Inhibitory effect of dextran sulfate and heparin on the replication of human immunodeficiency virus (HIV) in vitro

The polyanionic substances dextran sulfate and heparin were investigated for their antiviral effect on the human immunodeficiency virus (HIV) in vitro. Dextran sulfate and heparin effected a 50% reduction in the cytopathogenicity of HIV for MT-4 cells at a concentration of 4.7 and 7.5 micrograms/ml, respectively. In Molt-4 (clone 8) cells, these values were slightly higher (14.1 and 15.6 micrograms/ml, respectively). No toxicity for the host cells was noted with these compounds at a concentration up to 400 micrograms/ml, so that the selectivity indexes, as based on the ratio of the 50% cytotoxic dose to the 50% antiviral effective dose, were well in excess of 100. These findings may have far reaching implications both diagnostically, when attempts are made to isolate HIV from heparinized blood samples, as therapeutically, to the extent that dextran sulfate or heparin may be useful in blocking HIV replication in vivo.     

Mutagenicity and antimutagenicity studies of tannic acid and its related compounds.

Tannic acid and its hydrolysed products such as ellagic acid, gallic acid and propyl gallate were tested for mutagenicities using Ames Salmonella tester strains TA98 and TA100. Also, the antimutagenic activities of these compounds against a number of direct mutagens including 2-nitrofluorene (2-NF), 4,4'-dinitro-2-biphenylamine, 1-nitropyrene, 1,3-dinitropyrene, 2-nitro-p-phenylenediamine, 3-nitro-o-phenylenediamine, 4-nitro-o-phenylenediamine were tested. None of these tannic acid compounds was mutagenic. They also failed to show antimutagenic activity towards the tested direct mutagens. However, tannic acid at non-growth inhibitory concentrations reduced the revertant numbers of TA98 in the presence of S9 mix when benzidine, 3,3'-4,4'-tetraminobiphenyl, 4-aminobiphenyl, and N,N-N', N'-tetramethylbenzidine were used as the mutagens. These results suggest that tannic acid, but not its hydrolytic products, affects the metabolic activation of these mutagens.     

Inhibitory effect of genistein on osteoclast-like cell formation in mouse marrow cultures.

The effect of genistein on osteoclast-like cell formation in mouse marrow culture in vitro was investigated. The bone marrow cells were cultured for 7 days in alpha-minimal essential medium containing a well-known bone resorbing agent [parathyroid hormone (1-34) (PTH), prostaglandin E2 (PGE2), 1,25 dihydroxyvitamin D3 (VD3), or lipopolysaccharide (LPS)] with an effective concentration. Osteoclast-like cell formation was estimated by staining for tartrate-resistant acid phosphatase (TRACP), a marker enzyme of osteoclasts. The presence of PTH (10(-8) M), PGE2 (10(-6) M), VD3 (10(-8) M), or LPS (1 microg/mL) induced a remarkable increase in osteoclast-like multinucleated cells. These increases were inhibited significantly in the presence of genistein (10(-7) to 10(-5) M). The inhibitory effect of genistein (10(-5) M) was equal to that of 17 beta-estradiol (10(-8) M), calcitonin (10(-9) M), or zinc sulfate (10(-5) M). Genistein (10(-5) M) significantly inhibited dibutyryl cyclic adenosine monophosphate (10(-5) M)-induced osteoclast-like cell formation. However, genistein (10(-5) M) did not inhibit phorbol 12-myristate 13-acetate-induced osteoclast-like cell formation. The present study demonstrated that genistein has a potent inhibitory effect on osteoclast-like cell formation in mouse marrow culture. The inhibitory action of genistein may involve in cyclic AMP signaling.     

Inactivation of human immunodeficiency virus type 1 by nonoxynol-9, C31G, or an alkyl sulfate, sodium dodecyl sulfate.

