Cytotoxicity of propolis nanopreparations in cancer cell monolayers: multimode of action including apoptotsis and nitric oxide production.

Natural products are invaluable resource of anticancer drug discovery. They generally viewed as safe but weak, within the framework of nanotechnology, they can serve as template for potent anticancer drugs. We first evaluated the cytotoxic activity of different propolis extracts (water, 70% ethanol, absolute ethanol and hexane) in many cancer cell lines, then the solid nanoparticles from the organic solvent extracts were prepared and their cytotoxicity was evaluated as well. Finally, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) liposomes were prepared from the most cytotoxic organic solvent extract and their cytotoxicity was also evaluated. All results collectively showed that hexane extract and its solid nanoparticles as well as its liposomal form exhibited high cytotoxic activity. DPPC/DOPC-hexane extract cytotoxicity selectively depends on the cell line and DOPC liposomal form was characterized by reduced IC50 compared with the other preparations/extracts, the average IC50 value is 165.8 ± 3 µg/ml. The antiproliferative activity of propolis was associated to multiple modes of actions including apoptosis and nitric oxide production and as indicated by the HPLC and FTIR results, it is functioning in many propolis ingredients rather than a single component and influenced by the presence of more lipophilic components within the extract and not by the extract mass yield. These results may have an impact on the multidrug resistivity issue.

Infrared spectroscopic investigation of erythrocyte membrane-smoke interactions due to chronic cigarette smoking.

Cigarette smoking is a serious health problem throughout the world, with a complicated and not totally clear bio-effect. In this study, erythrocytes were obtained from healthy male volunteers aged 22 ± 2 years and, the possible effects of three cigarette smoking rates namely 10, 15 and 20 cigarette/day on erythrocytes membrane characteristics were examined by Fourier transform infrared spectroscopy (FTIR). The results of this study indicate many smoking-dependent variations on erythrocytes membrane without an obvious dose-response relationship. There was disruption in the acyl chain packing; changes in membrane order and phases as well as membrane proteins becoming more folded. These physico-chemical changes should have an impact on the function of erythrocytes and may explain the complex interaction of cigarette smoke mainstream with erythrocyte membrane and to some extent clarify the pathological processes associated with cigarette smoking.