By-Products of Zea mays L.: A Promising Source of Medicinal Properties with Phytochemistry and Pharmacological Activities: A Comprehensive Review

Zea mays (Z. mays) is one of the main cereal crops in the world, and it′s by-products have exhibited medicinal properties to explore. This article intends to review the chemical compositions and pharmacological activities of by-products of Z. mays (corn silks, roots, bract, stems, bran, and leaves) which support the therapeutic potential in the treatment of different diseases, with emphasis on the natural occurring compounds and detailed pharmacological developments. Based on this review, 231 natural compounds are presented. Among them, flavonoids, terpenes, phenylpropanoids, and alkaloids are the most frequently reported. The by-products of Z. mays possess diuretic effects, hepatoprotective, anti-diabetic, antioxidant, neuroprotective, anti-inflammatory, anti-cancer, plant protection activity, and other activities. This article reviewed the phytochemistry and pharmacological activities of Z. mays for comprehensive quality control and the safety and effectiveness to enhance future application.     

On-line heat flux measurements improve the culture medium for the growth and productivity of genetically engineered CHO cells

With the increasingly competitive commercial production of target proteins by hybridoma and genetically engineered cells, there is an urgent requirement for biosensors to monitor and control on-line and in real time the growth of cultured cells. Since growth is accompanied by an enthalpy change, heat dissipation measured by calorimetry could act as an index for metabolic flow rate. Recombinant CHO cell suspensions producing interferon-γ were pumped to an on-line flow calorimeter. The results showed that an early reflection of metabolic change is size-specific heat flux obtained from dividing heat flow rate by the capacitance change of the cell suspension, using the on-line probe of a dielectric spectroscope. Comparison of heat flux with glucose and glutamine fluxes indicated that the former most accurately reflected decreased metabolic activity. Possibly this was due to accumulation of lactate and ammonia resulting from catabolic substrates being used as biosynthetic precursors. Thus, the heat flux probe is an ideal on-line biosensor for fed-batch culture. A stoichiometric growth reaction was formulated and data for material and heat fluxes incorporated into it. This showed that cell demand for glucose and glutamine was in the stoichiometric ratio of ∼3:1 rather than the ∼5:1 in the medium. It was demonstrated that the set of stoichiometric coefficients in the reaction were related through the extent of reaction (advancement) to overall metabolic activity (flux). The fact that this approach can be used for medium optimisation is the basis for an amino-acid-enriched medium which improved cell growth while decreasing catabolic fluxes. This revised version was published online in July 2006 with corrections to the Cover Date.     

高血压相关的线粒体DNA突变

线粒体DNA(mtDNA)突变是高血压发病的分子机制之一。已经报道的与原发性高血压相关的mtDNA突变包括:tRNAMet A4435G,tRNAMet/tRNAGln A4401G,tRNAIle A4263G,T4291C和A4295G突变。这些高血压相关的mtDNA突变改变了相应的线粒体tRNA的结构,导致线粒体tRNA的代谢障碍。而线粒体tRNAs的代谢缺陷则影响蛋白质合成,造成氧化磷酸化缺陷,降低ATP的合成,增加活性氧的产生。因此,线粒体的功能缺陷可能在高血压的发生发展中起一定的作用。mtDNA突变发病的组织特异性则可能与线粒体tRNAs的代谢以及核修饰基因相关。目前发现的这些高血压相关的mtDNA突变则应该作为今后高血压诊断的遗传风险因子。高血压相关的线粒体功能缺陷的深入研究也将进一步诠释母系遗传高血压的分子致病机制,为高血压的预防、控制和治疗提供依据。文章对高血压相关的mtDNA突变进行了综述。     

化学修饰提高胰岛素口服降血糖作用的研究

本文探索了用小分子化合物对胰岛素进行化学修饰,以增加口服降血糖的可能性.制备了乙酰胰岛素、琥珀酰胰岛素和半乳糖酰胰岛素.这些胰岛素不仅较好地保持了天然胰岛素的活性,而且其口服降血糖作用也较天然胰岛素明显增加,其中琥珀酰胰岛素是天然胰岛素的口服降血糖作用的二倍以上.这为口服或肛门给药的胰岛素新剂型的研制提供了科学依据.     

TMEM43-S358L mutation enhances NF-κBTGFβ signal cascade in arrhythmogenic right ventricular dysplasia/cardiomyopathy

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is a genetic cardiac muscle disease that accounts for approximately 30% sudden cardiac death in young adults. The Ser358Leu mutation of transmembrane protein 43 (TMEM43) was commonly identified in the patients of highly lethal and fully penetrant ARVD subtype, ARVD5. Here, we generated TMEM43 S358L mouse to explore the underlying mechanism. This mouse strain showed the classic pathologies of ARVD patients, including structural abnormalities and cardiac fibrofatty. TMEM43 S358L mutation led to hyper-activated nuclear factor κB (NF-κB) activation in heart tissues and primary cardiomyocyte cells. Importantly, this hyper activation of NF-κB directly drove the expression of pro-fibrotic gene, transforming growth factor beta (TGFβ1), and enhanced downstream signal, indicating that TMEM43 S358L mutation up-regulates NF-κB-TGFβ signal cascade during ARVD cardiac fibrosis. Our study partially reveals the regulatory mechanism of ARVD development.     

TGF-β超家族在软骨发生、发育和维持中的作用

转化生长因子b(Transforming growth factor b, TGF-b)超家族包括TGF-b和骨形态发生蛋白(Bone morphogenetic protein,BMP)两个亚家族。TGF-b超家族信号通路的配体、配体拮抗分子、受体、信号转导分子均在软骨内成骨过程中发挥各自独特的作用, 参与调控软骨细胞的谱系分化、增殖、成熟、凋亡和矿化。BMP信号能起始间充质细胞向软骨细胞分化并维持软骨细胞的特性, 在软骨发生过程中起主导作用; 在生长板发育的过程中, BMP信号促进软骨细胞的成熟, 促进成骨, 而TGF-b信号抑制软骨细胞的肥大分化, 维持生长板中适量的软骨细胞; TGF-b信号和BMP信号对于关节软骨的维持和修复都是不可或缺的。因此, TGF-b超家族的重要作用贯穿骨骼发育过程的始终。     

Molecular phylogenetics of Triculine snails (Gastropoda: Pomatiopsidae) from southern China

Triculine (Gastropoda: Rissooidea: Pomatiopsidae) snails are involved in the transmission of schistosomiasis and paragonimiasis; their distributions are mainly across southeastern Asia and southern China. In the present investigation, partial sequences of COI, 16S, and 28S were examined to infer the phylogenetic relationships among the species rich and poorly understood gastropod. Samples were collected from 12 geographic locations in six provinces of southern China. Several methods such as maximum parsimony, maximum likelihood and distance analysis were used in phylogenetic analyses among these taxa. The resultant phylogenetic trees showed a similar topology irrespective of the phylogenetic methods used. The taxa fell into two clades, with those from Fujian, Guangxi, and Zhejiang Provinces in one clade and those from Hunan, Sichuan and Hubei in the other. Among the taxa in Hubei Province, five formed a monophyletic clade, but Tricula sp. H-SHY fell into a sister clade of Tricula hortensis of Sichuan, whilst Tricula hongshanensis formed a single clade. Sister taxa Tricula pingi and Tricula hsiangi formed well-supported clade within almost all the trees. These results, while preliminary, represent the first attempt to reconstruct a phylogeny for Triculinae across China.