A highly desirable approach to prevention of human immunodeficiency virus type 1 (HIV-1) transmission during sexual intercourse is the development of nontoxic, topical, broad spectrum microbicides effective against transmission of cell-associated and cell-free virus. Toward this end, the HIV-1 inactivation potential of surface active agents C31G and an alkyl sulfate, sodium dodecyl sulfate (SDS) was assessed. Because of its extensive use as a microbicidal agent, nonoxynol-9 (N-9) was used as a reference against which C31G and SDS were compared. Viral inactivation was measured using HIV-1 LTR-beta-galactosidase indicator cells (expressing CD4 or CD4/CCR5) derived from HeLa cells, a cell line of human cervical adenocarcinoma origin. In experiments which examined inactivation of cell-free HIV-1, C31G was generally more effective than N-9. Viral inactivation by SDS occurred at twice the concentration necessary to achieve similar levels of inactivation using either N-9 or C31G. Using HeLa and HeLa-derived cells in cytotoxicity studies, it was demonstrated that SDS is as much as 11 and five times less cytotoxic than N-9 or C31G, respectively, during 48 h of continuous exposure. SDS (unlike C31G and N-9) can inactivate non-enveloped viruses such as human papillomavirus (HPV) [Howett, M.K., Neely, E.B., Christensen, N.D., Wigdahl, B., Krebs, F.C., Malamud, D., Patrick, S.D., Pickel, M.D., Welsh, P.A., Reed, C.A., Ward, M.G., Budgeon, L.R., Kreider, J.W., 1999. A broad-spectrum microbicide with virucidal activity against sexually transmitted viruses. Antimicrob. Agents Chemother. 43(2), 314-321]. Since addition of SDS to C31G or N-9 may make the resulting microbicidal mixtures broadly effective against both enveloped and non-enveloped viruses, several surface active agent combinations were evaluated for their abilities to inactivate HIV-1. Addition of SDS to either C31G or N-9 resulted in mixtures that were only slightly less effective than equivalent concentrations of C31G or N-9 alone. To investigate inactivation of cell-associated infectivity, HIV-1 IIIB-infected SupT1 cells were treated with N-9, C31G, or SDS. Inactivation of cell-associated infectivity required higher microbicide concentrations than were needed for inactivation of cell-free virus. However, the relative activities of N-9, C31G, or SDS were similar to those seen in assays of inactivation using cell-free virus. These studies suggest that C31G and SDS may be attractive candidates for human trials as topical microbicides effective against HIV-1 transmission since both function at concentrations that provide effective viral inactivation with low levels of cytotoxicity. SDS microbicides (used alone or with other microbicides) may provide the added advantage of protection from HPV infection.     

人类免疫缺陷病毒相关性口腔念珠菌的药物敏感性分析

目的探讨HIV/AIDS病人口腔念珠菌对常用抗真菌药物的敏感性。方法采用微量液基稀释法,测定念珠菌对氟康唑、酮康唑、氟胞嘧啶和两性霉素B共4种常用抗真菌药物的敏感性(MIC值)。结果60株HIV相关性念珠菌对上述4种药物敏感性的几何均数分别为0.871、0.050、0.179和0.329 mg·L~(-1);耐药率分别为2%、5%、3%和5%;白色念珠菌和非白色念珠菌对氟康唑和两性霉素B的耐药率差异均具有显著性;有1株光滑念株菌对氟康唑、酮康唑和两性霉素B同时耐药。结论上述4种临床常用抗真菌药物可选作HIV/AIDS病人口腔念珠菌病的治疗,但应注意某些菌株的耐药和交叉耐药现象,尤其是非白色念珠菌。     

Inhibitory effect of conjugated eicosapentaenoic acid on mammalian DNA polymerase and topoisomerase activities and human cancer cell proliferation

Conjugated eicosapentaenoic acid (cEPA) selectively inhibited the activities of mammalian DNA polymerases (pols) and human DNA topoisomerases (topos) [Yonezawa Y, Tsuzuki T, Eitsuka T, Miyazawa T, Hada T, Uryu K, et al. Inhibitory effect of conjugated eicosapentaenoic acid on human DNA topoisomerases I and II. Arch Biochem Biophys 2005;435:197-206]. In this report, we investigated the inhibitory effect of cEPA on a human promyelocytic leukemia cell line, HL-60, to determine which enzymes influence cell proliferation. cEPA inhibited the proliferation of HL-60 cells (LD(50)=20.0 microM), and the inhibitory effect was stronger than that of non-conjugated EPA. cEPA arrested the cells at G1/S-phase, increased cyclin A and E protein levels, and prevented the incorporation of thymidine into the cells, indicating that it blocks the primary step of in vivo DNA replication by inhibiting the activity of replicative pols rather than topos. This compound also induced apoptosis of the cells. These results suggested the therapeutic potential of cEPA as a leading anti-cancer compound that poisons pols.     

Sulfonic acid polymers as a new class of human immunodeficiency virus inhibitors.

