De Marco A, De Simone C, D'Ambrosio C, Owczarek M
Centro di Genetica Evoluzionistica, C.N.R., Università La Sapienza, Rome,
Mutat Res. 1999 Jan 13;438(2):89-95. doi: 10.1016/s1383-5718(98)00154-5.
A significant reduction of the genotoxic effects caused by herbicide maleic hydrazide (MH) in Vicia faba seedlings was observed to be induced by a growth step in an organic soil as well as by a pretreatment with highly purified humic substances. In addition, such protective activity was resulted quite similar to that observed when the conditioning pretreatment was carried out with metal salts, so suggesting the involvement of the GSH biosynthesis in determining the protective activity observed. In agreement with this hypothesis, a previous exposure to buthionine sulfoximine (BSO), an inhibitor of the phytochelatins production, through the inhibition of GSH synthesis, prevented the reduction of the genotoxic activity of MH. The findings provide evidence for the involvement of the GSH biosynthesis pathway in determining the antigenotoxic activity revealed and suggest a possible involvement of the phytochelatins in this process. However, yet to be clarified is whether the stimulation of GSH production results as a consequence of a nonspecific influence on the protein synthesis by humic substances or of its direct activation due to the presence, as contaminants, of some heavy metals in both organic soil and humic acids extracts.
观察到，在有机土壤中的生长步骤以及用高度纯化的腐殖物质进行预处理，均可诱导蚕豆幼苗中由除草剂马来酰肼（MH）引起的遗传毒性效应显著降低。此外，这种保护活性与用金属盐进行预处理时观察到的保护活性非常相似，因此表明谷胱甘肽生物合成参与了所观察到的保护活性的决定过程。与该假设一致，先前通过抑制谷胱甘肽合成而接触丁硫氨酸亚砜胺（BSO）（一种植物螯合肽生产的抑制剂），可阻止MH遗传毒性活性的降低。这些发现为谷胱甘肽生物合成途径参与所揭示的抗遗传毒性活性的决定过程提供了证据，并表明植物螯合肽可能参与了这一过程。然而，腐殖物质对蛋白质合成的非特异性影响，还是由于有机土壤和腐殖酸提取物中作为污染物存在的某些重金属的直接激活而导致谷胱甘肽产量的刺激，这一点仍有待阐明。
