2型糖尿病肾病患者瘦素与尿微量蛋白检测

目的探讨瘦素(leptin)、尿微量白蛋白(mALB)、α1-微球蛋白(α1-MG)、N-乙酰--βD氨基葡萄糖苷酶(NAG)对2型糖尿病肾病早期诊断的价值。方法采用放射免疫分析法、免疫比浊法和比色法分别检测36例健康体检者、24例单纯2型糖尿病患者和53例2型糖尿病肾病患者的leptin、mALB、α1-MG、NAG水平浓度。结果血清中男性与女性的瘦素水平存在显著性差异(P<0.05),女性普遍高于男性。2型糖尿病肾病组的leptin、mALB、NAG、α1-MG水平明显高于正常对照组、单纯2型糖尿病患者组(P<0.01),并且随着病情的加重,血清中的leptin和尿微量蛋白逐渐升高。2型糖尿病肾病患者leptin与mALB、α1-MG存在显著正相关(r=0.295,r=0.416,P<0.05)。结论瘦素与尿微量蛋白是早期诊断2型糖尿病肾病及预后的良好指标。

蛋白丢失性胃肠病诊治进展

蛋白丢失性胃肠病(PLG)不是一个独立的原发疾病,而是继发于其他多种基础疾病的临床综合征,以水肿、腹泻、发热为主要临床表现。诊断是治疗的基础,因此不仅要确定存在蛋白质从胃肠道丢失的情况,还要明确其病因。利用放射性核素标记蛋白或其他特殊物质来检测胃肠道中的放射性,推算蛋白从胃肠道丢失的比率是PLG的特异性诊断方法之一。PLG的预后与原发病控制与否相关,因此最根本的治疗是对基础疾病的治疗,即在给予支持治疗的同时有针对性地治疗原发病,只有彻底消除引起蛋白丢失的病因,PLG才有可能得到彻底的治愈。

去甲斑蝥素和康莱特对肝癌病人肝动脉化疗栓塞术后肝功能影响的观察

目的:观察去甲斑蝥素和康莱特对原发性肝癌行经皮动脉化疗栓塞术(TACE)后肝功能的保护作用。方法:对去甲斑蝥素和康莱特并用与否的59例患者的肝功能进行析因设计的双因素方差分析。结果:使用去甲斑蝥素与不使用1周后总胆红素、直接胆红素和白蛋白数值不同,不使用胆红素较高,而白蛋白则较低。康莱特则对TACE后胆红素和白蛋白无明显影响。结论:使用去甲斑蝥素可改善TACE术后患者肝功能情况,而康莱特则无此效果。这也提示在使用中药相关的药品时,应当结合中医的辨证原则而应用。

Alzheimer’s disease:epidemiology,genetics,and beyond

Alzheimer＇s disease （AD） is an increasing epidemic threatening public health. Both men and women are susceptible to the disease although women are at a slightly higher risk. The prevalence of AD rises exponentially in elderly people from 1% at age of 65 to approximately 40%-50% by the age of 95. While the cause of the disease has not been fully understood, genetics plays a role in the onset of the disease. Mutations in three genes （APP, PSENI, and PSEN2） have been found to cause AD and APOE4 allele increases the risk of the disease. As human genomic research progresses, more genes have been identified and linked with AD. Genetic screening tests for persons at high risk of AD are currently available and may help them as well as their families better prepare for a later life with AD.

蛋白丢失性肠病61例临床分析

目的 通过对蛋白丢失性肠病临床资料的总结分析，提高对本病的认识。方法 对北京侨和医院1997至2009年诊断的6l例蛋白丢失性肠病进行分析总结。结果 男26例，女35例，年龄16～77（40±15）岁。水肿为首发症状5l例；腹水为主要症状4l例；合并双侧胸腔积液23例；腹痛16例，腹泻33例；所有患者均有显著的低蛋白血症。37例患者经核素^99Tc^m标记白蛋白显像汪实存在肠道蛋白丢火，24例为临床诊断。原发病主要为系统性红斑狼疮（28例），先天件淋巴管扩张（12例）。治疗上以原发病治疗为主。结论 蛋白丢失性肠病临床并非罕见，以严霞的低蛋白血症和多浆膜腔积液为特征，核素＾99Tc＾m标记白蛋白显像是特异性的诊断方法之一，治疗上以原发病治疗为主，预后与原发病控制与否相关。

Affinity Chromatography Purification of Recombinant Human Interleukin-6 from Its Fusion Protein with GST

