Influence of fasting on muscle composition and antioxidant defenses of market-size Sparus macrocephalus

The study was conducted to investigate fasting effects on flesh composition and antioxidant defenses of market-size Sparus macrocephalus. Two hundred fish (main initial weight 580 g) were divided into two groups (control and fasted) and reared in 6 cages. After two weeks of adaptation, group I fasted for 28 d; group II was fed normally as a control. In 3, 7, 14, 21 and 28 d, 6 fish per group were sampled for proximate flesh composition, liver antioxidant enzyme activities and malondialdehyde flesh content analyses. In fasted fish, the reduction of lipid content in muscle occurred after day 3, and, compared to controls, the content of protein decreased from day 14, the activities of liver antioxidative enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX) increased from day 3, and flesh malondialdehyde levels increased from day 21. Flesh fat reduction shows that fasting may be used as a technique to reduce flesh lipid content in Sparus macrocephalus. However, considering flesh protein loss and the subsequent oxidative stress, the fasting technique should be used with precautions. Project (No. 2006C12098) supported by the Science and Technology Department of Zhejiang Province, China     

Effects of α-tocopheryl acetate supplementation in preslaughter diet on antioxidant enzyme activities and fillet quality of commercial-size Sparus macrocephalus

This study examined the effects of dietary α-tocopheryl acetate supplementation on antioxidant enzyme activities and fillet quality in commercial-size Sparus macrocephalus. Three hundred fish [main initial weight （350±12） g] were divided into three groups （E250, E500 and El000） and reared in 9 cages. The fish were fed for 8 weeks with three diets containing different levels of dietary α-tocopheryl acetate （289, 553, 1069 mg/kg）. Over the experimental period, fish were fed to satiation and reached a final mean weight of （465±28） g without significant body weight difference and proximate composition difference. Fillet α-tocopherol was significantly （P〈0.05） different between groups, reaching levels of 14.2, 22.1, 30.9 pg/mg fillet for groups E250, E500 and El000, respectively. Total serum superoxide dismutase （SOD） activity increased significantly （P〈0.05） in fish fed the diets high in α-tocopheryl acetate, but serum glutathione peroxidase （GPX） activity was unaffected. In storage on ice, fillets of fish fed the diets high in α-tocopheryl acetate exhibited significantly lower （P〈0.05） levels of oxidation. These results suggested that increased dietary α-tocopheryl acetate could increase its flesh deposition, increase the activity of SOD and prevent lipid peroxidation ofSparus macrocephalus fillets in retail storage on ice.     

Study on the neurotoxic effects of low-level lead exposure in rats

Objective: To investigate effects of developmental lead exposure on nitric oxide synthase (NOS) activity in different brain regions and on N-methyl-D-aspartate (NMDA) receptor mRNA expression in the hippocampus of rats. On the basis of these observations, we explored possible mechanisms by which lead exposure leads to impaired learning and memorizing abilities in children. Methods: A series of rat animal models exposed to low levels of lead during the developing period was established (drinking water containing 0.025%, 0.05% and 0.075% lead acetate). NOS activities in the hippocampus, the cerebral cortex, the cerebellum and the brain stem were determined with fluorescence measurement and levels of mRNA expression of the NMDA receptor 2A (NR2A) subunit and NMDA receptor 2B (NR2B) subunit in the rat hippocampus were measured with Retro-translation (RT-PCR). Results: There were no differences in the body weight of rat pups between any of the groups at any given time (P>0.05). The blood lead level of Pb-exposed rat pups showed a systematic pattern of change: at 14 d of age, it was lower than that at 7 d of age, then rising to the peak level at 21 d and finally falling to lower levels at 28 d. The hippocampal NOS activities of lead-exposed groups were all lower than that of the control group on the 21st and 28th day (P<0.01). NOS activities in the cerebellum of lead-exposed groups were all lower than that of the control group on the 21st and 28th day (P<0.001) and the NOS activity of the 0.025% group was significantly lower than that of the 0.05% and 0.075% groups on the 28th day (P<0.05). NOS activity in the cerebral cortex of the 0.075% group was significantly lower than that of the control, 0.025% and 0.05% groups on the four day spans (P<0.001). There was no significant difference of NOS activity in the brain stem between any lead-exposed group and the control group on the four day spans. In the 0.05% and the 0.075% groups, the level of NR2A mRNA expression was higher than that in the control group at 7 d and 14 d of age (P<0.05). In the 0.025% group, the level of NR2A was found to be higher than that in the control group at 7 d of age only (P<0.05). No significant differences were found for the levels of NR2B mRNA expression between any of the groups at any given time. Conclusions: NOS activity in the hippocampus, the cerebral cortex and the cerebellum are inhibited by lead exposure. The degree of the inhibitory effect depends on the time span of exposure and the lead concentration. Developmental low-level lead exposure was found to raise the level of NR2A mRNA expression in the hippocampus of rats. Developmental low-level lead exposure does not affect the level of NR2B mRNA expression in the hippocampus.     

