Cellular uptake and efflux of trans-piceid and its aglycone trans-resveratrol on the apical membrane of human intestinal Caco-2 cells.

Two stilbenes (trans-piceid and its aglycone trans-resveratrol) were investigated in the uptake across the apical membrane of the human intestinal cell line Caco-2 in order to determine their mechanisms of transport. The uptake was quantified using a reverse phase high-performance liquid chromatography method with fluorescence detection. The rate of cellular accumulation in the cells was found to be higher for trans-resveratrol than for trans-piceid.

Implications of oxidative stress and inflammatory process in the cytotoxicity of capsaicin in human endothelial cells: lack of DNA strand breakage.

Capsaicin, a natural product of Capsicum species is known to induce excitation of nociceptive terminals involved in pain perception. Nevertheless, it is utilized by topical application in humans, giving rise to blood capsaicin concentration up to 10-20 microM. The effect of capsaicin on human endothelial cells ECV 304 has been investigated.

Cytotoxicity of capsaicin in monkey kidney cells: lack of antagonistic effects of capsazepine and Ruthenium red.

Capsaicin is a natural product of Capsicum peppers, excitatory effects of which have been shown to be mediated by the recently cloned vanilloid receptor 1 (VR1). Since previous studies have shown that capsaicin inhibits protein synthesis, experiments were performed to investigate whether this effect is mediated by VR1 receptor on cultured monkey kidney cells (Vero cells). The capsaicin uptake was assessed in cellular homogenate and in medium by high-performance liquid chromatography (HPLC) separation and quantification on C18 reverse-phase column and fluorescence detection.

Cytotoxicity and genotoxicity of capsaicin in human neuroblastoma cells SHSY-5Y.

Capsaicin, a natural product of Capsicum species, induces excitation of pain perception at nociceptive terminals. Our previous studies have shown that capsaicin inhibits protein synthesis in cultured monkey kidneys cells (Vero cells) and in primoculture of rat astrocytes. We have now investigated the effect of capsaicin on human neuroblastoma cells SHSY-5Y.

Oxythiamine and dehydroepiandrosterone induce a G1 phase cycle arrest in Ehrlich's tumor cells through inhibition of the pentose cycle.

Transketolase (TK) reactions play a crucial role in tumor cell nucleic acid ribose synthesis utilizing glucose carbons, yet, current cancer treatments do not target this central pathway. Experimentally, a dramatic decrease in tumor cell proliferation after the administration of the TK inhibitor oxythiamine (OT) was observed in several in vitro and in vivo tumor models. Here, we demonstrate that pentose cycle (PC) inhibitors, OT and dehydroepiandrosterone (DHEA), efficiently regulate the cell cycle and tumor proliferation processes.

Aspirin and heparin prevent hepatic blood stasis and thrombosis induced by the toxic glycoprotein Bolesatine in mice.

Bolesatine is a toxic glycoprotein isolated from Boletus satanas Lenz, which inhibits protein synthesis in vivo and in vitro. The LD50 (24 h) is 1 mg /kg bw (i.p.

Cytotoxicity of fumonisin B1: implication of lipid peroxidation and inhibition of protein and DNA syntheses.

The effects of fumonisin B1 (FB1) from Fusarium moniliforme on lipid peroxidation and protein and DNA syntheses were studied in monkey kidney cells (Vero cells). FB1 was found to be a potent inducer of malondialdehyde (MDA), one of the secondary products formed during lipid peroxidation. At 0.

SECMA 1, a mitogenic hexapeptide from Ulva algeae modulates the production of proteoglycans and glycosaminoglycans in human foreskin fibroblast.

SECMA 1 is a polypeptide purified from a green algeae of the Ulva species by several gel chromatographies, showing the following sequence (Glu-Asp-Arg-Leu-Lys-Pro). In order to determine the effect of SECMA 1 on human skin fibroblasts extracellular matrix, proteoglycans (PGs) and glycosaminoglycans (GAGs) were assayed after 24 h incubation of 20 day-old foreskin fibroblasts at the 2nd passage. The results revealed that most of [35S]sulphate was associated with fibroblast membranes, which contained (67%) of the total de novo synthesized sulphated PGs, in two distinct forms: one hydrophilic (39%), and one hydrophobic (28%).

Bolesatine induces agglutination of rat platelets and human erythrocytes and platelets in vitro.

Bolesatine is a toxic glycoprotein isolated from the mushroom Boletus satanas Lenz, which has been shown to inhibit protein synthesis in cell-free systems and cell culture. It is toxic to rodents, the LD50% 24 h being 1 mg kg-1 (i.p.

Lipid peroxidation induced by bolesatine, a toxin of Boletus satanas: implication in m5dC variation in Vero cells related to inhibition of cell growth.

Bolesatine, a glycoprotein from Boletus satanas Lenz, has previously been shown to be mitogenic in rat and human lymphocytes at very low concentrations, whereas higher concentrations inhibited protein synthesis in vitro and in several in vivo systems. The low concentrations (1-10 ng/ml) of bolesatine were shown to activate protein kinase C (PKC) in vitro (cell-free system) and in Vero cells. In the same time, Vero cells significantly proliferated when incubated with bolesatine concentrations ranging from 1 to 10 ng/ml; the DNA synthesis increased by 27-59% as referred to the control, and InsP3 release increased in a concentration-dependent manner, up to 142%.

Effects of bolesatine on a cell line from the SP2/O thymic lymphosarcoma.

Bolesatine, a toxic protein isolated from Boletus satanas Lenz inhibits in vitro protein synthesis in a concentration-dependent manner in a cell line from a radiation-induced thymic lymphosarcoma (SP2/O) with a 50% inhibitory concentration (IC50) of 9.5 nM (0.6 microgram/ml).

Mode of action of bolesatine, a cytotoxic glycoprotein from Boletus satanas Lenz. Mechanistic approaches.

Bolesatine is a potent cytotoxic glycoprotein purified from Boletus satanas Lenz, which has previously been shown to be an inhibitor of protein synthesis in several in vitro systems and in vivo. For a better understanding of its mechanism of action on protein synthesis at the ribosomal level, rat liver ribosomes were pretreated with bolesatine (1 to 10 micrograms) added to in vitro polyuridylic acid (poly(U)) translation systems before and after washing. The fact that ribosomes were still active confirmed that bolesatine cannot be included in the group of protein synthesis inhibitors of plant origin, known as ribosome-inactivating proteins (RIPs).

Effect of bolesatine on phospholipid/calcium dependent protein kinase in Vero cells and in rat thymus.

Bolesatine, a glycoprotein from Boletus satanas Lenz, has previously been shown to be mitogenic to rat and human lymphocytes at very low concentrations, whereas higher concentrations inhibit protein synthesis in vitro and in several in vivo systems. The mechanism whereby this mitogenic activity occurs was previously unknown. To elucidate this mechanism, the effects of bolesatine have been studied in a cell-free system, VERO cells, and in vivo in rat thymus.

Effect of bolesatine, a glycoprotein from Boletus satanas, on rat thymus in vivo.

Bolesatine is a glycoprotein purified to homogeneity from Boletus satanas Lenz, a toxic mushroom which causes serious gastroenteritis. This lectin possesses a mitogenic activity on human lymphocytes at very low concentrations, whereas higher concentrations inhibit protein synthesis in vitro in several systems. The mitogenic activity on peripheral blood T lymphocytes in vitro has been shown to be at least 200-fold higher than the activity of the well studied phytohemagglutinin (PHA).