半天筍為檳榔樹頂端的生長點，可做為食材，為台灣獨特的食用方式。但有關半天筍食用後的生理作用之研究並不多。已知單一大劑量灌食半天筍的丙酮萃取液後，雌性SD 大鼠的心跳明顯加快。而半天筍的醋酸及丙酮萃取液則均使雌性SD 大鼠的平均血壓明顯增加。由此結果可知，若短時間內攝取大量的半天筍可能會影響心跳及血壓。但若長時間食用少量的半天筍，對身體產生的影響如何？則不得而知。因此本研究欲評估半天筍的亞急毒性及基因毒性。以胃管餵食SD 大鼠，連續灌食不同劑量的半天筍萃取物28 天後，偵測其體重與心血管參數及生化值。動物體內的基因毒性則是以微核試驗進行分析，人體體外的基因毒性則是以彗星試驗進行分析。在亞急毒性方面，連續28 天灌食不同劑量的半天筍萃取液後，SD 大鼠之體重、心血管參數及大多數的生化值與對照組相比較，並無明顯差異。在基因毒性方面，連續灌食5 天的半天筍醋酸萃取液雖然稍微增加雄性ICR 小鼠微核的數目，但也不具差異性。而半天筍丙酮萃取液則造成人類白血球細胞彗星托尾長度增加的現象，但因個體白血球間的差異性過大，因此不具統計上的差異。由以上結果可知，半天筍對SD 大鼠及ICR 小鼠並不具亞急毒性及基因毒性，但對人類白血球細胞的影響，則需更進一步的研究。 The tender shoot is the terminal part of the young stem of Areca catechu, which is locally consumed as vegetables in Taiwan. There are a few of studies about the physiological effects after consumption of this edible part of Areca catechu. In a single high dose oral gavage, acetone tender shoot extracts increased the heart rate in female SD rats. Acetate and acetone tender shoot extracts also increased the mean blood pressure in female SD rats. These results suggest that ingestion of large amount of tender shoot may affect the heart rate and blood pressure. However, the physiological effects after ingestion of low amount of tender shoot for a long time have not been reported. The object of this study was to estimate the subacute toxicity and genotoxicity in animals and human leukocytes. The body weight, cardiovascular parameters and biomarkers were estimated when oral gavage the extracts with multiple doses for continued 28 days in SD rats. The genotoxicity of the extracts in mice were estimate by using a micronuclei test and in human leukocyte by using a Comet assay. In a continued 28 days treatment, there are not significant differences in body weight, heart rate, blood pressure and various biomarkers between control and tender shoot extracts treatment. In the genotoxicity, acetate and acetone tender shoot extracts did not induced significantly micronuclei in ICR mice. But acetone tender shoot extracts slightly increased the Olive tail moment in human leukocytes. These results suggest that there is no subacute toxicity and genotoxicity after ingestion of low amount of tender shoot in SD rats and in ICR mice. However, the effects of tender shoot in human leukocytes are needed further study
