In vivo antitumour activity of amphiphilic silicon(IV) phthalocyanine with axially ligated rhodamine B

We explore the possible cellular cytotoxic activity of an amphiphilic silicon(IV) phthalocyanine with axially ligated rhodamine B under ambient light experimental environment as well as its in vivo antitumour potential using Hep3B hepatoma cell model. After loading into the Hep3B hepatoma cells, induction of cellular cytotoxicity and cell cycle arrest were detected. Strong growth inhibition of tumour xenograft together with significant tumour necrosis and limited toxicological effects exerted on the nude mice could be identified.     

The Role of Physical Activity in Harm Reduction among Betel Quid Chewers from a Prospective Cohort of 419,378 Individuals

ObjectiveTo assess the benefits of regular exercise in reducing harms associated with betel quid (BQ) chewing.MethodsThe study cohort, 419,378 individuals, participated in a medical screening program between 1994 and 2008, with 38,324 male and 1,495 female chewers, who consumed 5–15 quids of BQ a day. Physical activity of each individual, based on “MET-hour/week”, was classified as “inactive” or “active”, where activity started from a daily 15 minutes/day or more of brisk walking (≥3.75 MET-hour/week). Hazard ratios for mortality and remaining years in life expectancy were calculated.ResultsNearly one fifth (18.7%) of men, but only 0.7% of women were chewers. Chewers had a 10-fold increase in oral cancer risk; and a 2-3-fold increase in mortality from lung, esophagus and liver cancer, cardiovascular disease, and diabetes, with doubling of all-cause mortality. More than half of chewers were physically inactive (59%). Physical activity was beneficial for chewers, with a reduction of all-cause mortality by 19%. Inactive chewers had their lifespan shortened by 6.3 years, compared to non-chewers, but being active, chewers improved their health by gaining 2.5 years. The improvement, however, fell short of offsetting the harms from chewing.ConclusionsChewers had serious health consequences, but being physically active, chewers could mitigate some of these adverse effects, and extend life expectancy by 2.5 years and reduce mortality by one fifth. Encouraging exercise, in addition to quitting chewing, remains the best advice for 1.5 million chewers in Taiwan.     

Alpha-glucosidase inhibitory and antiplasmodial properties of terpenoids from the leaves of Buddleja saligna Willd

In our continuing search for biologically active natural product(s) of plant origin, Buddleja saligna, a South African medicinal plant, was screened in line with its traditional use for antidiabetic (yeast alpha glucosidase inhibitory) and antiplasmodial (against a chloroquine sensitive strain of Plasmodium falciparum (NF54)) activities. The hexane fraction showed the most promising activity with regards to its antidiabetic (IC₅₀?=?260?±?0.112?µg/ml) and antiplasmodial (IC₅₀?=?8.5?±?1.6?µg/ml) activities. Using activity guided fractionation three known terpenoids (betulonic acid, betulone and spinasterol) were isolated from this species for the first time. The compounds displayed varying levels of biological activities (antidiabetic: 27.31?µg/ml?≥?IC₅₀?≥?5.6?µg/ml; antiplasmodial: 14?µg/ml?≥?IC₅₀?≥?2?µg/ml) with very minimal toxicity.     

A Desolvated Solid–Solid Interface for a High‐Capacitance Electric Double Layer

Understanding the electric double layer is essential for achieving efficient electrochemical energy storage technologies. A conventional solid–liquid electrode interface suffers from serious self‐discharge and a narrow voltage window, which makes the development of a solid–solid interface imperative. However, an in‐depth understanding of the electric double layer with a solid–solid interface is lacking. Here, a solid–solid interfacial electric double layer is proposed with excellent electrochemical performance. The solid layer is constructed by the electrochemical decomposition of lithium difluoro(oxalate)borate, which provides a desolvated environment for the establishment of a electric double layer. This makes a stronger interaction between the electrode surface and the ions. Based on this unique property, it is found that the solid–solid interfacial electric double layer has an increased capacitance, which suggests a way to develop high‐energy electrochemical capacitors.     

Medium optimization for the production of recombinant nattokinase by Bacillus subtilis using response surface methodology