Influence of dietary conjugated linoleic acid on growth, fatty acid composition and hepatic lipogenesis in large yellow croaker (Pseudosciaena crocea R.)

We examined the effects of conjugated linoleic acid (CLA) on growth, fatty acid composition and enzyme activity of fatty acid oxidation in the liver of large yellow croaker. We divided 1600 fish (average initial weight 150 g) into 4 groups and reared them in 8 cages. Four dietary treatments were formulated to contain 0%, 1%, 2% and 4% (w/w) CLA, respectively. The fish were fed for 10 weeks ad libitum twice daily. We found that the dietary CLA had no effect on growth, biometric parameters and whole body proximate (P>0.05), but showed some significant effects on the fatty acid composition in both muscle and the liver.The activities oflipogenic enzymes were slightly depressed in fish fed with increasing levels of CLA when compared with control (P>0.05). Dietary CLA supplementation had no effects on liver lipid content, but significantly increased the contents of saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) (P＜0.05) and decreased monounsaturated fatty acid (MUFA) content in both muscle and the liver. Dietary CLA inclusion resulted in significant increases of the biologically active cis-9, trans-11 and trans-10, cis-12 isomers in both tissues (P＜0.05). The total accumulation of CLA was higher in the liver (3.83%, w/w) than in muscle (3.77%, w/w) when fed with 4% (w/w) CLA. This study demonstrates that large yellow croakers are capable of absorbing and depositing CLA and long-chain n-3 PUFA in the liver and muscle, showing that this species fed with CLA could be an important human food source for these healthful fatty acids.     

脱氢表雄酮对鸡脂质代谢的调节与抗氧化作用的研究

研究DHEA对淮南王鸡脂质代谢与抗氧化的影响。240只8日龄健康雏鸡随机分为4组:对照组(饲喂基础饲料)以及试验Ⅰ、Ⅱ、Ⅲ组(分别饲喂含有5、15和45 mg DHEA/kg的饲料)。42和56日龄各组随机抽取发育正常的12只个体,空腹称重,按常规方法屠宰,测定肝脏、腹脂、皮下脂肪相对重以及胸肌、腿肌肌内脂肪含量,并测定56日龄时血清丙二醛(MDA)、葡萄糖(Glu)、甘油三酯(TG)和胆固醇(TC)含量以及总抗氧化能力(T-AOC)、脂蛋白脂酶(LPL)和肝脂酶(HL)活性等。结果显示:在42日龄,试验Ⅱ组肝脏以及试验III组腹脂、皮下脂肪相对重显著低于对照组(P<0.05);在56日龄,试验Ⅱ组肝脏、腹脂相对重以及试验Ⅲ组的腹脂、皮下脂肪相对重皆显著降低(P<0.05);DHEA处理有降低血糖、血脂的趋势,其中试验Ⅱ组血清血糖、TC、TG和VLDL含量均显著低于对照组,差异显著(P<0.05);试验Ⅱ、Ⅲ组血清LPL活性显著升高(P<0.05),试验Ⅰ组血清HL活性显著增加(P<0.05);试验Ⅰ、Ⅱ组血清MDA含量显著降低(P<0.05),而T-AOC水平显著增加(P<0.05)。结论:DHEA具有降低鸡的脂质代谢和增强抗氧化的作用。     

