巴西洋菇對人類白血病U937細胞生長抑制機制及對Balb/c鼠尾靜脈注射CT26細胞之腫瘤轉移抑制效果

Abstract

巴西洋菇具有增強免疫力、抗腫瘤、抗氧化、抗病毒、抗致突變等功用。在此研究中分成細胞與動物兩部分進行實驗。在細胞實驗中，利用4℃冷水粗萃物、50℃水粗萃物、沸水粗萃物、4℃冷水粗萃酒精沉澱物與沸水粗萃酒精沉澱物對人類白血病U937細胞株進行抑制及誘導分化之作用，並探討巴西洋菇對U937細胞週期蛋白控調機制。由實驗結果顯示，沸水粗萃酒精沉澱物具有較高的直接生長抑制效果，在濃度400μg /mL的生長抑制率可達78%，再由流式細胞儀測得巴西洋菇沸水粗萃酒精沉澱物於濃度400μm/mL作用五天時，可使U937細胞週期停滯於G2/M期，但無凋亡之現象產生。 在動物實驗中，於Balb/c雄鼠尾部靜脈注射鼠大腸癌 (CT26) 細胞株，建立腫瘤轉移肺臟之模式，並餵食不同劑量之巴西洋菇沸水粗萃酒精沉澱物，探討巴西洋菇對抗腫瘤轉移之效果。結果顯示，控制組腫瘤轉移肺臟上之群落個數，於每隻小鼠兩葉肺臟有121個小結節；依小鼠每公斤體重給予200、400與600 mg/kg bw/day劑量之組別，其腫瘤轉移肺臟上之群落個數，於每隻小鼠兩葉肺臟分別有36、36、55個小結節，均能有效抑制腫瘤轉移肺臟 (p<0.05)。於顯微鏡下觀察肺臟及腎臟病理組織切片，於肺臟組織切片圖可以明顯看到腫瘤轉移後肺臟細胞間質增厚使肺臟組織產生病變；由腎臟組織切片圖顯示巴西洋菇沸水粗萃酒精沉澱物在此3組劑量下對小鼠腎臟細胞不具有毒性。

Abstract Agaricus blazei (AB) is a dietary mushrooms and known for its immunoenhancing, antitumor, antioxidation, antiviral, and anti- mutagenesis actions. In the present study, furiting body of AB was used to investigate the immunoenhancing and antitumor activities in vitro and in vivo. First, 4℃ cold-water extracts, boiled-water extracts, and ethanol (75%) precipitates of both cold- and boiled-water extracts from AB were incubated with human leukemic U937 cells to observe the changes in growth inhibition (%) and differentiation-inducing effect by conditioned medium (CM) method or co-cultivation method, followed by the cell cycle arrest test by a flow cytometry. Results showed that remarkable growth inhibition (about 78 %) was observed when U937 cells were incubated with 400 mg/mL of ethanol precipitates of boiled-water extracts from AB, while cell cycle of U937 cells were arrested at G0/G1 phase when were incubated for 5 days with ethanol precipitates of boiled-water extracts from AB without apoptosis occurrence (< 0.2 %). On the other hand, in vivo, male Balb/c mice, orally administrated with different amounts (200~600 mg/kg/day) of ethanol precipitates of boiled-water extracts from AB, were injected with 2 × 105 CT26 (colon tumor) cells intraveneously via a tail vein to establish pulmonary metastases and then sacrificed after 12 days of inoculation. Metastatic lung nodules in control group were counted to be 121/mouse and experimental group fed with 200, 400, and 600 mg/kg/day were counted to show 36/mouse, 36/mouse, and 55/mouse, respectively, revealing significantly (p < 0.05) the anti-metastatic effect of AB. Histopathologic results in lungs was also consistent with the finding in vivo. Insignificant changes in renal functions and immunohistograph were observed in mice fed with Agaricus blazei at those three dosages.