Nattokinase is a potent fibrinolytic enzyme with the potential for fighting cardiovascular diseases. Most recently, a new Bacillus subtilis/Escherichia coli (B. subtilis/E. coli) shuttle vector has been developed to achieve stable production of recombinant nattokinase in B. subtilis (Chen; et al. 2007, 23, 808-813). With this developed B. subtilis strain, the design of an optimum but cost-effective medium for high-level production of recombinant nattokinase was attempted by using response surface methodology. On the basis of the Plackett-Burman design, three critical medium components were selected. Subsequently, the optimum combination of selected factors was investigated by the Box-Behnken design. As a result, it gave the predicted maximum production of recombinant nattokinase with 71 500 CU/mL for shake-flask cultures when the concentrations of soybean hydrolysate, potassium phosphate, and calcium chloride in medium were at 6.100, 0.415, and 0.015%, respectively. This was further verified by a duplicated experiment. Moreover, the production scheme based on the optimum medium was scaled up in a fermenter. The batch fermentation of 3 L was carried out by controlling the condition at 37 degrees C and dissolved oxygen reaching 20% of air saturation level while the fermentation pH was initially set at 8.5. Without the need for controlling the broth pH, recombinant nattokinase production with a yield of 77 400 CU/mL (corresponding to 560 mg/L) could be obtained in the culture broth within 24 h. In particular, the recombinant B. subtilis strain was found fully stable at the end of fermentation when grown on the optimum medium. Overall, it indicates the success of this experimental design approach in formulating a simple and cost-effective medium, which provides the developed strain with sufficient nutrient supplements for stable and high-level production of recombinant nattokinase in a fermenter.     

银耳深层发酵浸膏多糖抗氧化活性的研究

对银耳液体深层发酵多糖浸膏进行乙醇分级,得到乙醇终浓度为35%,50%,65%的3个多糖组分,即TF1,TF2,TF3。对其抗氧化活性进行了比较研究,结果表明:TF3的抗氧化活性最强,对超氧阴离子的清除率为16.9%,对羟基自由基的清除率为23.6%。     

Radiation modulating properties of derivates of 1,4-dihydropyridine and 1,2,3,4,5,6,7,8,9,10-decahydroacridine-1,8 dione

First attempt to analyse radiation modifying action of 52 compounds--derivatives of 1,4-dihydropyridine is presented. Many of these compounds have electrodonating and antioxidative activities. Local radioprotective effects of the substances has been studied using experimental model with partial beta- and X-rays exposure of sole skin in rats to doses of 40 and 30 Gy. Comparison of drug effectiveness and chemical structure revealed the changes of activity dependence due to modification of peripheral radicals of 1,4-dihydropyridine ring. Radioprotective and radiosensitizing compounds with general low toxicity have been found. It is suggested to use the most active compounds for the development of medicinal forms for prevention of local skin and mucosal radiation injuries. Positive results have been obtained with dieton a radioprotective compound of the same type, in radiotherapy.     

An engineered PrPsc-like molecule from the chimera of mammalian prion protein and yeast Ure2p prion-inducing domain

Production of the pathogenic prion isoform PrP^sc-like molecules is thought to be useful forunderstanding the mysterious mechanism of conformational conversion process of prion diseases andproving the “protein-only“ hypothesis. In this report, an engineered PrP^sc-like conformation was producedfrom a chimera of mammalian bovine prion protein (bPrP) and yeast Ure2p prion-inducing domain (UPrD).Compared with the normal form of bPrP, the engineered recombinant protein, termed bPrP-UPrD,spontaneously aggregated into ordered fibrils under physiological condition, displaying amyloid-likecharacteristics, such as fibrillar morphology, birefringence upon binding to Congo red and increasedfluorescence intensity with Thioflavine T. Limited resistance to protease K digestion and CD spectroscopyexperiments suggested that the structure of bPrP-UPrD had been changed, and adopted a new, high contentB-sheet conformation during the fibrils formation. Moreover, bPrP-UPrD amyloid fibrils could recruit moresoluble forms into the aggregates. Therefore, the engineered molecules could mimic significant behaviors of PrP^se and will be helpful for further understanding the mechanism of conformational conversion process.     

Neither lipophilicity nor membrane-perturbing potency of phenothiazine maleates correlate with the ability to inhibit P-glycoprotein transport activity

Although phenothiazines are known as multidrug resistance modifiers, the molecular mechanism of their activity remains unclear. Since phenothiazine molecules are amphiphilic, the interactions with membrane lipids may be related, at least partially, to their biological effects. Using the set of phenothiazine maleates differing in the type of phenothiazine ring substitution at position 2 and/or in the length of the alkyl bridge-connecting ring system and side chain group, we investigated if their ability to modulate the multidrug resistance of cancer cells correlated with model membrane perturbing potency. The influence exerted on lipid bilayers was determined by liposome/buffer partition coefficient measurements (using the absorption spectra second-derivative method), fluorescence spectroscopy and calorimetry. Biological effects were assessed by a flow cytometric functional test based on differential accumulation of fluorescent probe DiOC(2)(3) by parental and drug-resistant cells. We found that all phenothiazine maleates were incorporated into lipid bilayers and altered their biophysical properties. With only few exceptions, the extent of membrane perturbation induced by phenothiazine maleates correlated with their lipophilicity. Within the group of studied derivatives, the compounds substituted with CF(3)- at position 2 of phenothiazine ring were the most active membrane perturbants. No clear relation was found between effects exerted by phenothiazine maleates on model membranes and their ability to modulate P-glycoprotein transport activity.