cytochrome-c-t and liquiritigenin

The purpose of this study was to investigate antitumour effects of liquiritigenin (LQ) on pituitary adenoma in in-vitro and in-vivo models.. The effects of LQ on cell viability, apoptosis rate, mitochondrial membrane potential (MMP), intracellular reactive oxygen species (ROS) level and various apoptosis-related mediators were examined in MMQ and GH3 cells that are derived from rat pituitary adenoma. Antitumour effect of LQ was also examined in the mouse model of GH3-xenografted tumour.. LQ inhibited cell viability, caused G1 phase arrest and initiated apoptosis in both MMQ and GH3 cells. LQ dissipated MMP, increased intracellular ROS level and cytosol cytochrome C, and reduced the expression of Ras, B-cell lymphoma 2 and B-cell lymphoma-extra large. LQ also inhibited the activation of extracellular signalling-regulated kinases (ERKs) and the translocation of from cytoplasm to nucleus. LQ markedly reduced tumour size without affecting bodyweight in mice with GH3 cells xenograft.. LQ effectively inhibits pituitary adenoma tumour growth and induces cell apoptotic death mainly via Ras/ERKs and ROS-dependent mitochondrial pathways, suggesting that LQ is a potential suppressor of pituitary adenoma.

Topics: Animals; Antineoplastic Agents, Phytogenic; Biological Transport; Cytochromes c; Extracellular Signal-Regulated MAP Kinases; Flavanones; Membrane Potential, Mitochondrial; Mitochondria; Mitogen-Activated Protein Kinases; Phytotherapy; Pituitary Neoplasms; Plant Extracts; Rats; Reactive Oxygen Species; Signal Transduction; Xenograft Model Antitumor Assays

It has been demonstrated that many flavonoids possess a potent and broad spectrum of antitumor activity. Liquiritigenin is a flavanone extracted from Glycyrrhizae. This study investigated the effects of liquiritigenin on cell viability and apoptosis induction in human cervical carcinoma (HeLa) cells. The results show that liquiritigenin significantly suppressed cell proliferation in a dose- and time-dependent manner in HeLa cells. In addition, liquiritigenin promoted apoptosis in HeLa cells, evidenced by apoptotic morphological changes and Annexin-V binding. The apoptosis induction with liquiritigenin is associated with the up-regulation of p53 and Bax, along with down-regulation of Bcl-2 and survivin. Finally, examination of the mitochondrial pathway of apoptosis revealed that cytochrome c is released from mitochondria to cytosol, associated with the activation of caspase-9 and -3, and the cleavage of poly (ADP-ribose) polymerase (PARP). Overall, the results indicate that liquiritigenin induces apoptosis in part via the mitochondrial pathway, which is associated with p53 up-regulation, release of cytochrome c and elevated activity of caspase-9 and -3 in HeLa cells.

Topics: Apoptosis; Caspase 3; Caspase 9; Cell Survival; Cytochromes c; Cytosol; Flavanones; HeLa Cells; Humans; Inhibitor of Apoptosis Proteins; Microtubule-Associated Proteins; Mitochondria; Mitochondrial Proteins; Proto-Oncogene Proteins c-bcl-2; Survivin; Tumor Suppressor Protein p53

Glycyrrhizae radix has been popularly used as one of the oldest and most frequently employed botanicals in herbal medicine in Asian countries, and currently occupies an important place in food products. Cadmium (Cd) induces both apoptotic and non-apoptotic cell death, in which alterations in cellular sulfhydryls participate. In the present study, we determined the effects of G. radix extract (GRE) and its representative active components on cell death induced by Cd and explored the mechanistic basis of cytoprotective effects of G. radix. Incubation of H4IIE cells with GRE inhibited cell death induced by 10 microM Cd. Also, GRE effectively blocked Cd (1 microM)-induced cell death potentiated by buthionine sulfoximine (BSO) without restoration of cellular GSH. GRE prevented both apoptotic and non-apoptotic cell injury induced by Cd (10 microM) or Cd (0.3-1 microM) + BSO. Inhibition of Cd-induced cell injury by pretreatment of cells with GRE suggested that the cytoprotective effect result from alterations in the levels of the protein(s) responsible for cell viability. GRE inhibited mitochondrial Bad translocation by Cd or CD+BSO, and caused restoration of mitochondrial Bcl(xL) and cytochrome c levels. Cd-induced poly(ADP-ribose)polymerase cleavage in control cells or in cells deprived of sulfhydryls was prevented by GRE treatment. Among the major components present in GRE, liquiritigenin, but not liquiritin, isoliquiritigenin or glycyrrhizin, exerted cytoprotective effect. These results demonstrated that GRE blocked Cd-induced cell death by inhibiting the apoptotic processes involving translocation of Bad into mitochondria, decreases in mitochondrial Bcl(xL) and cytochrome c, and poly(ADP-ribose)polymerase cleavage.

Topics: Animals; bcl-Associated Death Protein; bcl-X Protein; Cadmium Chloride; Carrier Proteins; Cell Line; Cell Survival; Cytochromes c; Cytoprotection; Flavanones; Flavonoids; Glycyrrhiza; Hepatocytes; Mitochondria, Liver; Plant Extracts; Poly(ADP-ribose) Polymerases; Proto-Oncogene Proteins c-bcl-2; Rats