基于临床中药安全观的“毒”-“效”药物研究及实践:以《本草图经》为例

基于临床中药安全观的"毒"-"效"药物研究及实践的视角和观点,在理论与实践相结合的基础之上,以《本草图经》为例,探究毒效相关的理论基础及科学实践认知。主要从"毒"-"效"中药的涵变及认识发展变化、"毒"-"效"与《本草图经》及药味分析、基于"毒"-"效"的《本草图经》药味的认识发展变化、临床中药安全观及实践方面来研究以《本草图经》为例的"毒"-"效"药物理论基础及实践转化情况,主要从毒效相关、毒效转化、毒效同质、毒效衍化、毒效安全/警戒的角度进行分析总结,进而为"毒"-"效"相关的科学内涵认知及实践转化,尤其是"毒性"药物的研究及临床安全/警戒合理用药提供一定的参考依据。

Construction and Immunogenicity of Associated DNA Vaccine of PRRS and PCV-2 Disease

[ Objective ] The aim of the study was to construct associated DNA vaccine of PRRS （Porcine reproductive and respiratory syndrome） and PCV-2 （Porcine circovirus type 2） disease and study its immunogenicity. [ Method] In_ this study, the ORF5 gene of PRRSV isolated in Liaoning was cloned into plRES-neo expression vector, and the neo gene of plRES-neo expression vector was substituted by the ORF2 gene of the PCV-2 Mongolia strain to construct the recombinant expression vector. The expression in BHK cells was detected through Western blot and IFA. Then the ELISA antibody level and the number of spleen T lymphocytes were detected after Balb/c mice were immunized with this DNA vaccine. E Result] The recombinant plasmid plRES-ORF2-ORF5 was constructed successfully and could express the target proteins in BHK cells, as indicated by Western blot and IFA. There was no significant difference in ELISA antibody between plRES-ORF2-ORF5 immunized group and inactived vaccine immunized groups, while the number of spleen T lymphocytes induced by DNA vaccine was higher than that induced by inactived vaccine. [ Conclusion] The recombinant plasmid plRES-ORF2-ORF5 should induce good humoral immune response and cellular immune response in mice, providing the conditions for better prevention and control of PRRS and PCV-2 disease.

Observation of the Immune Effect of Fusion Protein VP4-STI

The aim of the study was to investigate the immune effect of fusion protein VP4-STI. 40 mouse were randomly divided into 4 groups of test bacterin group （30 μg VP4-STI ＋0.6 μg LTB）, aluminiumhydroxide vaccine group （30 μg VP4-STI ＋Al（OH）3 gel ） , pure protein VP4- STI vaccine group （30μg VP4-STI ） and PBS control group were immunized by rhinal dripping. And then, the antibody levels of the mouse were determined. The protection effects of mouse in all immune groups were observed after the toxicity test with strong virulent strain C83902 of E. coli. Anti-VP4-STI antibodies were produced in other groups with the highest at the 6th week, except PBS control group. The antibody level in aluminiumhydroxide bactetin group was higher than that in test vaccine group. The antibody level in pure protein VP4-STI bacterin group was lower, being extremely significantly different from that in test vaccine group （ P 〈0. 001 ）. Mouse in test vaccine group and aluminium hydroxide bacterin group had better immuno-protection effect on strong virulent strain C83902 of E. coli, obviously different from that in PBS control group. The research provided basis for further improving the immunogeneticity of STI.

UGT1A1 gene polymorphism: Impact on toxicity and efficacy of irinotecan-based regimens in metastatic colorectal cancer

