Curcuma longa L. extract (CLE) exerts various biological functions including antioxidant, anti-inflammation, anticancer, and antiallergenic effects. However, its immune-enhancing capacity remains unclear. Therefore, the immune-enhancing effect of CLE was investigated in RAW 264.7 cells and cyclophosphamide (CPP)-induced immunosuppression model. CLE upregulated nitric oxide (NO) and reactive oxygen species production and increased inducible nitric oxide synthase and cyclooxygenase-2 expression without affecting the RAW 264.7 cells viability. The results of quantitative real-time reverse transcription polymerase chain reaction and sandwich enzyme-linked immunosorbent assay showed that CLE increased the gene expression and protein levels of tumor necrosis factor-α, interleukin-6, and interleukin-1β in RAW 264.7 cells. Moreover, CLE upregulated p65, I kappa B kinase α/β, and I kappa B α (IκBα) phosphorylation and downregulated IκBα expression in RAW 264.7 cells. CLE also increased p65 translocation from the cytoplasmic to the nucleus in RAW 264.7 cells. The oral administration of CLE increased organ indexes (including the spleen and thymus) and NO production in peritoneal macrophages and improved natural killer cell activity in CPP-induced immunosuppression BALB/c mice. Overall, CLE could be a useful health functional food material that can improve innate immunity via macrophage activation.

中文翻译：

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姜黄提取物增强 RAW 264.7 细胞和环磷酰胺诱导的 BALB/c 小鼠的免疫反应

姜黄提取物 (CLE) 具有多种生物功能，包括抗氧化、抗炎、抗癌和抗过敏作用。然而，其免疫增强能力仍不清楚。因此，我们在RAW 264.7细胞和环磷酰胺（CPP）诱导的免疫抑制模型中研究了CLE的免疫增强作用。CLE 上调一氧化氮 (NO) 和活性氧的产生，并增加诱导型一氧化氮合酶和环氧合酶-2 的表达，而不影响 RAW 264.7 细胞的活力。实时定量逆转录聚合酶链反应和夹心酶联免疫吸附试验结果表明，CLE 增加了 RAW 264.7 细胞中肿瘤坏死因子-α、白细胞介素 6 和白细胞介素 1β 的基因表达和蛋白水平。此外，CLE 上调 RAW 264.7 细胞中 p65、I kappa B 激酶 α/β 和 I kappa B α (IκBα) 磷酸化并下调 IκBα 表达。CLE 还增加了 RAW 264.7 细胞中 p65 从细胞质到细胞核的易位。口服 CLE 增加了 CPP 诱导的免疫抑制 BALB/c 小鼠的器官指数（包括脾脏和胸腺）和腹膜巨噬细胞中 NO 的产生，并提高了自然杀伤细胞的活性。总体而言，CLE 可能是一种有用的健康功能食品材料，可以通过巨噬细胞激活来提高先天免疫力。