascophyllan and fucoidan[J].Nitric Oxide Biology&Chemistry,2011,25(4):407-415.DOI:10.1016/j.niox.2011.10.001.
[10]NAKANO K,KIM D,JIANG Z D,et al.Immunostimulatory activities of the sulfated polysaccharide ascophyllan from Ascophyllum nodosum in in vivo and in vitro systems[J].Bioscience Biotechnology and Biochemistry,2012,76(8):1573-1576.DOI:10.1271/bbb.120232.
[11]WANG Y,JIANG Z,KIM D,et al.Stimulatory effect of the sulfated polysaccharide ascophyllan on the respiratory burst in RAW264.7macrophages[J].International Journal of Biological Macromolecules,2012,52(1):164-169.DOI:10.1016/j.ijbiomac.2012.09.008.
[12]ZHANG W,DU J Y,JIANG Z,et al.Ascophyllan purified from Ascophyllum nodosum induces Th1 and Tc1 immune responses by promoting dendritic cell maturation[J].Marine Drugs,2014,12(7):4148-4164.DOI:10.1016/j.ijbiomac.2012.09.008.
[13]刘旭,曲桂燕,周裔彬,等.泡叶藻及海带藻渣中岩藻聚糖硫酸酯的提取及其抗氧化活性[J].海洋科学,2013,37(12):34-39.
[14]ABU R,JIANG Z,UENO M,et al.In vitro antioxidant activities of sulfated polysaccharide ascophyllan isolated from Ascophyllum nodosum[J].International Journal of Biological Macromolecules,2013,59(4):305-312.DOI:10.1016/j.ijbiomac.2013.04.035.
[15]ABU R,JIANG Z,UENO M,et al.Anti-metastatic effects of the sulfated polysaccharide ascophyllan isolated from Ascophyllum nodosum on B16 melanoma[J].Biochemical&Biophysical Research Communications,2015,458(4):727-732.DOI:10.1016/j.bbrc.2015.01.061.
[16]JIANG Z,ABU R,ISAKA S,et al.Inhibitory effect of orallyadministered sulfated polysaccharide ascophyllan isolated from Ascophyllum nodosum on the growth of sarcoma-180 solid tumor in mice[J].Anticancer Research,2014,34(4):1663-1672.DOI:10.1245/s10434-014-3495-y.
[17]MOHSIN S,KURUP G M,MAHADEVAN R.Effect of ascophyllan from brown algae Padina tetrastromaticaon inflammation and oxidative stress in carrageenan-induced rats[J].Inflammation,2013,36(6):1268-1278.DOI:10.1007/s10753-013-9665-4.
[18]JIANG Z,UENO M,NISHIGUCHI T,et al.Importance of sulfate groups for the macrophage-stimulating activities of ascophyllan isolated from the brown alga Ascophyllum nodosum[J].Carbohydrate Research,2013,380:124-129.DOI:10.1016/j.carres.2013.05.018.
[19]DEUX J F,MEDDIAHIPELLE A,LE B A,et al.Low molecular weight fucoidan prevents neointimal hyperplasia in rabbit iliac artery in-stent restenosis model[J].Arteriosclerosis,Thrombosis,and Vascular Biology,2002,22(10):1604-1609.DOI:10.1161/01.ATV.0000032034.91020.0A.
[20]YE J,LI Y P,TERUYA K,et al.Enzyme-digested fucoidan extracts derived from seaweed Mozuku of Cladosiphon novae-caledoniae kylin inhibit invasion and angiogenesis of tumor cells[J].Cytotechnology,2005,47(1/2/3):117-126.DOI:10.1007/s10616-005-3761-8.
[21]ZHAO T T,ZHANG Q B,QI H M,et al.Degradation of porphyran from Porphyra haitanensis and the antioxidant activities of the degraded porphyrans with different molecular weight[J].International Journal of Biological Macromolecules,2006,38(1):45-50.DOI:10.1016/j.ijbiomac.2005.12.018.
[22]ZHAO X,GUO F J,HU J.et al.Antithrombotic activity of oral administered low molecular weight fucoidan from Laminaria japonica[J].Thrombosis Research,2016,144:46-52.DOI:10.1016/j.thromres.2016.03.008.
[23]LI B,LIUS,XING R,et al.Degradation of sulfated polysaccharides from Enteromorpha prolifera and their antioxidant activities[J].Carbohydrate Polymers,2013,92(2):1991-1996.DOI:10.1016/j.carbpol.2012.11.088.