AIM: To investigate the correlation between uridine diphosphate glucuronosyl transferase 1A1 (UGT1A1) gene polymorphisms and irinotecan-associated side effects and parameters of drug efficacy in patients with metastatic colorectal cancer (mCRC) receiving a low-dose weekly irinotecan chemotherapeutic regimen. METHODS: Genotypes were retrospectively evaluated by gene scan analysis on the ABI 310 sequencer of the TATAA box in the promoter region of the UGT1A1 gene in blood samples from 105 patients who had received 1st line irinotecan-based chemotherapy for mCRC. RESULTS: The distribution of the genotypes was as follows: wild type genotype (WT) (6/6 ) 39.0%, heterozygous genotype (6/7) 49.5%, and homozygous genotype (7/7) 9.5%. The overall response rate (OR) was similar between patients carrying the (6/7, 7/7) or the WT genotype (6/6) (44.3% vs 43.2%, P = 0.75). Neither time to progression [(TTP) 8.1 vs 8.2 mo, P = 0.97] nor overall survival [(OS) 21.2 vs 18.9 mo, P = 0.73] differed significantly in patients who carried the(6/6) when compared to the (6/7, 7/7) genotype. No significant differences in toxicity were observed: Grade 3 and 4 delayed diarrhoea [(6/7, 7/7) vs (6/6); 13.0% vs 6.2%, P =0.08], treatment delays [(6/7, 7/7) vs (6/6); 25.1% vs 19.3%, P = 0.24] or dose reductions [(6/7, 7/7) vs (6/6); 21.5% vs 27.2%, P = 0.07].CONCLUSION: This analysis demonstrates the non-significant influence of the UGT1A1 gene polymorphism on efficacy and rate of irinotecan-associated toxicity in mCRC patients receiving low-dose irinotecan based chemotherapy.

Toxicity of Selected Imidazolium-based Ionic Liquids on Caenorhabditis elegans： a Quantitative Structure-Activity Relationship Study

Due to the large number of ionic liquids （ILs） and their potential environmental risk, assessing the toxicity of ILs by ecotoxicological experiment only is insufficient. Quantitative structure- activity relationship （QSAR） has been proven to be a quick and effective method to estimate the viscosity, melting points, and even toxicity of ILs. In this work, the LC50 values of 30 imidazolium-based ILs were determined with Caenorhabditis elegans as a model animal. Four suitable molecular descriptors were selected on the basis of genetic function approximation algorithm to construct a QSAR model with an R^2 value of 0.938. The predicted lgLC50 in this work are in agreement with the experimental values, indicating that the model has good stability and predictive ability. Our study provides a valuable model to predict the potential toxicity of ILs with different sub-structures to the environment and human health.

Biodegradation of microcystin-RR and -LR by an indigenous bacterial strain MC-LTH11 isolated from Lake Taihu

The indigenous bacterial strain MC-LTH11 with the capability of degrading microcystin-RR MC-RR and microcystin-LR MC-LR was successfully isolated from Lake Taihu.The bacterium was identified as Stenotrophomonas sp. which possessed a mlrA gene. The MC-LTH11 thoroughly degraded MC-RR and MC-LR with the initial concentration of 37.13 mg/L and 18.49 mg /L respectively in the medium containing crude microcystins extract within 6 d.The degradation rates were affected by temperature pH initial MCs concentration and the kinds of media. Additionally the bacterial strain MC-LTH11 also degraded thoroughly microcystins in the water body of Lake Taihu within 1 d.These results suggest that the Stenotrophomonas sp.MC-LTH11 has the capacity to bioremediate water bodies contaminated by microcystins and may contribute to the degradation of microcystins after the outbreak of harmful cyanobacterial blooms in Lake Taihu.

Induction of hepatitis C virus-specific cytotoxic T and B cell responses by dendritic cells expressing a modified antigen targeting receptor

AIM: To find a novel antigen (Ag) presentation strategy to improve the immune responses induced by dendritic cell (DC)vaccine expressing hepatitis C virus (HCV) core antigen (pcDNA3HCV C-Fc) in Balb/c mice (H-2d).METHODS: pcDNA3HCV C-Fc plasmid and eukaryotic expression vector pcDNA3 were injected into mice sc. Immune responses to pcDNA3HCV C-Fc were studied. Meanwhile the effect of pcDNA3HCV C-Fc on anti-translated subcutaneous tumor of SP2/0 cells stably expressing HCV C Ag (SP2/0-HCV C-FC) was also studied. Anti-HCV C in serum was detected by enzyme-linked immunoadsordent assay (ELISA) and HCV specific cytotoxic T lymphocyte (CTL) activity was measured by LDH release assay. After 3 wk of DNA immunization,the cells of SP2/0-HCV C-FC were inoculated into mice subcutaneously and tumor growth was measured every 5 d.The survival rate and living time of mice were also calculated.RESULTS: After 4 wk of DC immunization, the A450 nm values of sera in mice immunized with pcDNA3HCV C-Fc-DC and pcDNA3-DC were 0.56±0.17 and 0.12±0.03 respectively. The antibody titres in mice codeliveried with pcDNA3HCV C-Fc with DC were significantly higher than those of mice injected with pcDNA3-DC. The HCV specific CTL activities in mice coinjected with DC and pcDNA3HCV C-Fc or empty expression vectors were(73.2±3.1) % and (24.4±8.8) %, which were significantly higher than those of mice injected with water.The DC vaccine could evidently inhibit tumor growth, prolong the survival time of mice and improve the survival rate of mice and these effects could be improved by HCV C-Fc (pcDNA3HCV C-Fc) gene codelivered.CONCLUSION: DC vaccine has a strong antigenicity in humoral and cellular immunities, which can be promoted by transduced pcDNA3HCV C-Fc expressing HCV C or Fc.Thus, pcDNA3HCV C-Fc-transduced DCs may be a promising candidate for a CTL-based vaccine against HCV.

