cytochrome-c-t and plumbagin

The folate (FA)-functionalized human serum albumin (HSA) carrier (FA-HSA) is promising for improving the target and efficiency of anticancer drugs. To develop FA-HSA carrier for metal anticancer drugs, we investigated anticancer properties and mechanism of FA-HSA carrier for Cu(II) complexes derived from plumbagin. The fluorescence spectroscopy and molecular docking revealed that Cu(II) complexes bind to IIA subdomain of HSA. Compared with Cu(II) complex alone, FA-HSA-metallodrug complex enhances cytotoxicity to FA-positive cancer cells (HeLa) but do not raise cytotoxicity levels in normal cells in vitro through selectively accumulating in cancer cells to some extent; FA-HSA-metallodrug complex has a stronger capacity for cell cycle arrest in the G2/M phase of HeLa cells, and down-regulating the expression of cyclin-dependent kinase 1 (CDK1) and cyclin B1. Moreover, FA-HSA-metallodrug complex promotes HeLa cells apoptosis through intrinsic reactive oxygen species (ROS) mediated mitochondrial pathway, accompanied by the regulation of Bcl-2 family proteins.

Topics: Antineoplastic Agents; Apoptosis; bcl-2-Associated X Protein; bcl-Associated Death Protein; CDC2 Protein Kinase; Coordination Complexes; Copper; Cyclin B1; Cyclin-Dependent Kinases; Cytochromes c; Drug Carriers; Folic Acid; HeLa Cells; Humans; MCF-7 Cells; Naphthoquinones; Serum Albumin

The purpose of this study is to elucidate the possible mechanism of superoxide formation through redox cycling of plumbagin (PLG) in pig heart. Of four 1,4-naphthoquinones tested in this study, PLG was most efficiently reduced in the cytosolic fraction of pig heart. On the other hand, lawsone (LAS) was little reduced. Thus, whether or not PLG and LAS induce the formation of superoxide anion radical in pig heart cytosol was examined, by using the methods of cytochrome c reduction and chemiluminescence. PLG significantly induced the formation of superoxide anion radical, even though LAS had no ability to mediate superoxide formation. PLG was a significant inhibitor for the stereoselective reduction of 4-benzoylpyridine (4-BP) catalyzed by tetrameric carbonyl reductase (TCBR) in pig heart cytosol. Furthermore, PLG was confirmed to competitively inhibit the 4-BP reduction, and the optimal pH for the PLG reduction was around 6.0 similar to that for the 4-BP reduction. These results suggest that PLG mediates superoxide formation through its redox cycling involved in the two-electron reduction catalyzed by TCBR, and induces oxidative stress in pig heart.

Topics: Animals; Antineoplastic Agents, Phytogenic; Cytochromes c; Myocardium; Naphthoquinones; Oxidation-Reduction; Pyridines; Superoxides; Swine

Successful embryogenesis is a critical rate limiting step for the survival and transmission of parasitic worms as well as pathology mediated by them. Hence, blockage of this important process through therapeutic induction of apoptosis in their embryonic stages offers promise for developing effective anti-parasitic measures against these extra cellular parasites. However, unlike in the case of protozoan parasites, induction of apoptosis as a therapeutic approach is yet to be explored against metazoan helminth parasites.. For the first time, here we developed and evaluated flow cytometry based assays to assess several conserved features of apoptosis in developing embryos of a pathogenic filarial nematode Setaria digitata, in-vitro as well as ex-vivo. We validated programmed cell death in developing embryos by using immuno-fluorescence microscopy and scoring expression profile of nematode specific proteins related to apoptosis [e.g. CED-3, CED-4 and CED-9]. Mechanistically, apoptotic death of embryonic stages was found to be a caspase dependent phenomenon mediated primarily through induction of intracellular ROS. The apoptogenicity of some pharmacological compounds viz. DEC, Chloroquine, Primaquine and Curcumin were also evaluated. Curcumin was found to be the most effective pharmacological agent followed by Primaquine while Chloroquine displayed minimal effect and DEC had no demonstrable effect. Further, demonstration of induction of apoptosis in embryonic stages by lipid peroxidation products [molecules commonly associated with inflammatory responses in filarial disease] and demonstration of in-situ apoptosis of developing embryos in adult parasites in a natural bovine model of filariasis have offered a framework to understand anti-fecundity host immunity operational against parasitic helminths.. Our observations have revealed for the first time, that induction of apoptosis in developing embryos can be a potential approach for therapeutic intervention against pathogenic nematodes and flow cytometry can be used to address different issues of biological importance during embryogenesis of parasitic worms.

Topics: Animals; Antinematodal Agents; Apoptosis; Caenorhabditis elegans Proteins; Calcium-Binding Proteins; Caspases; Cattle; Cell Membrane; Chloroquine; Curcumin; Cytochromes c; Cytoplasm; Embryo, Nonmammalian; Female; Flow Cytometry; Lipid Peroxidation; Microscopy, Fluorescence; Naphthoquinones; Primaquine; Reactive Oxygen Species; Setaria Nematode

There is an emerging evidence that plumbagin (5-hydroxy-2-methyl-1, 4-naphthoquinone) may have potential as a chemotherapeutic agent. However, the growth inhibitory mechanisms of plumbagin have remained unexplored. The aim of the study was to determine whether plumbagin-induced cell death in human cervical cancer cell line, ME-180, exhibited biochemical characteristics of apoptosis and to check whether N-acetyl-l-cysteine (NAC), which is a free radical scavenger, can reverse the cytotoxic effects of plumbagin. It can be concluded from the results that plumbagin inhibits the growth of ME-180 cells in a concentration and time-dependent manner. The cytotoxic effect of plumbagin induced cell death is through the generation of reactive oxygen species (ROS) and subsequent induction of apoptosis as demonstrated by the present data. Treatment of cells with plumbagin caused loss of mitochondrial membrane potential (DeltaPsi(m)), and morphological changes characteristic of apoptosis, such as the translocation of phosphatidyl serine, nuclear condensation, and DNA fragmentation. Moreover, plumbagin-induced apoptosis involved release of mitochondrial cytochrome c and apoptosis inducing factor (AIF), thus activation of caspase-dependent and -independent pathways, as shown by the plumbagin-mediated activation of caspase-3 and -9. Our results also show that pretreatment of ME-180 cells with NAC blocks plumbagin-induced loss of DeltaPsi(m) and subsequent release of cytochrome c, AIF, and caspase-9 and -3 activation, thus inhibiting the apoptotic ability of plumbagin.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Caspases; Cell Nucleus; Cytochromes c; Dose-Response Relationship, Drug; Female; Humans; Mitochondria; Naphthoquinones; Phosphatidylserines; Reactive Oxygen Species; Time Factors; Uterine Cervical Neoplasms