Galvanostatic stripping chronopotentiometric study for determination of selenium: pharmacokinetic application in experimental mice.

Purpose: The aim of this study was to determine the selenium content in various tissues of the mouse employing the galvanostatic stripping chronopotentiometry (SCP) technique and to investigate the distribution profile of selenium as well as its pharmacokinetics in a mouse model.

Methods: The animals received 0.25 μg/g Se orally for 5 days.

Research on biomodulatory effect of natural compounds.

Objectives: The purpose of this study was to determine whether the extract isolated from the artichoke Cynara cardunculus L. (ECC) had antimutagenic effect and was able to enhance the therapeutic effect of cytostatic drug cis-platinum (cis-Pt).

Methods: The potential antimutagenic activity of ECC was assayed by a test on sex-linked recessive lethal mutations detection in Drosophila melanogaster males treated with ethylmethane sulfonate (EMS).

The role of natural biopolymers in genotoxicity of mutagens/carcinogens elimination.

Nowadays naturally occurring compounds with the potential antimutagenic and anticarcinogenic effects are of great importance for their prospective use in cancer chemoprevention and treatment. The new water soluble derivative of microbial polysaccharide beta-D-glucan-carboxymethyl glucan (CMG) belongs to such a category of natural substances. CMG isolated from the cell wall of baker's yeast Saccharomyces cerevisiae is included into the class of biopolymers known as biological response modifiers (BRMs) with a broad range of activities, above all ones interfering with cancer therapy.

Dual activity of triterpenoids: apoptotic versus antidifferentiation effects.

Triterpenoids are natural, biologically active compounds extracted from many plants. They possess antiinflammatory, anticancer, and antioxidant properties. In the report presented, antiproliferative effects and leukemia cell growth and apoptosis modulating activities of ursolic acid (UA) and oleanolic acid (OA) were investigated.

Diverse biomodulatory effects of glucomannan from Candida utilis.

Using four experimental model systems, it was demonstrated that glucomannan (GM) isolated from the cell wall of the industrial yeast Candida utilis revealed a broad range of protective activities. This effect depended on the nature and mode of action of the counteracting genotoxic compound as well as on the experimental model system used. In the Saccharomyces bioprotectivity assay, GM increased resistance towards ofloxacin-induced toxicity in the wild type and recombination repair-deficient yeast strains significantly enhancing survival of the cells.

Potentiation of the activity of cisplatin and cyclophosphamide by trimidox, a novel ribonucleotide reductase inhibitor, in leukemia-bearing mice.

We describe the use of the new ribonucleotide reductase inhibitor, trimidox (TDX), in combination chemotherapy under in vitro and in vivo conditions with cisplatin and cyclophosphamide. In vitro, the combination of TDX and cisplatin was tested in L1210 cells. The combination caused concentration dependent antagonistic or additive effects.

In vitro and in vivo antitumor activity of novel amphiphilic dimers consisting of 5-fluorodeoxyuridine and arabinofuranosylcytosine.

Various heterodinucleoside phosphates of 5-fluorodeoxyuridine (5-FdUrd) and arabinofuranosylcytosine (Ara-C) have recently been synthesized as potent chemotherapeutic agents. 5-Fluorodeoxyuridine is being used in patients with colorectal carcinoma, whereas Ara-C is one of the most effective agents in the treatment of hematological malignancies. We now investigated the action of three novel amphiphilic dimers with different structures in various 5-fluorouracil (5-FU) sensitive and resistant human colon tumor cell lines (CCL228, CCL227, 5-FU resistant CCL227 and HT-29) as well as in L1210 murine leukemia cells.

Combination effects of Ara-C and 5-fluorodeoxyuridine against leukemia cells in vitro and in mice.

Background: Ara-C (1-beta-D-arabinofuranosylcytosine) is widely used for treatment of human leukemia. However, due to emergence of resistance, new drug combinations need to be developed.

Materials And Methods: We tested the combination of Ara-C with 5-FdUrd (5-fluorodeoxyuridine) in L1210 and P388D1 mouse leukemia cells in vitro and in vivo by growth inhibition and recovery assay in leukemia-bearing mice.

Fungal chitin-glucan derivatives exert protective or damaging activity on plasmid DNA.

Water-soluble derivatives of the chitin-glucan (Ch-G) complex isolated from the fungal mycelium of the industrial strain of Aspergillus niger have been previously shown to possess potent antimutagenic protective activity in vivo. Their direct action on DNA has not been yet evaluated. Using carboxymethylation, sulfoethylation and subsequent ultrasonic treatment, lower molecular weight water-soluble derivatives were obtained from the crude fungal Ch-G.

Effects of flavonoids on cisplatin-induced apoptosis of HL-60 and L1210 leukemia cells.

Effects of three flavonoids, quercetin (QU), galangin (GA), and chrysin (ChR) on cisplatin (cis-Pt)-induced apoptosis of human promyelocytic leukemia HL-60 cells and murine leukemia L1210 cells were investigated. The quantitative analysis of apoptotic DNA fragmentation was used to show that preincubation of cells with flavonoids can influence cis-Pt-induced apoptosis in different way. ChR had no effect, QU enhanced, and GA reduced apoptotic DNA fragmentation.

Antitumor activity of benzamide riboside in vitro and in vivo.

Benzamide riboside (BR), a recent synthetic nucleoside analogue, is a new compound demonstrating potent cytotoxic activity in malignant cell lines in vitro and in vivo in L1210 leukemia. It exhibits at least two different mechanisms of action. These are, first, the inhibition of inosine 5'-monophosphate dehydrogenase (IMPDH, EC 1.