In vitro cytotoxicity of Gymnema montanum in human leukaemia HL-60 cells; induction of apoptosis by mitochondrial membrane potential collapse.

OBJECTIVES: Gymnema montanum Hook, an Indian Ayurvedic medicinal plant, is used traditionally to treat a variety of ailments. Here, we report anti-cancer effects and molecular mechanisms of ethanolic extract of G. montanum (GLEt) on human leukaemia HL-60 cells, compared to peripheral blood mononuclear cells. MATERIALS AND METHODS: HL-60 cells were treated with different concentrations of GLEt (10-50 µg/ml) and cytotoxicity was assessed by MTT assay. Levels of lipid peroxidation, antioxidants, mitochondrial membrane potential and caspase-3 were measured. Further, apoptosis was studied using annexin-V staining and the cell cycle was analyzed by flow cytometry. RESULTS: GLEt had a potent cytotoxic effect on HL-60 cells (IC50 -20 µg/ml), yet was not toxic to normal peripheral blood mononuclear cells. Exposure of HL-60 cells to GLEt led to elevated levels of malonaldehyde formation, but to reduced glutathione, superoxide dismutase, catalase and glutathione peroxidase activities (P < 0.05). Induction of apoptosis was confirmed by observing annexin-V positive cells, associated with loss of mitochondrial membrane potential. Cell cycle arrest at G0/G1 was observed in GLEt-treated HL-60 cells, indicating its potential at inducing their apoptosis. CONCLUSIONS: Findings of the present study suggest that G. montanum induced apoptosis in the human leukaemic cancer cells, mediated by collapse of mitochondrial membrane potential, generation of reactive oxygen species and depletion of intracellular antioxidant potential.

Barriers to nurse entrepreneurship: a study of the process model of entrepreneurship.

PURPOSE: The potential for nurse entrepreneurship to contribute to the effectiveness of healthcare delivery is well acknowledged, yet it has not been fully realized. Using the process model of entrepreneurship, we attempted to glean information from nursing professionals through focus groups on the barriers to starting a business. DATA SOURCES: Two focus groups were used and expert moderators conducted these exercises. The first focus group included two hospital administrators, a nurse entrepreneur, an ophthalmology entrepreneur, and a dean of the nursing school familiar with nurse entrepreneurship. The second focus group used 20 students in a nurse practitioner program. CONCLUSIONS: The study findings indicate nurse practitioners and other nursing professionals do recognize the potential of nurse entrepreneurship. However, several barriers prevent them from exploiting the identified opportunity. IMPLICATIONS FOR PRACTICE: While the barriers are significant, we believe they can be overcome with coordinated action by individual nurses, professional associations, and public policy initiatives. Several suggestions are offered to nurses seeking to become nurse entrepreneurs.