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Biomedical subjects

I Mucsi

Publications and source records attributed to I Mucsi.

43 records · Page 3Linked to original sources
PubMedDate not supplied

Biological activity of a fruit vegetable, "Anastasia green", a species of sweet pepper.

Russian green sweet pepper (Anastasia Green) was successively extracted with hexane, acetone, methanol and 70% methanol and the extracts were further separated into a total of twenty fractions by silica gel or ODS column chromatographies. The biological activities of these extracts and fractions were compared. The extracts and fractions showed higher cytotoxic activity against two human oral tumor cell lines than against normal human gingival fibroblasts, suggesting their tumor-specific action. Several fractions [H3, H4, A4] reversed the multidrug resistant gene (MDR1) against L5178 mouse T-cell lymphoma more effectively than (+/-) verapamil (positive control). All extracts and fractions showed no anti-human immunodeficiency virus (HIV) nor anti-Helicobacter pylori activity. These data suggest the medicinal importance of an Anastasia Green extract.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Effects of butaclamol, clopenthixol, mepromazine and cannabinol stereoisomers on apoptosis induction.

The efflux pump of multidrug resistant mdr cells have different sensitivities to some stereoisomeric forms of CNS-active compounds. The ABC transporters of mdr cells were more sensitive to (-)butaclamol than to its stereoisomeric counterpart (8), which may function to alter the membrane structure. We suppose that the drug-accessible membrane structure possesses an important role in the induction (or prevention) of apoptosis. Therefore the apoptosis-inducing effect of three stereoisomeric pairs was studied on mouse lymphoma cells. In these experiments levo- and dextromepromazine had similiar effects. The cis- and trans-clopenthixol were less effective in apoptosis induction than the 12H-benzo(a)-phenothiazine used as a positive control. The effect of stereoisomeric pairs on induced apoptosis was studied when the cells were exposed to the stereoisomers for 60 minutes before subjection apoptosis induction by benzo(a)phenothiazine, a well-known apoptosis inducer. Then the pretreated cells were exposed to 12H-benzo(a)-phenothiazine for 60 minutes. The samples were washed and incubated for 24 hours. The cells were stained with annexin-V-FITC and propidium iodine and investigated by flow cytometry. The mdr cells with increased membrane integrity may result in the preferential killing of multidrug resistant cancer cells in the presence of some stereoisomers.

Animals↗
PubMedDate not supplied

New silicon compounds as resistance modifiers against multidrug-resistant cancer cells.

The efficiency of chemotherapy is often decreased by the development of resistance of cancer cells to cytostatic drugs. This phenomenon is in most cases caused by the activity of the various ABC transporters, multidrug-resistance (MDR) gene-encoded p-glycoproteins, that pump anticancer drugs out of the cells. The inhibition of the activities of the MDR proteins MDR1 and MRP was investigated via the administration of two new organosilicon compounds, alis-409 and alis-421. The study was focused on the inhibition of MDR by blocking the ADR1 gene expression and through the inhibition of the pump-function of mdr-p-glycoprotein, in human breast cancer cell lines expressing mrp and prostate cancer cell line (PC-3). Apoptosis induction and the interaction between epirubicin and the silicon-substituted compounds were studied in human MDR-1 gene-transfected mouse lymphoma and its parent cell line, Colo320/MDR-LRP and sensitive subline Colo205, by means of rhodamine 123 accumulation. The activity of MRP1 p-glycoprotein was studied in human breast cancer cell lines such as HTB-26/MRP1 and two MRP-negative breast cancer cell lines, T47D and MCF7, by carboxyfluorescein accumulation, and on a stomach cancer cell line. The activity of MRP in 257P/MDR and its drug-sensitive derivative were studied in human stomach cancer cells by daunorubicin accumulation in a flow cytometer. The two representative organosilicon derivatives, alis-409 and alis-421, showed antiproliferative effects without apoptosis induction. The drug accumulation in the human MDR1 gene-transfected mouse lymphoma cells was increased without down-regulation of the MDR1 gene expression tested by RT-PCR assay. The rhodamine uptake was increased in L5178/MDR1 and Colo320/MDR1-LRP, but not drug-sensitive human breast cancer MCF-7 and T47D, and L5178 mouse lymphoma parent cells in the presence of alis-409 and alis-421. The MRP-mediated carboxyfluorescein accumulation in HTB-26/MRP human breast cancer cells and daunorubicin accumulation in human stomach cancer cells 257P/MDR were not modified by these alis compounds. A synergistic interaction between epirubicin and the silicon-substituted resistance modifiers was found only in MDR1-mediated MDR in the case of colo-320/MDR1-LRP cells and mouse lymphoma cells transfected with the human MDR1 gene. The results indicate that the organosilyl derivatives specifically act on MDR1 p-glycoprotein 170. The alis compounds act on pgp170 in a way which is similar to verapamil isomers.

