Conjugated fatty acids in food and their health benefits

Conjugated fatty acids (CFAs) are a mixture of positional and geometric isomers of polyunsaturated fatty acids with conjugated double bonds. Reports indicate that CFAs have potent beneficial effects, including antitumor, antiobese, antiatherogenic and antidiabetic activities. The molecules have also been shown to prevent the onset of hypertension. Recent reports suggest that each CFA isomer has different functions, for example the 10trans,12cis isomer of conjugated linoleic acid (CLA) has anticarcinogenic, antiobese and antidiabetic effects, whereas the 9cis,11trans-CLA isomer exerts an anticancer effect. Although it would be interesting to know the effects of CFAs on humans, there are only few reports concerning the anticancer and antiobese effects of CLA in humans. More detailed evaluations of the physiological bioactivities of CFA isomers on lifestyle-related diseases in humans and animals will be of great interest in future studies.     

白毛藤多糖对宫颈癌细胞系体外增殖的影响及机制研究

探讨白毛藤多糖对宫颈癌细胞系SiHa细胞体外增殖的影响及机制。将不同浓度白毛藤多糖作用SiHa细胞后,用MTT法检测细胞增殖抑制率,用流式细胞仪分析细胞周期各时相的变化。白毛藤多糖能抑制宫颈癌细胞的体外增殖,其机制可能与细胞周期阻滞有关。     

Isoflavone content and apoptotic effect in HT-29 cancer cells of a soy germ extract

Colon cancer is one of the leading causes of death and a major public health problem in western countries. We examined the isoflavone content of 70% ethanol extract of soy germ (SG) and its apoptotic effect in HT-29 colon cancer cells. Our results showed that the major isoflavones of the SG extract were daidzein and genistein, and it effectively induced apoptosis in HT-29 cancer cells. In addition, nuclear factor-kappa B (NF-κB) expression was reduced in cells treated with the SG extract, which reduced cyclooxygenase-2 (COX-2) and nitric oxide synthase (iNOS) expression. These combined effects ultimately resulted in apoptosis via caspase-3 activation. In addition, daidzein and genistein, the major isoflavones of SG extract, also exerted the apoptotic effect against HT-29 cancer cells. These results suggest that the inhibition of NF-κB expression is the most important factor in the induction of apoptosis in HT-29 cells treated with the SG extract.     

Some natural flavonoids are competitive inhibitors of Caspase-1, -3 and -7 despite their cellular toxicity

A common feature of both apoptosis and inflammation is the activation of caspases. Caspases are aspartate-directed cysteine proteases that have numerous cellular targets. It has been discovered that several flavonoids are inhibitors of caspases. Flavonoids are members of a family of polyphenolic compounds from plants that have many biological properties, one of which is the ability to induce cell death. Some flavonoids are selective inhibitors of particular caspases. Since some of the inhibitory flavonoids are nevertheless cytotoxic, these results suggest that flavonoid-induced cell death may be occurring through a non-classical apoptosis pathway that is not dependent on caspase activity.     

草苁蓉提取物抑制肺癌细胞增殖分子机制的研究

草苁蓉提取物可通过促进肿瘤细胞凋亡抑制A549肺癌细胞增殖。继续探讨草苁蓉提取物(BRE)抑制肺癌细胞增殖的分子机制。采用流式细胞术检测A549细胞周期分布和细胞凋亡,免疫细胞化学法检测凋亡相关蛋白Bax、Bc1-2、P53和Fas蛋白的表达,ELISA法检测sFAS蛋白的表达。结果表明,BRE改变肺癌细胞周期分布,使多数细胞阻滞于G0/G1期。同时,BRE诱导肺癌细胞凋亡,明显增加Fas表达,增加Bax表达和降低Bc1-2表达,但不改变P53表达以及sFas蛋白水平。提示,BRE抗肺癌细胞增殖作用与其改变细胞周期分布、增高Fas表达和降低Bcl-2/Bax比值而诱导肺癌细胞凋亡相关。     

