Anti-platelet aggregation and plasma fibrinolysis-accelerating activities in oyster fungus (Pleurotus ostreatus)

平菇（Pleurotus ostreatus）对ADP、胶原蛋白和凝血酶引起的人血小板聚集具有较强的阻断活性（220 × 10^6/ml）。活性物质（命名为ASK-1）经曲霉/根霉酶在pH 4.5条件下处理24h后，可以很容易地用水提取。在100℃下加热停止反应5 min，膜过滤、冻干后，1.7 kg的香菇可得约27 g的暗黄色粉末。用人PRP和ADP计算的IC_<50>值约为11.6 ~ 27.1 mg/ml。通过口服给药，ASK-1对大鼠和人血液中血小板聚集均有较强的抑制作用。6名18 ~ 37岁的健康志愿者，以10 μ M ADP为诱导剂，给药500 mg/kg时，血小板聚集率由65±8%降至50±13%。而EFA和tPA测定的纤溶活性升高。通过酶谱联用纤维蛋白溶解加速物质（FAS），发现人细胞释放的活化纤维蛋白溶解酶为tPA型纤溶酶原激活剂，分子量约为70000。牡蛎菌具有较强的SOD和抗氧化活性。亚硝酸盐法测定的CU SOD活性为958±402 /g（干重），高于文献报道的纳豆。Celite 545柱浓缩后的提取物对2-脱氧核糖也具有抗氧化活性。在健康的人类志愿者摄入这种成分后，证明了对食欲和体重减轻的强烈抑制作用。

Oyster fungus (Pleurotus ostreatus) had strong activity for blocking of the aggregation of human platelets (220 × 10^6/ml) caused by ADP, collagen or thrombin. Active substance (named ASK-1) treated with Aspergillus/Rhizopus enzyme for 24 hrs at pH 4.5 could be easely extracted with water. After stopping the reaction by heating at 100 ℃ for 5 min, and then membrane filtering and lyophilizing, approximately 27 g of dark yellow powder were obtained from 1.7 kg mushroom. The IC_<50> value calculated with human PRP and ADP for the inducer was about 11.6-27.1 mg/ml.By oral administration, ASK-1 showed strong inhibition for platelet aggregation in blood of both rats and humans. When administerd 500 mg/kg body in 6 healthy volunteers of 18-37 years, the platelet aggregation was decreased from 65±8% to 50± 13% using 10 μ M ADP for the inducer. Whereas the fibrinolytic activity determined by EFA and tPA were increased. By using zymography coupled with fibrinolysis accelerating substance (FAS), the activated fibrinolytic enzyme released from human cell was found to be tPA type plasminogen activator with molecular weight of about 70,000.Oyster fungus had strong SOD and anti-oxidative activities. Values of 958±402 CU SOD activity/g (dry weight) determined by nitrite method was higher than that of Natto reported previously. The concentrated fraction using Celite 545 column had also anti-oxidative activity against 2-deoxylibose. After ingestion of this fraction in healthy human volunteers, both strong inhibitions for apetite and loss of weight were proved.