四溴二苯醚与高氯酸盐联合暴露对成年斑马鱼肝脏抗氧化系统的影响

实验选择四溴二苯醚（BDE-47）与高氯酸盐（PER）作为研究对象,系统研究了二者联合暴露对成年斑马鱼肝脏抗氧化系统的影响。实验设置（BDE-47 8.5+PER 335） mg/L,（BDE-47 0.85+PER 33.5） mg/L,（BDE-47 0.085+PER 3.35） mg/L三种联合暴露组及二者各自单一的暴露组。暴露14天后,分别测定雌雄斑马鱼肝脏内超氧化物歧化酶（SOD）活性、过氧化氢酶（CAT）活性、谷胱甘肽过氧化物酶（Gpx）活性以及脂质过氧化物（MDA）水平。结果显示,与两种物质单一暴露相比,联合暴露致使肝脏内SOD,CAT的活性增加,MDA水平增加,而GSH活性降低,实验说明,PER诱导加剧了BDE-47对成年斑马鱼肝脏抗氧化酶的影响,进一步产生了氧化应激。     

Effects of soybean isoflavone on intestinal antioxidant capacity and cytokines in young piglets fed oxidized fish oil

To investigate the effect of glycitein, a synthetic soybean isoflavone (ISF), on the intestinal antioxidant capacity, morphology, and cytokine content in young piglets fed oxidized fish oil, 72 4-d-old male piglets were assigned to three treatments. The control group was fed a basal diet containing fresh fish oil, and the other two groups received the same diet except for the substitution with the same dosage of oxidized fish oil alone or with ISF (oxidized fish oil plus ISF). After 21 d of feeding, supplementation of oxidized fish oil increased the levels of malondialdehyde (MDA), oxidized glutathione (GSSG), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin-2 (IL-2), nuclear factor κ B (NF-κB), inducible nitric oxide synthase (iNOS), NO, and Caspase-3 in jejunal mucosa, and decreased the villous height in duodenum and the levels of secretory immunoglobulin A (sIgA) and IL-4 in the jejunal mucosa compared with supplementation with fresh oil. The addition of oxidized fish oil plus ISF partially alleviated this negative effect. The addition of oxidized fish oil plus ISF increased the villous height and levels of sIgA and IL-4 in jejunal mucosa, but decreased the levels of IL-1β and IL-2 in jejunal mucosa (P<0.05) compared with oxidized fish oil. Collectively, these results show that dietary supplementation of ISF could partly alleviate the negative effect of oxidized fish oil by improving the intestinal morphology as well as the antioxidant capacity and immune function in young piglets.     

海藻多糖抗氧化作用的实验研究

目的:研究海藻多糖(Polysaechrides from Spirulina Platensis,PSP)对小鼠肝损伤动物模型与肝匀浆脂质过氧化模型的抗氧化作用。方法:采用腹腔注射CCL4的方法,制造小鼠肝损伤动物模型,金氏法测定血清谷氨酸丙酮酸转氨酶(SGPT)和肝脏的过氧化脂质(Lipoper-oxides,LPO)含量;Fenton反应诱导小鼠肝匀浆脂质过氧化动物模型,采用硫代巴比妥酸(TBA)法测定肝匀浆LPO。结果:在体外,海藻多糖可剂量依赖性地抑制Fenton反应导致的CCL4毒化小鼠肝匀浆中LPO的生成,其IC50为1.6×10-4。在体内,灌胃250mg/kg的海藻多糖组可明显降低CCL4毒化小鼠血清SGPT活性(P<0.01)。结论:海藻多糖对体内外的肝组织有一定程度的抗氧化作用。     

复方中草药对AA肉鸡肌肉抗氧化能力的影响

目的:研究复方中草药对肉鸡肌肉抗氧化能力的影响。方法:选用健康1日龄AA肉鸡400羽,随机分为对照组和试验Ⅰ、Ⅱ、Ⅲ组,每组100羽。对照组饲喂玉米-豆粕基础日粮,试验Ⅰ、Ⅱ、Ⅲ组分别在基础日粮中添加0.5%、1.0%和1.5%的复方中草药,试验期42 d。结果:21日龄时,与对照组相比,试验Ⅰ、Ⅱ、Ⅲ组肉鸡胸肌和腿肌SOD和T-AOC活性及GSH-PX含量不同程度升高,MDA含量不同程度降低,其中试验Ⅱ组胸肌T-AOC活性和GSH-PX含量显著升高,胸肌MDA含量显著降低(P0.05);试验Ⅰ和Ⅲ组胸肌SOD活性和试验Ⅲ组腿肌SOD活性和GSH-PX含量也显著升高(P0.05);而各试验组腿肌MDA含量均显著降低(P0.05)。42日龄时,与对照组相比,各试验组胸肌MDA含量均显著降低(P0.05),而试验Ⅱ组胸肌GSH-PX含量显著升高(P0.05),且各试验组腿肌T-AOC活性也均有不同程度的提高。结论:添加不同剂量的复方中草药可不同程度提高肉鸡胸肌和腿肌抗氧化酶活性,降低MDA含量,其中以添加1.0%的复方中草药提高胸肌抗氧化能力效果最好,而添加1.5%的复方中草药提高腿肌抗氧化能力效果较好。     

