Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of this work was to determine the influence of liposomal solubilization of poorly water soluble drugs exhibiting apical efflux on permeation kinetics and cell toxicity in Caco-2 cells. The HIV-protease inhibitors indinavir and saquinavir were incorporated in phosphatidylcholine liposomes at maximal drug-to-lipid mass ratios and their absorption was determined in Caco-2 cell cultures grown on Transwell inserts using purely aqueous drug solutions as reference. A novel mathematical model was developed to quantitatively delineate the contribution of passive membrane permeation and carrier mediated efflux to transport across the cell monolayer and passive permeability coefficient and maximal efflux rate and affinity constant of the transporter system were determined. Cell toxicity of phospholipids was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and the lactate dehydrogenase (LDH) assay. Cell integrity was not significantly affected by phospholipid concentrations of up to 150 mg/ml with respect to the used standard tests. Maximum drug concentration was increased 10- and 750-fold for indinavir and saquinavir, respectively, by the use of liposomes. The passive membrane permeability coefficient differed between the two drugs in accordance with their lipophilicity and the affinity for apical efflux transporters was on average 4-fold greater for saquinavir than for indinavir. Liposomal solubilization diminished the passive permeability coefficient of both drugs but the passive apical-to-basal delivery rate was increased by the liposomes compared to the purely aqueous solutions at maximal donor concentrations for at least one of the two drugs. Efflux rate reached a maximum for the liposomal formulations reflecting transporter saturation. Hence, liposomal solubilization considerably increased drug concentration in the media and altered absorption behavior by affecting both the passive diffusion and the carrier mediated efflux components of cell monolayer permeation.
 ...
PMID:Absorption of poorly water soluble drugs subject to apical efflux using phospholipids as solubilizers in the Caco-2 cell model. 1707 Oct 65

A human cervical explant culture was utilized for the preclinical assessment of anti-human immunodeficiency virus type 1 (HIV-1) activity and tissue toxicity of formulated, candidate topical microbicides. Products tested included cellulose acetate 1,2-benzene dicarboxylate (CAP), a carrageenan-based product (PC-515), a naphthalene sulfonate polymer (PRO 2000), a lysine dendrimer (SPL7013), a nonnucleoside reverse transcriptase inhibitor (UC781), and an antimicrobial peptide (D2A21), along with their placebos. Cervical explants were cultured overnight with HIV-1 with or without product, washed, and monitored for signs of HIV-1 infection. HIV-1 infection was determined by p24gag levels in the basolateral medium and by immunohistochemical analysis of the explant. Product toxicity was measured by the MTT [1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan] assay and histology. CAP, PRO 2000, SPL7013, and UC781 consistently prevented HIV-1 infection in all explants tested. PC-515 and D2A21 prevented HIV-1 infection in 50% or fewer of the explants tested. Placebos did not prevent infection in any of the explants tested. With the exception of PRO 2000 (4%), the MTT assay and histological analysis of the other products and placebos showed minimal toxicity to the epithelium and submucosa. Collectively, these data suggest that this culture system can be used for evaluating the safety and efficacy of topical microbicides designed for vaginal use.
 ...
PMID:Preclinical testing of candidate topical microbicides for anti-human immunodeficiency virus type 1 activity and tissue toxicity in a human cervical explant culture. 1735 37

A series of prodrugs of didanosine were synthesized in an effort to enhance the anti-HIV activity. The 5'-OH function of didanosine was esterified with different aryl piperazine acetic acid derivatives and evaluated for anti-HIV-1 activity in MT-4 cell line using the MTT assay method. Among the synthesized compounds, (tetrahydro-5-(1,6-dihydro-6-oxopurin-9-yl)furan-2-yl)methyl 2-(4-(4-chlorophenyl)piperazin-1-yl)acetate (4b) was found to be the most potent compound with EC50 of 0.64 microM and was not toxic to the MT-4 cells up to 1000 microM with a selectivity index of > 1562. Compound 4b was found to be seven times more potent than the parent drug didanosine (EC50 of 4.8 microM) in vitro. In vitro hydrolysis of the various esters in human plasma indicated that these agents were relatively stable toward plasma esterases with t1/2 ranging from 20-60 min.
 ...
PMID:Synthesis and in vitro anti-HIV activities of didanosine prodrugs. 1737 47