Recombinant E.coli JM109, containing pHZ1818 plasmid which included the fused gene encoding human interleukin 6(IL 6), expressed a fusion protein with glutathion S transferase(GST). The fusion protein existed both in the supernatant and inside the bacterial cell,but the insoluble protein had no biological activity and could not be refolded. The rotative speed of the shaker and the temperature of induction were optimized to maximize the expression of the soluble fusion protein. From the supernatant of the cell sonicates Glutathion Sephrose 4B affinity column chromatography was employed to isolate the fusion protein which could be purified to >80 0 0 in a single step. The yield of soluble GST IL 6 was about 10 mg per liter culture. The GST was site specifically cloven by 6 hours of treatment with thrombin and from the thrombin digest mixture IL 6 was purified by Q high performance ion exchange chromatography. From 1 liter of E.coli culture 2 mg refined IL 6 was obtained. The purified IL 6 had a purity of more than 95 0 0 and a biological activity of 1.02×10 8 IU/mg.

Meta-analysis of the Use of ACEI for Inhibiting Albuminuria in Diabetic Patients

Aim To examine whether AER(albumin excretion rate) in normotensive diabeticpatients can be effectively inhibited by ACEI. Methods Literature on randomized controlled trials ofACEI for inhibiting AER in normotensive diabetic patients was searched. The electronic databasesretrieved were Medline (1980 ― 2003), Embase database (1980 ― 2000), Cochrane Library, CL( 1980 ―2004), CBMdisc( 1980 ― 2002), and IPA( 1980 ― 2002). Seven studies were chosen. Data werecombined by Revman 4.2. Results: The pooled effect of change in AER is - 56.31 μg·min^(-1)) [ -81.96, -30.66] (P<0.0001). According to the analysis of subgroups, the pooled effects of 1 - 5 yearsare - 11.97 μg·min^(-1)[-22.04, -1.89] (P = 0.02), -28.01 μg·min^(-1)[-34.50, -21.52](P<0.00001), -43.24 μg·min^(-1) [ -57.15, -29.32] (P< 0.00001), -61.65 μg·min^(-1)[77.77,-45.54] (P< 0.00001), and -98.41 μg·min^(-1)[-162.02,-34.79] (P = 0.002). Regarding progression toclinincal proteinuria as end-point, the pooled Peto OR =0.27 [0.18,0.40] (95% CI), P < 0.00001.According to the analysis of subgroups, the pooled effects of 2 and 5 years are Peto OR = 0.30[0.18,0.51] (P<0.00001) and Peto OR=0.25 [0.13, 0.50](P<0.0001). Publication bias is small.Conclusion In normotensive diabetic patients, ACEI inhibits AER effectively and reduces theprobability of progression of microalbuminuria to clinical proteinuria.

Expression of albumin, IGF-1, IGFBP-3 in tumor tissues and adjacent non-tumor tissues of hepatocellular carcinoma patients with cirrhosis

AIM： To explore the expression of albumin （ALB）, insulinlike growth factor （IGF）-I, and insulin-like growth factor binding protein （IGFBP）-3 in tumor tissues and adjacent non-tumor tissues of hepatocellular carcinoma （HCC） patients with cirrhosis.METHODS： Twenty-four HCC patients with cirrhosis who underwent hepatectomy were studied. ALB mRNA, IGF-1 mRNA, and IGFBP-3 mRNA in liver tissues （including tumor tissues and adjacent non-tumor tissues） were detected by reverse transcriptase-polymerase chain reaction（RT-PCR）. Liver Ki67 immunohistochemistry staining was studied. At the same time, 12 patients with cholelithiasis or liver angioma who underwent operation were segregated as normal control.RESULTS： In HCC patients with cirrhosis, hepatic ALB mRNA, IGF-1 mRNA, and IGFBP-3 mRNA of tumor tissues or adjacent non-tumor tissues were lower than the normal liver tissues, while in tumor tissues, hepatic ALB mRNA and IGFBP-3 mRNA were lower, hepatic IGF-1 mRNA was higher than in adjacent non-tumor tissues. Liver Ki67 labeling index （Ki67 LI） in tumor tissues or adjacent nontumor tissues were higher than that in the normal liver tissues, while in tumor tissues it was higher than that in adjacent non-tumor tissues.CONCLUSION： Imbalance of IGF-1 and IGFBP-3 may play a role in hepatocarcinogenesis and tumor development of liver cirrhosis patients.

