Yeum Kyung-Jin, Beretta Giangiacomo, Krinsky Norman I, Russell Robert M, Aldini Giancarlo
The Jean Mayer USDA-Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts, USA.
Nutrition. 2009 Jul-Aug;25(7-8):839-46. doi: 10.1016/j.nut.2009.01.011. Epub 2009 Apr 23.
The antioxidant activity of fat- and water-soluble antioxidant nutrients and their interactions in physiologic concentrations were determined in an in vitro biological model system.
Reconstituted human serum consisting of delipidized human serum (DHS) combined with phosphatidylcholine liposomes (PCL) was used to determine antioxidant activities of physiologic concentrations of antioxidant nutrients. Radicals were initiated with 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (2mmol/L), and oxidation was monitored by 4,4-difluoro-5-(4-phenyl-1,3-butadienyl)-4-bora-3a,4a-diaza-s-indacene-3-undecanoic acid. Fat-soluble antioxidant nutrients were incorporated into the PCL prepared by sonication and suspended in DHS to avoid any interference by the endogenous fat-soluble antioxidants. Water-soluble antioxidants were added directly into the DHS. The oxidation kinetics were monitored every 5 min up to 210 min using a microplate reader (excitation wavelength 500 nm, emission wavelength 520 nm).
We confirmed the synergistic protective effect of the combination of ascorbic acid (1-5 microM) and alpha-tocopherol (1-5 mircoM) against the oxidation of DHS with PCL. Furthermore, physiologic concentrations of 1) beta-carotene (0.1, 0.5 microM) and alpha-tocopherol (2.5, 5.0 microM), 2) beta-carotene (0.1, 0.5 microM) and ascorbic acid (2.5 microM), and 3) uric acid (10 uM) and alpha-tocopherol (2.5, 5.0 microM) synergistically protected oxidation of reconstituted human serum.
The present study results suggest a wide antioxidant network between water- and fat-soluble antioxidant nutrients in a biological system, although their actions in vivo warrant further study.
在体外生物模型系统中测定脂溶性和水溶性抗氧化营养素的抗氧化活性及其在生理浓度下的相互作用。
由脱脂人血清（DHS）与磷脂酰胆碱脂质体（PCL）组成的重组人血清用于测定生理浓度抗氧化营养素的抗氧化活性。用2,2'-偶氮二（4-甲氧基-2,4-二甲基戊腈）（2mmol/L）引发自由基，并通过4,4-二氟-5-（4-苯基-1,3-丁二烯基）-4-硼-3a,4a-二氮杂-s-茚满-3-十一烷酸监测氧化过程。将脂溶性抗氧化营养素掺入通过超声处理制备并悬浮在DHS中的PCL中，以避免内源性脂溶性抗氧化剂的任何干扰。将水溶性抗氧化剂直接加入DHS中。使用酶标仪（激发波长500nm，发射波长520nm）每5分钟监测一次氧化动力学，直至210分钟。
我们证实了抗坏血酸（1-5 microM）和α-生育酚（1-5 microM）组合对含PCL的DHS氧化具有协同保护作用。此外，生理浓度的1）β-胡萝卜素（0.1,0.5 microM）和α-生育酚（2.5,5.0 microM），2）β-胡萝卜素（0.1,0.5 microM）和抗坏血酸（2.5 microM），以及3）尿酸（10 uM）和α-生育酚（2.5,5.0 microM）对重组人血清的氧化具有协同保护作用。
本研究结果表明生物系统中水溶性和脂溶性抗氧化营养素之间存在广泛的抗氧化网络，尽管它们在体内的作用有待进一步研究。
