The inhibitory effect of intestinal bacterial metabolite of ginsenosides on CYP3A activity

The intestinal bacterial metabolites of ginsenosides are responsible for the main pharmacological activities of ginseng. The purpose of this study was to find whether these metabolites influence hepatic metabolic enzymes and to predict the potential for ginseng-prescription drug interactions. Utilizing the probe reaction of CYP3A activity, testosterone 6beta-hydroxylation, the effects of derivatives of 20(S)-protopanaxadiol and 20(S)-protopanaxatriol families on CYP3A activity in rat liver microsomes were assayed. Our results showed that ginsenosides from the 20(S)-protopanaxadiol and 20(S)-protopanaxatriol family including Rb-1, Rb-2, Rc, Compound-K, Re, and Rg(1), had no inhibitory effect, whereas Rg(2), 20(S)-panaxatriol and 20(S)-protopanaxatriol exhibited competitive inhibitory activity against CVP3A activity in these microsomes with the inhibition constants (K) of 86.4+/-0.8mum, 1.7+/-0.1mum, and 3.2+/-0.2 mum, respectively. This finding demonstrates that differences in their chemical structure might influence the effects of ginsenosides on CYP3A activity and that ginseng-derived products might have potential for significant ginseng-drug interactions.

The characteristics of nutrient removal and inhibitory effect of Ulva clathrata on Vibrio anguillarum 65

To investigate the ecological effect of macroalgae on de-eutrophication and depuration of mariculture seawater, the variation of dissolved inorganic nitrogen (DIN) and phosphate (DIP), the amount of Vibrio anguillarum, and total heterotrophic bacteria in Ulva clathrata culture, as well as on the algal surface, were investigated by artificially adding nutrients and V. anguillarum strain 65 from February to April 2006. The results indicated that U. clathrata not only had strong DIN and DIP removal capacities, but also showed a significant inhibitory effect on V. anguillarum, although not reducing the total heterotrophic bacteria. Vibrio anguillarum 65 dropped from 5 similar to 8 x 10(7) cfu mL(-1) to 10 cfu mL(-1) (clone-forming units per mL) in 10 g L-1 of fresh U. clathrata culture within 2 days; i.e., almost all of the Vibrios were efficiently eradicated from the algal culture system. Our results also showed that the inhibitory effect of U. clathrata on V. anguillarum strain 65 was both DIN- and DIP-dependent. Addition of DIN and DIP could enhance the inhibitory effects of the algae on the Vibrio, but did not reduce the total heterotrophic bacteria. Further studies showed that the culture suspension in which U. clathrata was pre-cultured for 24 h also had an inhibitory effect on V. anguillarum strain 65. Some unknown chemical substances, either released from U. clathrata or produced by the alga associated microorganisms, inhibited the proliferation of V. anguillarum 65.

Isolation and preliminary characterization of a 22-kDa protein with trypsin inhibitory activity from toad Bufo andrewsi skin

A novel trypsin inhibitor termed BATI was purified to homogeneity from the skin extracts of toad Bufo andrewsi by successive ion-exchange, gel-filtration and reverse-phase chromatography. BATI is basic single chain glycoprotein, with apparent molecular weight of 22 kDa in SDS-PAGE. BATI is a thermal stable competitive inhibitor and effectively inhibits trypsin's catalytic activity on peptide substrate with the inhibitor constant (K-i) value of 14 nM and shows no inhibitory effect on chymotrypsin, thrombin and elastase. The N-terminal sequence of BATI is EKDSITD, which shows no similarity with other known trypsin inhibitors. (c) 2005 Elsevier Ltd. All rights reserved.

Inhibitory effects of the androgenic gland on ovarian development in the mud crab Scylla paramamosain

Isolation and characterization of androgenic hormone in decapod crustaceans depend on an effective bioassay of its action. In the present study, the effect of androgenic gland on ovarian development in the mud crab Scylla paramamosain was investigated with a view to develop a bioassay for androgenic hormone. Ovarian regression with degeneration of oocytes occurred in some female crabs implanted with androgenic gland in vivo. In vitro incubation of ovarian tissues at secondary vitellogenesis in extract of androgenic gland resulted in a significant decrease in amino acid uptake by the tissues. We propose that this inhibitory effect could be established as an effective bioassay for the isolation of androgenic hormone in the mud crab. (c) 2005 Published by Elsevier Inc.