獒肉与狗肉营养价值的测定与比较

对獒肉和狗肉中的蛋白质、氨基酸、脂肪、总糖、和脂肪酸几种生物大分子含量进行了初步分析.结果表明:獒肉中蛋白质含量15.53％,家狗肉蛋白质含量14.19%,獒的总脂肪含量30.50％,狗的脂肪含量20.31％.獒的总糖含量1.59％,狗的总糖含量1.43％,17种氨基酸中人体必需氨基酸含量均略高,其中赖氨酸的含量獒是狗的近三倍.脂肪酸含量均非常丰富,其中油酸含量达40％多.獒与狗的部分指标含量差异明显.     

肉鸡肺动脉高压肝脏和心脏线粒体氧自由基变化研究

400只艾维茵肉鸡按常规方法育雏在21日龄时随机分为两组,A组200只在24℃下饲养,B组200只在低温12℃下饲养。在28、35、42、49日龄测定腹水心脏指数和红细胞压积,分离鉴定腹水肉鸡心、肝线粒体,测定其所含的MnSOD活性以及线粒体膜结构的MDA含量变化经。结果表明:(1)低温处理后一周和二周,在肝脏和心脏线粒体中,SOD含量升高或显著升高(p<0.05)。MDA含量降低或显著降低(p<0.05)。(2)低温处理三周后,SOD的含量降低或显著降低。MDA的含量升高或显著升高(p<0.05)。本实验结果显示肝脏和心脏的线粒体SOD和MDA的变化与肉鸡腹水综合征的发生发展关系密切,氧自由基在亚细胞水平上参与了疾病的病理过程。     

三叶悬钩子对大鼠酒精性肝炎保护作用

目的：：观察三叶悬钩子乙醇提取物对大鼠酒精性肝炎的保护作用。方法：90只大鼠,随机分为6组,每天上午8：00灌胃1次,正常组大鼠灌胃给蒸馏水,其余5组大鼠灌胃给白酒,连续灌胃28 d,建立大鼠酒精性肝炎模型;第15天开始,每天上午9：00各组大鼠均以相应药物灌胃1次,连续灌胃14 d;第28天末次灌胃后,取血、取肝脏,检测血清天门冬氨酸氨基转移酶（GOT）、丙氨酸氨基转移酶（GPT）活性及肝组织丙二醛（MDA）含量、超氧化物歧化酶（SOD）活性;观察肝脏指数及肝组织病理变化。结果：三叶悬钩子乙醇提取物能显著降低肝炎大鼠GPT、GOT活性和MDA含量,能显著提高肝炎大鼠SOD活性;能显著降低肝炎大鼠肝脏指数;能显著减轻肝炎大鼠肝组织水肿和脂肪变性。结论：三叶悬钩子对大鼠酒精性肝炎有保护作用。     

竹茶酒对D-半乳糖衰老模型小鼠抗衰老作用的研究

为了研究竹茶酒的抗衰老作用,将60只小鼠随机分成正常对照组,衰老模型组,阳性对照组,竹茶酒高、中、低剂量组,除正常对照组外,其余各组均通过腹腔注射300mg/（kg·d）D-半乳糖建立衰老小鼠模型,在建模的同时,给药组分别灌胃相应剂量的竹茶酒,其余组灌胃等量的生理盐水,连续6周灌胃后测定其血清及肝脏的抗氧化指标,实验结果显示不同剂量的竹茶酒均能显著提高小鼠肝脏、血清中超氧化物歧化酶活性、谷胱甘肽过氧化物酶的活性,并有效降低丙二醛的含量,由此认为竹茶酒可提高自由基的清除率,减少自由基对机体产生的损伤,具有抗衰老作用。     

Evaluation of organ distribution of microcystins in the freshwater phytoplanktivorous fish <Emphasis Type="Italic">Hypophthalmichthys molitrix</Emphasis>