C-reactive protein,procalcitonin,interleukin-6,vascular endothelial growth factor and oxidative metabolites in diagnosis of infection and staging in patients with gastric cancer

AIM:The current study was to determine the serum/pLasma levels of VEGF,IL-6,malondialdehyde (MDA),nitric oxide (NO),PCT and CRP in gastric carcinoma and correlation with the stages of the disease and accompanying infection. METHODS:We examined the levels of serum VEGF,IL-6, PCT,CRP and plasma MDA,NO in 42 preoperative gastric cancer patients and 23 healthy subjects.There were infection anamneses that had no definite origin in 19 cancer patients. RESULTS:The VEGF levels (mean±SD; pg/mL) were 478.05±178.29 and 473.85±131.24 in gastric cancer patients with and without infection,respectively,and these values were not significantly different (P>0.05).The levels of VEGF, CRP,PCT,It-6,MDA and NO in cancer patients were significantly higher than those in healthy controls and the levels of CRP,PCT,It-6,MDA and NO were statistically increased in infection group when compared with non- infection group (P<0.001). CONCLUSION:Although serum VEGF concentrations were increased in gastric cancer,this increase might not be related to infection.CRP,PCT,IL-6,MDA and NO have obvious drawbacks in the diagnosis of infections in cancer patients. These markers may not help to identify infections in the primary evaluation of cancer patients and hence to avoid unnecessary antibiotic treatments as well as hospitalization. According to the results of this study,IL-6,MDA,NO and especially VEGF can be used as useful parameters to diagnose and grade gastric cancer.

Nuclear effects of ethanol-induced proteasome inhibition in liver cells

Alcohol ingestion causes alteration in several cellular mechanisms, and leads to inflammation, apoptosis, immunological response defects, and fibrosis. These phenomena are associated with significant changes in the epigenetic mechanisms, and subsequently, to liver cell memory. The ubiquitin-proteasome pathway is one of the vital pathways in the cell that becomes dysfunctionial as a result of chronic ethanol consumption. Inhibition of the proteasome activity in the nucleus causes changes in the turnover of transcriptional factors, histone modifying enzymes, and therefore, affects epigenetic mechanisms. Alcohol consumption has been associated with an increase in histone acetylation and a decrease in histone methylation, which leads to gene expression changes. DNA and histone modifications that result from ethanol-induced proteasome inhibition are key players in regulating gene expression, especially genes involved in the cell cycle, immunological responses, and metabolism of ethanol. The present review highlights the consequences of ethanol-induced proteasome inhibition in the nucleus of liver cells that are chronically exposed to ethanol.

Interleukin-6, desmosome and tight junction protein expression levels in reflux esophagitis-affected mucosa

AIM： To investigate the correlation between the expression levels of interleukin （IL）-6 and proteins in tight junctions （TJs） in the esophageal mucosa of rats modeling different types of reflux esophagitis （RE）, and the ability of aluminum phosphate to protect against RE-induced mucosal damage via these proteins. METHODS： Male SPF Wistar rats aged 56 d were divided randomly into acid RE, alkaline RE, mixed RE, and control groups. Various surgical procedures were performed to establish rat models of acid RE. At 14 d after the procedure, some of the rats started aluminum phosphate treatment. Transmission electron microscopy （TEM） was used to observe the morphological features of TJs and desmosomes in the esophageal epithelium. Immunohistochemical methods and Western blotting were used to measure expression of claudin 1, occludin, ZO-1, JAM-l, DSG-1 and IL-6; reverse transcription polymerase chain reaction （RT- PCR） was used to measure expression of mRNA of claudin 1, occludin, ZO-1, JAM-1, DSG-1 and IL-6. RESULTS： At day 14 alter the procedures, an RE model was established in all subsequently sacrificed rats of groups A, B and C. By both gross and microscopic observation, the mucosa was damaged and thickened as the disease progressed. With TEM observation, a widened intercellular space was noticed, with significantly fewer desmosomes. Immunohistochemistry showed significantly higher levels of all proteins in all RE models compared to control rats at 3 d after operation （65.5% ± 25.6% vs 20.5% ± 2.1%, P 〈 0.05, respectively）. At 14 d after operation, along with continuing hyperplasia in the basal layer, the expression of TJ proteins in individual cells gradually decreased （12.4% ± 2.1% vs 20.5% ± 2.1%, P 〈 0.05, respectively）. Western blottings and RT-PCR showed a directly proportional increase in IL-6 levels in relation to TJ proteins, as compared to controls （0.878 ± 0.024 vs 0.205 ± 0.021 and 0.898±0.022 vs 0.205 ± 0.021, P 〈 0.05, respectively）. Upon treatment with aluminum phosphate, however, these protein levels were restored to normal gradually over 30-60 d in rats with acid RE （30.4% ± 2.1% vs 20.5% ± 2.1%, P 〉 0.05, treated vs untreated, respectively）. These levels increased in the rat with alkaline RE, and this increase was accompanied by continued hyperplasia in comparison with controls （85.5% ± 25.6% vs 20.5% ± 2.1%, P 〈 0.05, respectively）. Furthermore, the expression of TJ proteins was not correlated significantly with that of IL-6 in this group. CONCLUSION： These findings indicate that TJ proteins are highly expressed as an early molecular event involved in RE development, and that IL-6 is an inflammatory factor in this process,

