共振瑞利散射法测定微量唑来膦酸

建立了共振瑞利散射法测定微量唑来膦酸。在酸性条件下,唑来膦酸被破坏后产生的无机磷进一步与钼酸铵结合形成磷钼杂多酸,再与罗丹明B形成磷钼杂多酸-罗丹明B三元离子缔合物后共振瑞利散射急剧增加,并于370nm处有最大散射峰,唑来膦酸在6.25～100ng/ml浓度范围内线性关系良好,检测限为1.55ng/ml。     

Determination of bismuth in pharmaceutical products using methyltriphenylphosphonium bromide as a molecular probe by resonance light scattering technique

A method for the determination of bismuth in pharmaceutical products using methyltriphenylphosphonium bromide as a molecular probe based on the resonance light scattering (RLS) technique was developed. In the presence of Tween-20, bismuth reacts with a large excess of I(-) to form [BiI(4)](-), which further reacts with methyltriphenylphosphonium bromide (MTPB) to form an ion-association compound. This resulted in a significant enhancement of RLS intensity and the appearance of the corresponding RLS spectral characteristics. The enhanced RLS intensity was directly proportional to the concentration of Bi(III) in the range of 0.001-1.50 microg/ml for the system. The detection limit was 0.98 ng/ml. The characteristics of RLS spectra of the complex, the optimum conditions and the influencing factors were investigated. The method has high selectivity and was applied to the determination of Bi(III) in pharmaceutical products with satisfactory results, which were in agreement with those of the official method and atomic absorbance spectrometry (AAS).     

共振瑞利散射光谱法测定血浆和尿样中的帕珠沙星

目的建立了共振瑞利散射光谱法测定血浆、尿样中帕珠沙星含量的新方法。方法于pH4.8～5.9的Britton-Robinson缓冲溶液中,帕珠沙星与钴(Ⅱ)形成阳离子配合物,其共振瑞利散射(resonance rayleigh scattering,RRS)十分微弱,但当其进一步通过静电引力和疏水作用与刚果红(congo red,CR)阴离子反应形成三元离子缔合物时,RRS出现新的共振瑞利散射光谱,其2个散射峰分别位于380和562nm处。结果在380nm处,帕珠沙星的质量浓度在0.031～3.18μg.mL-1范围内,与RRS强度有良好的线性关系,其检出限(3σ)为24.6ng.mL-1。结论该方法简单、快速,具有良好的选择性和重复性,可用于不同体液中帕珠沙星的测定。     

Determination of a novel angiotensin-AT1 antagonist CR 3210 in biological samples by HPLC

A simple and sensitive method for the determination of a new angiotensin-AT(1) antagonist i.e. CR 3210, 4-[4-[(2-ethyl-5,7-dimethylimidazo[4,5-b]pyridin-3-yl)methyl]phenyl]-3-(2H-tetrazol-5-yl)quinoline, is described. The assay was utilised to describe the pharmacokinetic profile of the title compound after intravenous and intraperitoneal administration to Sprague Dawley rats. CR 3210 and the internal standard CR 1505 (loxiglumide, 4-[(3,4-dichlorobenzoyl)amino-5-[(3-methoxypropyl)pentylamino]-5-oxopentanoic acid) were isolated from rat plasma by solid-phase extraction. The sorbent extraction material along with the pH in the conditioning solution and the washing volume were considered pivotal parameters for the optimisation of the procedure. The separations were performed by reversed-phase high-performance liquid chromatography with ultraviolet detection. The samples were injected onto the analytical column (Tracer Extrasil ODS1) and detected at 238 nm, giving a retention time of 6.19 min for CR 3210 and 4.39 min for the internal standard, respectively. The selectivity of the method showed to be satisfactory. The mean recovery of CR 3210 from spiked rat plasma was 80.3 at 1 microg/ml and 79.9 at 2 microg/ml. The lower limit of detection (LOD) was taken as 0.014 microg/ml in plasma samples. The lower limit of quantification (LOQ) was taken as 0.02 microg/ml, the lowest calibration standard using 500 microg rat plasma. The procedures were validated according to international standards with a good reproducibility and linear response from 0.02 to 2 microg/ml. The sensitivity of the method allowed for its application to pharmacokinetic studies. The maximal concentration was detected 5' after the IV administration, whereas no significant absorption was evident after IP administration of CR 3210 to Sprague-Dawley rats. Our study suggests the absence of extensive bio-transformation of the drug in vivo, supported by the evidence that no metabolites were detected in plasma samples.     

Effect of Bothrops leucurus venom in chick biventer cervicis preparations.

