Induction of necrosis and apoptosis to KB cancer cells by sanguinarine is associated with reactive oxygen species production and mitochondrial membrane depolarization

Comparative cytotoxicity of five current dentin bonding agents: role of cell cycle deregulation

To compare the cytotoxicity of three nano-dentin bonding agents (nano-DBAs) and two non-nano-DBAs using Chinese hamster ovary (CHO-K1) cells. We found that nano fillers were not the major contributing factor in DBA cytotoxicity, as analyzed by colony forming assay and 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Exposure of CHO-K1 cells to all three tested total-etching DBAs led to G(0)/G(1) cell cycle arrest, whereas exposure to higher concentrations of two tested nano-DBAs induced G(2)/M arrest. All five DBAs further induced apoptosis at the highest concentration, as analyzed by propidium iodide staining flow cytometry. The toxicity of all DBAs (1:4000v/v or higher) is related to increased reactive oxygen species (ROS) production, as analyzed by single cell DCF fluorescence flow cytometry. These results indicate that clinical application of DBAs may be potentially toxic to dental pulp tissues. Cytotoxicity of DBAs is associated with ROS production, cell cycle deregulation and apoptosis. Presence of methacrylate monomers such as PENTA and UDMA is possibly the major cytotoxic factor for DBAs. Further studies on other toxicological endpoints of nano-DBAs are necessary to highlight their safe use.

Areca nut-induced micronuclei and cytokinesis failure in Chinese hamster ovary cells is related to reactive oxygen species production and actin filament deregulation

Epidemiological studies have shown a strong association between environmental exposure to betel quid (BQ) and oral cancer. Areca nut (AN), an ingredient of BQ, contains genotoxic and mutagenic compounds. In this study, we found that AN extract (ANE) inhibited the growth of Chinese hamster ovary cells (CHO-K1) in a dose- and time-dependent manner. Intracellular reactive oxygen species (ROS) levels and micronuclei (MN) frequency were significantly increased following ANE treatment in CHO-K1 cells. Addition of catalase markedly inhibited ANE-induced MN formation, indicating that ANE-induced genotoxicity was correlated with intracellular H(2)O(2). Incubation of CHO-K1 cells with ANE (400-800 microg/ml) for 24 hr caused G2/M arrest, and prolonged exposure to ANE (800 microg/ml) significantly induced cell death. Surprisingly, ANE itself caused cytokinesis failure and subsequent increase in binucleated cell formation. Coexposure to catalase (2,000 U/ml) and ANE (800 microg/ml) reduced the generation of binucleated cells, indicating that ANE-induced cytokinesis failure was associated with oxidative stress. Following prolonged exposure to ANE, an accumulation of hyperploid/aneuploid cells concomitant with bi-, micro- or multinucleated cells was found. In summary, our results demonstrate that ANE exposure to CHO-K1 cells caused increased MN frequency, G2/M arrest, cytokinesis failure, and an accumulation of hyperploid/aneuploid cells. These events are associated with an increase in intracellular H(2)O(2) level and actin filament disorganization.

Induction of hepatotoxicity by sanguinarine is associated with oxidation of protein thiols and disturbance of mitochondrial respiration

Sanguinarine (SANG) has been suggested to be one of the principle constituents responsible for the toxicity of Argemone mexicana seed oil. In this study, we focused on the possible mechanism of SANG-induced hepatotoxicity. The serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) activities, hepatic vacuolization, lipid accumulation and lipid peroxidation of the liver were increased, and triglyceride (TG) was decreased in SANG-treated mice (10 mg kg(-1) i.p.), indicating damage to the liver. SANG induced cell death and DNA fragmentation, in a concentration- (0-30 microm) and time-dependent (0-24 h) manner, and the cytotoxicity of SANG (15 microm) was accompanied by an increase in reactive oxygen species and a lessening in protein thiol content; these outcomes were reversed by glutathione, N-acetyl-l-cysteine and 1,4-dithiothretol, and slightly improved by other antioxidants in hepatocytes. SANG can affect the function of mitochondria, leading to the depletion of the mitochondrial membrane potential and adenosine 5'-triphosphate content of hepatocytes. SANG caused an uncoupling effect of the respiratory chain at lower concentrations, but inhibited the respiratory chain at higher concentrations in mitochondria isolated from rat liver. In conclusion, the data suggest that SANG is a liver toxin that induces cytotoxicity in liver cells, possibly through oxidation of protein thiols, resulting in oxidative stress on the cells and disturbance of mitochondrial function.

