Levantamentos etnobotânicos de plantas nativas do cerrado evidenciam que as folhas deCeltis iguanaea (Jacq.) Sargent (Cannabaceae), popularmente conhecidas como “esporão-de-galo” são usadas na medicina popular para dores no corpo, asma, cólicas, má-digestão, infecções urinárias, disfunções renais, como estimulante ou como diurético. O presente trabalho teve como objetivo avaliar as possíveis atividades citotóxica, genotóxica e antigenotóxica do extrato aquoso das folhas de C. Iguanaea (CALE) através do teste do micronúcleo em medula óssea de camundongos. Para avaliar a genotoxicidade de CALE, os camundongos foram tratados por via oral com três diferentes concentrações de extrato (100, 300 e 500 mg.kg−1). Para a investigação da atividade antigenotóxica, foram utilizadas as mesmas doses concomitantemente a uma única dose i.p. de Mitomicina C (MMC, 4mg.kg−1). Com exceção do controle negativo (apenas 24h), todas as outras doses tiveram as frequências de eritrócitos policromáticos micronucleados (EPCMN) avaliadas em 24 e 48 horas após o tratamento. A Genotoxicidade foi avaliada por meio da frequência de eritrócitos policromáticos micronucleados (MNPCE), enquanto que a citotoxicidade foi mensurada pela razão entre eritrócitos policromáticos e normocromáticos (PCE / NCE). Os resultados mostraram que CALE não apresentou uma redução significativa na razão PCE/NCE, nem um aumento considerável na frequência de EPCMN. No entanto, CALE reduziu a toxicidade na medula óssea (aumento na razão PCE/NCE) e diminuiu a frequência de micronúcleos induzidos pela MMC. Nos resultados obtidos, CALE não apresentou efeitos citotóxicos e genotóxicos, contudo apresentou ações antigenotóxicas e anticitotóxicas nas condições experimentais aplicadas neste estudo.

Ethnobotanical surveys of Cerrado native plants show that leaves of Celtis iguanaea (Jacq.) Sargent (Cannabaceae), popularly known in Brazil as “esporão de galo”, are used in folk medicine for body pain, asthma, cramps, poor digestion, urinary infection, kidney dysfunctions, as well as a stimulant and diuretic. This work aimed at evaluating possible C. iguanaea aqueous leaf extract (CALE) cytotoxicity, genotoxicity, and antigenotoxicity using the mouse bone marrow micronucleous test. To assess CALE genotoxicity, Swiss mice were orally treated with three different extract concentrations (100, 300, and 500 mgkg−1). To evaluate its antigenotoxicity, the same doses were used simultaneously with a single i.p. dose of mitomycin C (MMC, 4mg.kg−1). The frequencies of micronucleated polychromatic erythrocytes (MNPCE) were evaluated 24 h and 48 h after administration except for the negative control (24 h). Genotoxicity was evaluated using the frequency of micronucleated polychromatic erythrocytes (MNPCE), whereas cytotoxicity was assessed by the polychromatic and normochromatic erythrocytes ratio (PCE/NCE). The results showed that CALE did not exhibit a significant reduction in the PCE/NCE ratio, neither a considerable increase in the frequency of MNPCE. Nonetheless, CALE reduced bone marrow toxicity (increased PCE/NCE ratio) and decreased the micronuclei frequency induced by MMC. We can conclude that CALE presented no cytotoxic and genotoxic effects, but showed antigenotoxic and anticytotoxic actions under the experimental conditions applied in this study.

This study evaluated the clastogenic and/or aneugenic potential of three nucleoside reverse transcriptase inhibitors (zidovudine - AZT, lamivudine - 3TC and stavudine - d4T) using the cytokinesis-block micronucleus (CBMN) assay in human lymphocyte cultures. All three inhibitors produced a positive response when tested in binucleated cells. The genotoxicity of AZT and 3TC was restricted to binucleated cells since there was no significant increase in the frequency of micronuclei in mononucleated cells. This finding indicated that AZT and 3TC caused chromosomal breakage and that their genotoxicity was related to a clastogenic action. In addition to the positive response observed with d4T in binucleated cells, this drug also increased the frequency of micronuclei in mononucleated cells, indicating clastogenic and aneugenic actions. Since the structural differences between AZT and 3TC and AZT and d4T involve the 3' position in the 2'-deoxyribonucleoside and in an unsaturated 2',3',dideoxyribose, respectively, we suggest that an unsaturated 2', 3', dideoxyribose is responsible for the clastogenic and aneugenic actions of d4T.