Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 05029, Korea.
Department of Environmental and Occupational Health, University of Arkansas for Medical Science, Arkansas 72205, USA.
Poult Sci. 2017 Sep 1;96(11):3872-3878. doi: 10.3382/ps/pex205.
Egg yolk phosvitin is one of the most phosphorylated proteins in nature, and the extraordinarily high concentration of phosphate groups in its structure provides a strong metal-binding ability. Phosvitin is known to possess various functional activities, including metal-chelating, antioxidant, emulsifying, antimicrobial, and cytotoxic activities. However, little is known about the immune-enhancing activity of phosvitin. The objective of this study was to evaluate the immune-enhancing activity of phosvitin in murine RAW 264.7 macrophages. Griess reagents and quantitative real-time PCR were used to determine the effect of phosvitin (at 12.5, 25, 50, and 100 μg/mL) on the levels of pro-inflammatory mediators NO and inducible nitric oxide synthase (iNOS), cytokines TNF-α and IL-1β in RAW 264.7 macrophages. The effect of phosvitin on the phagocytic activity of RAW 264.7 macrophages was also measured using the Neutral-Red Uptake method. Lipopolysaccharides was used as a positive control. Phosvitin significantly (P < 0.05) increased the production of NO in RAW 264.7 macrophages in a dose-dependent manner, but did not show any cytotoxicity. The amounts of NO produced were 3.47, 7.12, 10.23, and 14.57 μM in 12.5 to 100 μg/mL range of phosvitin (control: 0.46 μM). Compared with the untreated group, phosvitin treatment at a 100 μg/mL level increased the production of NO by 31.67 times. Phosvitin also significantly increased the mRNA expression of the RAW 264.7 macrophages: 100 μg/mL of phosvitin treatment increased the expression of mRNA for iNOS, TNF-α, and IL-1β by 46.25, 9.09, and 85.18 times of the control, respectively. The phagocytic activity of RAW 264.7 macrophages was also increased significantly by phosvitin treatment. These results demonstrated that phosvitin dramatically improved the immune functions RAW 264.7 macrophages by enhancing the production of immune mediators and increasing phagocytic activity. Therefore, phosvitin has a potential to be used as an immune-enhancing agent by food or nutraceutical industries.
卵黄高磷蛋白是自然界中磷酸化程度最高的蛋白质之一，其结构中磷酸基团的浓度极高，提供了很强的金属结合能力。卵黄高磷蛋白具有多种功能活性，包括金属螯合、抗氧化、乳化、抗菌和细胞毒性活性。然而，人们对卵黄高磷蛋白的免疫增强活性知之甚少。本研究旨在评估卵黄高磷蛋白对鼠 RAW 264.7 巨噬细胞的免疫增强活性。使用格里塞试剂和实时定量 PCR 来确定卵黄高磷蛋白（12.5、25、50 和 100μg/mL）对 RAW 264.7 巨噬细胞中促炎介质 NO 和诱导型一氧化氮合酶（iNOS）、细胞因子 TNF-α 和 IL-1β 水平的影响。还使用中性红摄取法测量了卵黄高磷蛋白对 RAW 264.7 巨噬细胞吞噬活性的影响。脂多糖被用作阳性对照。卵黄高磷蛋白显著（P<0.05）增加了 RAW 264.7 巨噬细胞中 NO 的产生，呈剂量依赖性，但没有显示出任何细胞毒性。在 12.5 至 100μg/mL 的卵黄高磷蛋白范围内产生的 NO 量分别为 3.47、7.12、10.23 和 14.57μM（对照：0.46μM）。与未处理组相比，100μg/mL 卵黄高磷蛋白处理使 NO 的产生增加了 31.67 倍。卵黄高磷蛋白还显著增加了 RAW 264.7 巨噬细胞的 mRNA 表达：100μg/mL 的卵黄高磷蛋白处理使 iNOS、TNF-α 和 IL-1β 的 mRNA 表达分别增加了 46.25、9.09 和 85.18 倍。卵黄高磷蛋白处理还显著增加了 RAW 264.7 巨噬细胞的吞噬活性。这些结果表明，卵黄高磷蛋白通过增强免疫介质的产生和增加吞噬活性，显著改善了 RAW 264.7 巨噬细胞的免疫功能。因此，卵黄高磷蛋白有可能被食品或营养保健品行业用作免疫增强剂。
