巴西唇花藤是一种生长在亚马逊地区的植物，因其含有的生物碱而具有免疫调节和抗肿瘤效果，能够通过增强或抑制巨噬细胞分泌的细胞因子来改变免疫应答，无论是通过经典途径（M1）还是通过替代途径（M2）。M1途径活化的巨噬细胞将L-精氨酸转化为L-瓜氨酸和一氧化氮（NO），而M2途径活化的巨噬细胞则使用精氨酸酶的酶活性将同样的底物转化为L-鸟氨酸和尿素。本研究旨在评估巴西唇花藤树皮粗乙醇提取物对RAW 264.7巨噬细胞的免疫刺激活性。通过测定NO产生和精氨酸酶酶活性，测试了0.2、0.1和0.05毫克/毫升的巴西唇花藤提取物与LPS、INF-γ和IL-4诱导剂的联合作用。巴西唇花藤提取物在与LPS和LPS + INF-γ诱导剂联合使用时可以增强一氧化氮的产生。在精氨酸酶酶活性方面，该提取物抑制了IL-4对酶的刺激作用，尤其是在0.2毫克/毫升浓度下。因此，可以得出结论，巴西唇花藤树皮粗乙醇提取物在RAW 264.7巨噬细胞中，以0.2毫克/毫升的浓度显示出显著的促炎活性。

Uncaria tomentosa is a plant native to the Amazon that has immunomodulatory and antitumor properties due to the alkaloids found in the plant, being able to modify the immune response by potentiating or suspending the action of cytokines secreted by macrophages that induce the immune response, either by the classical route (M1) or through the alternative route (M2). Macrophages activated by M1 convert L-arginine into L-citrulline and nitric oxide (NO), whereas macrophages activated by the M2 pathway use the enzymatic activity of arginase to convert the same substrate into L-ornithine and urea. The aim of this work was to evaluate the immunostimulating activity of the crude hydroalcoholic extract from the bark of the U. tomentosa stem in RAW 264.7 macrophages. Concentrations of 0.2, 0.1 and 0.05 mg/mL of U. tomentosa extract associated with LPS, INF-γ and IL-4 inducers were tested by determining NO production and arginase enzyme activity. Nitric oxide production was enhanced by the extract when associated with LPS and LPS + INF-γ inducers. In the activity of the arginase enzyme, the extract decreased the stimulation of IL-4 on the enzyme, mainly at 0.2 mg/mL concentration. Therefore, it is concluded that the crude hydroalcoholic extract of the stem bark of U. tomentosa in RAW 264.7 cells, at a concentration of 0.2 mg/mL, showed considerable pro-inflammatory activity.