Enhancement of cisplatin-induced apoptosis and caspase 3 activation by depletion of mitochondrial DNA in a human osteosarcoma cell line.

Cisplatin is an anticancer drug that can induce apoptosis. In this study, we investigated the effect of mitochondrial DNA (mtDNA) depletion on cisplatin-induced cell death using a human osteosarcoma cell line (143B) and mtDNA-depleted 143B cells (143B-rho0). Results showed that cisplatin decreased cell survival in 143B-rho0 cells. Moreover, cisplatin induced a greater extent of apoptosis-associated DNA fragmentation and caspase 3 activation in 143B-rho0 cells. The release of mitochondrial cytochrome c into cytosol by cisplatin was enhanced more obviously in 143B cells than in 143B-rho0 cells; however, in the control group of 143B-rho0 cells, it was already dramatically greater. Depletion of mtDNA may increase sensitivity of cells to cisplatin-induced apoptosis by enhancing caspase 3 activation via both cytochrome c-dependent and -independent pathways.

Molecular screening of Chinese medicinal plants for progestogenic and anti-progestogenic activity.

Estrogen and progestins have adverse effects, and many of these adverse effects are caused by progestins. Due to this, many women choose to use botanical alternatives for hormone replacement therapy, which does not trigger steroidogenic properties. Therefore, it is necessary to screen these herbs for progestogenic and anti-progestogenic properties. Extract of 13 Chinese medicinal plants were analysed for progestogenic and anti-progestogenic activities by using progesterone response element-driven luciferase reporter gene bioassay. MTT assay was carried out to investigate the cytotoxic effect of herb extract on PAE cells. Among the 13 herbs, Dipsacus asperoides extract exhibited progestogenic activity, and 10 species - Cortex eucommiae, Folium artemisiae argyi, Glycyrrhiza uralensis, Angelica sinensis, Atractylodes macrocephala koidz, Scutellaria baicalensis, Cuscuta chinensis, Euscaphis japonica, Ailanthus altissima, and Dioscorea opposita - were recognized to have anti-progestogenic like activities. Extract of Dipsacus asperoides demonstrated dose-dependent progestogenic activity, and the progestogenic activity of 100 (mu)g/mL extracts was equivalent to 31.45 ng/mL progesterone activity. Herbs extracts that exhibited anti-progestogenic-like activity also inhibited the 314.46 ng/mL progesterone activity in a dose-response manner. None of the herb extracts shown significant toxic effect on PAE cells at 40-100 (mu)g/mL compared to control. This discovery will aid selection of suitable herbs for hormone replacement therapy.