Santos Raquel Alves Dos, Jordão Alceu Afonso, Vannucchi Hélio, Takahashi Catarina Satie
Department of Genetics, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, 14040-900, Ribeirão Preto, SP, Brazil.
Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirão Preto, SP, Brazil.
Nutr Res. 2007 Jun;27(6):343-348. doi: 10.1016/j.nutres.2007.04.007. Epub 2007 Jun 26.
The importance of selenium in human nutrition is well recognized. It is an important micronutrient involved in antioxidant defense and is of fundamental importance in the maintenance of genomic stability. However, questions relating to the appropriate chemical form of selenium used for supplementation and its beneficial dose is still being debated. Therefore, the present study investigated the ability of 2 selenium compounds-sodium selenite (SS) and selenomethionine (SM)-to protect DNA against the damage induced by doxorubicin (DXR). Wistar rats were supplemented orally for 10 consecutive days with SS or SM (1 and 2 mg/kg bw); 24 hours before euthanasia a single dose of DXR (90 mg/kg bw) was injected intraperitoneally. DNA lesions were assessed by the comet assay and micronucleus test; the concentrations of thiobarbituric acid reactive substances, vitamin E, and reduced glutathione were determined by using liver homogenates. The results obtained showed that SS and SM prevented the induction of DNA damage by DXR. It was also observed that these 2 selenium compounds increased the hepatic concentration of glutathione, maintained the thiobarbituric acid reactive substances, and allowed for the maintenance of hepatic concentrations of vitamin E even after DXR treatment, confirming the antioxidant properties of selenium compounds. Sodium selenite and SM supplementation exhibited very similar patterns of protection. In conclusion, SS and SM supplementation was effective in protecting DNA against DXR-induced DNA damage in Wistar rats, probably because of their antioxidant properties.
硒在人体营养中的重要性已得到广泛认可。它是一种参与抗氧化防御的重要微量营养素，对维持基因组稳定性至关重要。然而，关于用于补充的硒的合适化学形式及其有益剂量的问题仍在争论中。因此，本研究调查了两种硒化合物——亚硒酸钠（SS）和硒代蛋氨酸（SM）——保护DNA免受阿霉素（DXR）诱导损伤的能力。将Wistar大鼠连续10天口服补充SS或SM（1和2毫克/千克体重）；在安乐死24小时前，腹腔注射单剂量的DXR（90毫克/千克体重）。通过彗星试验和微核试验评估DNA损伤；使用肝脏匀浆测定硫代巴比妥酸反应性物质、维生素E和还原型谷胱甘肽的浓度。所得结果表明，SS和SM可防止DXR诱导的DNA损伤。还观察到，这两种硒化合物增加了肝脏中谷胱甘肽的浓度，维持了硫代巴比妥酸反应性物质的水平，并且即使在DXR处理后也能维持肝脏中维生素E的浓度，证实了硒化合物的抗氧化特性。亚硒酸钠和SM补充剂表现出非常相似的保护模式。总之，补充SS和SM可有效保护Wistar大鼠的DNA免受DXR诱导的DNA损伤，这可能是由于它们的抗氧化特性。
