Cytotoxic and potent CYP1 inhibitors from the marine algae Cymopolia barbata.
Cytotoxic and potent CYP1 inhibitors from the marine algae Cymopolia barbata.
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DOI：
10.1186/2191-2858-2-21
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发表时间：
2012-06-11
期刊：
影响因子：
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通讯作者：
Delgoda, Rupika
中科院分区：
文献类型：
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作者：
Badal, Simone;Gallimore, Winklet;Delgoda, Rupika
未标记：背景：从海洋藻类Cymopolia barbata提取物已显示出有前途的药理活性，包括抗真菌，抗肿瘤，抗微生物和抗突变特性。尽管浸提物已证明具有此类生物活性，但导致此类生物活性的分离成分仍未指明。本研究对从海藻C.方法：使用MTS测定法评价PBQ对细胞系（MCF-7、HT 29、HepG和CCD 18 Co）的活力的影响。此外，它们对异源表达的细胞色素P450（CYP）酶活性的抑制作用使用荧光测定法评价CYP 1A 1、CYP 1A 2、CYP 1B 1、CYP 2C 19、CYP 2D 6和CYP 3A 4。采用液相色谱和柱色谱分离7-羟基环己基色满酮（PBQ 1）和7-羟基环己基酚酮（PBQ 2），使用1H和13 C NMR光谱进行鉴定，并与之前分离的PBQ的光谱进行比较。PBQ 2选择性地影响HT 29的生存力，HT 29是结肠癌细胞，具有与已知化疗药物氟尿嘧啶相似的效力。（IC 50分别为19.82±0.46 μ M和23.50±1.12 μ M），对正常结肠细胞的影响也相当（分别为55.65±3.28和55.51±3.71 μ M），而PBQ 1对这些细胞没有影响。两种PBQ均对CYP 1A 1和CYP 1B 1的活性具有强效抑制作用，后者已知是癌症的通用标志物和药物发现的靶点。CYP 1酶抑制剂通过防止致癌物如苯并-a-芘的活化而作为潜在的化学预防剂引起了人们的注意。PBQ 2有效抑制CYP 1B 1的活性（IC 50为0.14±0.04 μ M），而PBQ 1和PBQ 2均有效抑制CYP 1A 1的活性（IC 50分别为0.39±0.05 μ M和0.93±0.26 μ M）。进一步表征显示PBQ 2与CYP 1B 1的部分非竞争性酶动力学，Ki为4.7 * 10-3±5.1 * 10-4 μ M，与CYP 1A 1的非竞争性动力学Ki = 0.84±0.07 μ M;而PBQ 1与CYP 1A 1表现出部分非竞争性酶动力学（Ki = 3.07±0.69 μ M）、与CYP 1A 2的非竞争性动力学（Ki=9.16±4.68 μ M）和与CYP 1B 1的非竞争性动力学（Ki = 0.26±0.03 μ M）。barbata，PBQ 1和PBQ 2，显示出作为有价值的化疗化合物的潜力。与所研究的三种其他恶性细胞系相比，PBQ 2中的羟基部分似乎对于针对结肠癌细胞HT 29的选择性和效力至关重要。PBQ还显示出对CYP 1酶活性的效力，这可能是化学预防的先导。这项研究是第一个从这些海藻中分离出来的研究，证实了在自然界中寻找可以显示多种生物活性的独特结构基序的价值。
UNLABELLED:BACKGROUND: Extracts from the marine algae Cymopolia barbata have previously shown promising pharmacological activity including antifungal, antitumor, antimicrobial, and antimutagenic properties. Even though extracts have demonstrated such bioactivity, isolated ingredients responsible for such bioactivity remain unspecified. In this study, we describe chemical characterization and evaluations of biological activity of prenylated bromohydroquinones (PBQ) isolated from the marine algae C. barbata for their cytotoxic and chemopreventive potential.METHODS: The impact of PBQs on the viability of cell lines (MCF-7, HT29, HepG, and CCD18 Co) was evaluated using the MTS assay. In addition, their inhibitory impact on the activities of heterologously expressed cytochrome P450 (CYP) enzymes (CYP1A1, CYP1A2, CYP1B1, CYP2C19, CYP2D6, and CYP3A4) was evaluated using a fluorescent assay.RESULTS: 7-Hydroxycymopochromanone (PBQ1) and 7-hydroxycymopolone (PBQ2) were isolated using liquid and column chromatography, identified using 1H and 13C NMR spectra and compared with the spectra of previously isolated PBQs. PBQ2 selectively impacted the viability of HT29, colon cancer cells with similar potency to the known chemotherapeutic drug, fluorouracil (IC50, 19.82±0.46 muM compared to 23.50±1.12 muM, respectively) with impact toward normal colon cells also being comparable (55.65±3.28 compared to 55.51±3.71 muM, respectively), while PBQ1 had no impact on these cells. Both PBQs had potent inhibition against the activities of CYP1A1 and CYP1B1, the latter which is known to be a universal marker for cancer and a target for drug discovery. Inhibitors of CYP1 enzymes by virtue of the prevention of activation of carcinogens such as benzo-a-pyrene have drawn attention as potential chemopreventors. PBQ2 potently inhibited the activity of CYP1B1 (IC50 0.14±0.04 muM), while both PBQ1 and PBQ2 potently inhibited the activity of CYP1A1 (IC50s of 0.39±0.05 muM and 0.93±0.26 muM, respectively). Further characterizations showed partial noncompetitive enzyme kinetics for PBQ2 with CYP1B1 with a Ki of 4.7 * 10-3±5.1 * 10-4 muM and uncompetitive kinetics with CYP1A1 (Ki = 0.84±0.07 muM); while PBQ1 displayed partial non competitive enzyme kinetics with CYP1A1 (Ki of 3.07±0.69 muM), noncompetitive kinetics with CYP1A2 (Ki=9.16±4.68 muM) and uncompetitive kinetics with CYP1B1 (Ki = 0.26±0.03 muM) .CONCLUSIONS: We report for the first time, two isolated ingredients from C. barbata, PBQ1 and PBQ2, that show potential as valuable chemotherapeutic compounds. A hydroxyl moiety resident in PBQ2 appears to be critical for selectivity and potency against the cancer colon cells, HT29, in comparison to the three other malignant cell lines studied. PBQs also show potency against the activities of CYP1 enzyme which may be a lead in chemoprevention. This study, the first on isolates from these marine algae, exemplifies the value of searching within nature for unique structural motifs that can display multiple biological activities.