[Influence of excipients on glucocorticoid determination in dermatological preparations].
Explore the source record for details and available documents.
SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Fifteen 1-aryl-3-(3'-nitro-4'-methoxyphenyl)-5-phenyl formazans and five 3-aryl-5-(3'-nitro-4'-methoxy phenyl)-2-phenyl tetrazolium bromides have been tested against Escherichia coli and Pseudomonas aeruginosa for their antibacterial and against Aspergillus flavus and Helminthosporium gramineum for their antifungal activities. Most of the compounds have shown promising antibacterial and antifungal action. These compounds were also found to exhibit significant antiviral activity against sunnhemp rosette virus in Cyamopsis tetragonoloba plants in vivo as well as in vivo.
The enzyme succinate dehydrogenase was demonstrated histochemically in organs of rats, especially in experimentally infarcted hearts. 88 tetrazolium salts were used as indicators, the resulting formazans were examined for birefringence. Formazans with cristalline shapes show birefringence, but formazans of amorphous character do not. In the atypic species of nitrogroup-substituted monoformazans it is possible to form an oriented association to cell structures in spite of an amorphous precipitation. Therefore, anomalous colours of polarization, and dichroism is observed. Relations are discussed between shape of formazan deposits, polarity of formazans, and the occurrence of optical anisotropism.
Since palladium complexes have been reported to show fewer side effects relative to other heavy metal anticancer compounds, in this study a new class of four structurally related anticancer Pd(II) complexes including 2,2'-bipyridin-n-butyl dithiocarbamato Pd(II) nitrate (Com-1), 2,2'-bipyridin-n-hexyl dithiocarbamato Pd(II) nitrate (Com-2), 2,2'-bipyridin glycinato Pd(II) nitrate (Com-3) and 2,2'-bipyridin octylglycinato Pd(II) nitrate (Com-4) was designed. The effect of four synthesized ligands on the protein structure and cell proliferation were investigated. Whey carrier proteins beta-lactoglobulin-A and-B (BLG-A and-B) and chronic myelogenous leukemia cell line K562 were the targets. Fluorescence and CD instruments were used to assess effect of the ligands on the protein structure. Growth inhibitory effect of the Pd(II) complexes towards the cancer cells was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Results of fluorescence studies revealed that the complexes had no dithiocarbamate moiety (compounds 3 and 4) could quench the intrinsic fluorescence emission of the proteins at lower concentrations than those had such moiety (compounds 1 and 2). The far-UV-CD studies revealed that the regular secondary structure of BLG-A and -B did not show any noticeable alteration upon interaction with different of Pd(II)-complexes. The results of cell proliferation assay also displayed that Com-1 and Com-2 had more growth inhibitory activity against K562, than Com-3 and Com-4. Our results suggested that addition of dithiocarbamate moiety to structure of Pd(II) complexes probably has important role to improve the antiproliferative properties of the anticancer ligands and fewer effects on the carrier protein structure.
Explore the source record for details and available documents.
The 21-aminosteroids (lazaroids) are a new family of steroid compounds that inhibit lipid peroxidation reactions. They are novel antioxidant agents, which have been shown to have antiproliferative properties on cancer cells and also are thought to prevent free radical-mediated blood-brain barrier damage. In order to understand the effect of lazaroids on glioma, we tested U-83836E and U-74389G at doses ranging between 0.1 100 m mM on primary cultures of glioblastoma multiforme from three patients, rat C6 glioma cell line, and 5 th subculture established from one of the patients. The effects of both compounds on cell proliferation were determined using 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay. U-83836E in the primary cultures was found to have 50% inhibitory concentrations (IC50 ) of 6.30, 6.75 and 6.50 m mM, respectively. The IC50 value of U-74389G was calculated as 91 m mM in only one of the patients. On C6 glioma cells, while the IC50 of U-83836E was 45 m mM, U-74389G showed no cytotoxic effect. On the 5 th subculture, U-83836E had an IC50 of 37.5 m mM, but the cytotoxic effects of U-74389G was less than in that of the primary culture. In conclusion, these compounds were found to be more cytotoxic in primary culture than the cell lines and there were also differences between their members in the inhibition of cell survival.