Bothrops leucurus is a poorly studied pitviper found in northeastern Brazil. We examined the action of B. leucurus venom (5-100 microg/ml) on contractile responses in chick biventer cervicis preparations. Muscle damage was assessed by quantifying the release of creatine kinase (CK) and by histological analysis. B. leucurus venom dose-dependently inhibited the contractile responses of indirectly stimulated preparations, the maximum inhibition with 100 microg of venom/ml being 74.0+/-6.6% (mean+/-SEM) after 120 min. The venom also reduced contractures to exogenous acetylcholine (55 and 110 microM) and K(+) (13.4mM) (85-100% reduction with 100 microg of venom/ml) and increased the release of CK (348+/-139 U/ml in controls vs 1260+/-263 U/ml with 20 microg of venom/ml after 120 min, p<0.05). The accompanying morphological changes included multivacuolated, swollen, amorphous fibers and agglutinated myofibrils. These results indicate that B. leucurus venom can adversely affect neuromuscular transmission and produce muscle damage in avian preparations.     

Activation of cellular functions in macrophages by venom secretory Asp-49 and Lys-49 phospholipases A(2).

The in vitro effects of myotoxin III (MT-III), an Asp-49 catalytically-active phospholipase A(2), and myotoxin II (MT-II), a catalytically-inactive Lys-49 variant, isolated from Bothrops asper snake venom, on phagocytosis and production of hydrogen peroxide (H(2)O(2)) by thioglycollate-elicited macrophages were investigated. MT-II and MT-III were cytotoxic to mouse peritoneal macrophages at concentrations higher than 25 microg/ml. At non-cytotoxic concentrations, MT-II stimulated Fcgamma, complement, mannose and beta-glucan receptors-mediated phagocytosis, whereas MT-III stimulated only the mannose and beta-glucan receptors-mediated phagocytosis. Moreover, both myotoxins induced the release of H(2)O(2) by thioglycollate-elicited macrophages, MT-III being the most potent stimulator. MT-II induced the release of H(2)O(2) only at a concentration of 3.2 microg/ml (130% increment) while MT-III induced this effect at all concentrations tested (0.5-2.5 microg/ml; average of 206% increment). It is concluded that, at non-cytotoxic concentrations, MT-II and MT-III activate defense mechanisms in macrophages up regulating phagocytosis, mainly via mannose and beta-glucan receptors, and the respiratory burst.     

Renal and antibacterial effects induced by myotoxin I and II isolated from Bothrops jararacussu venom.

Bothrops jararacussu myotoxin I (BthTx-I; Lys 49) and II (BthTX-II; Asp 49) were purified by ion-exchange chromatography and reverse phase HPLC. In this work we used the isolated perfused rat kidney method to evaluate the renal effects of B. jararacussu myotoxins I (Lys49 PLA2) and II (Asp49 PLA2) and their possible blockage by indomethacin. BthTX-I (5 microg/ml) and BthTX-II (5 microg/ml) increased perfusion pressure (PP; ct120=110.28+/-3.70 mmHg; BthTX I=171.28+/-6.30*mmHg; BthTX II=175.50+/-7.20*mmHg), renal vascular resistance (RVR; ct120=5.49+/-0.54 mmHg/ml.g(-1)min(-1); BthTX I=8.62+/-0.37*mmHg/ml g(-1)min(-1); BthTX II=8.9+/-0.36*mmHg/ml g(-1)min(-1)), urinary flow (UF; ct(120)=0.14+/-0.01ml g(-1)min(-1); BthTX I=0.32+/-0.05*ml g(-1)min(-1); BthTX II=0.37+/-0.01*ml g(-1)min(-1)) and glomerular filtration rate (GFR; ct120=0.72+/-0.10 ml g(-1)min(-1); BthTX I=0.85+/-0.13*ml g(-1)min(-1); BthTX II=1.22+/-0.28*ml g(-1)min(-1)). In contrast decreased the percent of sodium tubular transport (%TNa(+); ct(120)=79,76+/-0.56; BthTX I=62.23+/-4.12*; BthTX II=70.96+/-2.93*) and percent of potassium tubular transport (%TK(+);ct120=66.80+/-3.69; BthTX I=55.76+/-5.57*; BthTX II=50.86+/-6.16*). Indomethacin antagonized the vascular, glomerular and tubular effects promoted by BthTX I and it's partially blocked the effects of BthTX II. In this work also evaluated the antibacterial effects of BthTx-I and BthTx-II against Xanthomonas axonopodis. pv. passiflorae (Gram-negative bacteria) and we observed that both PLA2 showed antibacterial activity. Also we observed that proteins Also we observed that proteins chemically modified with 4-bromophenacyl bromide (rho-BPB) decrease significantly the antibacterial effect of both PLA2. In conclusion, BthTx I and BthTX II caused renal alteration and presented activity antimicrobial. The indomethacin was able to antagonize totally the renal effects induced by BthTx I and partially the effects promoted by BthTx II, suggesting involvement of inflammatory mediators in the renal effects caused by myotoxins. In the other hand, other effects could be independently of the enzymatic activity of the BthTX II and the C-terminal domain could be involved in both effects promoted for PLA2.     

