In vitro genotoxicity and cytotoxicity in murine fibroblasts exposed to EDTA, NaOCl, MTAD and citric acid

The aim of the present study was to evaluate the capacity of some root canal irrigants to induce genetic damage and/or cellular death in vitro. Murine fibroblast cells were exposed to ethylenediaminetetraacetic acid (EDTA), sodium hypochlorite (NaOCl), MTAD™ and citric acid in increasing concentrations for 3 h at 37ºC. The negative control group was treated with vehicle control (phosphate buffer solution - PBS) for 3 h at 37°C, and the positive control group was treated with methylmetanesulfonate, 1 μM. for 3 h at 37°C. Cytotoxicity was assessed by the trypan blue test and genotoxicity was evaluated by the single cell gel (comet) assay. The results showed that exposure to 2.5% and 5% NaOCl and 8.5% citric acid resulted in a significant cytotoxic effect. NaOCl, EDTA and citric acid did not produce genotoxic effects with respect to the comet assay data for all evaluated concentrations. Although MTAD was not a cytotoxic agent, it showed significant genotoxic effects at all tested concentrations (ANOVA and Tukey's test; p<0.05). NaOCl, EDTA and citric acid were found to be cytotoxic in a dose-dependent manner, but they were not genotoxic. MTAD did not cause cell death, but presented genotoxic effects.

O objetivo do presente estudo foi avaliar a capacidade de alguns irrigantes endodônticos em induzir danos genéticos e/ou morte celular in vitro. Células de fibroblastos murinos foram expostas ao ácido etilenodiaminotetracético (EDTA), hipoclorito de sódio (NaOCl), MTAD™ e ácido cítrico em concentrações crescentes durante 3 h a 37°C. O grupo controle negativo foi tratado com solução tampão fosfato - PBS por 3 h a 37° C e o grupo controle positivo foi tratado com metilmetanesulfonato a 1 μM por 3 h a 37° C. A citotoxicidade foi testada pelo azul de tripan e a genotoxicidade foi avaliada pelo teste do cometa. Os resultados apontaram que a exposição ao NaOCl a 2,5% e 5%, e ácido cítrico a 21% resultou em efeitos citotóxicos significativos. O NaOCl, EDTA e o ácido cítrico não produziram efeitos genotóxicos no que diz respeito aos dados obtidos pelo ensaio do Cometa em todas as concentrações testadas. Embora o MTAD não tenha sido um agente citotóxico, mostrou efeitos genotóxicos significativos em todas as concentrações testadas (ANOVA e teste de Tuckey; p<0,05). O NaOCl, o EDTA e o ácido cítrico mostraram-se citotóxicos de maneira dose-dependente, mas não genotóxicos. Por outro lado, apesar do MTAD não ter causado a morte celular, foi genotóxico em todas as concentrações testadas.

impact of pH on cytotoxic effects of three root canal irrigants

Cytotoxicity of root canal irrigants is important due to their close contact with host tissues. This study was to assess the possible impact of pH on cytotoxic effects of MTAD, 17% EDTA, and 2.6% NaOCl on the human gingival fibroblasts using MTT assay. Human gingival fibroblasts were exposed to the irrigants and their viability was assessed after 1, 6, and 12 h. The pH of the medium was measured in each interval. Light absorption values were measured for each culture medium using Elisa Reader device. NaOCl had significantly less cytotoxicity than EDTA and MTAD. Also irrigants cytotoxicity decreased in 12, 1, and 6 h, respectively. It seems that variation of the pH resulted in variation in the cytotoxicity of solutions; i.e., it follows the pattern of the pH variation

Brucellosis as trigger for autoimmune hepatitis in susceptible individual

Autoimmune hepatitis [AIH] is a rare chronic liver disease of unknown etiology, characterized by hypergammaglobulinemia, characteristic autoantibodies, and a favorable response to immunosuppressive treatment. Strong circumstantial evidences denoted that there is quite long list of environmental factors such as [food additives and drugs], viruses and toxins which play an important role in precipitating this disease. Brucellosis is endemic in Iraq. It may involve any organ in the body. Liver is frequently involved. Doxycycline used for treatment occasionally may lead to hepatotoxicity. The aim of the study is to show the relationship between brucellosis, AIH, and hepatotoxicity of doxycycline. The study was performed on 2 Iraqi patients with brucellosis, attending the teaching hospital for gastroenterology and liver disease in the period between November 2003 and July 2004. Brucella were studied by Rose Bengal test and confirmed by indirect immuno florescence assay [IIF]. Anti-SLA/LP Abs was detected in 2 patients with brucellosis. Brucellosis or doxycycline is a trigger of AIH

Effect of methionine on doxycycline induced hepatotoxicity in albino rats

To study the effect of methionine in doxycycline induced hepatotoxicity in relation to body weight and liver weight in albino rats. The body weight and liver weight were measured in thirty male albino rats of six weeks age, after methionine therapy in doxycycline induced hepatotoxicity. It was observed that there was significant increase in body weight and non-significant change in liver v/w ratio. It is concluded that methionine antagonizes the hepatotoxic effect of doxycycline

study on the possible doxycycline-ginkgo biloba extract phototoxic interaction in mice

Doxycycline is considered as the most phototoxic drug in tetracycline group. Its phototoxic potential has been demonstrated in human being as well as in laboratory animals. The aim of the resent work was to evaluate the possible protective effect of Ginkgo biloba extract, against doxycycline-induced phototoxicity. The study was performed on Swiss albino mice. Doxycycline [400 mg/kg] was administered orally. Two dose levels of Ginkgo biloba extract were utilized [100 and 200 mg/kg p.o.]. Mice were exposed to UV-A radiation one hour after administration of doxycycline. UV-A radiation was directed to the animal's ears for 210 min. at a dose of 25 Jol/cm[2]. Immediately after irradiation, animals were given a single dose of Ginkgo biloba extract. Twenty four hours later, the erythmatous photoreaction was examined by the naked eye according to a score index. Edema was evaluated by measuring ear pinna thickness using digital micrometer. Ears were then excised and subjected to histopathological evaluation. The obtained results showed significant protection by Kingo biloba extract against doxycycline-induced phototoxicity. The protection was dose dependent, where each of erytherma and ear pinna thickness were reduced by 33% and 44%, and 28% and 39% following the low and high used doses of Ginkgo biloba extract, respectively