Animals↗
PubMedDate not supplied

Epitope mapping of the 273-284 region of HSV glycoprotein D by synthetic branched polypeptide carrier conjugates.

To investigate the antigenicity of a predicted epitope region of herpes simplex virus gD, peptides comprising the 273-284 sequence have been synthesized and conjugated to a branched polypeptide with polylysine backbone (poly[L-Lys-(DL-Alam)], AK). In order to analyze the effect of the carrier on the solution conformation of the potential peptide-epitopes, three peptides (273-284, 273-281 and 276-284) and their polypeptide conjugates were studied by CD spectroscopy in PBS or in TFE. In immunized BALB/c and CBA mice, the level of peptide-, conjugate- and carrier-specific antibody responses were measured. Conjugates with synthetic polypeptide carrier AK induced epitope-specific IgG responses, accompanied by the appearance of a low level of carrier-specific antibodies. The cross-reactivity pattern of induced antibodies revealed the presence of at least two functionally distinct, overlapping epitopes, the availability of which was influenced by flanking residues at the N-terminus. Preimmunization of BALB/c or CBA mice with the [276-284]-AK conjugate resulted in the production of HSV-specific antibodies and in prolonged survival of animals infected with a lethal dose of herpes simplex virus. The degree of protection was comparable to that of [1-23]-AK conjugate (30).

Alanine↗
PubMedDate not supplied

Effect of acridine derivatives on the multiplication of herpes simplex virus.

The antiviral effect of 22 acridine derivatives was studied on the multiplication of herpes simplex virus type 2 (HSV-2) in Vero cells. The inhibitory effect of four acridine derivatives on the multiplication of HSV-2 is emphasised, six other compounds have moderate activity and three only slightly affect the virus multiplication, while nine compounds are inactive. Some of the effective derivatives inhibit the virus replication without any direct effect on the virus particles. However, the mechanism of the antiviral effect is still not known.

Acridines↗
PubMedDate not supplied

Multidrug resistance reversal in mouse lymphoma cells by heterocyclic compounds.

Due to the close homology between bacterial and tumor cell transporter proteins, some antiplasmid and anticancer compounds were tested for their ability to reserve the multidrug resistance (mdr) of lymphoma cells. Some known anticancer medicines such as platidiam, novantron, fluorouracil, bleomycin and methotrexate were ineffective/while vinca alkaloids exerted a strong reversal effect on the mdr of lymphoma cells. The structurally related reserpine and yohimbine do not affect the activity of efflux pump. Some selected antitumor phenothiazines and benzo[a]phenothiazines, including trifluoperazine inhibit the P-glycoprotein (pgp) function. This fact is independent from the antiproliferative- or differentiation inducing effects. Since the polylactosamine specific tomato lectin prevents the action of the chemosensitizers tested, it is supposed that the site of action of phenothiazines can be at the 1st loop in the transmembrane glycoprotein. The efflux pump activity of the pgp in brain capillary endothel which is responsible for blood brain barrier (BBB) was also inhibited by some phenothiazines. However, the tomato lectin sensitivity of pgp was different in mouse lymphoma and human brain capillary endothelial cells. The mdr-gene expression of the mouse lymphoma cells (which were transfected with the human mdr-1 gene) could be reduced by phenothiazines such as promethazine and trifluoperazine, when the cells were cultured in the presence of 0.5 microgram/mL phenothiazines. Further synergism was found between two resistance modifiers i.e. verapamil and trifluoperazine on the inhibition of mdr-glycoprotein.

ATP Binding Cassette Transporter, Subfamily B, Mem↗