PIKA Provides an Adjuvant Effect to Induce Strong Mucosal and Systemic Humoral Immunity Against SARS-CoV

Severe Acute Respiratory Syndrome （SARS） is a deadly infectious disease caused by SARS Coronavirus （SARS-CoV）. Inactivated SARS-CoV has been explored as a vaccine against SARS-CoV. However, safe and potent adjuvants, especially with more efficient and economical needle-free vaccination are alw needed more urgently in a pandemic. The development of a safe and effective mucosal adjuvant and vaccine ays for prevention of emergent infectious diseases such as SARS will be an important advancement. PIKA, a stabilized derivative of Poly （I：C）, was previously reported to be safe and potent as adjuvant in mouse models. In the present study, we demonstrated that the intraperitoneal and intranasal co-administration of inactivated SARS-CoV vaccine together with this improved Poly （I：C） derivative induced strong anti-SARS-CoV mucosal and systemic humoral immune responses with neutralizing activity against pseudotyped virus. Although intraperitoneal immunization of inactivated SARS-CoV vaccine alone could induce a certain level of neutralizing activity in serum as well as in mucosal sites, co-administration of inactivated SARS-CoV vaccine with PIKA as adjuvant could induce a much higher neutralizing activity. When intranasal immunization was used, PIKA was obligatorily for inducing neutralizing activity in serum as well as in mucosal sites and was correlated with both mucosal IgA and mucosal IgG response. Overall, PIKA could be a good mucosal adjuvant candidate for inactivated SARS-CoV vaccine for use in possible future pandemic.

Comparison of pharmacokinetics,efficacy and toxicity profile of gemcitabine using two different administration regimens in Chinese patients with non-small-cell lung cancer

Objective： To conduct a randomized comparative trial of pharmacokinetics, efficacy and toxicity profile treatment with 1200 mg/m^2 gemcitabine using standard 30-min infusion or fixed dose rate （FDR） infusion [10 mg/（m^2-min）] on days 1 and 8 plus carboplatin AUC （area under curve） 5 on day 1 in Chinese non-small-cell cancer patients. Twelve patients were enrolled in this study. Methods： Plasma gemcitabine concentrations were measured by ion-pair reversed phase high performance liquid chromatography. Antitumoral activity and toxicity of gemcitabine was assessed according to World Health Organization criteria. Results： The obtained mean parameters, such as T1/2 （elimination half time）, AUC, and CL （clearance）, were consistent with those reported in literature. Qualified response rate in our study was 33.3% for standard arm and 50% for FDR ann. Additional 50% and 33.3% patients contracted stable disease （SD） in standard arm and FDR arm, respectively. The predominant toxicity was hematologic, and patients in the standard infusion ann experienced consistently more hematologic toxicity, Conclusion： Pharmacokinetic and clinical data in this trial support the continued evaluation of the FDR infusion strategy with gemcitabine.

A comparative effect of 3 disinfectants on heterotrophic bacteria, iron bacteria and sulfate-reducing bacteria

The disinfection effect of chlorine dioxide, chlorine and their mixture on heterotrophic bacteria, iron bacteria and sulfate-reducing bacteria in circulating cooling water was studied. The results of the test indicated that high purity chlorine dioxide was the most effective biocide in the 3 disinfectants, and with a dosage of 0.5 mg/L, chlorine dioxide could obtain perfect effect. High purity chloride dioxide could have the excellent effect with the pH value of 6 to 10, and could keep it within 72 h. Chlorine and their mixture couldn’t reach the effect of chlorine dioxide.

