Increased accumulation of heavy metal ions such as Cr6+ and Co2+ due to release from prostheses and metallic implants has been reported. These metal ions have been shown to affect both resting and activated lymphocytes. Natural remedies towards mitigating the cytotoxic effects of metal ions are clearly warranted. Polyphenolic compounds which are part of hydrolysable tannins from natural plant sources are considered effective in cheating heavy metal ions in a biological system. We have isolated and characterized a polyphenolic compound (ellagic acid) from Terminalia arjuna fruits that has been tested for its ability to attenuate the metal ion toxicity in primary human lymphocytes in culture. Cr6+ and Co2+ (100 μM) decreased lymphocyte viability and proliferation and increased apoptosis of resting as well as CD3 and/or CD28-stimulated lymphocytes. Metal ions markedly diminished the cytokine (interleukin-2 and interferon-γ) secretion from activated lymphocytes. Pretreatment with ellagic acid at 25, 50, and 100 μM concentrations effectively improved viability and proliferative responses of both resting and activated lymphocytes, while attenuating the apoptotic index. Ellagic acid also tended to normalize the cytokine secretion from the activated lymphocytes even in the presence of metal ions, suggesting broad effects on the adaptive immune system.

中文翻译：

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Terminalia arjuna 果实中的鞣花酸可防止原代人淋巴细胞中的铬和钴毒性。

据报道，由于假体和金属植入物的释放，重金属离子如 Cr6+ 和 Co2+ 的积累增加。这些金属离子已被证明会影响静止和活化的淋巴细胞。减轻金属离子的细胞毒性作用的自然疗法显然是必要的。多酚化合物是天然植物来源的可水解单宁的一部分，被认为可有效欺骗生物系统中的重金属离子。我们从阿江榄仁果实中分离并表征了一种多酚化合物（鞣花酸），该化合物已经过测试其减弱培养的原代人淋巴细胞中金属离子毒性的能力。Cr6+ 和 Co2+ (100 μM) 降低了淋巴细胞的活力和增殖，增加了静息以及 CD3 和/或 CD28 刺激的淋巴细胞的凋亡。金属离子显着减少了活化淋巴细胞的细胞因子（白细胞介素-2和干扰素-γ）分泌。用 25、50 和 100 μM 浓度的鞣花酸预处理可有效提高静息和活化淋巴细胞的活力和增殖反应，同时减弱凋亡指数。即使在金属离子存在的情况下，鞣花酸也倾向于使活化淋巴细胞的细胞因子分泌正常化，这表明对适应性免疫系统有广泛的影响。