Takeuchi Paula Lumy, Antunes Lusânia Maria Greggi, Takahashi Catarina Satie
Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto (SP), Brazil.
Toxicol In Vitro. 2007 Jun;21(4):665-70. doi: 10.1016/j.tiv.2007.01.004. Epub 2007 Jan 14.
Insufficient intakes of many micronutrients found in fruits and vegetables, such as folic acid, vitamins C and B6 may lead to DNA damage, cancer, and degenerative disease. The investigation of dietary antioxidants is a field of great interest for elucidating mechanisms of mutagenesis/carcinogenesis. The present study was undertaken to investigate the effects of vitamin B6 on the induction of chromosomal aberrations in cultured human lymphocytes and to examine the possible anticlastogenic effect of this vitamin on chromosomal damage induced by the antitumor drug doxorubicin. The results showed that when the cultures treated with vitamin B6 were compared with the untreated control in terms of total chromosomal damage and abnormal metaphases, pre- and simultaneous treatment with this vitamin showed no significant differences. In the post-treatment, average and above average concentrations of vitamin B6 alone showed a clastogenic effect. In the simultaneous protocol, this vitamin (15, 90 and 120 microg/mL) was effective in inhibiting chromosomal aberrations induced by doxorubicin (p<0.05), with a reduction of 33.1% with the highest concentration tested. However, in the post-treatment, the associations of vitamin B6 and doxorubicin exerted a more evident clastogenic effect than that observed in the cultures exposed only to the antitumor drug. In the present investigation, the inability of vitamin B6 to decrease chromosomal damage induced by doxorubicin in the pre- and post-treatments could be justified by the instability of this vitamin as a free radical scavenger. In conclusion, the results from this study confirmed that vitamin B6 is protective against chromosomal damage induced by doxorubicin in cultured human lymphocytes, but that the effects depend on concentration and form of treatment.
水果和蔬菜中含有的许多微量营养素，如叶酸、维生素C和维生素B6摄入不足，可能会导致DNA损伤、癌症和退行性疾病。膳食抗氧化剂的研究是阐明诱变/致癌机制的一个备受关注的领域。本研究旨在探讨维生素B6对培养的人淋巴细胞染色体畸变诱导的影响，并研究该维生素对抗肿瘤药物阿霉素诱导的染色体损伤可能的抗断裂作用。结果显示，当比较用维生素B6处理的培养物与未处理的对照在总染色体损伤和异常中期方面的情况时，该维生素的预处理和同时处理均未显示出显著差异。在处理后，单独使用平均浓度及以上的维生素B6显示出断裂剂作用。在同时处理方案中，该维生素（15、90和120微克/毫升）能有效抑制阿霉素诱导的染色体畸变（p<0.05），在测试的最高浓度下减少了33.1%。然而，在处理后，维生素B6与阿霉素的联合作用比仅暴露于抗肿瘤药物的培养物中观察到的断裂剂作用更明显。在本研究中，维生素B6在预处理和处理后无法降低阿霉素诱导的染色体损伤，这可能是由于该维生素作为自由基清除剂的不稳定性所致。总之，本研究结果证实，维生素B6对培养的人淋巴细胞中阿霉素诱导的染色体损伤具有保护作用，但其效果取决于浓度和处理方式。