Fulminant hepatic failure in a case of autoimmune hepatitis in hepatitis C during peg-interferon-alpha 2b plus ribavirin treatment

A 27-year-old Caucasian female with hepatitis C virus (HCV) infection treated with interferon (IFN) who developed severe autoimmune hepatitis (AIH) is described. The infecting viral strain was of genotype Ib and the pre-treatment HCV viral load was at a high level. The patient was treated with pegylated IFN-alpha 2b and ribavirin,and her HCV-RNA became negative at wk 12,but after that she developed fulminant hepatic failure. The patient recovered after steroid pulse therapy consisting of methylprednisolone 1000 mg/d for three days which was administered twice. A needle liver biopsy revealed the typical pathological findings of AIH.

An Improved Strategy for Efficient Expression and Purification of Soluble HIV-1 Tat Protein in E.coli

Although the endogenous function of Tat has been elucidated in the past twenty years, the study of its exogenous activity has been hampered due to the difficulty of large scale preparation of the active Tat protein. To express the full-length Tat protein in E.coli, the tat gene was cloned from an HIV infected patient by overlapping PCR. Rare codon usage analysis showed that rare E.coli codons, especially consecutive rare codons for Arg, account for 14% (14 of 101) rare E.coli codons in the tat gene. The expression of the HIV-1 tat gene was verified to be very poor in strain BL21 (DE3) due to the abundance of rare codons; however, tat gene expression was found to be very efficient in the host strain of Rosetta-gami B (DE3), which was supplemented with six rare tRNAs for Arg, Leu, Ile and Pro. Subsequent purification revealed that the proteins are soluble and unusually, the tagged Tat can form dimers independent of cystine disulfide bonds. The purity, integrity and molecular weight of the Tat protein were demonstrated by MALDI-TOF mass spectrometry. Reporter gene activating assay was further confirmed by investigating the transactivation activity of the recombinant Tat protein. Our improved strategy for efficient high level expression and purification of soluble Tat protein has paved the way to fully investigate its exogenous function.

Virus-host Interactions during Hepatitis C Virus Entry-Implications for Pathogenesis and Novel Treatment Approaches

Hepatitis C virus (HCV) is a member of the Flaviviridae family and causes acute and chronic hepatitis. Chronic HCV infection may result in severe liver damage including liver cirrhosis and hepatocellular carcinoma. The liver is the primary target organ of HCV, and the hepatocyte is its primary target cell. Attachment of the virus to the cell surface followed by viral entry is the first step in a cascade of interactions between the virus and the target cell that is required for successful entry into the cell and initiation of infection. This step is an important determinant of tissue tropism and pathogenesis; it thus represents a major target for antiviral host cell responses, such as antibody-mediated virus neutralization. Following the development of novel cell culture models for HCV infection our understanding of the HCV entry process and mechanisms of virus neutralization has been markedly advanced. In this review we summarize recent developments in the molecular biology of viral entry and its impact on pathogenesis of HCV infection, development of novel preventive and therapeutic antiviral strategies.

The efficacy and toxicity of modified docetaxel,cisplatin and 5-fluorouracil combination therapy for 27 patients with advanced stage gastric adenocarcinoma

Objective: The aim of this study was to evaluate the efficacy and toxicity of modified docetaxel, cisplatin and calcium folinate (CF)/5-fluorouracil (mDCF) combination therapy for 27 patients with recurrent or metastatic gastric adeno- carcinoma (R/MGC). Methods: From May 2006 to July 2007, 27 R/MGC patients (18 were male and 9 were female) with a median age of 49 years (range19-66) were consecutively enrolled. The mDCF protocol included 50 mg/m2 docetaxel for 1 day and 25 mg/m2 cisplatin on d2-3, 200 mg/m2 CF on d2-3 and 2000 mg/m2 5-fluorouracil (5-FU) CIV (continous infusion) for 46 h on d2-3, repeated every 2 weeks. Results: Twenty-seven patients were evaluable for efficacy and toxicity. A median of 4.5 cycles was given. One complete and 12 partial responses were observed for an overall intent to treat response rate (RR) 48.1% [95% CI (confidence intervals): 32%-64%]. Median time-to-progression (TTP) was 6.2 months and overall survival (OS) was 11.8 months. Twenty-seven (100%) patients experienced bone marrow suppression, and of them 48.9% were Grade 3-4 (16.3% were Grade 4). Two patients (7.4%) ceased chemotherapy because of bone marrow suppression. WHO Grade 1-4 non-hematological toxicity, such as oral mucositis, nausea/emesia, peripheral neuropathy, liver dysfunction, diarrhea, nephrotoxicity and cardiotoxicity, occurred in 59.2%、51.9%, 48.1%, 44.4%, 25.9%, 18.5% and 11.1% patients, respectively, and most of them were Grade 1-2. No patient died due to chemotherapy toxicity. Conclusion: mDCF regimen is effective in treating R/MGC with a high RR and long TTP/OS in this trial. Despite its severe hematotoxicity, this regimen has some advantages such as no cross-resistance with paclitaxel (paclitaxel-resistant patients RR 2/6). These results suggested that the mDCF regimen worth further investigation in clinical study of R/MGC treatment.