[24]韦敬柳乙,陈艳红,杜希萍,等.泡叶藻聚糖脱色工艺的研究[J].集美大学学报(自然科学版),2017,22(6):24-33.DOI:10.3969/j.issn.1007-7405.2017.06.004.
[25]杨贤庆,刘名求,戚勃,等.龙须菜中多糖含量测定方法的比较研究[J].食品工业科技,2013,34(22):54-57.DOI:10.13386/j.issn1002-0306.2013.22.017.
[26]李楠,李卓,张燕,等.高效分子排阻色谱法同时测定白及多糖分子量和含量[J].药物分析杂志,2012,32(10):1801-1803.DOI:10.16155/j.0254-1793.2012.10.013.
[27]Y A S U N O S,K O K U B O K,K A M E I M.N e w m e t h o d f o r determining the sugar composition of glycoproteins,glycolipids,and oligosaccharides by high-performance liquid chromatography[J].Bioscience Biotechnology&Biochemistry,1999,63(8):1353-1359.DOI:10.1271/bbb.63.1353.
[28]YASUNO S,MURATA T,KOKUBO K,et al.Two-mode analysis by high-performance liquidchromatography ofρ-aminobenzoic ethyl ester-derivatized monosaccharides[J].Bioscience Biotechnology&Biochemistry,1997,61(11):1944-1946.DOI:10.1271/bbb.61.1944.
[29]BITTER T,MUIR H M.A modified uronic acid carbazole reaction[J].Analytical Biochemistry,1962,4(4):330-334.DOI:10.1016/0003-2697(62)90095-7.
[30]K A W A I Y,S E N O N,A N N O K.A m o d i f i e d m e t h o d f o r chondrosulfatase assay[J].Analytical Biochemistry,1969,32(2):314-321.DOI:10.1016/0003-2697(69)90091-8.
[31]KIM D,YAMASAKI Y,JIANG Z D,et al.Comparative study on modeccin-and phytohemagglutinin(PHA)-induced secretion of cytokines and nitric oxide(NO)in RAW264.7 cells[J].Acta Biochimica et Biophysica Sinica,2011,43(1):52-60.DOI:10.1093/abbs/gmq105.
[32]AKANDA M R,PARK B Y.Involvement of MAPK/NF-κB signal transduction pathways:Camellia japonica mitigates inflammation and gastric ulcer[J].Biomedicine&Pharmacotherapy,2017,95:1139-1146.DOI:10.1016/j.biopha.2017.09.031.
[33]LIAO X.The hypoglycemic effect of a polysaccharide(GLP)from Gracilaria lemaneiformis and its degradation products in diabetic mice[J].Food&Function,2015,6(8):2542-2549.DOI:10.1039/c4fo01185f.
[34]SOUZA B W S,CERQUEIRA M A,BOURBON A I,et al.Chemical characterization and antioxidant activity of sulfated polysaccharide from the red seaweed Gracilaria birdiae[J].Food Hydrocolloids,2012,27(2):287-292.DOI:10.1016/j.foodhyd.2011.10.005.
[35]SUDHARSAN S.Antioxidant and anticoagulant activity of sulfated polysaccharide from Gracilaria debilis(Forsskal)[J].International Journal of Biological Macromolecules,2015,81(1):1031-1038.DOI:10.1016/j.ijbiomac.20.15.09.046.
[36]ZHAN Y Z.Functional groups and antioxidant activities of polysaccharides from five categories of tea[J].Industrial Crops&Products,2014,58(1):31-35.DOI:10.1016/j.indcrop.2014.04.004.
[2]曲桂燕.五种褐藻岩藻聚糖硫酸酯提取纯化及其功能活性的比较研究[D].青岛:中国海洋大学,2013:3-5.DOI:10.7666/d.D326849.
[3]NAKAYASU S,SOEGIMA R,YAMAGUCHI K,et al.Biological activities of fucose-containing polysaccharide ascophyllan isolated from the brown aalga Ascophyllum nodosum[J].Bioscience Biotechnology&Biochemistry,2009,73(4):961-964.DOI:10.1271/bbb.80845.
[4]LARSEN B,HAUG A,PAINTER T,et al.Sulphated polysaccharides in brown algae.I.isolation and preliminary characterisation of three sulphated polysaccharides from Ascophyllum nodosum(L.)Le Jol[J].Acta Chemica Scandinavica,1966,20:219-230.DOI:10.3891/acta.chem.scand.20-0219.
[5]王晶.海带褐藻多糖硫酸酯的结构、化学修饰与生物活性研究[D].青岛:中国科学院研究生院(海洋研究所),2010:15.
