中文摘要 人體性激素的分泌被下視丘-腦垂體前葉-性腺軸線嚴密地的調控,以維持第二性徵及正常生理和生殖的運作,然而生活或疾病的因子卻會使體內性激素的平衡產生一些失調的狀況。近來的研究顯示,食品中一些成分可能會對性激素的分泌或作用造成影響,而食品一般又被認為是較安全或作用較緩慢的,暗示以食品基材運用為性激素調節之可行性。薏苡長久以來被認為是藥膳兼備的食材,一些研究也指出其在性激素調節方面之作用,故本研究以其為材料,探討其對雄性激素分泌的效應。大鼠間隙細胞及進一步利用密度梯度純化所得的萊氏細胞,以薏苡籽實各部位甲醇萃取物進行處理,培養液以放射免疫分析法檢測睪固酮含量,發現薏苡殼甲醇萃取物具有抑制睪固酮分泌的效應;進一步以液相分配層析法與矽膠管柱層析法將薏苡殼甲醇萃取物純化,發現其抑制活性來自於乙酸乙酯區分層之中極性部分;合併處理人絨毛膜性促素 (human chorionic gonadotropin) 、forskolin及8-Br-cAMP,發現抑制效應無法以forskolin消除,但8-Br-cAMP可以回復低劑量萃取物所造成之睪固酮抑制,推測萃取物可能會透過抑制adenylyl cyclase的活性達到抑制睪固酮之分泌;萃取物也能抑制睪固酮生成前驅物progesterone及androstenedione所刺激的睪固酮分泌,顯示其可能也會抑制睪固酮生成酵素P450c17及17β-HSD之活性。薏苡中存在具抑制雄性激素分泌的物質,可能可以運用在雄性素過高所引起之徵狀,如前列腺腫大、面皰及禿髮症之改善上。
Abstract The secretion of human sex hormones is regulated by the hypothalamic– pituitary– gonadal axis to maintain secondary sex characteristics, reproduction and some physiological functions. However, The sex endocrine system may be interfered by some life-styles and disease. It has been reported that many compounds of food may modulate the secretion or functions of sex hormones. These actions are generally recognized as safe or tardily effective. Therefore, it is potential to develop healthy food with regulatory effects for endocrine system. Adlay (Coix lachryma-jobi L.var. mayuen Stapf) has been used as food and medicine for a long time, and its regulatory effects on endocrine system has been confirmed. The objective of this study is to explore the effects of adlay on the production of androgen. In the in vitro system, testicular interstitial cells (TIC) and Leydig cells were employed. Methanolic extracts of adlay hull (AHM) inhibited the secretion of testosterone. After purification of liquid partition and column chromatography, we found that the major inhibitive activity of AHM came from the medium polar part of its ethyl acetate fraction. The inhibitive activity of these subfractions can’t be reversed by forskolin but 8-Br-cAMP. These subfractions also inhibited the testosterone release induced by progesterone and androstenedione, the precursors of testosterone biosynthesis. These results suggest that these subfractions acted through reducing the activity of adenylyl cyclase and biosynthesis enzymes of testosterone to inhibit testosterone production. By inhibiting androgen production, these compounds from adlay might be used for improvement of hypertrophy of the prostate, acne, baldness and other symptoms caused by hyperandrogenism.