Effectiveness of Disinfection of Anesthetics Tubes in Oral Surgery -An in Vitro Study

Context： Anesthetic tubes are always on the surgical table, for this reason, it＇s necessary to perform its disinfection, generally by chemicals. Aim： Was to analyze the effectiveness of tubes decontamination made by disinfectant substances used in a clinical setting and to identify the microorganisms found on their surface. Materials and Methods： 14 anesthetic tubes were collected from dental clinic, on 5 groups. 01 plastic and 01 glass tubes that were not submitted to any disinfection process composed the control group and they had been sown in Agar Blood. Experimental groups underwent immersion and fixation with the proposed chemicals for 1 minute, laminar flow hood was used to seed it in Agar Blood and then it was transferred to incubator for 24 hours at 37℃. Tests were used to identify the main Gram positive pathogenic genera. Gram-negative pathogenic colonies isolated were seeded in biochemical means of identification. Results： It was possible to identify the presence of Staphylococcus coagulase negative, Staphylococcus aureus, Streptococcus viridans, Staphylococcus saprophyticus, Escherichia coli and Acinetobacter spp, as well as the effectiveness of chemical solutions proposed in this study. Conclusions： All chemical solutions proposed in this study were effective for the surface disinfection process of anesthetic tubes.

Toxicity Screening of Water Sources in Flooded Agricultural Areas of Nen-Shkodra Lowland Using Allium cepa L. Assay

The reaction ofAllium cepa root tips to the presence of potential toxic chemicals was used to evaluate the cyto/genotoxic effects of some water sources of Nen-Shkodra lowland agricultural area after massive 2010-2011 flooding. MRL （Mean root length）, MI （mitotic index）, PI （phase index） and CA （chromosome abnormalities） endpoints of onion roots, grown in four water samples, were measured and compared with tap water and Cu solution 0.5 mg/L （negative and positive controls）. Inhibition of root growth, cell division and induction of mitotic and chromosomal aberrations were detected. The most polluted water sample caused MRL inhibition of 36%, MI decrease of 38%, and a considerable increase in chromosomal aberrations （7.8%） compared to the negative control. Most frequent CA types were： bridges and fragments, stickiness and C-metaphase. The results indicated a slight toxic tendency of analyzed natural waters, serving as an alert of environmental impact that chemical pollution had after flooding.

Biodegradation of Microcystin-RR by a New Isolated Sphingopyxis sp. USTB-05

A promising bacterial strain for the biodegradation of Microcystins(MCs)was isolated from Dianchi lake in China and identified as Sphingopyxis sp.USTB-05 by the analysis of 16s rDNA.Initial MC-RR of 42.3 mg·L -1 was completely degraded by USTB-05 within 36 h,which was a relatively high biodegradation rate of MC-RR.With the cell-free extract(CE)of Sphingopyxis sp.USTB-05,MC-RR was biodegraded at a more rapid biodegradation rate compared with its strain,so that initial MC-RR of 42.3 mg·L -1 was completely biodegraded within 10 h.During the bio-reaction of MC-RR catalyzed by CE,two intermediate metabolites and a dead-end product of MC-RR were observed on HPLC profiles and all of them had similar scanning profiles in the wavelength from 200 to 300 nm,indicating that the group of Adda in all products of MC-RR remained intact.

