Apoptosis of human gastric carcinoma cells induced by Euphorbia esula latex

AIM: To investigate the effect of Euphorbia esula(E. esula) extract in inhibiting proliferation and inducing apoptosis in SGC-7901 cells.METHODS: E. esula extract at different concentrations was used to inhibit proliferation and induce apoptosis of human gastric carcinoma SGC-7901 cells. Inhibition of proliferation was detected with thiazolyl blue assay, and apoptosis was detected with fluorescence microscopy, transmission electron microscopy, and flow cytometry. The mechanisms were studied by measurement of caspase-3 and caspase-8 activities and Bax and Bcl2 m RNA expression.RESULTS: The thiazolyl blue assay showed that SGC-7901 cell viability and proliferation were inhibited significantly by E. esula extract in a timeand concentration-dependent manner. Fluorescence microscopy revealed that the cell nuclei showed the characteristic changes of apoptosis, such as uneven staining and chromatin marginalization. Some key features of apoptosis were also observed undertransmission electron microscopy, which included cellular shrinkage and the foaming or bubbling phenomenon. When the cells were analyzed by flow cytometry, a sub-G1 peak could be seen clearly. Spectrophotometric assay of caspase-3 and caspase-8 activities in the treated cells showed an approximately two-fold increase. Reverse transcriptase polymerase chain reaction showed that Bax m RNA expression was upregulated, while Bcl2 m RNA expression was downregulated.CONCLUSION: E. esula extract inhibited proliferation and induced apoptosis in SGC-7901 cells, in a caspasedependent manner, involving upregulation of Bax and downregulation of Bcl2.

乳浆大戟植物杀虫水乳剂对枸杞蚜虫的毒力测定及田间防效

[目的]评价新型植物源农药乳浆大戟植物杀虫水乳剂对枸杞蚜虫的室内杀虫活性和田间防治效果。[方法]分别采用浸叶法和常规喷雾法进行室内毒力测定和田间药效试验。[结果]乳浆大戟植物杀虫水乳剂对枸杞蚜虫24h的LC50值为0.3977mg/L;在剂量为3000、6000ga.i./hm2时,药后1、3、5、7d,防效分别超过了72.0177%、59.953 9%、61.934 3%、65.016 1%。[结论]乳浆大戟植物杀虫水乳剂对枸杞蚜虫表现出很高的毒杀活性和良好的田间防治效果,且对作物和天敌安全。

乳浆大戟提取物的杀虫抑菌活性研究

生物农药开发前景广阔,乳浆大戟作为一种中草药,分布广、资源丰富,可利用其自身的毒性开发生物农药。以75%乙醇加热萃取法提取乳浆大戟中的活性成分,进行了杀虫抑菌生物活性试验,为乳浆大戟开发为新型生物农药提供科学依据。试验结果表明:提取物对果蝇及桃蚜具有良好的毒杀活性,提取物对果蝇的半致死量LC50为75.51 mg/m L,果蝇死亡率与提取物浓度呈正相关,对桃蚜毒性的半致死量LC50为9.35mg/m L,当提取物浓度为50 mg/m L时对桃蚜的校正死亡率为85.59%;提取物对大肠杆菌、金黄色葡萄球菌以及枯草芽孢杆菌均有一定的抑菌作用,其中对枯草芽孢杆菌抑制作用较强,最大抑菌圈直径为1.53 cm;25mg/m L的提取物对玉米大斑病菌落扩展有明显抑制作用,抑菌率45.28%,对盆栽玉米苗大斑病的防治效果为36.63%。