In vitro anti-proliferative effects on NB4 human leukemia cells and physicochemical screening of Pleurotus sp. (higher Basidiomycetes) mycelia from Cuba.

This study examined the phytochemical profile and the in vitro anti-proliferative effects of a hot water mycelial extract from the edible mushroom Pleurotus sp. on NB4 human leukemia cells. Flow-cytometry analyses were used to measure cell viability, cell cycle, and apoptosis in cells incubated 24 h with the extract at doses of 100 and 200 µg/mL. Pleurotus sp. extract reduced cell viability, particularly at the concentration of 200 µg/mL to 82% compared to control cells, and induced apoptosis demonstrated by an increase in the number of annexin V-FITC+ cells (25% at 200 µg/mL). The NB4 cells were arrested in the G2/M phase thus supporting a cell-cycle dependent anticancer mechanism. Although carbohydrates (76.8%, w/w) appear to be the most important antitumor compound, secondary metabolites-like phenolics would also contribute to the anti-proliferative activity. The results indicate that Pleurotus sp. mycelia obtained by submerged fermentation may be an interesting renewable resource for developing functional foods and new antitumor therapeutic agents.

Dequalinium induces apoptosis in peripheral blood mononuclear cells isolated from human chronic lymphocytic leukemia.

B-cell chronic lymphocytic leukemia (B-CLL) is an abnormal neoplasic proliferation of B cells, which accumulate mainly in the bone marrow and blood preventing both B cells development in the lymph nodes and the ability to fight against infection. The antitumor agents used in chemotherapy are aimed at inducing malignant cell death, thus limiting the growth and spreading of these cells. However, the lack of specificity for tumor cells exhibited by these agents causes undesirable side effects that have led to the investigation of new therapeutic strategies designed to specifically target malignant cells and thus trigger selective cell destruction. Dequalinium (DQA) is an antitumoral agent that selectively accumulates in the mitochondria and has been shown to display anticancer activity in cells from different malignancies. In the present study, the DQA-induced cytotoxicity in B-CLL cells was analyzed by measuring cell viability and cell death, either by necrosis or apoptosis. Our results support the importance of DQA as a selective and potential antileukemic drug with a higher cytotoxic effect on peripheral blood mononuclear cells from B-CLL patients than in those from healthy donors and encourage the performance of further studies in combination with other agents.