To evaluate the public health risk of exposure to microcystins in fish food in China, the distribution pattem of microcystin-LR and microcystin-RR in various organs （liver, intestine, kidney, muscle and lipid） of the dominant freshwater phytoplanktivorous fish Hypophthalmichthys molitrix in Hangzhou, China＇s Tiesha River was investigated with the method of HPLC-ESI-MS analysis. The distribution of microcystins was different in the fish organs and the major total microcystins （microcystin-LR and microcystin-RR） were present in the intestines （6.49 μg/g fresh weight）, followed by the livers （4.52 μg/g fresh weight） and the muscles （2.86 μg/g fresh weight）. Microcystins were detected in kidneys （1.35 μg/g fresh weight）, but not detected in lipid. The results suggested that the mean daily intake from fish was 0.03 μg/kg body weight which was very close to the recommended WHO tolerable daily intake （TDI） level of 0.04μg/kg body weight per day, and local people were wamed they may have health risk if they consumed fish from the river.     

Protective effects of Salvia miltiorrhizae on the hearts of rats with severe acute pancreatits or obstructive jaundice

Objective: To investigate the therapeutic effects and mechanisms of Salvia miltiorrhizae (Danshen) in the treatment of severe acute panereatitis (SAP)- or obstructive jaundice (OJ)-induced heart injury. Methods: A total of 288 rats were used for SAP-(n=108) and O J-associated (n=180) experiments. The rats were randomly divided into sham-operated, model control, and Salvia miltiorrhizae-treated groups. According to the difference of time points after operation, SAP rats in each group were subdivided into 3, 6 and 12 h subgroups (n=12), whereas OJ rats were subdivided into 7, 14, 21, and 28 d subgroups (n=15). At the corre-sponding time points after operation, the mortality rates of the rats, the contents of endotoxin and phospholipase A2 (PLA2) in blood, and pathological changes of the hearts were investigated. Results: The numbers of dead SAP and OJ rats in the treated groups declined as compared with those in the model control group, but not significantly (P>0.05). The contents ofendotoxin (at 6 and 12 h in SAP rats and on 7, 14, 21, and 28 d in OJ rats, respectively) and PLA2 (at 6 and 12 h in SAP rats and on 28 d in OJ rats, respectively) in the treated group were significantly lower than those in the model control group (P<0.01 and P<0.001, respec-tively). Besides, myocardial pathological injuries were mitigated in SAP and OJ rats. Conclusion: In this study, we found that Salvia miltiorrhizae improved myocardial pathological changes, reduced the content of PLA2 in blood, and decreased the mortality rates of SAP and OJ rats, exerting protective effects on the hearts of the rats.     

Survey of antioxidant capacity and phenolic composition of blueberry, blackberry, and strawberry in Nanjing

Berries are a good source of natural antioxidants. In the present study, the total antioxidant capacity and phenolic composition of three berry fruits (blueberry, blackberry, and strawberry) cultivated in Nanjing were investigated. Blueberry, with a Trolox equivalent antioxidant capacity (TEAC) value of 14.98 mmol Trolox/100 g dry weight (DW), exhibited the strongest total antioxidant capacity using both the 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods. Blueberry also had the highest total phenolic content (TPC, 9.44 mg gallic acid/g DW), total flavonoid content (TFC, 36.08 mg rutin/g DW), and total anthocyanidin content (TAC, 24.38 mg catechin/g DW). A preliminary analysis using high performance liquid chromatography (HPLC) showed that the blueberry, blackberry, and strawberry samples tested contained a range of phenolic acids (including gallic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, p-coumaric acid, ferulic acid, ellagic acid, and cinnamic acid) and various types of flavonoids (flavone: luteolin; flavonols: rutin, myricetin, quercetrin, and quercetin; flavanols: gallocatechin, epigallocatechin, catechin, and catechin gallate; anthocyanidins: malvidin-3-galactoside, malvidin-3-glucoside, and cyanidin). In particular, the blueberries had high levels of proanthocyanidins and anthocyanidins, which might be responsible for their strong antioxidant activities. These results indicate a potential market role for berries (especially blueberries) as a functional food ingredient or nutraceutical.     

