Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Montebello, N-0310 Oslo, Norway.
J Photochem Photobiol B. 2013 Sep 5;126:11-6. doi: 10.1016/j.jphotobiol.2013.05.011. Epub 2013 Jun 7.
Folate is essential for cell division and growth. Deficiency is linked to birth defects, magaloblastic anaemia, cardiovascular disease, etc. Folic acid is a synthetic form of folate and is used to fortify food and in supplements. In aqueous solutions, in blood and even in human skin, folic acid may be degraded by ultraviolet radiation. Consequently, photodegradation of folic acid in human blood may lead to folate deficiency. However, the degree and the health consequences of such photodegradation are unknown. It is not clear which spectral region plays the most important role in the photodegradation of folic acid. In this study the photodegradation of folic acid in aqueous solution under different wavelengths of ultraviolet radiation (260-400nm) was investigated by fluorescence spectroscopy. The photodegradation rate of folic acid was dependent on wavelength. Action spectrum for 1μM folic acid photodegradation was determined. Its action spectrum is not identical to its absorption or fluorescence excitation spectra. The action spectrum demonstrated that UVB and UVA degrade folic acid. Protecting skin against UVB and UVA radiation by sunscreens may help to protect folic acid in human blood under intense solar radiation.
叶酸对于细胞分裂和生长至关重要。缺乏叶酸会导致出生缺陷、巨幼细胞性贫血、心血管疾病等。叶酸是叶酸的合成形式，用于强化食品和补充剂。在水溶液、血液甚至人体皮肤中，叶酸可能会因紫外线辐射而降解。因此，人类血液中叶酸的光降解可能导致叶酸缺乏。然而，这种光降解的程度和对健康的影响尚不清楚。也不清楚哪个光谱区域在叶酸的光降解中起着最重要的作用。在这项研究中，通过荧光光谱法研究了在不同波长的紫外线（260-400nm）辐射下叶酸在水溶液中的光降解。叶酸的光降解速率取决于波长。确定了 1μM 叶酸光降解的作用光谱。它的作用光谱与吸收或荧光激发光谱不同。作用光谱表明，UVB 和 UVA 会降解叶酸。防晒霜可以保护皮肤免受 UVB 和 UVA 辐射，这可能有助于在强烈的太阳辐射下保护人体血液中的叶酸。
