Institute of Food Science, Technology and Nutrition (ICTAN-CSIC), José Antonio Novais, 6, 28040 Madrid, Spain.
Agricultural Technological Institute of Castilla and Leon, Government of Castilla and Leon, Finca Zamadueñas, Castilla and Leon, 47071 Valladolid, Spain.
Int J Mol Sci. 2023 Apr 18;24(8):7436. doi: 10.3390/ijms24087436.
Previous studies demonstrated that enzymatic hydrolysis enhances wheat bran (WB) biological properties. This study evaluated the immunostimulatory effect of a WB hydrolysate (HYD) and a mousse enriched with HYD (MH) before and after in vitro digestion on murine and human macrophages. The antiproliferative activity of the harvested macrophage supernatant on colorectal cancer (CRC) cells was also analyzed. MH showed significantly higher content than control mousse (M) in soluble poly- and oligosaccharides (OLSC), as well as total soluble phenolic compounds (TSPC). Although in vitro gastrointestinal digestion slightly reduced the TSPC bioaccessibility of MH, ferulic acid (FA) levels remained stable. HYD showed the highest antioxidant activity followed by MH, which demonstrated a greater antioxidant activity before and after digestion as compared with M. RAW264.7 and THP-1 cells released the highest amounts of pro-inflammatory cytokines after being treated with 0.5 mg/mL of digested WB samples. Treatment with digested HYD-stimulated RAW264.7 supernatant for 96 h showed the most anticancer effect, and spent medium reduced cancer cell colonies more than direct WB sample treatments. Although a lack of inner mitochondrial membrane potential alteration was found, increased Bax:Bcl-2 ratio and caspase-3 expression suggested activation of the mitochondrial apoptotic pathway when CRC cells were treated with macrophage supernatants. Intracellular reactive oxygen species (ROS) were positively correlated with the cell viability in CRC cells exposed to RAW264.7 supernatants (r = 0.78, < 0.05) but was not correlated in CRC cells treated with THP-1 conditioned media. Supernatant from WB-stimulated THP-1 cells may be able to stimulate ROS production in HT-29 cells, leading to a decrease of viable cells in a time-dependent manner. Therefore, our present study revealed a novel anti-tumour mechanism of HYD through the stimulation of cytokine production in macrophages and the indirect inhibition of cell proliferation, colony formation, and activation of pro-apoptotic proteins expression in CRC cells.
先前的研究表明，酶解可以增强麦麸的生物特性。本研究评估了麦麸水解物（HYD）和富含 HYD 的慕斯在体外消化前后对鼠和人巨噬细胞的免疫刺激作用。还分析了收获的巨噬细胞上清液对结直肠癌细胞（CRC）的抗增殖活性。与对照慕斯（M）相比，MH 具有明显更高的可溶性多聚糖和寡聚糖（OLSC）以及总可溶性酚类化合物（TSPC）含量。尽管体外胃肠道消化略微降低了 MH 的 TSPC 生物利用度，但阿魏酸（FA）水平保持稳定。HYD 显示出最高的抗氧化活性，其次是 MH，与 M 相比，MH 在消化前后具有更高的抗氧化活性。RAW264.7 和 THP-1 细胞在用 0.5 mg/mL 消化的 WB 样品处理后释放出最高量的促炎细胞因子。用消化的 HYD 刺激 RAW264.7 上清液 96 h 显示出最强的抗癌效果，而用过的培养基比直接用 WB 样品处理更能减少癌细胞集落。尽管没有发现线粒体膜电位改变，但当 CRC 细胞用巨噬细胞上清液处理时，Bax:Bcl-2 比值增加和 caspase-3 表达表明激活了线粒体凋亡途径。当 CRC 细胞暴露于 RAW264.7 上清液时，细胞内活性氧物种（ROS）与细胞活力呈正相关（r = 0.78，<0.05），但与用 THP-1 条件培养基处理的 CRC 细胞不相关。来自 WB 刺激的 THP-1 细胞的上清液可能能够刺激 HT-29 细胞中 ROS 的产生，导致细胞活力随时间的推移呈下降趋势。因此，本研究揭示了 HYD 通过刺激巨噬细胞中细胞因子的产生以及间接抑制 CRC 细胞的增殖、集落形成和促凋亡蛋白表达的激活来抑制肿瘤的新的抗肿瘤机制。