Four sulfonic acid polymers [poly(4-styrenesulfonic acid)(PSS), poly(anetholesulfonic acid)(PAS), poly(vinylsulfonic acid)(PVS), poly(2-acrylamido-2-methyl-1-propanesulfonic acid)(PAMPS)] have been found to inhibit the cytopathicity of HIV-1 and HIV-2 in MT-4 cells at concentrations that are not toxic to the host cells. The sulfonic acid polymers also inhibited syncytium formation in co-cultures of MOLT-4 cells with HIV-1- or HIV-2-infected HUT-78 cells. They also inhibited binding of anti-gp120 mAb to HIV-1 gp120 and blocked adsorption of HIV-1 virions to MT-4 cells. PSS and PAS, but not PVS and PAMPS, interfered with the binding of OKT4A/Leu3a to the CD4 receptor. The anti-HIV activity of these polyanionic compounds can be ascribed to inhibition of the gp120-CD4 interaction. Sulfonic acid polymers represent a lead of anti-HIV compounds that warrant further evaluation of their therapeutic potential.     

Evaluation of Cynanchum otophyllum glucan sulfate against human immunodeficiency virus and herpes simplex virus as a microbicide agent

Objective:

The root of Cynanchum otophyllum—also known as Qing Yang Sheng—is a traditional ethnical Chinese medicine. The objective of this study was to evaluate in vitro activities and safety of C. otophyllum glucan sulfate (PS20) against Human Immunodeficiency Virus (HIV) and Herpes Simplex Virus (HSV).

Materials and Methods:

Anti-HIV activity was detected with syncytial formation assay and quantitative P24 Enzyme-Linked Immunosorbent Assay (ELISA). Anti-HSV activity was detected with plaque reduction assay; cytotoxicity was tested with MTT colorimetric assay; and anti-bacterial activity was tested with microdilution method. Anti-HIV mechanism was investigated with fusion inhibition, time of addition, and pretreatment.

Results:

The 50% Inhibition Concentration (IC₅₀) of PS20 for HIV-1_IIIB, HIV-_Ada-M, HIV-1_Bal, HSV-I, and -II were 0.26 ± 0.02 mM, 0.46 ± 0.02 mM, 0.90 ± 0.04 mM, 3.45 ± 0.85 μM, and 0.70 ± 0.22 mM, respectively. Selectivity Indices (SI) were 653, 50, 39, 85, and 362, respectively. Studies on anti-HIV mechanism of PS20 showed that the target molecule should be the envelope protein. The 50% Cytotoxicity Concentrations (CC₅₀) of PS20 for HeLa and ME-180 cell lines and human foreskin fibroblast cells was more than 70 μM. The Minimum Inhibitory Concentration (MIC) for vaginal lactobacilli was more than 1000 μM.

Conclusion:

PS20 possesses anti-HIV and HSV effect and low cytotoxicity to epithelium cells and vaginal lactobacilli. It may be considered as a potential microbicide agent for further investigation.     

The inhibitory effect of tannic acid on cytochrome P450 enzymes and NADPH-CYP reductase in rat and human liver microsomes.

Tannic acid has been shown to decrease mutagenicity and/or carcinogenicity of several amine derivatives and polycyclic aromatic hydrocarbons in rodents. The purpose of this study was to evaluate the effect of tannic acid on cytochrome P450 (CYP)-catalyzed oxidations using rat liver microsomes (RLM) and human liver microsomes (HLM) as the enzyme sources. In RLM, tannic acid showed a non-selective inhibitory effect on 7-methoxyresorufin O-demethylation (MROD), 7-ethoxyresorufin O-deethylation (EROD), tolbutamide hydroxylation, p-nitrophenol hydroxylation and testosterone 6beta-hydroxylation activities with IC(50) values ranged from 14.9 to 27.4 microM. In HLM, tannic acid inhibited EROD, MROD and phenacetin O-deethylation activities with IC(50) values ranged from 5.1 to 7.5 microM, and diclofenac 4-hydroxylation, dextromethorphan O-demethylation, chlorzoxazone 6-hydroxylation and testosterone 6beta-hydroxylation with IC(50) values ranged from 20 to 77 microM. In baculovirus-insect cell-expressed human CYP 1A1 and 1A2, the IC(50) values of tannic acid for CYP 1A1- and 1A2-catalyzed EROD activities were 23.1 and 2.3 microM, respectively, indicating that tannic acid preferably inhibited the activity of CYP1A2. Tannic acid inhibited human CYP1A2 non-competitively with a Ki value of 4.8 microM. Tannic acid was also found to inhibit NADPH-CYP reductase in RLM and HLM with IC(50) values of 11.8 and 17.4 microM, respectively. These results suggested that the inhibition of CYP enzyme activities by tannic acid may be partially attributed to its inhibition of NADPH-CYP reductase activity.     

