Manda K, Ueno M, Moritake T, Anzai K
National Institute of Radiological Sciences, Chiba, Japan.
Cell Biol Toxicol. 2007 Mar;23(2):129-37. doi: 10.1007/s10565-006-0137-6. Epub 2006 Nov 8.
The development of nontoxic but effective radioprotectors is needed because of the increasing risk of human exposure to ionizing radiation. We have reported that alpha-lipoic acid confers considerable radio-protective effect in mouse tissues when given prior to x-irradiation. In the present study, alpha-lipoic acid supplementation prior to x-irradiation with 4 and 6 Gy significantly inhibited the radiation-induced decline in total antioxidant capacity (TAC) of plasma. Radiation-induced decline in non-protein sulfhydryl content (NPSH) of different tissues, namely, brain, liver, spleen, kidney, and testis, was also ameliorated significantly at both 4 and 6 Gy doses. Maximal augmentation of radiation-induced protein carbonyl content was observed in spleen followed by brain, kidney, testis, and liver. Maximal protection in terms of carbonyl content was observed in spleen (116%) at 6 Gy dose, and minimal protection was found in liver (22.94%) at 4 Gy dose. Maximal increase in MDA (malondialdehyde) content was observed in brain, followed by testis, spleen, kidney, and liver. Protection by alpha-lipoic acid pretreatment in terms of MDA content was maximal in brain (51.67%) and minimal in spleen. The findings support the idea that alpha-lipoic acid is a free-radical scavenger and a potent antioxidant.
由于人类暴露于电离辐射的风险不断增加，因此需要开发无毒但有效的辐射防护剂。我们曾报道，在进行X射线照射前给予α-硫辛酸，它能在小鼠组织中发挥显著的辐射防护作用。在本研究中，在4 Gy和6 Gy的X射线照射前补充α-硫辛酸，可显著抑制血浆总抗氧化能力（TAC）因辐射而下降。在4 Gy和6 Gy剂量下，不同组织（即脑、肝、脾、肾和睾丸）中辐射诱导的非蛋白巯基含量（NPSH）下降也得到了显著改善。在脾脏中观察到辐射诱导的蛋白质羰基含量增加最多，其次是脑、肾、睾丸和肝脏。在6 Gy剂量下，脾脏中羰基含量的保护作用最大（116%），而在4 Gy剂量下，肝脏中的保护作用最小（22.94%）。丙二醛（MDA）含量增加最多的是脑，其次是睾丸、脾、肾和肝脏。α-硫辛酸预处理对MDA含量的保护作用在脑中最大（51.67%），在脾脏中最小。这些发现支持了α-硫辛酸是一种自由基清除剂和强效抗氧化剂的观点。