Effect of light period on egg-discharge of gametophyte clones of Undaria pinnatifida (Phaeophyta)

A sporeling culture method using gametophyte clones developed in the early 1990s led to egg discharge occurring in the dark 5 min after the start of the dark period under growth under a 11:13 L-D photoperiod. The course of egg discharge could be disturbed by light, with irradiance as low as 5-6 mu mol photon m(-2) s(-1) causing 75-80% of the discharged eggs to detach from the oogonia and consequently to die within several hours. In order to enhance outgrowth rate of young sporophytes, a study was conducted to test the effect of controlling darkness in the period 2-3 h after dusk. When the slides were transferred from the standard 11:13 L-D regime to continuous light, eggs were discharged 5 min after the end of the light phase and peaked 5-l5 min later on first day after transfer, indicating that the female gametes "remember" the light-dark regime. This suggests the existence of an endogenous circadian rhythm. During the second and third days, very few eggs were discharged throughout the 11 h of the normal light phase of the L-D regime, indicating the inhibitory effect of continuous light and that the rhtyhm is easily damped by light.

The effect of the causative algae of large-scale HAB in the East China Sea on egg hatching of Argopecten irradians, and population growth of Brachionus plicatilis and Moina mongolica

The impacts of Prorocentrum donghaiense Lu and Alexandrium catenella Balech, causative species of the large-scale HAB in the East China Sea, were studied under laboratory conditions. According to bloom densities, the effects of monoculture and mixture of the two species were examined on the egg-hatching success of Argopecten irradians Lamarck, and the population growth of Brachionus plicatilis Muller and Moina mongolica Daday. The results showed that monoculture of A. catenella had a significant inhibition on the egg hatching success of A. irradians, and the population growth of B. plicatilis and M. mongolica. The median effective densities ( EDSo) inhibiting the egg hatching success of A. irradians for 24 h and the population growth of B. plicatilis and M. mongolica for 96 h were 800, 630, and 2 400 cells/cm(3), respectively. Monoculture of P. donghaiense has no such inhibitory effect on the egg hatching success of A. irradians; P. donghaiense at lower suitable densities could sustain the population growth of B. plicatilis (1 x 10(4) similar to 3 x 10(4)cells/cm(3)) and M. mongolica (2 x 10(4) similar to 5 x 10(4) cells/cm(3)); P. doaghaiense at higher densities had significantly adverse effect on the population growth of B. plicatilis (4 x 10(4) similar to 10 x 10(4) cells/cm(3)) and M. mongolica (10 x 10(4) cells/cm(3)). When the two algae were mixed according to bloom densities, P. donghaiense at suitable densities to some extent could decrease the toxicity of A. catenella to B. plicatilis and M. mongolica. The results indicated that the large-scale HAB in the East China Sea could have adverse effect on zooplankton, and might further influence the marine ecosystem, especially when there was also Alexandrium bloom.

Inhibition Effect of 2,3,5-Triphenyl-2H-tetrazolium Chloride and 2,4,6-Tri(2-pyridyl)-s-triazine on the Corrosion of Mild Steel in 1 mol/L HCl and Mechanism Study (II)

The inhibitory effect of 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) and 2,4,6-tri(2-pyridyl)-s-triazine (TPT) molecules on the corrosion of mild steel in 1 mol/L HCl and microcosmic inhibitory mechanism were investigated by X-ray photoelectron spectroscopy and ellipsometry. XPS results showed that C Is and N Is peaks of TTC, C Is and N Is peaks of TPT and their integral areas were obtained, which suggested the layer of the inhibitors (TTC or TPT) should have effectively protected the mild steel surface from the corrosion; and the depression from the inhibitors for the corrosion of mild steel surface was studied using ellipsometry combined with potentiodynamic polarization and the phasic difference was gained, which displayed the inhibitory coverage of the inhibitors formed.

Interactions of CO, HCl, and Sox in Pulverised Coal Flames

The effect of HCl and SO_2 on CO oxidation in pulverised coal flames was investigated experimentally and kinetically in an entrained flow combustion reactor. Two bituminous coals (German 'Goettelborn' and a Polish coal) were used as fuels with a feeding rate of 1 or 1.5 kg/h. HCl or SO_2 is introduced into the reactor premixed with the primary air. Experimental results indicate that HCl addition may inhibit CO oxidation in coal flames and increases CO emission. Reducing temperature in the reactor will enhance the inhibitory effect of HCl on CO oxidation. The measured CO profiles along the reactor height clearly show that the addition of HCl may inhibit CO oxidation. In the experimental range of SO_2 addition. The inhibiting effect of SO_2 on CO oxidation is less significant than HCl. A detailed kinetic mechanism is used to model the reactions. And the controlling reactions are analysed.