^(99m)Tc-MAA肺灌注显像对下肢创伤及手术后肺栓塞患者的疗效评价

目的利用Tc-大颗粒聚合白蛋白(MAA)肺灌注显像(PPI)监测下肢创伤及手术后(LEPP)肺99m栓塞(PE)患者疗效并对其评价。方法19例临床确诊的LEPP合并PE患者分别于溶栓治疗前、治疗2～4周后进行PPI;PPI图像上显示一个肺段灌注完全缺损记3分,缺损25%～75%记2分,<25%记1分,无异常记0分,根据记分变化分析溶栓治疗前后临床改善情况。结果19例患者溶栓治疗2～4周后临床症状完全消失10例、明显改善6例、有改善3例,治疗前(10.2±3.8)后(2.8±1.4)PPI记分有明显差异(t=7.75,P<0.01)。结论PPI为一种准确、可靠的无创性评价肺血流改善的手段,对LEPP合并PE患者疗效观察具有重要的临床价值。

Up-regulation interleukin-6 and interleukin-8 by activated protein C in lipopolysaccharide-treated human umbilical vein endothelial cells

Objective: To investigate the effect of activated protein C (APC) on inflammatory responses in human umbilical vein endothelial cells (HUVEC) stimulated with lipopolysaccharide (LPS). Methods: The second passage of collagenase digested HUVEC was divided into the following groups: serum free medium control group (SFM control), phosphate buffer solution control group (PBS control), LPS group with final concentration of 1 μg/ml (LPS group), APC group with final concentration of 7 μg/ml, Pre-APC group (APC pretreatment for 30 min prior to LPS challenge), and Post-APC group (APC administration 30 min after LPS challenge). Supernatant was harvested at 0, 4, 8, 12 and 24 h after LPS challenge. Interleukin-6 (IL-6) and Interleukin-8 (IL-8) levels were analyzed with ELISA. Cells were harvested at 24 h after LPS challenge, and total RNA was extracted. Mes-senger RNA levels for IL-6 and IL-8 were semi-quantitatively determined by RT-PCR. Results: Compared with control group, IL-6 and IL-8 levels steadily increased 4 to 24 h after LPS stimulation. APC treatment could increase LPS-induced IL-6 and IL-8 production. The mRNA levels of IL-6 and IL-8 exhibited a similar change. Conclusion: APC can further increase the level of IL-6 and IL-8 induced by LPS. The effect of these elevated cytokines is still under investigation.

MEK AND p38 MAPK-DEPENDANT PATHWAYS ARE INVOLOVED IN THE POSITIVE EFFECT OF INTERLEUKIN-6 ON HUMAN GROWTH HORMONE GENE EXPRESSION IN RAT MtT/S SOMATOTROPH CELLS

