Genotoxic and Cytotoxic Studies of Beta-Sitosterol and Pteropodine in Mouse

Beta-sitosterol (BS) and pteropodine (PT) are constituents of various plants with pharmacological activities potentially useful to man. The chemicals themselves possess biomedical properties related to the modulation of the immune and the nervous systems, as well as to the inflammatory process. Therefore, safety evaluation of the compounds is necessary in regard to their probable beneficial use in human health. The present study evaluates their genotoxic and cytotoxic potential by determining the capacity of the compounds to induce sister chromatid exchanges (SCE), or to alter cellular proliferation kinetics (CPK) and the mitotic index (MI) in mouse bone marrow cells. Besides, it also determines their capacity to increase the rate of micronucleated polychromatic erythrocytes (MNPE) in peripheral mouse blood, and the relationship polychromatic erythrocytes/normochromatic erythrocytes (PE/NE) as an index of cytotoxicity. For the first assay, four doses of each compound were tested: 200, 400, 600, and 1000 mg/kg in case of BS, and 100, 200, 300, and 600 mg/kg for PT. The results in regard to both agents showed no SCE increase induced by any of the tested doses, as well as no alteration in the CPK, or in the MI. With respect to the second assay, the results obtained with the two agents were also negative for both the MNPE and the PE/NE index along the daily evaluation made for four days. In the present study, the highest tested dose corresponded to 80% of the LD(50) obtained for BS and to 78% in the case of PT. The results obtained establish that the studied agents have neither genotoxic nor cytotoxic effect on the model used, and therefore they encourage studies on their pharmacological properties

Characterization of Plasma Shock Waves and Cavitation Bubbles Produced by a High Energy Laser Pulse through Optical and Electronic Techniques

Laser shock peening (LSP) is an established mechanical surface treatment technology. In the last years, some works have presented satisfactory results in the characterization of shock waves and plasma produced by high-energy laser pulses. These results contribute for the understanding of the LSP process. In this work, we present experimental results of the characterization of the plasma shock wave and cavitation bubbles produced by a high-energy laser pulse using optical beam deflection system, piezoelectric sensors (PZT) and strain gauges. The experimental process was carried out using Q-switched Nd:YAG laser, operated at two wavelength of 532 nm and 1064 nm with an energy of 0.5 and 1 J/pulse in single shot. These results can be applied to calculate some parameters used in the Laser Shock Processing simulation process

Characterization of Plasma Shock Waves and Cavitation Bubbles Produced by a High Energy Laser Pulse through Optical and Electronic Techniques

Laser shock peening (LSP) is an established mechanical surface treatment technology. In the last years, some works have presented satisfactory results in the characterization of shock waves and plasma produced by high-energy laser pulses. These results contribute for the understanding of the LSP process. In this work, we present experimental results of the characterization of the plasma shock wave and cavitation bubbles produced by a high-energy laser pulse using optical beam deflection system, piezoelectric sensors (PZT) and strain gauges. The experimental process was carried out using Q-switched Nd:YAG laser, operated at two wavelength of 532 nm and 1064 nm with an energy of 0.5 and 1 J/pulse in single shot. These results can be applied to calculate some parameters used in the Laser Shock Processing simulation process