The risk for breast and colon cancer may be lowered in part by high intake of fruits and vegetables. Fruits such as grapes are abundant in bioactive compounds such as anthocyanins. The potential anticancer activity of anthocyanins may be limited by their metabolism in the gut and liver. One metabolic transformation is due to the enzyme catechol-O-methyltransferase (COMT), which methylates polyphenols such as anthocyanins. Entacapone is a clinically used inhibitor of COMT, and has been shown to modulate the methylation of food-derived polyphenols. In this study, we compared the effect of entacapone on the cell viability of colon (Caco-2 and HT-29) and breast (MDA-MB-231) cancer cell lines treated with anthocyanins. Cells were treated with either cyanidin-3-glucoside, delphinidin-3-glucoside, or an anthocyanin-rich grape extract, in the absence or presence of entacapone. Cell viability was assessed using the thiazolyl blue tetrazolium bromide (MTT) assay. Entacapone in combination with the anthocyanins had a greater than additive effect on growth inhibition of the Caco-2 cells. In the MDA-MB-231 cell line, entacapone similarly enhanced the growth inhibitory activity of the anthocyanin extract. Entacapone also had antiproliferative effects when used as a single treatment. Total hydroperoxides was quantified in the cell culture media. Greater concentrations of the treatments resulted in higher levels of total hydroperoxides, indicating that oxidative stress may be an important mechanism for growth inhibition. In conclusion, the antiproliferative activity of fruit-derived anthocyanins was improved in human cancer cell lines by the clinically used drug entacapone. The efficacy and mechanisms of entacapone/anthocyanin combinations should be carefully studied in vivo. PRACTICAL APPLICATION Chemical components of grapes are good for our health and have been shown to lower risk for certain cancers. Their beneficial health effects could also be enhanced by consuming other molecules that improve their bioavailability.

中文翻译：

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增强鲜食葡萄花青素对癌细胞生长的抑制作用

摄入大量水果和蔬菜可以部分降低患乳腺癌和结肠癌的风险。葡萄等水果富含花青素等生物活性化合物。花青素的潜在抗癌活性可能受到它们在肠道和肝脏中的代谢的限制。一种代谢转化是由儿茶酚-O-甲基转移酶 (COMT) 引起的，它可以甲基化多酚，例如花青素。Entacapone 是一种临床使用的 COMT 抑制剂，已被证明可调节食物来源的多酚的甲基化。在这项研究中，我们比较了恩他卡朋对用花青素处理的结肠癌细胞系（Caco-2 和 HT-29）和乳腺癌细胞系（MDA-MB-231）细胞活力的影响。用花青素-3-葡萄糖苷、飞燕草素-3-葡萄糖苷或富含花青素的葡萄提取物处理细胞，在恩他卡朋不存在或存在的情况下。使用噻唑蓝四唑溴化物 (MTT) 测定法评估细胞活力。恩他卡朋与花青素组合对 Caco-2 细胞的生长抑制具有大于加和的作用。在 MDA-MB-231 细胞系中，恩他卡朋同样增强了花青素提取物的生长抑制活性。当作为单一治疗使用时，恩他卡朋也具有抗增殖作用。对细胞培养基中的总氢过氧化物进行定量。更高浓度的处理导致更高水平的总氢过氧化物，表明氧化应激可能是生长抑制的重要机制。总之，临床使用的药物恩他卡朋提高了果实来源的花青素在人类癌细胞系中的抗增殖活性。应在体内仔细研究恩他卡朋/花青素组合的功效和机制。实际应用葡萄的化学成分对我们的健康有益，并且已被证明可以降低患某些癌症的风险。食用其他可提高其生物利用度的分子也可以增强它们对健康的有益影响。