蕎麥在以前是備荒救災的作物，現在已轉變成經濟作物，其經濟價值高，因含有芸香?(rutin)、槲黃素(quercetin)等類黃酮物質，具有降低心血管疾病、抗氧化、消除自由基等功能，芸香?和槲黃素的抗氧化能力比維他命C和E高，農作物栽培季節與品種均會影響此類物質之含量，故本研究探討台灣生長之甜蕎、苦蕎及蒙古進口之甜蕎的萃取物，對肝細胞的保肝活性。藉由t-BHP誘導體外培養之肝細胞的氧化傷害，探討蕎麥萃取物對肝細胞的保護能力。結果顯示所有萃取物皆具有保護作用，可減少t-BHP對肝細胞造成的傷害。利用FRAP assay檢測萃取物的總抗氧化能力，萃取物隨著酒精萃取濃度升高，其抗氧化效果也越好。用HPLC定量芸香?和槲黃素含量，結果顯示，苦蕎的芸香?含量皆比甜蕎的含量更高，而在不同產地(二林與蒙古)、不同部位(蕎仁與蕎殼)，皆可發現芸香?的存在，且甜蕎殼中，芸香?含量比槲黃素含量高，苦蕎仁的芸香?含量和槲黃素含量皆比苦蕎殼的含量高，此結果與多篇文獻結果符合。但這些萃取物中，也有許多物質未被鑑定出來，而這些物質可能降低肝細胞的保護作用，綜合掉其他成分抗t-BHP氧化傷害之能力，另外在一些萃取物中含有過多類黃酮(芸香?和槲黃素)物質時，也有上述之情況產生。台灣二林生產的甜蕎仁萃取物比進口的蒙古甜蕎仁萃取物在肝細胞實驗中，具有更佳的保護作用，此結果顯示，本地生產之蕎麥有更高之附加價值。
Buckwheat used to be a product for natural disaster relief, but is now an industrial crop with high economic value. Bcckwheat is recognized as a valuable source of flavonoids. Flavonoids such as rutin and quercetin, are anti-oxidants known for reducing cardiovascular diseases and radical scavenging activity. Rutin and quercetin are more antioxidative effect than that of vitamin C and vitamin E. The phytochemical content are varied for variety of breads and cultivation. Therefore, this study compared the liver protection activity of extracts from different breeds, cultivation of buckwheat. By treating hepatocytes with t-BHP that induces the oxidative damage of in-vitro hepatocytes, the protective activity of buckwheat on the hepatocytes was determined. All the extracts demonstrated protective activity and reduced the extent of t-BHP damage on the hepatocytes. Total antioxidative activity of the extracts was measured by FRAP assay. As the concentration of the ethanol of the extracting solvents increased, the extract displayed better antioxidative effect. The rutin and quercetin of the extracts were analyzed by HPLC-UV. The results indicate that the rutin content of tartary buckwheat (Fagopyrum tataricum Gaertn) is higher than that of common buckwheat (Fagopyrium esculentum Moench), while the rutin was found in the groat and hull of buckwheat cultivated in Erlin and Mongolia. The rutin content is higher than the quercetin content in the hull of common buckwheat, and the rutin and quercetin content in the groat of the tartary buckwheat are higher than those of the hull of the tartary buckwheat. These results are consistent with those reported in the literatures. However, there are many substances not been identified in present work. These unidentified substances may cause cytotoxicity and set off the antioxidative effect of other components. Some extracts containing excessive flavonoids such as rutin and quercetin, may case over dose problems. The extracts of groat of common buckwheat cultivated in Taiwan show better protective activity compared to those imported from Mongolia. The results indicate that the locally cultivated buckwheat has higher added value.
