The multidrug resistance (MDR) of cancer cells is a major obstacle to cancer treatment. Glutathione S-transferase Pi (GSTP1-1) catalyzes the conjugation of glutathione with anticancer drugs and therefore reduces their efficacy. Phenolic compounds have the potential to inhibit GST P1-1 activity, which is a promising goal to overcome MDR and increase the efficacy of chemotherapy. Three fractions (dichloromethane, ethyl acetate, and n-butanol) were prepared from Tamarindus indica seeds to determine their phenolic and flavonoid properties as well as their antioxidant/pro-oxidant properties. The n-butanol fraction displayed the highest levels of phenol ( 378 ± 11.7 mg gallic acid equivalent/g DW) and flavonoids (83 ± 6.0 mg rutin equivalent/g DW). Inhibiting effects on purified GSTP1-1 activity in human erythrocytes (eGST), placenta (pGST), and hGSTP1-1 have been studied. The n-butanol fraction was the most effective in inhibiting eGST, hGSTP1-1, and pGST with IC50 values of 3.0 ± 0.7, 4.85 ± 0.35, and 6.6 ± 1.2 μg/ml, respectively. Cellular toxicity was investigated for the T. indica n-butanol fraction on various human cancerous cell lines. The only ones affected were MCF-7 cell lines (72%) and HePG2 (52%) indicated cytotoxicity. The value of IC50 is 68.5 μg/ml of T. indica n-butanol fraction was observed compared to 1.7 μg/ml tamoxifen in MCF-7 cell lines. The combination of treatment of T. indica extract with the medicinally approved drug tamoxifen had unexpected effects; complete elimination of the cytotoxic inhibition effect of tamoxifen and the plant extract was observed. However T. indica extract has a cytotoxic effect on the MCF-7 cell line; in certain situations, plant products can have an opposite effect to the intended drug, which decreases the impact of the drug.

中文翻译：

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罗望子种子的抗氧化剂或促氧化剂和谷胱甘肽转移酶P1-1抑制活性及其对MCF-7癌细胞的细胞毒性作用

癌细胞的多药耐药性（MDR）是癌症治疗的主要障碍。谷胱甘肽S-转移酶Pi（GSTP1-1）催化谷胱甘肽与抗癌药物的结合，因此降低了它们的功效。酚类化合物具有抑制GST P1-1活性的潜力，这是克服MDR并提高化疗功效的有希望的目标。从罗望子种子制备了三部分（二氯甲烷，乙酸乙酯和正丁醇），以确定它们的酚和类黄酮性质以及其抗氧化剂/助氧化剂性质。正丁醇馏分显示出最高水平的苯酚（378±11.7 mg没食子酸当量/ g DW）和类黄酮（83±6.0 mg芦丁当量/ g DW）。对人红细胞（eGST），胎盘（pGST）中纯化的GSTP1-1活性的抑制作用 已经研究了hGSTP1-1和hGSTP1-1。正丁醇级分最有效地抑制eGST，hGSTP1-1和pGST，IC50值分别为3.0±0.7、4.85±0.35和6.6±1.2μg/ ml。研究了印度。中正丁醇馏分对各种人类癌细胞系的细胞毒性。唯一受影响的是MCF-7细胞系（72％）和HePG2（52％）表明具有细胞毒性。在MCF-7细胞系中，观察到印度T正丁醇级分的IC50值为68.5μg/ ml，而他莫昔芬为1.7μg/ ml。T虫提取物与医学批准的药物他莫昔芬的联合治疗具有出乎意料的效果。完全消除了他莫昔芬的细胞毒性抑制作用，并观察到了植物提取物。然而，印度T提取物对MCF-7细胞系具有细胞毒性作用。在某些情况下