Platycodongrandiflorus (PG) root extract has been widely used as an oriental herbal medicine. Red PG root extract (RPGE), which is made by steaming and drying PG several times, contains more saponin than raw (white) PG. Although RPGE has been known to have anti-inflammatory activity, the effects of RPGE on the immune-enhancing response remain unclear. In this study, we aimed to investigate the immune-enhancing effects of RPGE and its mechanism in macrophage cells and splenocytes. Our results revealed that cell proliferation of both macrophages and splenocytes correlate positively with the concentration of RPGE. Moreover, RPGE treatment increased the phagocytic activity of macrophage cells, as well as nitric oxide and cytokines production. Furthermore, RPGE induced phosphorylation of the p38 mitogen-activated protein kinase, which contributed to nuclear factor-kappa B activation. Thus, our findings suggest that RPGE may be a potential functional food for improving immune function.

中文翻译：

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p38 MAPK介导的NF-κB活化对桔梗根提取物的免疫增强作用

桔梗大花（PG）根提取物已被广泛用作东方草药。红色PG根提取物（RPGE）是通过将PG蒸干几次而制成的，其皂苷的含量比原始（白色）PG高。尽管已知RPGE具有抗炎活性，但是RPGE对免疫增强反应的作用仍不清楚。在这项研究中，我们旨在研究RPGE在巨噬细胞和脾细胞中的免疫增强作用及其机制。我们的结果表明巨噬细胞和脾细胞的细胞增殖与RPGE的浓度呈正相关。而且，RPGE处理增加了巨噬细胞的吞噬活性以及一氧化氮和细胞因子的产生。此外，RPGE诱导了p38丝裂原活化蛋白激酶的磷酸化，这有助于核因子κB的活化。因此，我们的发现表明RPGE可能是改善免疫功能的潜在功能食品。