Nelfinavir diesters were prepared by reacting nelfinavir with two molar amount of an appropriate substituted aromatic/aliphatic acid in the presence of dicylohexyl carbodiimide as the carboxyl group activator and 4-dimethylamino pyridine as catalyst. The synthesized compounds were evaluated for their inhibitory effects on the replication of HIV-1 (IIIB) in MT-4 cells by MTT assay method and antimycobacterial activity against Mycobacterium tuberculosis H37Rv by agar dilution method. Compound 3f emerged as the most potent anti-HIV agent with EC(50) of 0.043 microM and CC(50) more than >10 microM and was more potent than parent nelfinavir (EC(50) of 0.060 microM) and also showed antimycobacterial activity (MIC 8.49 microM).
 ...
PMID:Synthesis, anti-HIV and antitubercular activities of nelfinavir diester derivatives. 1789 44

A series of 1-aryl-6,7-dihydroxyl(methoxy)-1,2,3,4-tetrahydroisoquinolines (compounds 1-36) were synthesized via Pictet-Spengler cyclization. All the synthesized compounds were assayed for activities against HIV-1(IIIB) in C8166 cell cultures by MTT method for the first time. The results of the anti-HIV screening revealed that 6,7-dihydroxytetrahydroisoquinolines possessed higher selective index than 6,7-dimethoxyl analogs due to the significantly decreased cytotoxicities. Compounds 6, 24, and 36 showed potent anti-HIV activities with EC(50) values of 8.2, 4.6, and 5.3microM respectively, and the cytotoxicities (CC(50)) of these three compounds were 784.3, 727.3, and 687.3microM, which resulted in SI values larger than 95, 159, and 130 respectively.
 ...
PMID:1-Aryl-tetrahydroisoquinoline analogs as active anti-HIV agents in vitro. 1831 90

Since its first description 20 years ago, the tetrazolium-based colorimetric (MTT) assay using MT-4 cells for the detection of anti-HIV compounds has been widely used. This method, which remains popular, provides more information than more recently developed methods and, therefore, represents a useful methodology on its own or in combination with other screening systems. The replication of HIV in MT-4 cells is usually monitored 5 d after infection; therefore, this protocol can be divided into three steps: the infection (at day 0), an incubation period (5 d) and the evaluation (at day 5). The long-standing and intensive use of the MTT method has taught users of the limitations and, equally importantly, the unexpected advantages of the MT-4/MTT assay. The use of this method can be extended to antiviral testing of compounds against other cyto-destructive viruses.
 ...
PMID:Tetrazolium-based colorimetric assay for the detection of HIV replication inhibitors: revisited 20 years later. 1832 14

To compare the anti-HIV-1 activities of (+/-)-11-demethyl-calanolide A and its mother compound (+/-)-calanolide A in vitro and in vivo, the inhibitory activities of the two compounds on HIV-1 reverse transcriptase (RT) were detected in vitro with isotope 3H assay. The cytotoxicity and inhibition of cytopathic effect (CPE) were studied in HIV-1 IIIB infected MT-4 cell cultures by MTT staining method; Mice were given with the two compounds 100 mg x kg(-1) once intraperitoneally, then the mouse sera taken on 30 min and 60 min after administration were detected for the inhibition of HIV-1 RT in vitro. The data showed that (+/-)-11-demethyl-calanolide A and (+/-)-calanolide A inhibited HIV-1 RT in vitro with 50% inhibitory concentration (IC50) of (3.028 +/- 2.514) micromol x L(-1) and (3.965 +/- 5.235) micromol x L(-1), and also inhibited CPE in HIV-1 IIIB infected MT-4 cell cultures with IC50 of (1.081 +/- 0.337) micromol x L(-1) and (1.297 +/- 0.076) micromol x L(-1), respectively. After intraperitoneal injection of 100 mg x kg(-1) of the two compounds in mice, all the mice sera taken 30 and 60 min afterward inhibited HIV-1 RT in vitro. In comparison with control mice sera, the inhibitory rates of the sera for (+/-)-11 -demethyl-calanolide A were (42.7 +/- 1.5)% at 30 min (P < 0.01) and (32.2 +/- 6.1)% at 60 min (P < 0.05), separately, while the inhibitory rates of the sera for (+/-)-calanolide A were (40.7 +/- 6.3)% at 30 min (P < 0.01) and (29.2 +/- 6.7)% at 60 min. The results suggested that (+/-)-11-demethyl-calanolide A is a new non-nucleoside HIV-1 RT inhibitor, its anti-HIV-1 activities in vitro, in cell cultures and in mice were slightly higher than that of its mother compound (+/-)-calanolide A and warrants further studies.
 ...
PMID:[Anti-HIV activities of HIV-1 reverse transcriptase inhibitor racemic 11-demethyl-calanolide A]. 1871 30

