Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY 14214, USA.
Int Immunopharmacol. 2010 Nov;10(11):1390-6. doi: 10.1016/j.intimp.2010.08.003. Epub 2010 Aug 20.
Among the many functions of vitamin D (VD) is its role in the immunomodulation of macrophage. As VD deficiency is a wide-spread nutritional problem, there is a tendency for the public to overdose with vitamin D supplementation which can result in hypercalcemia and several associated disorders. The present study was designed to investigate the possibility that combining low doses of vitamin D with β-sitosterol (SIT), a common phytosterol in the diet without toxicity, enhances the efficacy of the vitamin. Murine macrophages were stimulated with LPS and supplemented with VD3 (80 nM) and SIT (8 μM) for 24 hr and examined for cell proliferation, release of nitric oxide (NO) and cytokines and the activation of NFκB. SIT (8 μM) was found to reduce cell proliferation by 62% while VD3 was found to be not effective. In combination, SIT and VD3 reduced cell proliferation by 75%.The amount of NO released, as influenced by 8 μM SIT or 80 nM VD3 treatments, was not significantly different from control. Combining SIT and VD3, resulted in a 220% greater increase in NO release compared to control. The SIT + VD3 treatment brought about significant increase in all the cytokine release, regardless of whether they were pro- or anti-inflammatory. The effects were either additive or synergistic. We conclude that SIT enhances the action of VD3 on the immune function of macrophages which could be beneficial to vitamin D deficient individuals and to those with autoimmune diseases such as multiple sclerosis.
维生素 D（VD）具有多种功能，其中之一是其对巨噬细胞的免疫调节作用。由于 VD 缺乏是一种广泛存在的营养问题，因此公众倾向于过量补充维生素 D，这可能导致高钙血症和几种相关疾病。本研究旨在探讨将低剂量维生素 D 与 β-谷甾醇（SIT）结合使用的可能性，SIT 是饮食中一种常见的无毒植物固醇，可增强维生素的功效。用 LPS 刺激小鼠巨噬细胞，并用 VD3（80 nM）和 SIT（8 μM）补充 24 小时，然后检查细胞增殖、一氧化氮（NO）和细胞因子的释放以及 NFκB 的激活。发现 SIT（8 μM）可使细胞增殖减少 62%，而 VD3 则无效。联合使用 SIT 和 VD3 可使细胞增殖减少 75%。8 μM SIT 或 80 nM VD3 处理对 NO 释放的影响与对照无显著差异。SIT 和 VD3 的组合导致 NO 释放增加 220%，与对照相比。SIT + VD3 治疗无论是否具有促炎或抗炎作用，均导致所有细胞因子释放显著增加。这些作用要么是相加的，要么是协同的。我们得出结论，SIT 增强了 VD3 对巨噬细胞免疫功能的作用，这对维生素 D 缺乏症患者和多发性硬化症等自身免疫性疾病患者可能有益。
