Noni, nome Havaiano da fruta de Morinda citrifolia L., é uma planta medicinal e tradicional da Polinésia amplamente usada para o tratamento de muitas doenças entre as quais artrite, diabetes, asma, hipertensão e câncer. Neste trabalho, um suco comercial de noni (TNJ) foi avaliado para suas atividades protetoras contras as lesões induzidas por mitomicina C (MMC) e doxorrubicina (DXR) usando o teste de mutação e recombinação somática em Drosophila melanogaster. Larvas de terceiro estágio, trans-heterozigotas para dois genes marcadores (mwh e flr3 ), foram cotratadas com TNJ mais MMC ou DXR. Observamos uma redução dos efeitos genotóxicos de MMC e DXR pelo suco. TNJ induziu uma forte redução em todos os tipos de manchas mutantes induzidas por MMC e DXR principalmente devido a uma atividade antirecombinante. Os efeitos protetotes de TNJ foram dependentes da concentração, indicando uma correlação dose-resposta, os quais podem ser atribuídos a uma potente ação antioxidante e/ou habilidade de sequestrar radicais livres pelo TNJ.

Noni, a Hawaiian name for the fruit of Morinda citrifolia L., is a traditional medicinal plant from Polynesia widely used for the treatment of many diseases including arthritis, diabetes, asthma, hypertension and cancer. Here, a commercial noni juice (TNJ) was evaluated for its protective activities against the lesions induced by mitomycin C (MMC) and doxorrubicin (DXR) using the Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster. Three-day-old larvae, trans-heterozygous for two genetic markers (mwh and flr3 ), were co-treated with TNJ plus MMC or DXR. We have observed a reduction in genotoxic effects of MMC and DXR caused by the juice. TNJ provoked a marked decrease in all kinds of MMC- and DXR-induced mutant spots, mainly due to its antirecombinagenic activity. The TNJ protective effects were concentration-dependent, indicating a dose-response correlation, that can be attributed to a powerful antioxidant and/or free radical scavenger ability of TNJ.

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.