Five abietane diterpenes were isolated from a hexane extract obtained from the roots of Aegiphila lhotzkyana and identified as uncinatone, cyrtophyllone B, teunvicenone E, sugiol and 12,16-epoxy-11,14-dihydroxy-6-methoxy-17(15 - 16)- abeo-abieta-5,8, 11,13,15-pentaene-3,7-dione. The last compound has only been described for this species. These compounds were tested for their antiproliferative effects on tumor cell lines using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl- 2H-tetrazolium bromide (MTT) assay and on sea urchin egg development, as well as for their lytic properties on mouse erythrocytes. All diterpenes reduced the viability of tumor cells and inhibited sea urchin egg cleavage. None of the tested compounds presented hemolytic activity.
AIM: To develop a leukemia cell line K562-based assay for high-throughput screening. METHODS: The screening was carried out on 96-well plates with monitoring cell proliferation by a combined 3-[4,5-dimethylthiazol-2-yl]-5-[3-carboxymethoxyphenyl]-2-[4-sulfophenyl]-2H-tetrazolium (MTS)/phenazine methosulfate (PMS) method. Conditions for evaluating effects on the proliferation of K562 cells by individual compounds on the 96-well plates were optimized. RESULTS: A set of 800 small organic compounds was screened for anticancer activity by this cell-based assay, with consumption of each compound at 500 ng. Eleven compounds were identified with >80 % inhibitory activity at 5 mg/L, among which 9 compounds were confirmed by subsequent testing at multiple concentrations. The most potent compound showed an IC50 at 170 nmol/L, and there were total of 7 compounds showed IC50 less than 10 micromol/L. CONCLUSION: The high-throughput method using K562 cell line is fast, economical, effective, and practical in identifying inhibitors as potential therapeutic agents for cancer.
To develop a mammalian in vitro system for teratogenicity testing, cytotoxicity of xenobiotics was evaluated in pluripotent euploid embryonal stem cells (ESC) derived from mouse blastocysts. The dimethyl-thiazol-diphenyl tetrazolium bromide (MTT) assay was the most appropriate test system for cytotoxicity determinations with ESC. Only compounds that do not require metabolic activation were selected for testing from the database for validation of in vitro teratogenesis assays by Smith et al. Results obtained with ESC were compared to corresponding data from fibroblasts from day-14 mouse embryos to detect differences in sensitivity between undifferentiated and differentiated cells. ESC showed a higher sensitivity to known teratogens than fibroblast cultures, which allows calculation of a sensitivity ratio of "adult" cells (differentiated fibroblasts) to embryonal cells (undifferentiated ESC) in a mammalian system similar to the hydra assay. Although some xenobiotics had to be classified as false negatives in our system, the ESC cytotoxicity assay holds promise as a new in vitro screening assay in teratology.
The reduction of a new series of tetrazolium salts to red fluorescent formazans by Ehrlich ascites tumor cells is described. The qualitative effect on this reaction of two cell surface-active compounds and of six exogenous electron carriers was investigated by varying the incubation conditions. After incubation of Ehrlich ascites cells with the new colourless, water soluble 5-cyan-2.3-ditolyltetrazolium salts, bright red water-insoluble formazan crystals on the cell surface can be observed under fluorescence microscopy. The production of formazan is enhanced by 12-0-tetradecanoyl-phorbol-13-acetate (TPA) or digitonin (DIG), two potent stimulators of oxygen consumption or by the electron carriers phenazine methosulphate (PMS), 1-methoxy-phenazine methosulphate (MPMS), meldola blue (MB), methylene blue (MTB), and 2.6-dichlorindophenol (DCIP). These results provide further evidence for the existence of redox enzymes bound to the plasma membrane of intact ascites cells and for a free radical mechanism of tetrazolium salt reduction. The fluorescence property of the new redox dyes offers the advantage of high sensitivity. Moreover, their greater homogeneity relative to the commonly used di-tetrazolium salts lowers the chances of misinterpretations due to impurities. The possible application of these new mono-tetrazolium salts to cytochemical investigations of oxidative metabolic reactions is discussed.
Explore the source record for details and available documents.