Chronic Toxicity of a Novel Recombinant Human Granulocyte Colony-stimulating Factor in Rats

Objective To assess the severity and reversibility of the chronic toxicity of a novel recombinant human granulocyte colony-stimulating factor (rhG-CSFa) in rats and the dose-effect relationship.Methods A total of 100 Sprague-Dawley rats (equal numbers of male and female) were randomly divided into five groups (20 rats in each group):four groups were treated with rhG-CSFa at 500,100,10,1 μg/kg,respectively,and one group was treated with vehicle only to serve as the control.The rats were received subcutaneous injections of rhG-CSFa or vehicle daily for 13 weeks.During the course of the chronic toxicity study,the physical status,body weight,and food consumption were monitored.Half of the rats in each group (n=10) were sacrificed after the last rhG-CSFa administration,and the other half were sacrificed at five weeks after the last rhG-CSFa administration.Urinalyses,blood biochemistry,hematological analysis,histopathological examination,and immunological tests were performed for each of the rats.Results The hematological analyses revealed that the mean white blood cells count,neutrophils count,and neutrophils percentage were increased in male rats at the dose of 10 μg/kg or higher,and these were related with the biological activity of rhG-CSFa.Some small abnormalities were observed in the spleen of a few rats when used highest dose (500 μg/kg,a dosage of 200 folds higher than the normal clinical dosage),but these abnormalities were recovered within 5-week recovery period.No other rhG-CSFa-related abnormalities were observed in this chronic toxicity study.Conclusion No significant toxicity and immunogenicity are observed with rhG-CSFa administration to rats in the chronic toxicity studies.

Long-term treatment outcomes of clevudine in antiviral-naive patients with chronic hepatitis B

AIM:To evaluate the treatment outcomes of clevudine compared with entecavir in antiviral-naive patients with chronic hepatitis B(CHB).METHODS:We retrospectively analyzed the clinical data of CHB patients treated with clevudine 30 mg/d and compared their clinical outcomes with patients treated with entecavir 0.5 mg/d.The biochemical response,as assessed by serum alanine aminotransferase(ALT) activity,virologic response,as assessed by serum hepatitis B virus DNA(HBV DNA) titer,serologic response,as assessed by hepatitis B e antigen(HBeAg) status,and virologic breakthrough with genotypic mutations were assessed.RESULTS:Two-hundred and fifty-four patients [clevudine(n = 118) vs entecavir(n = 136)] were enrolled.In clevudine-treated patients,the cumulative rates of serum ALT normalization were 83.9% at week 48 and 91.5% at week 96(80.9% and 91.2% in the entecavir group,respectively),the mean titer changes in serum HBV DNA were-6.03 and-6.55 log 10 copies/mL(-6.35 and-6.86 log 10 copies/mL,respectively,in the entecavir group),and the cumulative non-detection rates of serum HBV DNA were 72.6% and 83.1%(74.4% and 83.8%,respectively,in the entecavir group).These results were similar to those of entecavir-treated patients.The cumulative rates of HBeAg seroconversion were 21.8% at week 48 and 25.0% at week 96 in patients treated with clevudine,which was similar to patients treated with entecavir(22.8% and 27.7%,respectively).The virologic breakthrough in the clevudine group occurred in 9(7.6%) patients at weeks 48 and 15(12.7%) patients at week 96,which primarily corresponded to genotypic mutations of rtM204I and/or rtL180M.There was no virologic breakthrough in the entecavir group.CONCLUSION:In antiviral-naive CHB patients,longterm treatment outcomes of clevudine were not inferior to those of entecavir,except for virologic breakthrough.

In Vitro Anti-influenza Virus Activities of Sulfated Polysaccharide Fractions from Gracilaria lemaneiformis

In this paper, in vitro anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiforrnis were investigated. Cytotoxicities and antiviral activities of Gracilaria lemaneiformis polysaccharides （PGL）, Gracilaria lemaneiformis polysaccharide fraction-1 （GL-1）, Gracilaria lemaneiformis polysaccharide fraction-2 （GL-2） and Gracilaria lemaneiformis polysaccharide fraction-3 （GL-3） were studied by the Methyl thiazolyl tetrazolium （MTT） method, and the inhibitory effect against Human influenza virus H1-364 induced cytopathic effect （CPE） on MDCK cells were observed by the CPE method. In addition, the antiviral mechanism of PGL was explored by Plaque forming unit （PFU）, MTT and CPE methods. The results showed： i） Cytotoxicities were not significantly revealed, and H1-364 induced CPE was also reduced treated with sulfated polysaccharide fractions from Gracilaria lemaneiformis; ii） Antiviral activities were associated with the mass percentage content of sulfate groups in polysaccharide fractions, which was about 13%, in polysaccharides （PGL and GL-2） both of which exhibited higher antiviral activity; iii） A potential antiviral mechanism to explain these observations is that viral adsorption and replication on host cells were inhibited by sulfated polysaccharides from Gracilaria lemaneiformis. In conclusion, Anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis were revealed, and the antiviral activities were associated with content of sulfate groups in polysaccharide fractions