Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto

About: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto is a based out in . It is known for research contribution in the topics: Population & Catalysis. The organization has 2143 authors who have published 3674 publications receiving 71071 citations. The organization is also known as: FFCLRP & FFCLRP-USP.

Cytotoxicity screening of essential oils in cancer cell lines

Abstract: This study evaluated the cytotoxicity activity of the essential oils of Tagetes erecta L., Asteraceae (TE-OE), Tetradenia riparia (Hochst.) Codd, Lamiaceae (TR-OE), Bidens sulphurea (Cav.) Sch. Bip., Asteraceae (BS-OE), and Foeniculum vulgare Mill., Apiaceae (FV-OE), traditionally used in folk medicine, against the tumor cell lines murine melanoma (B16F10), human colon carcinoma (HT29), human breast adenocarcinoma (MCF-7), human cervical adenocarcinoma (HeLa), human hepatocellular liver carcinoma (HepG2), and human glioblastoma (MO59J, U343, and U251). Normal hamster lung fibroblasts (V79 cells) were included as control. The cells were treated with essential oil concentrations ranging from 3.12 to 400 µg/ml for 24 h. The cytotoxic activity was evaluated using the XTT assay; results were expressed as IC50, and the selectivity index was calculated. The results were compared with those achieved for classic chemotherapeutic agents. TE-OE was the most promising among the evaluated oils: it afforded the lowest IC50 values for B16F10 cells (7.47 ± 1.08 µg/ml) and HT29 cells (6.93 ± 0.77 µg/ml), as well as selectivity indices of 2.61 and 2.81, respectively. The major BS-EO, FV-EO and TE-EO chemical constituents were identified by gas chromatography mass spectrometry as being (E)-caryophyllene (10.5%), germacrene D (35.0%) and 2,6-di-tert-butyl-4-methylphenol (43.0%) (BS-EO); limonene (21.3%) and (E)-anethole (70.2%) (FV-EO); limonene (10.4%), dihydrotagetone (11.8%), α-terpinolene (18.1%) and (E)-ocimenone (13.0%) (TE-EO); and fenchone (6.1%), dronabinol (11.0%), aromadendrene oxide (14.7%) and (E,E)–farnesol (15.0%) (TR-EO). 2,6-di-tert-butyl-4-methylphenol (43.0%), (E)-anethole (70.2%) and α-terpinolene (18.1%), respectively. These results suggest that TE-OE may be used to treat cancer without affecting normal cells.

Probing chitosan and phospholipid interactions using Langmuir and Langmuir-Blodgett films as cell membrane models.

Abstract: The interaction between chitosan and Langmuir and Langmuir-Blodgett (LB) films of dimyristoyl phosphatidic acid (DMPA) is investigated, with the films serving as simplified cell membrane models. At the air-water interface, chitosan modulates the structural properties of DMPA monolayers, causing expansion and decreasing the monolayer elasticity. As the surface pressure increased, some chitosan molecules remained at the interface, but others were expelled. Chitosan could be transferred onto solid supports alongside DMPA using the LB technique, as confirmed by infrared spectroscopy and quartz crystal microbalance measurements. The analysis of sum-frequency vibration spectroscopy data for the LB films combined with surface potential measurements for the monolayers pointed to chitosan inducing the ordering of the DMPA alkyl chains. Furthermore, the morphology of DMPA LB films, studied with atomic force microscopy, was affected significantly by the incorporation of chitosan, with the mixed chitosan-DMPA films displaying considerably higher thickness and roughness, in addition to chitosan aggregates. Because chitosan affected DMPA films even at pressures characteristic of cell membranes, we believe this study may help elucidate the role of chitosan in biological systems.

Evaluation of Chromosomal Aberrations, Micronuclei, and Sister Chromatid Exchanges in Hospital Workers Chronically Exposed to Ionizing Radiation

Abstract: Cytogenetic analysis was performed in peripheral blood lymphocytes from hospital workers chronically exposed to ionizing radiation in comparison to matched non-exposed individuals. The accumulated absorbed doses calculated for the radiation workers ranged from 9.5 to 209.4 mSv. The endpoints used were chromosomal aberrations (CA), micronuclei (MN), and sister chromatid exchanges (SCE). The frequencies of CA/100 cells observed for the exposed group were significantly (P=0.018) higher than in the control group: 3.2 and 2.6, respectively. Similarly, the mean numbers of SCE per cell were statistically higher (P=0.025) in the exposed group (6.2) in comparison with the control group (5.8). In the case of micronuclei analysis, no significant (P=0,06) difference between both groups was found, but these data should be cautiously interpreted since an increase in the frequencies of MN was found for radiation workers (3.0 MN/100 cells), compared to the control group (2.6 MN/100 cells) and this increase occur in parallel to CA and SCE frequencies. The difference between the results could be explained by the nature of CA and MN generation. The increased frequencies of CA and SCE in radiation workers indicate the cumulative effect of low-level chronic exposure to ionizing radiation, and the relevance of conducting cytogenetic analysis in parallel to physical dosimetry in the working place.