丙戊酸联合顺铂对体外人非小细胞肺癌细胞的增殖抑制作用

目的探讨丙戊酸（VPA）联合顺铂（DDP）对人非小细胞肺癌细胞A549、NCI．H460增殖抑制及细胞凋亡的影响,以及两药联合影响肺癌细胞增殖的机制。方法3组不同质量浓度的VPA与DDP单药及联合作用于人非小细胞肺癌细胞A549、NCI—H460,培养24、48、72h后,观察细胞数量和形态的变化,用MTF法分析药物对细胞增殖的抑制率（IR）及联合用药对细胞增殖抑制率q值,Hoechst／PI双染检测细胞凋亡的数量变化,Westernblot观察联合用药对Bcl．2、Caspase．3、Caspase．8蛋白的表达变化。结果培养48h后,各用药组细胞数目减少十分明显,其中VPA＋DDP组较单独用药组减少更为显著,其细胞形态发生较大改变;MTF法及q值计算结果显示,对A549细胞,VPA的增殖抑制作用呈现明显的时间与浓度依赖性,在高质量浓度时（300mg·L-1）与DDP具有协同作用;对NCI—H460细胞,当VPA的质量浓度≤100mg·L-1时,未显示出明显的时间与浓度依赖性,所有浓度均未显示出VPA与DDP的协同作用。VPA联合DDP可以进一步促进A549与NCI—H460的细胞凋亡,导致两细胞中凋亡因子Bcl-2水平的明显下调。联合作用对A549细胞更为明显,可能与该细胞中抑凋亡因子Bcl-2低表达及促凋亡因子Caspase-3、Caspasel8高表达有关。结论VPA能增强DDP对人非小细胞肺癌细胞的增殖抑制作用,联合作用的协同性与药物浓度及细胞类型有关,不同类型细胞对药物敏感性的差异可能与细胞自身表达的凋亡因子的含量有关。     

新城疫病毒对荷瘤小鼠的抑瘤作用

目的 观察新城疫病毒（NDV）对裸鼠人肺癌移植瘤的抗肿瘤作用。方法 建立人肺腺癌细胞系spc-a-1在裸小鼠皮下移植瘤动物模型,瘤体内1次注射NDV病毒作抗肿瘤研究,同时设PBS对照,观察6周,绘制肿瘤生长曲线,比较两组肿瘤体积变化。结果 NDV组肿瘤生长迟缓,PBS组肿瘤生长迅速,6周后PBS组瘤重明显大于NDV组（P〈0．01）。结论 NDV对裸小鼠人肺腺癌移植瘤有明显的抑制作用。     

大蒜素对甲状腺未分化癌细胞的抑制作用及相关机制探讨

目的 通过体内外研究探讨大蒜素对甲状腺未分化癌细胞的抑制作用及潜在的分子机制.方法 采用MTT法检测不同浓度大蒜素(0、20、40、80μg·mL-1)作用于人甲状腺未分化癌细胞株FRO 24 h、48 h、72 h的增殖抑制率;细胞划痕及Transwell实验分别检测经大蒜素处理后FRO细胞的迁移及侵袭能力;Anne...     

Inhibitory effect of mycophenolic acid on the replication of infectious pancreatic necrosis virus and viral hemorrhagic septicemia virus

Infectious pancreatic necrosis virus (IPNV) and viral hemorrhagic septicemia virus (VHSV) remain two of the most important pathogens of farmed trout worldwide. Mycophenolic acid (MPA) is an inhibitor of cellular inosine monophosphate dehydrogenase (IMPDH), an enzyme that catalyzes an essential step in the biosynthesis of GTP. In this report, the antiviral activity of MPA against IPNV and VHSV in cell culture was assessed. Cell viability, virus yield, protein and RNA synthesis determinations were used to evaluate the inhibitory effect of MPA. MPA caused a dose-dependent inhibition of IPNV and VHSV replication. It was found that MPA had a particularly potent effect against IPNV, inhibiting the production of infectious virus more than 10⁵-fold. MPA was also highly effective in preventing viral protein synthesis. Quantitative real-time RT-PCR was used to measure viral RNA in cells infected by IPNV or VHSV to evaluate the inhibitory capacity of MPA as well as to compare MPA to the established antiviral drug ribavirin. MPA showed a good efficacy in decreasing accumulation of viral RNA at low concentrations. Finally, time of addition and wash out experiments suggested that MPA may have a dual mechanism of action, targeting both a cell and a viral function. This study provides evidence that MPA can function as a broad-spectrum antiviral drug for use in therapy of rainbow trout diseases.