Department of Biochemistry and Molecular Biology, Beijing Normal University, Beijing Key Laboratory, Beijing, China.
Pharm Biol. 2010 Oct;48(10):1177-84. doi: 10.3109/13880200903573169.
Calcineurin (CN), a unique protein phosphatase, plays an important role in immune regulation. Our laboratory has established an effective molecular drug-screening model based on CN activity.
Our aim is to search for an effective immunosuppressant from Glycyrrhiza uralensis (Leguminosae).
As guided by CN inhibitory test, an active compound was purified and identified as glycyrol. Immunosuppressive activity of glycyrol in vitro was assayed by T lymphocytes proliferation and mixed lymphocyte reaction (MLR). In addition, delayed-type hypersensitivity reaction (DTH) and skin allograft test in vivo were also carried out. Further, we have investigated the effect of glycyrol on phorbol 12-myristate 13-acetate (PMA)/ionomycin (Io)-stimulated IL-2 expression in Jurkat cells.
The enzymatic assay showed glycyrol (IC(50) = 84.6 μM) inhibited calcineurin activity in a dose-dependent manner. Glycyrol, at the non-cytotoxic concentration, significantly inhibited proliferation of murine spleen T lymphocytes induced by Concanavalin A (Con A) and mixed lymphocyte reaction (MLR) in vitro. In addition, mice treated with glycyrol had shown the dose-dependent decrease in delayed type hypersensitivity (DTH) and prolonged the graft survival by 59% compared to the control group (*p < 0.05). RT-PCR showed glycyrol suppressed IL-2 production in a concentration-dependent manner.
Our results show the immunosuppressive activity of glycyrol and this activity should be due to its inhibitory effect on CN activity, thereby suppressing IL-2 production and regulating T lymphocytes. Thus, glycyrol could be a candidate for development as a novel immunomodulatory drug.
钙调神经磷酸酶（CN）是一种独特的蛋白磷酸酶，在免疫调节中发挥重要作用。我们的实验室已经建立了一种基于 CN 活性的有效的分子药物筛选模型。
我们的目的是从甘草（豆科）中寻找一种有效的免疫抑制剂。
根据 CN 抑制试验的指导，对一种活性化合物进行了纯化和鉴定，鉴定为甘草醇。甘草醇在体外的免疫抑制活性通过 T 淋巴细胞增殖和混合淋巴细胞反应（MLR）进行测定。此外，还进行了体内迟发型超敏反应（DTH）和皮肤同种异体移植试验。进一步，我们研究了甘草醇对佛波醇 12-肉豆蔻酸 13-乙酸酯（PMA）/离子霉素（Io）刺激的 Jurkat 细胞中 IL-2 表达的影响。
酶活性测定显示甘草醇（IC（50）= 84.6 μM）呈剂量依赖性抑制钙调神经磷酸酶活性。甘草醇在非细胞毒性浓度下，显著抑制刀豆蛋白 A（Con A）诱导的小鼠脾 T 淋巴细胞增殖和混合淋巴细胞反应（MLR）。此外，与对照组相比，给予甘草醇的小鼠迟发型超敏反应（DTH）呈剂量依赖性下降，移植物存活时间延长 59%（*p < 0.05）。RT-PCR 显示甘草醇呈浓度依赖性抑制 IL-2 的产生。
我们的结果表明甘草醇具有免疫抑制活性，这种活性可能是由于其对 CN 活性的抑制作用，从而抑制 IL-2 的产生并调节 T 淋巴细胞。因此，甘草醇可能是一种新型免疫调节药物的候选药物。