金樱子多糖对免疫抑制小鼠肝功能及血脂代谢的调节作用

为探讨金樱子多糖对免疫抑制小鼠肝功能及血脂代谢的调节作用,取50只昆明小鼠随机平均分为正常对照组、模型组、RLP低剂量组、RLP中剂量组、RLP高剂量组．低、中、高剂量组分别按100ms／kg·d、200mg／kg·d、400mg／kg·d连续灌胃30d;正常对照组和模型组灌胃生理盐水．于试验前一周在继续灌胃的基础上,除正常对照组外,分剐于第l、3、5天给小鼠按25mg／kg体重腹腔注射地塞米松（Dex）建立免疫抑制动物模型．摘小鼠眼球取血,用试剂盒测定小鼠血清的总胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDL—C）、低密度脂蛋白胆固醇（LDL—C）、谷草转氨酶（AST）、谷丙转氨酶（ALT）．结果表明,金樱子多糖能显著降低免疫抑制小鼠血清中TC、LDL—C、AST、Au含量,对HDL—C和TG有一定的调节作用．因此,金樱子多糖对免疫抑制小鼠肝功能及血脂代谢具有一定的调节作用．     

实验性脂肪肝大鼠的脂肪代谢、细胞因子、瘦素方面的变化

目的:观察脂肪肝大鼠在生化、病理、脂肪代谢、细胞因子、胰岛素及瘦素各方面指标的变化.方法:雄性Wistar大鼠22只,按体重层次随机分为2组,对照组(A)11只,脂肪肝组(B)11只.对照组饲以普通鼠饲料,脂肪肝组饲以高脂饲料.8周后,全部处死,取血及肝组织,测定血中AIT、AST、TG、CHO、INS、FBS、FFA、Ieptin、II-6、TNF.肝组织匀浆测定肝组织TC,TG,SOD、MDA,观察肝脏组织学变化.结果:脂肪肝大鼠存在明显脂肪代谢紊乱,肝功能异常,胰岛素抵抗及瘦素表达增高;细胞因子升高.结论:实验性高脂饮食脂肪肝大鼠存在瘦素抵抗及胰岛素抵抗.     

Imbalanced free radicals and antioxidant defense systems in schizophrenia： A comparative study

Objective： To examine changes of blood oxidative-antiovidative level in schizophrenic patients and its relationship with clinical symptoms. Methods： Forty-six Chinese patients met DSM-IV （Diagnostic and Statistical Manual of Mental Disorders-iV） criteria for schizophrenia and fifty age- and sex-matched healthy controls were enrolled in the present study. Baseline psychiatric symptom severity was assessed with brief psychiatric rating scale, positive and negative syndrome scale on the blood draw day. Fresh blood samples were collected to measure levels of nitric oxide and lipid peroxide in plasma as well as activities of superoxide dismutase, catalase and glutathione peroxidase in red blood cells by spectrophotometric assays simultaneously. Results Comparison of the biochemical parameters indicated that the level of nitric oxide and lipid peroxide increased in patient group, which represented a positive correlation with positive scale scores; while the activities of three critical enzymes decreased and showed a negative linear correlation. Conclusion： This study showed that there are dysregulation of free radical metabolism and poor activities of the antioxidant defense systems in schizophrenic patients. Excess free radicals formation may play a critical role in the etiology of schizophrenia. Using antioxidants might be an effective therapeutic approach to partially alleviate or prevent the symptoms of schizophrenia.     

Preliminary studies on the chemical characterization and antioxidant properties of acidic polysaccharides from Sargassum fusiforme

In order to investigate the antioxidant properties of the polysaccharides from the brown alga Sargassum fusiforme, the crude polysaccharides from S.fusiforme (SFPS) were extracted in hot water, and the lipid peroxidation inhibition assay exhibited that SFPS possessed a potential antioxidant activity. Hence, two purely polymeric fractions, SFPS-1 and SFPS-2 were isolated by the column of DEAE (2-diethylaminoethanol)-Sepharose Fast Flow, with their molecular weights of 51.4 and 30.3 kDa determined by high performance gel permeation chromatography (HPGPC). They were preliminarily characterized using chemical analysis in combination of infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies and found to contain large amounts of uronic acids and β-glycosidical linkages. The antioxidant activities of these two SFPS fractions were evaluated using superoxide and hydroxyl radical-scavenging assays. The results show that the antioxidant ability of SFPS-2 was higher than that of SFPS-1, probably correlating with the molecular weight and uronic acid content.