Department of Immunology, Shiraz University of Medical Sciences, Shiraz, Iran.
J Immunotoxicol. 2011 Oct-Dec;8(4):265-73. doi: 10.3109/1547691X.2011.590828. Epub 2011 Jun 28.
Plants may have the ability to modulate immune responses. In the present study, the effects of three plants belonging to Labiatae family, each traditionally used for the treatments of infections and inflammatory diseases, as well as the role of thymol (as one the major components of these plants), were investigated for their potential to affect the activation of lymphocytes. Four organic extracts of Thymus vulgaris and two other plants (i.e., T. daenensis and Zataria multiflora) were prepared. The effect of the extracts on mitogen (PHA)-stimulated peripheral blood lymphocytes was determined using a cell proliferation assay. The hexane extracts obtained from the three plants showed the strongest inhibitory effects on PHA-induced proliferation. Use of preparative thin layer and gas chromatographies in conjunction with the proliferation assay confirmed that thymol was the major component responsible for the observed effects from the three plants. Thymol inhibited inducible lymphocyte proliferation in a concentration-dependent manner, with reductions ranging from 62.8% at 50 µg/ml to 89.8% at 200 µg/ml (> 0.1 µg/ml (p < 0.01). Flow cytometric analysis using propidium iodide staining showed that the inhibitory effect of thymol at 200 µg/ml was due to a cytotoxic activity. In conclusion, the three Labiatae plants studied here each showed immunosuppressive effects against lymphocytes and it was most likely that thymol was the compound in these plants responsible for this effect.
植物可能具有调节免疫反应的能力。在本研究中，研究了三种属于唇形科的植物的作用，这些植物传统上用于治疗感染和炎症性疾病，以及百里香酚（作为这些植物的主要成分之一）的作用，以研究它们对淋巴细胞激活的潜在影响。制备了四种普通百里香和另外两种植物（即 T. daenensis 和 Zataria multiflora）的有机提取物。使用细胞增殖测定法测定提取物对有丝分裂原（PHA）刺激的外周血淋巴细胞的影响。三种植物的正己烷提取物对 PHA 诱导的增殖显示出最强的抑制作用。使用制备性薄层和气相色谱法结合增殖测定法证实，百里香酚是三种植物中观察到的作用的主要成分。百里香酚以浓度依赖性方式抑制诱导性淋巴细胞增殖，在 50 µg/ml 时降低 62.8%，在 200 µg/ml 时降低 89.8%（> 0.1 µg/ml（p < 0.01）。使用碘化丙啶染色的流式细胞术分析表明，200 µg/ml 时百里香酚的抑制作用是由于细胞毒性活性。总之，研究的三种唇形科植物均对淋巴细胞表现出免疫抑制作用，而百里香酚很可能是这些植物中具有这种作用的化合物。