非病毒基因载体在肺癌基因治疗中的应用

对近年采用非病毒载体(裸DNA、阳离子聚合物、阳离子脂质体)治疗肺癌的基本原理和研究进展作一综述。此法有望成为治疗肺癌的新方案。     

Anti‐proliferative activity of bovine blood hydrolysates towards cancer cells in culture

Four proteins, α/β globulin, serum albumin, γ‐globulin and fibrinogen, were isolated from bovine blood and hydrolysed using papain. Hydrolysates were assessed for non‐cellular and cellular antioxidant activity. The anti‐proliferative activity of hydrolysed fractions was assessed in a number of cancer cell lines including U937 lymphoma cells, MCF‐7 breast cancer cells, HepG2 hepatocytes and Caco‐2 epithelial colorectal adenocarcinoma cells. Anti‐inflammatory activity of the hydrolysates was also assessed. Hydrolysates generated from γ‐globulin or fibrinogen had significant antioxidant activity in non‐cellular assays. Hydrolysates were also found to be highly toxic to different cancer cell lines, in particular U937 lymphoma cells when assessed using the MTT assay. The fibrinogen hydrolysate was the most toxic sample and toxicity appeared to correlate with its non‐cellular antioxidant activity. None of the hydrolysates had significant anti‐inflammatory activity. The high cytotoxicity of the γ‐globulin and the fibrinogen hydrolysates towards cancer cells may indicate a potential use as anti‐proliferative agents.     

根据毛发中微量元素含量用多变量统计分类技术进行肝癌辅助诊断

根据毛发中微量元素的含量,应用逐步判别分析、主成分分析和逐步聚类分析等多变量统计分类技术,进行了肝癌辅助诊断的研究。所得结果令人满意,特别显示了用统计方法筛选出的几种元素在区分是否肝癌上起着显著作用。     

N‐Arylsulfonyl Indolines as Retinoic Acid Receptor‐Related Orphan Receptor γ (RORγ) Agonists

The nuclear retinoic acid receptor‐related orphan receptor γ (RORγ; NR1F3) is a key regulator of inflammatory gene programs involved in T helper 17 (T_H17) cell proliferation. As such, synthetic small‐molecule repressors (inverse agonists) targeting RORγ have been extensively studied for their potential as therapeutic agents for various autoimmune diseases. Alternatively, enhancing T_H17 cell proliferation through activation (agonism) of RORγ may boost an immune response, thereby offering a potentially new approach in cancer immunotherapy. Herein we describe the development of N‐arylsulfonyl indolines as RORγ agonists. Structure–activity studies reveal a critical linker region in these molecules as the major determinant for agonism. Hydrogen/deuterium exchange coupled to mass spectrometry (HDX‐MS) analysis of RORγ–ligand complexes help rationalize the observed results.     

Accumulation and Toxicity of Superparamagnetic Iron Oxide Nanoparticles in Cells and Experimental Animals

The uptake and distribution of negatively charged superparamagnetic iron oxide (Fe₃O₄) nanoparticles (SPIONs) in mouse embryonic fibroblasts NIH3T3, and magnetic resonance imaging (MRI) signal influenced by SPIONs injected into experimental animals, were visualized and investigated. Cellular uptake and distribution of the SPIONs in NIH3T3 after staining with Prussian Blue were investigated by a bright-field microscope equipped with digital color camera. SPIONs were localized in vesicles, mostly placed near the nucleus. Toxicity of SPION nanoparticles tested with cell viability assay (XTT) was estimated. The viability of NIH3T3 cells remains approximately 95% within 3–24 h of incubation, and only a slight decrease of viability was observed after 48 h of incubation. MRI studies on Wistar rats using a clinical 1.5 T MRI scanner were showing that SPIONs give a negative contrast in the MRI. The dynamic MRI measurements of the SPION clearance from the injection site shows that SPIONs slowly disappear from injection sites and only a low concentration of nanoparticles was completely eliminated within three weeks. No functionalized SPIONs accumulate in cells by endocytic mechanism, none accumulate in the nucleus, and none are toxic at a desirable concentration. Therefore, they could be used as a dual imaging agent: as contrast agents for MRI and for traditional optical biopsy by using Prussian Blue staining.