Objective To investigate the effect of interleukin-6(IL-6)on the human growth hormone(hGH)gene expression in a rat somatotropic pituitary cell line MtT/S.Methods The plasmids containing various lengths of hGH gene 5'-promoter fragments were constructed.Stably transfected MtT/S cells were created by cotransfecting the above plasmids and pcDNA3.1(+)with DMRIE-C transfection reagent.After the administration of these cells with IL-6 and/or various inhibitors of signaling transduction pathways,the luciferase activities in MtT/S cells lysis were assayed to demonstrate the effects of IL-6 on hGH gene promoter activity and possibly involved mechanism.Results The 103 U/mL IL-6 stimulated GH secretion and synthesis,and promoted the 5'-promoter activity of GH gene in stably transfected MtT/SGL cells with the action of 1.69 times above the control.Among inhibitors of signaling transduction pathways,mitogen-activated protein kinase kinase(MAPKK/MEK)inhibitor PD98059(40 μmol/L)and p38 mitogen-activated protein kinase(MAPK)inhibitor SB203580(5 μmol/L)completely blocked the stimulatory effect of IL-6.Western blot analysis further confirmed the activation of phosphorylated MEK and p38 MAPK in MtT/SGL cells.Neither over-expression of Pit-1 nor inhibition of Pit-1 expression affected IL-6 induction of hGH promoter activity.A series of deletion constructs of hGH promoter were created to identify the DNA sequence that mediated the effect of IL-6.The results showed that the stimulatory effect of IL-6 was abolished following deletion of the-196 to-132 bp fragment.Conclusions IL-6 promotes GH secretion and synthesis by rat MtT/S somatotroph cells.The stimulatory effect of IL-6 on hGH gene promoter appears to require the activation of MEK and p38 MAPK,and a fragment of promoter sequence that spans the-196 to-132 bp of the gene,but may be unlinked with Pit-1 protein.

In situ tumor vaccination with adenovirus vectors encoding measles virus fusogenic membrane proteins and cytokines

AIM： To evaluate whether intratumoral expression of measles virus fusogenic membrane glycoproteins H and F （MV-FMG）, encoded by an adenovirus vector Ad.MV-HI F, alone or in combination with local coexpression of cytokines （IL-2, IL-12, IL-18, IL-21 or GM-CSF）, can serve as a platform for inducing tumor-specific immune responses in colon cancer.METHODS： We used confocal laser scanning microscopy and flow cytometry to analyze cell-cell fusion after expression of MV-FMG by dye colocalization. In a syngeneic bilateral subcutaneous MC38 and Colon26 colon cancer model in C57BL/6 and BALB/c mice, we assessed the effect on both the directly vector-treated tumor as well as the contralateral, not directly vector- treated tumor. We assessed the induction of a tumorspecific cytotoxic T lymphocyte （CTL） response with a lactate dehydrogenase （LDH） release assay.RESULTS： We demonstrated in vitro that transduction of MC38 and Colon26 cells with Ad.MV-H/F resulted in dye colocalization, indicative of cell-cell fusion, in addition, in the syngeneic bilateral tumor model we demonstrated a significant regression of the directly vector-inoculated tumor upon intratumoral expression of MV-FMG alone or in combination with the tested cytokines. We observed the highest anti-neoplastic efficacy with MV-FMG and lL-21 coexpression. The degree of tumor regression of the not directly vector-treated tumor correlated with the anti-neoplastic response of the directly vector-treated tumor. This regression was mediated by a tumor-specific CTL response.CONCLUSION： Our data indicate that intratumoral expression of measles virus fusogenic membrane glycoproteins is a promising tool both for direct tumor treatment as well as for tumor vaccination approaches that can be further enhanced by cytokine coexpression.

Effect of recombinant human interleukin-11 on expressions of interleukin-11 receptorα-chain and glycoprotein 130 in intestinal epithelium cell line-6 after neutron irradiation

AIM： To explore the effect of recombinant human interleukin-11 （rhIL-11） on the expressions of interleukin-11 receptor α-chain （IL-11Rα） and an additional signal transducer glycoprotein 130 （gp130） in intestinal epithelium cell line-6 （IEC-6） after neutron irradiation. METHODS： Cultured IEC-6 cells were exposed to 4.0Gy neutron and treated with 100 ng/mL rhIL-11 12 h prior to or immediately after irradiation. The apoptosis and necrosis rates and expressions of IL-11Rα and gp130 were observed by flow cytometry, immunohistochemistry, Western blot and image analysis. RESULTS： The apoptosis rate of IEC-6 cells was increased by irradiation at 6 h （P 〈 0.01）, IL-11 stimulation resulted in a decreased apoptosis rate in irradiated IEC-6 cells （P 〈 0.05）. In normal control IEC-6 cells, intense immunoreactivity of IL-11Rα was located within the cell membrane and cytoplasm. The level of IL-11Rα expression significantly decreased at 6 h after irradiation （P 〈 0.01） and restored at 24 h after irradiation. In IEC-6 cells treated with both radiation and rhIL-11, the level of IL- 11Rα expression was higher than that of irradiated cells （P 〈 0.05）. When it came to gp130 protein, it was located in the cytoplasm of IEC-6 cells. After irradiation, we found a progressive decrease in the expression of gp130 protein （P 〈 0.05） in 48 hours post-radiation, while in rhIL-11-stimulated cells, it came back to normal level at 24 h after irradiation and decreased at 48 h, but was still higher than that of only irradiated cells （P 〈 0.05）. CONCLUSION： rhIL-11 can protect IEC-6 cells from neutron irradiation. The protective effect of rhIL-11 might be connected with its ability to up-regulate the expressions of specific ligand-binding subunit IL-11Rα and signal-transducing subunit gp130.