[6]LARSEN B,HAUG A,PAINTER T J.Sulphated polysaccharides in brown algae.3.the native state of dfucoidan in Ascophyllum nodosum and fucus vesiculosus[J].Acta Chemica Scandinavica,1970,24(9):3339-3352.DOI:10.3891/acta.chem.scand.24-3339.
[7]K L O A R E G B,D E M A R T Y M,M A B E A U S.P o l y a n i o n i c characteristics of purified sulphated homofucans from brown algae[J].International Journal of Biological Macromolecules,1986,8(6):380-386.DOI:10.1016/0141-8130(86)90060-7.
[8]MEDCALF D G,LARSEN B.Structural studies on ascophyllan and the fucose-containing complexes from the brown alga Ascophyllum nodosum[J].Carbohydrate Research,1977,59(2):539-546.DOI:10.1016/S0008-6215(00)83191-2.
[9]JIANG Z D,OKIMURA T,KENICH Y,et al.The potent activity of sulfated polysaccharide,ascophyllan,isolated from Ascophyllum nodosum to induce nitric oxide and cytokine production from mouse macrophage RAW264.7 cells:comparison between ascophyllan and fucoidan[J].Nitric Oxide Biology&Chemistry,2011,25(4):407-415.DOI:10.1016/j.niox.2011.10.001.
[10]NAKANO K,KIM D,JIANG Z D,et al.Immunostimulatory activities of the sulfated polysaccharide ascophyllan from Ascophyllum nodosum in in vivo and in vitro systems[J].Bioscience Biotechnology and Biochemistry,2012,76(8):1573-1576.DOI:10.1271/bbb.120232.
[11]WANG Y,JIANG Z,KIM D,et al.Stimulatory effect of the sulfated polysaccharide ascophyllan on the respiratory burst in RAW264.7macrophages[J].International Journal of Biological Macromolecules,2012,52(1):164-169.DOI:10.1016/j.ijbiomac.2012.09.008.
[12]ZHANG W,DU J Y,JIANG Z,et al.Ascophyllan purified from Ascophyllum nodosum induces Th1 and Tc1 immune responses by promoting dendritic cell maturation[J].Marine Drugs,2014,12(7):4148-4164.DOI:10.1016/j.ijbiomac.2012.09.008.
[13]刘旭,曲桂燕,周裔彬,等.泡叶藻及海带藻渣中岩藻聚糖硫酸酯的提取及其抗氧化活性[J].海洋科学,2013,37(12):34-39.
[14]ABU R,JIANG Z,UENO M,et al.In vitro antioxidant activities of sulfated polysaccharide ascophyllan isolated from Ascophyllum nodosum[J].International Journal of Biological Macromolecules,2013,59(4):305-312.DOI:10.1016/j.ijbiomac.2013.04.035.
[15]ABU R,JIANG Z,UENO M,et al.Anti-metastatic effects of the sulfated polysaccharide ascophyllan isolated from Ascophyllum nodosum on B16 melanoma[J].Biochemical&Biophysical Research Communications,2015,458(4):727-732.DOI:10.1016/j.bbrc.2015.01.061.
[16]JIANG Z,ABU R,ISAKA S,et al.Inhibitory effect of orallyadministered sulfated polysaccharide ascophyllan isolated from Ascophyllum nodosum on the growth of sarcoma-180 solid tumor in mice[J].Anticancer Research,2014,34(4):1663-1672.DOI:10.1245/s10434-014-3495-y.
[17]MOHSIN S,KURUP G M,MAHADEVAN R.Effect of ascophyllan from brown algae Padina tetrastromaticaon inflammation and oxidative stress in carrageenan-induced rats[J].Inflammation,2013,36(6):1268-1278.DOI:10.1007/s10753-013-9665-4.
[18]JIANG Z,UENO M,NISHIGUCHI T,et al.Importance of sulfate groups for the macrophage-stimulating activities of ascophyllan isolated from the brown alga Ascophyllum nodosum[J].Carbohydrate Research,2013,380:124-129.DOI:10.1016/j.carres.2013.05.018.
[19]DEUX J F,MEDDIAHIPELLE A,LE B A,et al.Low molecular weight fucoidan prevents neointimal hyperplasia in rabbit iliac artery in-stent restenosis model[J].Arteriosclerosis,Thrombosis,and Vascular Biology,2002,22(10):1604-1609.DOI:10.1161/01.ATV.0000032034.91020.0A.
[20]YE J,LI Y P,TERUYA K,et al.Enzyme-digested fucoidan extracts derived from seaweed Mozuku of Cladosiphon novae-caledoniae kylin inhibit invasion and angiogenesis of tumor cells[J].Cytotechnology,2005,47(1/2/3):117-126.DOI:10.1007/s10616-005-3761-8.
