Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University.
J Nutr Sci Vitaminol (Tokyo). 2023;69(1):62-70. doi: 10.3177/jnsv.69.62.
Siphonein is a C19 acylated siphonaxanthin found in some edible green algae (e.g., Codium fragile and Caulerpa lentillifera). Although the content of siphonein in these green algae is similar to or higher than that of siphonaxanthin, studies of health-related biological activity of siphonein are much less than those of siphonaxanthin. Given the difference in the position of the acyl chain, one cannot infer intestinal absorption of siphonein from other general carotenoid fatty acid esters. In this study, we first investigated the intestinal absorption of siphonein using mouse and cell culture models. A small amount of siphonein was detected in the plasma of treated mice, and its concentration was higher than that of siphonaxanthin (i.e., the hydrolyzed product of ingested siphonein) from 1 to 6 h after administration. Pharmacological inhibition tests with differentiated Caco-2 cells showed that Nieman-Pick C1-like 1-mediated facilitated diffusion was involved in the cellular uptake of siphonein. These results indicate that, unlike general carotenoid fatty acid esters, siphonein can be absorbed without hydrolysis. We also evaluated the anti-inflammatory effect of siphonein in differentiated Caco-2 cells. Siphonein pretreatment modulated lipopolysaccharide-induced cellular lipidome alterations and suppressed mRNA expression of proinflammatory chemokines, CXCL8 protein release, and activation of NF-κB. This study provides new insights into the absorption processes of carotenoids and shows the anti-inflammatory effect of siphonein for the first time.
硅甲藻黄素是一种 C19 酰化的硅甲藻黄素，存在于一些可食用的绿藻中（例如，脆性 Codium 和 Lentillifera Caulerpa）。尽管这些绿藻中硅甲藻黄素的含量与硅甲藻黄素相似或更高，但对硅甲藻黄素相关健康生物活性的研究却远少于硅甲藻黄素。鉴于酰基链位置的差异，不能从其他一般类胡萝卜素脂肪酸酯推断硅甲藻黄素的肠道吸收。在这项研究中，我们首先使用小鼠和细胞培养模型研究了硅甲藻黄素的肠道吸收。在给予处理后的小鼠的血浆中检测到少量的硅甲藻黄素，其浓度在给药后 1 至 6 小时高于硅甲藻黄素（即摄入的硅甲藻黄素的水解产物）。用分化的 Caco-2 细胞进行的药理学抑制试验表明，尼曼-皮克 C1 样 1 介导的易化扩散参与了硅甲藻黄素的细胞摄取。这些结果表明，与一般的类胡萝卜素脂肪酸酯不同，硅甲藻黄素可以在不水解的情况下被吸收。我们还评估了硅甲藻黄素在分化的 Caco-2 细胞中的抗炎作用。硅甲藻黄素预处理调节了脂多糖诱导的细胞脂类组改变，并抑制了促炎趋化因子 CXCL8 的 mRNA 表达、蛋白释放和 NF-κB 的激活。这项研究为类胡萝卜素的吸收过程提供了新的见解，并首次显示了硅甲藻黄素的抗炎作用。
