灵芪胶囊对H22荷瘤小鼠p53和bcl-2蛋白表达的影响

目的：探讨灵芪胶囊对H22荷瘤小鼠的抑瘤作用及其抑瘤作用机制。方法：采用体内实验法,于无菌条件下抽取传代7d、生长良好的H22荷瘤小鼠腹水,无菌0．9％氯化钠溶液1：3稀释（约含瘤细胞2×10^6／ml）,按0．2ml／7,接种于消毒后的小鼠右前肢腋部皮下,制成肿瘤模型,灌胃给药灵芪胶囊11d后,称取小鼠体重,脱椎处死小鼠,取脾脏及胸腺称重并计算胸腺指数和脾脏指数。用免疫组化法检测各组凋亡相关基因突变型p53和bcl-2基因的表达。结果：灵芪胶囊在明显抑制肿瘤生长的同时不降低体重,在一定剂量对荷瘤动物的免疫器官指数无明显影响;灵芪胶囊三个剂量组突变型p53基因和bcl-2基N的表达均低于模型组。结论：灵芪胶囊对H22荷瘤小鼠有明显抑瘤作用,其机制可能与抑制突变型p53基N和bcl-2基因表达有关。     

Anisomycin induces glioma cell death via down-regulation of PP2A catalytic subunit in vitro

Aim:

To examine the effects of anisomycin on glioma cells and the related mechanisms in vitro.

Methods:

The U251 and U87 human glioblastoma cell lines were tested. The growth of the cells was analyzed using a CCK-8 cell viability assay. Apoptosis was detected using a flow cytometry assay. The expression of proteins and phosphorylated kinases was detected using Western blotting.

Results:

Treatment of U251 and U87 cells with anisomycin (0.01–8 μmol/L) inhibited the cell growth in time- and concentration-dependent manners (the IC₅₀ values at 48 h were 0.233±0.021 and 0.192±0.018 μmol/L, respectively). Anisomycin (4 μmol/L) caused 21.5%±2.2% and 25.3%±3.1% of apoptosis proportion, respectively, in U251 and U87 cells. In the two cell lines, anisomycin (4 μmol/L) activated p38 MAPK and JNK, and inactivated ERK1/2. However, neither the p38 MAPK inhibitor SB203580 (10 μmol/L) nor the JNK inhibitor SP600125 (10 μmol/L) prevented anisomycin-induced cell death. On the other hand, anisomycin (4 μmol/L) reduced the level of PP2A/C subunit (catalytic subunit) in a time-dependent manner in the two cell lines. Treatment of the two cell lines with the PP2A inhibitor okadaic acid (100 nmol/L) caused marked cell death.

Conclusion:

Anisomycin induces glioma cell death via down-regulation of PP2A catalytic subunit. The regulation of PP2A/C exression by anisomycin provides a clue to further study on its role in glioma therapy.     

3-芳基/芳氧甲基-6-芳基-1,2,4-三唑并［3,4-b］-1,3,4-噻二唑衍生物的合成及生物活性

噻二唑类杂环化合物有广泛的生物活性,如消炎、驱虫、除草、调节植物生长、防止水稻白叶枯病、柑桔溃疡病、蕃茄青枯病等［１～３］。而１,２,４三唑类杂环化合物也有相当广泛的生物活性,如抗菌、抗痉挛、消炎、抗血小板凝聚及调节植物生长等［４～６］。如果合成既...     

Fate and distribution of brevetoxin (PbTx) following lysis of Karenia brevis by algicidal bacteria, including analysis of open A-ring derivatives

Flavobacteriaceae (strain S03) and Cytophaga sp. (strain 41-DBG2) are algicidal bacteria active against the brevetoxin (PbTx)-producing, red tide dinoflagellate, Karenia brevis. Little is known about the fate of PbTx associated with K. brevis cells following attack by such bacteria. The fate and distribution of PbTx in K. brevis cultures exposed to these algicidal strains were thus examined by receptor binding assay and liquid chromatography/mass spectrometry (LC/MS) in three size fractions (>5, 0.22–5, <0.22 μm) over a 2-week time course. In control cultures, brevetoxin concentrations in the >5 μm particulate size fraction correlated with changes in cell density, whereas significant increases in dissolved (i.e., <0.22 μm) toxin were observed in the later stages of culture growth. Exposure of K. brevis to either of the two algicidal bacteria tested caused cell lysis, coinciding with a rapid decline in the >5 μm PbTX size fraction and a simultaneous release of dissolved toxin into the growth medium. Upon cell lysis, dissolved brevetoxin accounted for ca. 60% of total toxin and consisted of 51–82% open A-ring derivatives. Open A-ring PbTx-2 and PbTx-3 derivatives bound with lower affinity (approximately 22- and 57-fold, respectively) to voltage-gated sodium channels and were considerably less cytotoxic (86- and 142-fold, respectively) to N2A cells than their individual parent toxins (i.e., PbTx-2 and PbTx-3). These novel findings of changes in PbTx size-fractioned distribution and overall reduction in K. brevis toxicity following attack by algicidal bacteria improve our understanding of potential trophic transfer routes and the fate of PbTx during red tide events. Moreover, this information will be important to consider when evaluating the potential role of algicidal bacteria in harmful algal bloom (HAB) management strategies involving control of bloom populations.     

The latest review on the polyphenols and their bioactivities of Chinese Morus plants

The mulberry tree (Morus alba) plays a key role in agriculture, and its different parts have been used as popular Traditional Chinese Medicines for thousands of years. There are 16 species belonging to the Morus genus. Among them, 11 species distribute in China, most of which have been used as the substitutes of M. alba in local provinces. This review summarizes the structural characters of polyphenols, the main components in Morus, including Diels–Alder-type adducts, flavonoids, 2-arylbenzofurans, and stilbenes, and also their related bioactivities in the last 10 years.     

选择性保护合成2-〔4(S)-4-酰氨基-3-氧代-2-异噁唑烷基〕-5-氧代-2-四氢呋喃甲酸类化合物及其体外抑菌活性

采用两种新选择性保护方法由L-丝氨酸和α-酮戊二酸为原料经几步合成了8个目标化合物。体外抑菌该验表明除TMV外,对金葡球菌209P和大肠杆菌44822具有中等到强的活性。     

VEGF、COX-2在复发性鼻息肉中的表达及意义

目的探讨环氧化酶2（COX-2）和血管内皮生长因子（VEGF）在复发性鼻息肉中的表达及其临床意义。方法应用免疫组化Envision法检测VEGF和COX-2在复发性鼻息肉、初发鼻息肉和正常鼻黏膜中的表达。结果（1）COX-2在复发性鼻息肉、初发鼻息肉中的表达较正常鼻黏膜组明显增强,差异有显著意义（P〈0．05）;COX-2在复发性鼻息肉中的表达比在初发鼻息肉中的表达要强,两组间比较差异有显著意义（P〈0．05）。（2）VEGF在复发性鼻息肉、初发鼻息肉中的表达较正常鼻黏膜组明显增强,差异有显著意义（P〈0．05）,VEGF在复发性鼻息肉和初发鼻息肉中的表达差异有显著意义（P〈0．05）。（3）VEGF COX-2和在鼻息肉中的表达呈正相关（P〈0．05,r=0．895）。结论VEGF和COX-2是参与调控血管生成最重要的血管生长因子,提示它们可能在鼻息肉的发生、发展和复发过程中发挥重要作用。