Experiments have been carried out to explore the use of a tetrazolium salt, MTT(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide in the detection of intracellularly generated superoxide in HeLa cells. From the use of a low molecular weight lipophilic mimic of superoxide dismutase, as well as superoxide dismutase, and inhibitors of superoxide dismutase, it is suggested that at least 20-30% of the intracellular reduction of MTT is due to superoxide. Whilst this may arise from mitochondria another possible intracellular source in HeLa cells may be xanthine oxidase. The overall rate of intracellular MTT reduction in HeLa cells is inversely dependent on levels of serum in the culture medium. Serum components with a modulatory role in this context are those with antioxidant function. Reduced MTT is also detectable extracellularly in cultures of HeLa cells and at least 80% of this is due to superoxide. Use of inhibitors suggest that whilst a small proportion (30%) may arise through an NADPH-oxidase type enzyme, other sources of extracellular superoxide in HeLa cells remain a possibility.
The antioxidant action of a series of benzylisoquinoline alkaloids has been investigated. Laudanosoline, protopapaverine, anonaine, apomorphine, glaucine, boldine, bulbocapnine, tetrahydroberberine and stepholidine produced a dose-dependent inhibition of microsomal lipid peroxidation induced by Fe2+/ascorbate, CCl4/NADPH or by Fe3+ ADP/NADPH. Apomorphine exerted the highest inhibitory effects in the three systems of induction used, with a potency higher than propyl gallate. Laudanosoline was particularly effective in the first system, while bulbocapnine and anonaine were more potent when CCl4/NADPH or Fe3(+)-ADP/NADPH were used as inducers. Laudanosoline, protopapaverine, apomorphine, tetrahydroberberine and stepholidine were also potent inhibitors of nitroblue tetrazolium (NBT) reduction. The presence of a free hydroxyl group or preferably of a catechol group is a feature relevant for inhibition of lipid peroxidation and NBT reduction, nevertheless the antioxidant activity of benzylisoquinoline alkaloids cannot be only ascribed to the formation of phenoxy radicals and other free radical species may be formed during aporphine and tetrahydroprotoberberine oxidation. The influence of this series of compounds on the time course of lipid peroxidation suggests that some of them, like apomorphine and boldine act as chain-breaking antioxidants.
Explore the source record for details and available documents.
This report describes tests with Evan's Blue and MTT (3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromide) for the assessment of the viability of rhinosporidial endospores. MTT stained a proportion of the spherical bodies that we regard as the Electron Dense Bodies (EDBs), and the cytoplasm of freshly prepared endospores or ones that were stored at 4 degrees. Slow-freezing at -20 degrees C, exposure to 10% formalin, or 0.1% sodium azide of the endospores abolished MTT-staining in both sites. Evan's Blue stained the EDBs and cytoplasm of fresh endospores or those stored at 4 degrees, and of sodium azide-treated or frozen (-20 degrees)-thawed endospores. TMRE (tetramethyl-rhodamine ethyl ester) specifically labelled the spherical bodies, supporting the conclusion that these spherical bodies have a mitochondrial-like structure. TMRE-staining was however retained in endospores after their treatment with formalin, sodium azide and slow-freezing while MTT-staining was abolished in all these treated endospores. These results indicate that EvB and TMRE were capable of revealing the morphological integrity of endospores but failed to identify the metabolic inactivation of the endospores after treatment with formalin, sodium azide or slow-freezing. Only MTT was capable of identifying metabolically active endospores and hence their viability and could prove to be of value in standardizing models of infection.