湖北光周期敏感核不育水稻雄性器官发育中长日抑制作用的研究

本文研究了HPGMR农垦58S及农垦58品种与雄性器官发育有关的基本光周期反应特性。探索了与光周期反应过程有关的叶片特异蛋白变化，对HPGMR的研究及这一材料在光周期现象研究中的意义提出了一些看法。 实验得到以下三点主要结果： 1、58S及58生长发育过程在不同阶段均可受到光周期的影响，共同的表现是长日起抑制效应而短日起促进效应。这种效应的基本特征是累积性。对于生殖器官发生而言，存在有一定的短日需求阈值，当所给短日少于需求阈值时，器官的发生过程受阻乃至中断，在幼穗分化上表现为不抽穗;在雄性器官发育上，对予58S这一特殊材料而言，可表现出发育的中止，即mst。在58上不能引起类似的反应，这是由两个材料不同的遗传背景决定的。 2、对于58S及58，10天14h的长日光周期可以在键壮的功能叶片中诱导出一个35KDPI5.1的蛋白质。在本实验所用的电泳系统中，尚未检测到其他受光周期调节的蛋白质。 3、不同品种（系）的叶片蛋白电泳结果表明，在58S及由其转育的晚粳类型的PGMR材料中，均存在一个60KDPI5.5的蛋白。在只对光周期有反应但不出现不育的材料（58）和只表现不育但无光周期反应的材料（野败型不育系珍汕97A等）中，均不存在该蛋白。 根据以上结果，本文提出以下三点看法： 1、HPGMR中光周期控制的雄性不育，是水稻这种短日植物在幼穗分化过程中，短日需求未得到满足而在特殊遗传背景中表现出的雄性器官正常发育的中止。这一概念包括两个方面，一是幼穗发育过程有短日需求，二是雄性器官对经叶片转换的日长信号有特殊的反应。根据这种看法，建议在育种上应以幼穗发育有短日需求的材料为不育性状的转育对象;在机理研究上应更加注意雄性器官发生过程的研究。 2、60KD蛋白可能是判断一个水稻材料是否具有稳定光敏不育特性的有效指标。这一看法若经进一步实验确认，则不仅可在MPGMR的应用上起积极的作用，而且还可为光敏不育性状的遗传控制及操作的研究提供一个很好的入手点。 3、长日诱导35KD蛋白在不同叶位的叶片中出现、结合长日对不同生育阶段的抑制，暗示光周期反应中叶片和顶端关系上存在这样一种可能：即叶片是信号转换器，把环境的日长信号转换为顶端可以接受的生物信号，这种转换只要有环境信号存在即可进行，但顶端是否对此做出相应的反应则取决于顶端自身的状态。这样一种对光周期反应的假设可能将有助于对光周期现象的认识。但若要对它进行实验研究，必须用同样的光周期可以在顶端引起不同反应的实验系统。HPGMR即是这样一种合适的实验系统。从这个意义上，HPGMR及其叶片中的35KD蛋白有可能对光周期反应这一重要的植物发育现象的研究做出有意义的贡献。

长日照处理对短日植物紫花牵牛开花的仰制

本文以日本紫花牵牛花为材料，观察分析了其对不同光周期的反应应特性以及不同光周期处理条件下子叶蛋白质和mRNA的变状况。实验结果归纳如下：1、经不同天数短日照处理的幼苗导致植株开花特性明显不同。2、实验结果表明，12小时暗期长度可能是诱导光周期的临界暗期长度。3、经双向电泳分析观察到，长日照处理的牵牛子叶内存在着分子量分别为16.5KD(PI4.1), 16.5KD(PI4.2), 21.6KD(PI8.8)及21.7KD(PI8.3)四种蛋白质，它们在短日诱导条件下消失，表明这些蛋白质的存在可能与抑制花芽分化有关。4、提取经短日照诱导和连续光照子叶内的PolY(A~+)RNA, 进行体外翻译，观察表明光周期诱导过程是在转录水平上的调节。短日照处理不仅有促进芽分化的作用，同时还有消除长日照的抑制效应。