Are anthocyanins necessary for oral cancer chemoprevention by berries?

描述（由申请人提供）： 许多流行病学研究表明，食用新鲜水果和蔬菜与降低口腔癌风险之间存在很强的相关性。几项临床前研究表明，两种浆果，黑树莓和草莓，在体外抑制人类口腔癌细胞增殖和化学诱导的动物呼吸消化道肿瘤的发展显着的化学预防活性。一个紧迫的，但尚未回答的问题仍然是“什么类型的多酚在水果中主要负责这些活动？“以前的研究使用了冻干粉或成熟水果的提取物，其中含有浆果多酚的复杂混合物，其中主要成分是花青素。流行病学证据表明，富含花青素（有色水果和蔬菜）的饮食可以降低癌症的总体风险，实验室证据表明可以抑制培养中的肿瘤细胞增殖并预防动物模型中的肿瘤。然而，浆果中还有许多其他的水果酚类物质，它们在细胞培养和癌症动物模型中都表现出抗氧化、抗增殖和化学预防活性。其中包括酚酸（没食子酸、原儿茶酸、对羟基苯甲酸、咖啡酸、对香豆酸、阿魏酸、绿原酸和鞣花酸）、黄酮醇（槲皮素、山奈酚、麦黄酮和异鼠李素）和复合多酚（木酚素、鞣花单宁和没食子单宁）。为了研究这些后浆果酚类化合物的化学预防能力，与它们与花青素的组合活性分开，我们建议评估绿色浆果（具有最小花青素含量）和成熟浆果（具有高水平的花青素）在动物模型中抑制口腔肿瘤发生，并确定它们对癌症相关基因的调节作用。假设：我们假设，在绿色草莓和黑树莓中发现的生物活性酚类物质，独立于花青素，将在口腔癌动物模型中与成熟浆果一样有效地抑制肿瘤发生，并将调节与口腔癌相关的关键基因的表达。方法：将使用5%和10%的绿色和成熟草莓和黑树莓制备微丸。开始用浆果颗粒喂养后7天开始，将用化学致癌物7，12-二甲基苯并（a）蒽每周3次涂抹颊囊，持续6周。浆果颗粒将在致癌物治疗期间和治疗后六周给予。在12-13周时，将评价颊囊的总病变和肿瘤以及癌症相关基因表达的调节。重要性：本文概述的新研究将提供对基本上不含花青素的浆果的化学预防潜力的实际评估，以及确定其调节口腔癌中特定分子靶点的能力的机会。该结果将为深入研究提供合适的基础，旨在阐明各种生物活性浆果成分对口腔癌的化学预防潜力。

DESCRIPTION (provided by applicant): Numerous epidemiological studies have shown a strong correlation between consumption of fresh fruits and vegetables and a decreased risk of oral cancer. Several preclinical studies demonstrate the remarkable chemopreventive activity of two berry fruits, black raspberries and strawberries, that inhibit human oral cancer cell proliferation in vitro and development of chemically-induced aerodigestive tract tumors in animals. A pressing, yet unanswered, question remains "What types of polyphenols in fruit are primarily responsible for these activities?" Prior studies have employed lyophilized powders or extracts of ripe fruits containing a complex mixture of berry polyphenols of which a major group is the anthocyanins. Epidemiological evidence suggests that diets rich in anthocyanins (colored fruits and vegetables) reduce the overall risk of cancer and laboratory evidence illustrates the inhibition of proliferation of tumor cells in culture and prevention of tumors in animal models. However, there are numerous other fruit phenolics in berries that have demonstrated antioxidant, antiproliferative, and chemopreventive activity in both cell cultures and animal models of cancer. Among these are the phenolic acids, (gallic, procatechuic, p-hydroxybenzoic, caffeic, p- coumaric, ferulic, chlorogenic, and ellagic acids), the flavonols (quercetin, kaempferol, mycetrin, and isorhamntin), and complex polyphenols (lignans, ellagitannin, and gallotannin). To examine the chemopreventive capacity of these latter berry phenolics, separate from their combined activity with anthocyanins, we propose to evaluate green berry fruits (with minimal anthocyanin content) and ripe berry fruits (with high levels of anthocyanins) for inhibition of oral tumorigenesis in an animal model and to determine their effect on modulation of cancer-associated genes. Hypothesis: We hypothesize that bioactive phenolics found in green strawberries and black raspberries, independent of the anthocyanins, will inhibit tumorigenesis just as effectively as ripe berries in an animal model of oral cancer and will modulate the expression of critical genes associated with oral cancer. Methods: Hamster pellets will be prepared using 5% and 10% green and ripe strawberries and black raspberries. Beginning 7 days after commencement of feeding with berry pellets, cheek pouches will be painted 3x/week for six weeks with the chemical carcinogen 7,12-dimethylbenz(a)anthracene. Berry pellets will be given during, and for six weeks after, carcinogen treatment. At 12-13 weeks, cheek pouches will be evaluated for total lesions and tumors and for modulation of caner- associated gene expression. Significance: The novel studies outlined herein will provide a practical assessment of the chemopreventive potential of berries that are essentially devoid of anthocyanins, as well as an opportunity to determine their ability to modulate specific molecular targets in oral cancers. The outcome will provide a suitable foundation for in-depth studies designed to elucidate the chemoprevention potential for oral cancer of various bioactive berry components.