Forty caffeate analogues were synthesized via a convenient method starting from vanillin with moderate to good yields. The testing of biological activity of these compounds against HIV-1 integrase indicates that four compounds: bornyl caffeate, bornyl 2-nitrocaffeate, 5-nitrocaffeic acid and 5-nitrocaffeic acid phenethyl ester (5-nitroCAPE) possess a good HIV integrase inhibitory activity, IC(50) 19.9, 26.8, 25.0 and 13.5 microM , respectively. Twelve caffeate analogues were tested by MTT assay on growth of human hepatocellular carcinoma BEL-7404, human breast MCF-7 adenocarcinoma, human lung A549 adenocarcinoma and human gastric cancer BCG823 cell lines, respectively. And the best result is IC(50) 5.5 microM for CAPE against BEL-7404.
 ...
PMID:Synthesis of trans-caffeate analogues and their bioactivities against HIV-1 integrase and cancer cell lines. 1895 20

The antiretroviral activities of extracts of Euphorbia hirta were investigated in vitro on the MT4 human T lymphocyte cell line. The cytotoxicities of the extracts were tested by means of the MTT cell proliferation assay, and then the direct effects of the aqueous extract on HIV-1, HIV-2 and SIV(mac251) reverse transcriptase (RT) activity were determined. A dose-dependent inhibition of RT activity was observed for all three viruses. The HIV-1 inhibitory potency of E. hirta was studied further, and the activities of the aqueous and 50% methanolic extracts were compared. The 50% methanolic extract was found to exert a higher antiretroviral effect than that of the aqueous extract. The 50% MeOH extract was subjected to liquid-liquid partition with dichloromethane, ethyl acetate and water. Only the remaining aqueous phase exhibited significant antiviral activity; all the lipophilic extracts appeared to be inactive. After removal of the tannins from the aqueous extract, the viral replication inhibitory effect was markedly decreased, and it was therefore concluded that tannins are most probably responsible for the high antiretroviral activity.
 ...
PMID:Antiviral activities of extracts of Euphorbia hirta L. against HIV-1, HIV-2 and SIVmac251. 1945 10

Combination therapies have proven vital in the fight against HIV and cancer. However, the identification and optimization of such combination therapies is largely experience driven and an activity of clinicians rather than of systematic screening efforts. Here we present a diffusion device, compatible with the format of a 12-well microtiter plate, to create and test all possible mixtures of two substances with only two pipetting steps. Applications to the testing of different drug combinations and the parallel screening of different leukemia cell lines as well as primary patient cells are presented. The diffusion device yields qualitatively and quantitatively comparable results to an MTT viability assay conducted in a standard 96-well format albeit with a tremendous reduction of processing steps. In addition, a fluorescence-based annexin V binding assay of cell death was implemented. Next to the reduction of processing steps, the diffusion device constitutes a considerable assay miniaturization that overcomes the problems typically associated with miniaturization as a consequence of small sample volumes. Given its ease of handling, the device will greatly advance the development and optimization of combination drugs and the identification of optimum drug combinations in personalized medicine.
 ...
PMID:Diffusion-driven device for a high-resolution dose-response profiling of combination chemotherapy. 1947 43


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>