[21]ZHAO T T,ZHANG Q B,QI H M,et al.Degradation of porphyran from Porphyra haitanensis and the antioxidant activities of the degraded porphyrans with different molecular weight[J].International Journal of Biological Macromolecules,2006,38(1):45-50.DOI:10.1016/j.ijbiomac.2005.12.018.
[22]ZHAO X,GUO F J,HU J.et al.Antithrombotic activity of oral administered low molecular weight fucoidan from Laminaria japonica[J].Thrombosis Research,2016,144:46-52.DOI:10.1016/j.thromres.2016.03.008.
[23]LI B,LIUS,XING R,et al.Degradation of sulfated polysaccharides from Enteromorpha prolifera and their antioxidant activities[J].Carbohydrate Polymers,2013,92(2):1991-1996.DOI:10.1016/j.carbpol.2012.11.088.
[24]韦敬柳乙,陈艳红,杜希萍,等.泡叶藻聚糖脱色工艺的研究[J].集美大学学报(自然科学版),2017,22(6):24-33.DOI:10.3969/j.issn.1007-7405.2017.06.004.
[25]杨贤庆,刘名求,戚勃,等.龙须菜中多糖含量测定方法的比较研究[J].食品工业科技,2013,34(22):54-57.DOI:10.13386/j.issn1002-0306.2013.22.017.
[26]李楠,李卓,张燕,等.高效分子排阻色谱法同时测定白及多糖分子量和含量[J].药物分析杂志,2012,32(10):1801-1803.DOI:10.16155/j.0254-1793.2012.10.013.
[27]Y A S U N O S,K O K U B O K,K A M E I M.N e w m e t h o d f o r determining the sugar composition of glycoproteins,glycolipids,and oligosaccharides by high-performance liquid chromatography[J].Bioscience Biotechnology&Biochemistry,1999,63(8):1353-1359.DOI:10.1271/bbb.63.1353.
[28]YASUNO S,MURATA T,KOKUBO K,et al.Two-mode analysis by high-performance liquidchromatography ofρ-aminobenzoic ethyl ester-derivatized monosaccharides[J].Bioscience Biotechnology&Biochemistry,1997,61(11):1944-1946.DOI:10.1271/bbb.61.1944.
[29]BITTER T,MUIR H M.A modified uronic acid carbazole reaction[J].Analytical Biochemistry,1962,4(4):330-334.DOI:10.1016/0003-2697(62)90095-7.
[30]K A W A I Y,S E N O N,A N N O K.A m o d i f i e d m e t h o d f o r chondrosulfatase assay[J].Analytical Biochemistry,1969,32(2):314-321.DOI:10.1016/0003-2697(69)90091-8.
[31]KIM D,YAMASAKI Y,JIANG Z D,et al.Comparative study on modeccin-and phytohemagglutinin(PHA)-induced secretion of cytokines and nitric oxide(NO)in RAW264.7 cells[J].Acta Biochimica et Biophysica Sinica,2011,43(1):52-60.DOI:10.1093/abbs/gmq105.
[32]AKANDA M R,PARK B Y.Involvement of MAPK/NF-κB signal transduction pathways:Camellia japonica mitigates inflammation and gastric ulcer[J].Biomedicine&Pharmacotherapy,2017,95:1139-1146.DOI:10.1016/j.biopha.2017.09.031.
[33]LIAO X.The hypoglycemic effect of a polysaccharide(GLP)from Gracilaria lemaneiformis and its degradation products in diabetic mice[J].Food&Function,2015,6(8):2542-2549.DOI:10.1039/c4fo01185f.
[34]SOUZA B W S,CERQUEIRA M A,BOURBON A I,et al.Chemical characterization and antioxidant activity of sulfated polysaccharide from the red seaweed Gracilaria birdiae[J].Food Hydrocolloids,2012,27(2):287-292.DOI:10.1016/j.foodhyd.2011.10.005.
[35]SUDHARSAN S.Antioxidant and anticoagulant activity of sulfated polysaccharide from Gracilaria debilis(Forsskal)[J].International Journal of Biological Macromolecules,2015,81(1):1031-1038.DOI:10.1016/j.ijbiomac.20.15.09.046.
[36]ZHAN Y Z.Functional groups and antioxidant activities of polysaccharides from five categories of tea[J].Industrial Crops&Products,2014,58(1):31-35.DOI:10.1016/j.indcrop.2014.04.004.