Bloodroot (Sanguinaria canadensis L., Papaveraceae) Enhances Proliferation and Cytokine Production by Human Peripheral Blood Mononuclear Cells in an In Vitro Model

Previous studies have suggested that phytomedicinal preparations from bloodroot (Sanguinaria canadensis L.) may harbor immunomodulatory properties. The purpose of this investigation was to determine the effects of alcohol tinctures and water infusions generated from bloodroot flowers, leaves, rhizomes, and roots on human peripheral blood mononuclear cell (PBMC) cytokine production and proliferation in vitro. PBMCs were collected from 16 healthy young adults and cultured with bloodroot extracts or respective controls for interleukins-1β, -2, -8, -10, interferon-γ, and tumor necrosis factor. Proliferative capabilities of both PBMCs and K562 cells (an immortalized human myelogenous leukemia cell line) following extract treatment were determined. High-pressure liquid chromatography was used to quantify berberine, chelerythrine, and sanguinarine in the extracts and to correlate extract composition with observed effects. Overall, infusions demonstrated greater immunomodulatory capabilities than tinctures, and flower- and root-based extracts showed greater immunomodulatory properties than leaf- or rhizome-based extracts (some effects seen with root-based extracts may be due to endotoxin). Several extracts were able to augment PBMC proliferation and diminish K562 proliferation, suggesting a selective anti-carcinogenic activity. The rhizome alcohol tincture had a markedly stronger effect against K562 cells than other extracts. Chelerythrine, sanguinarine, and endotoxin (but not berberine) sometimes correlated with observed effects. The in vitro activities demonstrated here suggest bloodroot extracts may have potential as therapeutic immunomodulators.

Sanguinarine induces apoptosis in A549 human lung cancer cells primarily via cellular glutathione depletion

Sanguinarine is a plant-derived benzophenanthridine alkaloid and has been shown to possess anti-tumor activities against various cancer cells. In this study, we investigated whether sanguinarine induces apoptosis in A549 human lung cancer cells. Treatment of A549 cells with sanguinarine induced apoptosis in a dose- and time-dependent manner. Treatment with sanguinarine led to activation of caspases and MAPKs as well as increased MKP-1 expression. Importantly, pretreatment with z-VAD-fmk, a pan caspase inhibitor suppressed the sanguinarine-induced apoptosis in A549 cells. Moreover, pretreatment with NAC, a sulfhydryl group-containing reducing agent strongly suppressed the apoptotic response and caspase activation to sanguinarine. However, the sanguinarine-mediated cytotoxicity in A549 cells was not protected by pharmacological inhibition of MAPKs or MKP-1 siRNA-mediated knockdown of MKP-1. These results collectively suggest that sanguinarine induces apoptosis in A549 cells through cellular glutathione depletion and the subsequent caspase activation.

Anti-invasive activity of sanguinarine through modulation of tight junctions and matrix metalloproteinase activities in MDA-MB-231 human breast carcinoma cells

Tight junctions (TJs) are critical structures for the maintenance of cellular polarity, acting as paracellular permeability barriers and playing an essential role in regulation of the diffusion of fluid, electrolytes and macromolecules through the paracellular pathway. Matrix metalloproteinases (MMPs) have been implicated as possible mediators of invasiveness and metastasis in some cancers. In this study, it was investigated the effect of sanguinarine, a benzophenanthridine alkaloid, on the correlation between the tightening of TJs and the anti-invasive activity in human breast carcinoma MDA-MB-231 cells. The inhibitory effects of sanguinarine on cell proliferation, motility and invasiveness were found to be associated with the increased tightness of the TJ, which was demonstrated by an increase in transepithelial electrical resistance (TER). Additionally, immunoblotting results indicated that sanguinarine repressed the levels of the claudin proteins, major components of TJs that play a key role in the control and selectivity of paracellular transport. Furthermore, the activities of MMP-2 and -9 in MDA-MB-231 cells were dose-dependently inhibited by treatment with sanguinarine, and this was also correlated with a decrease in the expression of their mRNA and proteins.

Production of hydrogen peroxide and redox cycling can explain how sanguinarine and chelerythrine induce rapid apoptosis

Sanguinarine and chelerythrine are naturally occurring benzophenanthridines with multiple biological activities. Sanguinarine is believed to be a potential anticancer agent but its mechanism of action has not been fully elucidated. We previously found that it causes oxidative DNA damage and very rapid apoptosis that is not mediated by p53-dependent DNA damage signaling. Here we show that sanguinarine and chelerythrine cause the production of large amounts of reactive oxygen species (ROS), in particular hydrogen peroxide, which may deplete cellular antioxidants and provide a signal for rapid execution of apoptosis. Several oxidoreductases contribute to cell death induced by sanguinarine and chelerythrine which appear to be reduced upon entering the cell. We propose a model in which the generation of lethal amounts of hydrogen peroxide is explained by enzyme-catalyzed redox cycling between the reduced and oxidized forms of the phenanthridines and discuss the implications of such a mechanism for potential pharmaceutical applications.