台灣全年處於高溫多濕的典型海島型氣候，提供了黴菌生長繁衍及產生毒素的絕佳環境。在經濟動物的飼糧中，玉米與大豆為主要原料，在發霉的玉米中，鐮刀型黴菌屬所產生玉米赤黴烯酮(Zearalenone，ZEA)，是一種非固醇類的雌激素黴菌毒素，容易對經濟動物的生長、免疫及繁殖性能產生嚴重影響。另外，大豆中含有大豆異黃酮(Soybean isoflavone，ISO)，為黃酮類化合物，會引起抗氧化與雌激素效應。本研究利用具有雌激素受體細胞Michigan Cancer Foundation-7(MCF-7)來檢測動物飼糧中可能存在之ZEA及其與ISO 之交互作用，並利用家禽濾泡之粒性細胞(Granulosa cell)與MCF-7 作比較，藉由分析濾泡細胞之類固醇合成酵素及相關蛋白質 (StAR protein、P450scc、3β-HSD) 之基因表現，探討其對類固醇合成路徑之影響，進而建立家禽濾泡細胞平台之評估能力。研究結果顯示，ZEA (10-8-10-3μM)對MCF-7 細胞活性皆有抑制作用，但呈非線性的U 型趨勢，即最低及高的的濃度細胞抑制較小。在ZEA 與ISO 的交互作用下，對MCF-7 有更大的抑制效果，且仍然呈現U 型的趨勢。ZEA 對於Granulosa cell 的細胞活性作用趨勢與MCF-7 類似。而Granulosa cell 經ZEA 的刺激後，孕酮(Progesterone，P4)之分泌量無顯著影響，但卻抑制類固醇合成酵素基因的表達量，顯示類固醇合成相關酵素之活性可能有提高而ZEA 與ERα 之親和力亦有提高之可能。本研究已初步建立ZEA 檢測之平台，然其應用性尚待加強。
The weather in Taiwan is hot and humid all year round, therefore is suitable for fungal growth. Maize and soybean are the main feed stuffs used in animal diets, and zearalenone, a non-steroidal estrogenic mycotoxin, if produced by Fusarium, would have an impact on growth, immunity and reproductive performance to the animals. Soybean isoflavones (ISO) is a subgroup of flavonoids found in soybean. ISO elicits antioxidant and estrogenic effects on animals. In this study, Michigan Cancer Foundation-7 (MCF-7), known to have estrogen receptor (ERα), was used to evaluate ZEA activity and the interaction of ZEA and ISO. Avian granulosa cells were also used to compare with MCF-7 for the ZEA activity by analyzing the gene expression of the steroidogenic enzymes and the StAR protein. The results showed that the growth of MCF-7 was inhibition by ZEA in a U-type non-linear doseresponse (10-8-10-3μM) manner. The interaction effect of ZEA and ISO to the MCF-7 cell exhibited the same manner. The similar cytotoxic effect was also observed in the avian granulosa cell. The progesterone (P4) secretion in avian granulosa cell was not affected by ZEA, although the gene expression of steroidogenic enzymes was slightly inhibited by ZEA, so was the ERα. It is speculated that the enzyme activities and the affinity of the ERα might have been up regulated. We have established a platform of using cell line and /or avian granulosa cells to detect the ZEA in animal diets, further study is needed to refine the system.
