Veluri Ravikanth, Singh Rana P, Liu Zhengjie, Thompson John A, Agarwal Rajesh, Agarwal Chapla
Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Health Sciences Center, Denver, CO 80262, USA.
Carcinogenesis. 2006 Jul;27(7):1445-53. doi: 10.1093/carcin/bgi347. Epub 2006 Feb 10.
The anti-cancer efficacy of grape seed extract (GSE) against prostate cancer (PCA) via its anti-proliferative, pro-apoptotic and anti-angiogenic activities in both cell culture and animal models have recently been described by us. GSE is a complex mixture containing gallic acid (GA), catechin (C), epicatechin (EC) and several oligomers (procyanidins) of C and/or EC, some of which are esterified to GA. To determine which components are most active against PCA, an ethyl acetate extract of GSE was separated by reverse-phase high-performance liquid chromatography (HPLC) into three fractions. Fraction 1 was far more effective than others in causing growth inhibition and apoptotic death of human PCA DU145 cells. Of the components in this fraction, GA showed a very strong dose- and time-dependent growth inhibition and apoptotic death of DU145 cells, but C and procyanidins B1 (EC-C dimer), B2 (EC-EC dimer) and B3 (C-C dimer) were nearly ineffective. Mechanistic studies demonstrated a strong caspase-9, caspase-3 and poly (ADP-ribose) polymerase (PARP) cleavages by GA in DU145 cells. Procyanidin oligomers eluting in HPLC Fractions 2 and 3 were obtained in larger quantities by separating GSE into eight fractions (I-VIII) on a gel filtration column. All fractions were analyzed by HPLC-UV and negative-ion electrospray mass spectrometry. Fractions I-III contained the active compound GA and inactive components C, EC, B1 and B2. Fraction IV contained other dimers and a dimer-GA ester and was also less active than GSE in DU145 cells. Fractions V-VIII, however, caused significant growth inhibition and apoptosis with the highest activity present in the later fractions that contained procyanidin trimers and GA esters of dimers and trimers. Together, these observations identify GA as one of the major active constituents in GSE. Several procyanidins, however, and especially the gallate esters of dimers and trimers also may be efficacious against PCA and merit further investigation.
我们最近报道了葡萄籽提取物（GSE）在细胞培养和动物模型中通过其抗增殖、促凋亡和抗血管生成活性对前列腺癌（PCA）的抗癌功效。GSE是一种复杂的混合物，含有没食子酸（GA）、儿茶素（C）、表儿茶素（EC）以及C和/或EC的几种低聚物（原花青素），其中一些与GA酯化。为了确定哪些成分对PCA最具活性，将GSE的乙酸乙酯提取物通过反相高效液相色谱（HPLC）分离为三个馏分。馏分1在导致人PCA DU145细胞生长抑制和凋亡死亡方面比其他馏分有效得多。在该馏分的成分中，GA对DU145细胞表现出非常强的剂量和时间依赖性生长抑制和凋亡死亡，但C和原花青素B1（EC-C二聚体）、B2（EC-EC二聚体）和B3（C-C二聚体）几乎无效。机制研究表明，GA在DU145细胞中强烈切割半胱天冬酶-9、半胱天冬酶-3和聚（ADP-核糖）聚合酶（PARP）。通过在凝胶过滤柱上将GSE分离为八个馏分（I-VIII），获得了在HPLC馏分2和3中洗脱的原花青素低聚物。所有馏分均通过HPLC-UV和负离子电喷雾质谱分析。馏分I-III含有活性化合物GA和无活性成分C、EC、B1和B2。馏分IV含有其他二聚体和二聚体-GA酯，在DU145细胞中也比GSE活性低。然而，馏分V-VIII导致显著的生长抑制和凋亡，后期馏分中活性最高，其中含有原花青素三聚体以及二聚体和三聚体的GA酯。总之，这些观察结果确定GA是GSE中的主要活性成分之一。然而，几种原花青素，尤其是二聚体和三聚体的没食子酸酯也可能对PCA有效，值得进一步研究。
