Department of Applied Thai Traditional Medicine, Faculty of Medicine, Thammasat University, Pathumthani 12120, Thailand.
BMC Complement Altern Med. 2014 Oct 16;14:403. doi: 10.1186/1472-6882-14-403.
The rhizomes of Dioscorea membranacea Pierre, also called Hua-Khao-Yen by Thai name, are used as ingredients in many Thai traditional medicines for the alternative or complementary treatment of cancer and AIDs. Preliminary in vitro studies have indicated that D. membranacea extracts exhibited high cytotoxic activity with several cancer cell lines, but the underlining mechanisms are far from clear. The aims of this study were to investigate the effects of ethanolic and aqueous crude extracts from D. membranacea Pierre, and pure compound from D. membranacea Pierre, Dioscorealide B, on natural killer cells activity and on lymphocyte proliferation.
Immunomodulatory activity was investigated using PBMCs from healthy donors. NK cells activity was performed by the chromium release assay using PBMCs as effector cells, and K562 cells line labelled with chromium as target cells. Lymphocyte proliferation was determined by 3H-thymidine uptake. The degree of activation was expressed as the stimulation index.
The crude ethanolic extracts of D. membranacea Pierre significantly stimulated NK cells activity against K562 cells line at lower concentrations of 10 and 100 ng/ml, but not at higher concentrations. The ethanolic extracts showed no observable effect on lymphocyte proliferation. The crude water extracts significantly increased NK cell activity at concentrations of 10 ng/ml, 100 ng/ml, 1 μg/ml, 10 μg/ml and 100 μg/ml, and also activated lymphocyte proliferation at concentration of 1 ng/ml, 10 ng/ml, 100 ng/ml, 1 μg/ml, 5 μg/ml, 10 μg/ml and 100 μg/ml. However, Dioscorealide B had no significant effect at lower concentrations (0-1 μg/ml and 0-0.1 μg/ml, respectively) on NK cell activity and lymphocyte proliferation. In fact higher concentrations (>10 μg/ml and >0.5 μg/ml) of Dioscorealide B cause a significant decrease in NK cell activity and lymphocyte proliferation.
D. membranacea Pierre stimulated NK cells activity and lymphocyte proliferation, but Dioscorealide B either had no effect, and at higher concentrations decreased NK cell activity and lymphocyte proliferation. Our results suggest that both extracts of D. membranacea Pierre significantly increases immune function, but the underlining mechanism is not clearly understood.
盾叶薯蓣的根茎，泰语名为 Hua-Khao-Yen，被用作许多泰式传统药物的成分，用于癌症和艾滋病的替代或补充治疗。初步的体外研究表明，盾叶薯蓣提取物对几种癌细胞系表现出高细胞毒性活性，但潜在机制尚不清楚。本研究的目的是研究盾叶薯蓣 Pierre 的乙醇和水粗提取物以及盾叶薯蓣 Pierre 的纯化合物 Dioscorealide B 对自然杀伤细胞活性和淋巴细胞增殖的影响。
使用来自健康供体的 PBMC 研究免疫调节活性。使用 PBMC 作为效应细胞，用铬标记的 K562 细胞系作为靶细胞进行 NK 细胞活性测定。通过 3H-胸腺嘧啶摄取测定淋巴细胞增殖。激活程度表示为刺激指数。
较低浓度（10 和 100ng/ml）的盾叶薯蓣 Pierre 乙醇粗提取物显着刺激 NK 细胞对 K562 细胞系的活性，但较高浓度无明显作用。乙醇提取物对淋巴细胞增殖没有观察到影响。水粗提取物在 10ng/ml、100ng/ml、1μg/ml、10μg/ml 和 100μg/ml 浓度下显着增加 NK 细胞活性，并在 1ng/ml、10ng/ml、100ng/ml、1μg/ml、5μg/ml、10μg/ml 和 100μg/ml 浓度下激活淋巴细胞增殖。然而，Dioscorealide B 在较低浓度（分别为 0-1μg/ml 和 0-0.1μg/ml）对 NK 细胞活性和淋巴细胞增殖没有显着影响。事实上，较高浓度（>10μg/ml 和>0.5μg/ml）的 Dioscorealide B 会导致 NK 细胞活性和淋巴细胞增殖显着下降。
盾叶薯蓣 Pierre 刺激 NK 细胞活性和淋巴细胞增殖，但 Dioscorealide B 要么没有作用，要么在较高浓度下降低 NK 细胞活性和淋巴细胞增殖。我们的结果表明，盾叶薯蓣 Pierre 的两种提取物均显着增强免疫功能，但潜在机制尚不清楚。
