Showing papers by "Lusânia Maria Greggi Antunes published in 2005"

Evaluation of the clastogenicity and anticlastogenicity of the carotenoid bixin in human lymphocyte cultures

Abstract: Carotenoids are regarded as effective antioxidants, antimutagenic and anticarcinogenic agents. Annatto, a red-yellow extract obtained from seeds of Bixa orellana L. is a mixture of several carotenoids and one of them bixin (BXN), is known as its major coloring compound. Studies on BXN clastogenicity and anticlastogenicity in cultured human lymphocytes have not been reported so far. Therefore, the present study was undertaken to investigate the ability of BXN to induce chromosomal aberrations in human lymphocytes in vitro and to examine the possible anticlastogenic effect of this carotenoid in chromosomal damage induced by the clastogen cisplatin (cDDP). Human blood samples were obtained from six healthy, non-smoking volunteers; two females and four males aged 18–35 years. The concentrations of BXN (1.0; 2.5; 5.0 or 10 μg/mL) tested in combination with cDDP were established on the basis of mitotic index (MI) measurements. The data showed that BXN was not cytotoxic or clastogenic, when compared to untreated control. A marked decrease in the MI values compared to the untreated control and an increased percentage of aberrant metaphases was seen in all cultures treated with cDDP. The carotenoid efficiency in reducing the inhibitory effect of cDDP on lymphocyte MI is concentration-dependent. Cultures simultaneously treated with BXN and cDDP showed a statistically significant reduction in total chromosomal aberrations and aberrant metaphases. In our experiments, BXN may have acted as an antioxidant by intercepting free radicals generated by cDDP. The data obtained in the present study suggest that dietary carotenoids may act as protective agents against clastogenic effects of antitumor agents. However, extensive studies are necessary to elucidate the mechanism of action of BXN before its therapeutic use.

Effects of H2O2, Fe2+ and Fe3+ on curcumin-induced chromosomal aberrations in CHO cells

Abstract: The effects of H2O2, Fe2+ and Fe3+ on curcumin-induced clastogenicity were evaluated in CHO cells. Curcumin combined with H2O2 did not increase the chromosomal aberrations more than expected based on a simple additive effect. In contrast, the combination of curcumin-Fe significantly decreased the total number of chromosomal aberrations and the number of abnormal metaphases. The clastogenicity of curcumin may be related to its pro-oxidant properties and its ability to generate free radicals.

on curcumin-induced chromosomal aberrations in CHO cells

Abstract: The effects of H 2 O 2 ,Fe 2+ and Fe 3+ on curcumin-induced clastogenicity were evaluated in CHO cells. Curcumincombined with H 2 O 2 did not increase the chromosomal aberrations more than expected based on a simple additiveeffect. In contrast, the combination of curcumin-Fe significantly decreased the total number of chromosomalaberrations and the number of abnormal metaphases. The clastogenicity of curcumin may be related to itspro-oxidant properties and its ability to generate free radicals. Key words: CHO, chromosomal aberrations, curcumin, hydrogen peroxide, mutagenesis.Received: April 26, 2004; Accepted: August 18, 2004. Experiments in vitro and epidemiological studieshave shown that some compounds present in the diet haveantimutagenic and anticarcinogenic properties (Surh andFerguson, 2003). Turmeric, a spice obtained from the rhi-zome of Curcuma longa Linn (Zingiberaceae), and its ac-tive principle curcumin, have been studied for their abilityto protect cells from DNA damage (Polasa