curcumin and plumbagin

Cancer development is associated with the deregulation of various cell signaling pathways brought on by certain genetic and epigenetic alterations. Therefore, novel therapeutic strategies have been developed to target those pathways. The phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) (PI3K/Akt/mTOR) pathway is one major deregulated pathway in various types of cancer. Several anticancer drug candidates are currently being investigated in preclinical and/or clinical studies to target this pathway. Natural bioactive compounds provide an excellent source for anticancer drug development. Curcumin and plumbagin are two potential anticancer compounds that have been shown to target the PI3K/Akt/mTOR pathway individually. However, their combinatorial effect on cancer cells is still unknown. This study aims to investigate the synergistic effect of these two compounds on the PI3K/Akt/mTOR pathway by employing a sequential molecular docking and molecular dynamics (MD) analysis. An increase in binding affinity and a decrease in inhibition constant have been observed when curcumin and plumbagin were subjected to sequential docking against the key proteins PI3K, Akt, and mTOR. The MD simulations and molecular mechanics combined with generalized Born surface area (MM-GBSA) analyses validated the target proteins' more stable conformation when interacting with the curcumin and plumbagin combination. This indicates the synergistic role of curcumin and plumbagin against cancer cells and the possible dose advantage when used in combination. The findings of this study pave the way for further investigation of their combinatorial effect on cancer cells in vitro and in vivo models.

Topics: Curcumin; Humans; Molecular Docking Simulation; Neoplasms; Phosphatidylinositol 3-Kinase; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; TOR Serine-Threonine Kinases

Developing novel therapies to cure and manage endometriosis is a major unmet need that will benefit over 180 million women worldwide. Results from the current study suggest that inhibitors of oxidative phosphorylation may serve as novel agents for the treatment of endometriosis.. Current therapeutic strategies for endometriosis focus on symptom management and are not curative. Here, we provide evidence supporting the inhibition of oxidative phosphorylation (OXPHOS) as a novel treatment strategy for endometriosis. Additionally, we report an organotypic organ-on-a-chip luminal model for endometriosis. The OXPHOS inhibitors, curcumin, plumbagin, and the FDA-approved anti-malarial agent, atovaquone, were tested against the endometriosis cell line, 12Z, in conventional as well as the new organotypic model. The results suggest that all three compounds inhibit proliferation and cause cell death of the endometriotic cells by inhibiting OXPHOS and causing an increase in intracellular oxygen radicals. The oxidative stress mediated by curcumin, plumbagin, and atovaquone causes DNA double-strand breaks as indicated by the elevation of phospho-γH2Ax. Mitochondrial energetics shows a significant decrease in oxygen consumption in 12Z cells. These experiments also highlight differences in the mechanism of action as curcumin and plumbagin inhibit complex I whereas atovaquone blocks complexes I, II, and III. Real-time assessment of cells in the lumen model showed inhibition of migration in response to the test compounds. Additionally, using two-photon lifetime imaging, we demonstrate that the 12Z cells in the lumen show decreased redox ratio (NAD(P)H/FAD) and lower fluorescence lifetime of NAD(P)H in the treated cells confirming major metabolic changes in response to inhibition of mitochondrial electron transport. The robust chemotoxic responses observed with atovaquone suggest that this anti-malarial agent may be repurposed for the effective treatment of endometriosis.

Topics: Antimalarials; Antineoplastic Agents; Atovaquone; Cell Proliferation; Curcumin; Endometriosis; Female; Humans; NAD; Oxidative Phosphorylation

Transforming growth factor β (TGFβ) plays a central role in the pathogenesis of gingival overgrowth (GO). Connective tissue growth factor (CTGF; or CCN2) is induced by TGFβ in human gingival fibroblasts (HGFs) and is overexpressed in GO tissues. CCN2 creates an environment favorable for fibrogenesis and is required for the maximal profibrotic effects of TGFβ. We previously showed that Src, JNK, and Smad3 mediate TGFβ1-induced CCN2 protein expression in HGFs. Moreover, Src is an upstream signaling transducer of JNK and Smad3. Recent studies suggested that NADPH oxidase (NOX)-dependent redox mechanisms are involved in mediating the profibrotic effects of TGFβ. In this study, we demonstrated that TGFβ1 upregulated NOX4 protein expression and increased reactive oxygen species (ROS) production in HGFs. Genetic or pharmacologic targeting of NOX4 abrogated TGFβ1-induced ROS production; Src, JNK, and Smad3 activation; and CCN2 and type I collagen protein expression in HGFs. Our results indicated that NOX4-derived ROS play pivotal roles in activating Src kinase activity leading to the activation of canonical (Smad3) and noncanonical (JNK) cascades that cooperate to attain maximum CCN2 expression. Furthermore, we demonstrated that curcumin significantly inhibited the TGFβ1-induced NOX4 protein expression in HGFs. Curcumin potentially qualifies as an agent to control GO by suppressing TGFβ1-induced NOX4 expression in HGFs.

Topics: Acetylcysteine; Cell Culture Techniques; Cells, Cultured; Connective Tissue Growth Factor; Curcumin; Enzyme Inhibitors; Fibroblasts; Free Radical Scavengers; Gene Silencing; Gingiva; Gingival Overgrowth; Humans; MAP Kinase Signaling System; NADPH Oxidase 4; NADPH Oxidases; Naphthoquinones; Oxidation-Reduction; Reactive Oxygen Species; RNA, Small Interfering; Signal Transduction; Smad3 Protein; src-Family Kinases; Superoxides; Transforming Growth Factor beta1

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

Female adult bovine filarial worms Setaria digitata were extracted with phosphate-buffered saline (pH 7.4) and glutathione S-transferase (GST) activity and protein content were determined. The protein content, GST enzyme activity, and specific activity were 10.61 +/- 3.41 mg ml(-1), 0.09 +/- 0.019 micromol min(-1) ml(-1), and 0.009 +/- 0.002 micromol min(-1) mg(-1) protein, respectively. The GST inhibition studies were performed with and without the inhibitors resulted from earlier molecular docking studies viz., ethacrynic acid, plumbagin, and curcumin for which the IC(50) values were 19.42, 51.41, and 114.86 microM, respectively. The in vitro macrofilaricidal activity of these molecules was studied by worm motility and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction assay at 24- and 48-h incubation. Plumbagin and ethacrynic acid showed 100% inhibition in worm motility at lower concentrations of 3.19 and 6.6 microM, respectively, at 48-h incubation while curcumin was effective at 54.29 microM. In MTT reduction assay, the ED(50) values (50% inhibition in formazan formation) for plumbagin, ethacrynic acid, and curcumin at 48-h incubation were 1.20, 2.48, and 19.86 microM, respectively. MTT reduction assay showed that plumbagin was the most effective in killing the adult S. digitata worms followed by ethacrynic acid and curcumin. In conclusion, all the three molecules selected by molecular modeling and docking studies inhibited the GST enzyme isolated from S. digitata and exhibited macrofilaricidal activity in vitro.

Topics: Animals; Cattle; Cattle Diseases; Curcumin; Ethacrynic Acid; Female; Filariasis; Filaricides; Filarioidea; Glutathione Transferase; Helminth Proteins; Inhibitory Concentration 50; Locomotion; Naphthoquinones; Survival Analysis