薏仁麩皮不同萃取區分物其酚類化合物含量和抑制大腸癌之效果

Abstract

自民國84年以來，大腸癌為癌症死因第三位；民國95年，發生人數首次超越肝癌，成為我國發生人數最高的癌症，可見大腸癌威脅不容忽視。薏苡為禾本科薏苡屬一年生植物，具有多種植物化學成分，其中酚類化合物在許多研究中顯示具有良好的抗癌效果。本實驗設計以不同濃度乙醇進行萃取，探討其對薏仁麩皮酚類化合物含量的影響及抑制大腸癌的作用。此外，由於乙酸乙酯在食品中不得殘留，因此嘗試以70%乙醇進行區分，探討其與乙酸乙酯區分的差別，並進一步與阿斯匹靈合用，希望達到減少藥物劑量以降低副作用的效果。以高效液相層析儀定量11種酚酸/酚醛和13種類黃酮，結果顯示以80%乙醇萃取有最高的總量，且薏仁麩皮乙醇正己烷萃取物70%乙醇層(ABE-H-70% EtOH)11種酚酸/酚醛總量和13種類黃酮總量分別約為薏仁麩皮乙醇萃取物乙酸乙酯層(ABE-EA)的60~70%和80~90%。以大腸癌細胞株測其抗癌功效，80%乙醇萃取有最佳效果，ABE-EA的效果又較ABE-H-70% EtOH佳。以主成分分析探討不同萃取區分條件與酚類化合物含量的關係，結果發現分成兩群，syringaldehyde和liquiritigenin為造成分群主要原因，以正交最小平方區別分析酚類化合物含量和抑制大腸癌細胞株生長的關係，發現薏仁麩皮不同萃取區分物造成抑制大腸癌細胞生長活性之差異主要來自於syringaldehyde和liquiritigenin的含量。進一步將阿斯匹靈與80% ABE-EA或80% ABE-H-70% EtOH合用，具有相加作用，顯示合併使用80% ABE-EA或80% ABE-H-70% EtOH確實可以減少阿斯匹靈的使用量。

Colon cancer has been the third leading cause of cancer death in Taiwan since 1995, and it is also the first leading cause of cancer incidence since 2006. Adlay (Coix lachryma-jobi L. var. ma-yuen Stapf.) contains different kinds of phytochemicals, and a lot of studies have indicated that phenolic compounds have anti-cancer property. In this study, different concentrations of ethanol were used to extract adlay bran in order to investigate the relationship between the level of phenolic compounds and colon cancer cell viability. Moreover, as ethyl acetate is prohibited from use in the preparation of food products, therefore 70% ethanol was used in the extraction process and the yield was compared with the outcome from the use of ethyl acetate. Each adlay extract was combined with aspirin, with the hope that lowering the dose of aspirin could potentially decrease the associated side effects. Quantification of 11 phenolic acids/ aldehydes and 13 flavonoids were determined using high performance liquid chromatography and the result showed that the highest total content was based on extraction with 80% ethanol. The total content of 11 phenolic acids/ aldehydes in ABE-H-70% EtOH was 60-70% of that in ABE-EA; the total content of 13 flavonoids was 80-90%. Colon cancer cell lines were used to evaluate the anti-cancer efficacy of adlay bran extracts and the result showed that ABE-EA was better than ABE-H-70% EtOH. Principal component analysis showed that the correlation between different extraction methods and the content of phenolic compounds could be classified into two groups, where syringaldehyde and liquiritigenin were the major factors behind the classification. The results from orthogonal partial least squares discriminant analyses showed that the levels of syringaldehyde and liquiritigenin were the major determinants for the differences in colon cancer cell viability. Furthermore, combined use of aspirin with 80% ABE-EA or 80% ABE-H-70%EtOH would give an additive effect, whereas the combination of aspirin with 80% ABE-EA or 80% ABE-H-70%EtOH could reduce the dose of aspirin used.