9-Alkoxy-1,5-dichloroanthracenes were successfully prepared. Their cytotoxicity was evaluated in vitro on rat glioma C6 cell lines and human hepatoma G2 cell lines, respectively. Alkylation of 1,5-dichloro-9(10H)-anthracenone with either the appropriate alcohols or alkyl chlorides in the presence of sulfuric acid or sodium hydride, respectively, furnished this structural class of anthracenes. Contrary to mitoxantrone, cytotoxic properties were observed as documented by the reactivity of the novel compounds and potent in vitro activity against C6 cells and hep G2 cells over a wide range of structural variants. Among these compounds, 5c, 5h, 5l and 5n are potent cytotoxins. They inhibit C6 cell growth in culture, indicated by using 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide sodium salt (XTT) colorimetric assay. By using this assay it was also shown that 5c, 5d and 5l possess potent cytotoxicity on hep G2 cells. The most active compound displaying in vitro cytotoxicity was the 9-butoxy derivative 5h with IC50 values 0.02 microM against C6 cells, as compared with mitoxantrone with IC50 values 0.07 microM. The most active compound displaying in vitro cytotoxicity against hep G2 cells was 5c with IC50 values 1.7 microM (mitoxantrone: 0.8 microM). Structure-activity relationships (SAR) of these compounds with respect to the nature of the alkoxy substitution in the 9 position are discussed for both cell lines.
Screening methods for chemotherapeutic agents usually rely on the cytotoxic properties of the drugs. However, agents that inhibit invasion may have more efficacy and cause fewer side effects. Various cellular invasion assays have been used to evaluate these types of compounds, including the modified Boyden chamber, monolayer wound models and Matrigel outgrowth assays. In this report, we have combined the use of the Matrigel outgrowth assay with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) visualization and cell viability dye to visualize invasive cells on Matrigel without magnification. Extraction of the dye's formazan byproduct allows cell viability to be assessed. Using several invasive and noninvasive cell lines, the utility of the method for various target cells was verified. Several established chemotherapeutic agents were also screened for their anti-invasive and/or cytotoxic effects when cultured on Matrigel. Our results suggest that this method may be an easy, inexpensive and nonradioactive alternative for both enumerating cells on Matrigel and screening various tumor cell lines treated with chemotherapeutic agent to look for compounds with noncytotoxic but anti-invasive properties.
Based on the organotropic characteristics of bile acids towards the liver and the intestine, two novel compounds of the Bamet family, containing at least one bile acid moiety bound to platinum(II), have been synthesized and their cytostatic effect compared to their ability to become accumulated in tumor cells of hepato-intestinal origin. Bamet-UD2 [cis-diammine-bis-ursodeoxycholic platinum(II)] induced a marked inhibition of cell growth, which was more marked in human hepatoblastoma HepG2 and mouse hepatoma Hepa 1-6 cells than in rat hepatoma McA-RH7777 and human colon adenocarcinoma LS 174T cells. This effect was similar to that observed for cisplatin and stronger than that previously reported for other members of this family, such as Bamet-H2 and Bamet-R2. By contrast, Bamet-D3 [(N'N'' cis-dichloro N(3-3-amminepropylammine)propyl) glycocholamide platinum (II)] was only effective in reducing growth in human hepatoblastoma HepG2 cells. Because the in vitro DNA-reactivity was approximately 5-fold higher for Bamet-D3 than for Bamet-UD2, an additional cause for the difference in their cytostatic abilities was sought, investigating the relationship between cell load and the cytostatic effect of the drugs. Drug uptake by two cell lines, Hepa 1-6 and HepG2, with different sensitivities to these compounds was measured. The cellular uptake of Bamet-D3 and Bamet-UD2 was several-fold higher than that of cisplatin. No significant difference in the amount of both drugs taken up by these cell types was found. A study on sodium-dependency and substrate specificity indicated that Hepa 1-6 cells take up Bamet-D3 and Bamet-UD2 via similar mechanism(s), whereas these compounds do not seem to share the uptake pathways in HepG2 cells. Measurement of cell viability by formazan formation from tetrazolium salts and by neutral red uptake, after short-term (6 h) exposure to the desired drug, indicated that no acute toxic effect occurs in the presence of cisplatin or Bamet-D3 in either HepG2 or Hepa 1-6 cells. By contrast, in both cell lines Bamet-UD2 induced acute cell toxicity in a dose-dependent fashion. In sum, the results indicate that tumor cells efficiently take up these two novel compounds of the Bamet family. Although the exact uptake mechanism remains unknown, it seems to be dependent on the cell type. However, the cell load does not account for the differences in the anti-proliferative properties of the drugs. The strong and promising cytostatic activity of Bamet-UD2 is additionally related to its ability, absent in Bamet-D3, to acutely alter cellular functions other than proliferation.