Ornithine decarboxylase, mitogen-activated protein kinase and matrix metalloproteinase-2 expressions in human colon tumors

AIM: To investigate the expressions of omithine decarboxylase (ODC), MMP-2, and Erk, and their relationship in human colon tumors.METHODS: ODC activity, MMP-2 expression, and mitogenactivated protein (MAP) kinase activity (Erk phosphorylation) were determined in 58 surgically removed human colon tumors and their adjacent normal tissues, using [1-14C]-ornithine as a substrate, ELISA assay, and Western blotting, respectively.RESULTS: ODC activity, MMP-2 expression, and Erk phosphorylation were significantly elevated in colon tumors, compared to those in adjacent normal tissues. A significant correlation was observed between ODC activities and MMP-2 levels.CONCLUSION: This is the first report showing a significant correlation between ODC activities and MMP-2 levels in human colon tumors. As MMP-2 is involved in cancer invasion and metastasis, and colon cancer overexpresses ODC, suppression of ODC expression may be a rational approach to treat colon cancer which overexpresses ODC.

Intravenous injection of mesenchymal stem cells is effective in treating liver fibrosis

AIM: To compare the influence of different transplant sites in bone marrow mesenchymal stem cell (MSC)-based therapy for liver fibrosis. METHODS: MSCs isolated from Sprague Dawley (SD) rats were induced into hepatocyte-like cells. Liver fibrosis in SD rats was induced with carbon tetrachloride. Following hepatocyte induction in vitro, 4',6-diamidino- 2-phenylindole (DAPI)-labeled MSCs were transplanted by intravenous, intrahepatic, and intraperitoneal injection. Histopathological staining, immunohistochemistry, and biochemical analysis were used to compare the morphological and functional liver regeneration among different MSC injection modalities. The expression differences of interleukins, growth factor, extracellular matrix, matrix metalloproteinases, and tissue inhibitor of metalloproteinase were examined by real-time reverse transcription-polymerase chain reaction (RT-PCR) andenzyme linked immunosorbent assay (ELISA). RESULTS: Four days after exposure to hepatocyte differentiation medium, MSCs that did not express hepatocyte markers could express α-fetoprotein, albumin, and cytokeratin 18. The results of histopathological staining, immunohistochemistry, and biochemical analysis indicated that intravenous injection is more effective at rescuing liver failure than other injection modalities. DAPI-labeled cells were found around liver lobules in all three injection site groups, but the intravenous group had the highest number of cells. PCR and ELISA analysis indicated that interleukin-10 (IL-10) was highest in the intravenous group, whereas il1β, il6, tnfα and tgfβ, which can be regulated by IL10 and are promoters of liver fibrosis, were significantly lower than in the other groups. CONCLUSION: MSC administration is able to protect against liver fibrosis. Intravenous injection is the most favorable treatment modality through promotion of IL10 expression.

Purification of Proteins from Ginkgo Biloba Seeds and Their Antioxidant Activities

Ginkgo biloba seeds were widely used for food and traditional medicine in china. In the present study, antioxidant proteins named GP were purified from Ginkgo biloba seeds. The proteins （GP） were purified by homogenization of Ginkgo biloba seeds powder in the saline solution, precipitation with 70% ammonium sulphate, and filtration on DEAE-Cellulose 52 anion exchange column. GP showed protein content of 96%, and they showed three bands with approximate molecular weight of 15 kDa, 17 kDa, 21 kDa respectively by SDS-PAGE electrophoresis analysis. Compositions of amino acids obtained by Amino Acid Analyzer showed GP were rich in Glu, Ser ,His ,Asp, Gly, Ala, Leu and Lys compared with the other fractions. The antioxidant activities of GP were investigated using DPPH （the 1, 1-diphenyl-2-picrylhydrazyl） free radical-scavenging and ferric-reducing antioxidant power assays. The GP showed antioxidant activities higher than α-Tocopherol and BHA. Therefore, the present study demonstrates proteins from Ginkgo biloba seeds （GP） can be excellent antioxidant.