共振瑞利散射光谱法测定片剂、人体尿液和血浆中培氟沙星的含量

目的 建立测定片剂、人体尿液和血浆中的培氟沙星含量的共振瑞利散射光谱方法.方法 在pH4.8～5.9 Britton-Robinson缓冲溶液中,培氟沙星(PEFX)可与钴(Ⅱ)反应形成配阳离子,其共振瑞利散射(RRS)十分微弱,但当该配阳离子进一步与酸性染料刚果红(CR)阴离子反应形成三元离子缔合物时,RRS显著增强,3个散射峰别位于278、380和560nm,以380nm为测定波长.结果 线性范围为0.133～3.33μg/mL(r=0.9993),检出限(3σ)为26.4ng/mL.结论 方法简单、快速、并有良好的选择性,可用于片剂、人体尿液和血清中培氟沙星的测定.     

HPLC法测定灵芝二维甲硫氨酸胶囊中甲硫氨酸、维生素B1及维生素B2含量

目的：建立用HPLC法同时测定灵芝二维甲硫氨酸胶囊中甲硫氨酸、维生素B1及维生素B2含量的方法。方法：采用Ultimate？ AQ-C18色谱柱（250 mm ×4.6 mm,5μm,Welch公司）,流动相：甲醇-0.07 mol·L-1庚烷磺酸钠溶液（加14 ml三乙胺并加水至1000 ml,用磷酸调节pH至3.5）,线性梯度洗脱,检测波长为220 nm,流速：1.0 ml·min-1。结果：甲硫氨酸、维生素B1、维生素B2分别在0.5270~1.5100 mg·ml-1（r=0.9999）、0.04552~0.13656 mg·ml-1（r=0.9999）、0.01010~0.06058 mg·ml-1（r =0.9999）范围内线性关系良好,平均回收率分别为100.5%、97.7%、101.5%,RSD 分别为0.5%、1.0%、1.4%（n=9）。结论：本法操作简便、结果准确、可靠,可用于灵芝二维甲硫氨酸胶囊中甲硫氨酸、维生素B1、维生素B2的含量测定。     

Cytotoxicity of Lachesis muta muta snake (bushmaster) venom and its purified basic phospholipase A2 (LmTX-I) in cultured cells.

Human envenoming by Lachesis muta muta venom, although infrequent, is rather severe, being characterized by pronounced local tissue damage and systemic dysfunctions. Studies on the pharmacological actions of L. m. muta venom are relatively scant and the direct actions of the crude venom and its purified phospholipase A(2) (PLA(2)) have not been addressed using in vitro models. In this work, we investigated the cytotoxicity of L. m. muta venom and its purified PLA(2) isoform LmTX-I in cultured Madin-Darby canine kidney (MDCK) and in a skeletal muscle (C2C12) cell lines. As revealed by neutral red dye uptake assay, the crude venom (10 or 100 microg/ml) induced a significant decrease in cell viability of MDCK cells. LmTX-I at the concentrations tested (70-270 microg/ml or 5-20 microM) displayed no cytotoxicity in both MDCK and C2C12 cell lines. Morphometric analysis of Feulgen nuclear reaction revealed a significant increase in chromatin condensation (pyknosis), apparent reduction in the number of mitotic nuclei and nuclear fragmentation of some MDCK cells after incubation with L. m. muta venom. Monolayer exposure to crude venom resulted in morphological changes as assessed by scanning electron microscopy. The staining with TRITC-labelled phalloidin showed a marked disarray of the actin stress fiber following L. m. muta venom exposure. In contrast, LmTX-I had no effect on nucleus and cell morphologies as well as on stress fiber organization. These results indicate that L. m. muta venom exerts toxic effects on cultured MDCK cells. The LmTX-I probably does not contribute per se to the direct venom cytotoxicity, these effects are mediated by metalloproteinases/disintegrins and other components of the venom.     

The effects of mycotoxins,fumonisin B1 and aflatoxin B1, on primary swine alveolar macrophages

Mycotoxins were fungal metabolites that were widely present in feed and food; some of them were known to associate with human and animal disease. In the present study, the effects of fumonisin B1 (FmB1) and aflatoxin B1 (AFB1) on swine alveolar macrophages (AM) were examined by exposing primary cultures of swine AM to various concentrations of mycotoxins. Incubation of AM with 5 microg/ml of FmB1 for 72 h led to a reduction in the number of viable cells to 65% of the control levels. In the presence of 1.5 microg/ml of AFB1, the viability of AM falls to less than 41% of controls after 24 h exposure. FmB1, but not AFB1, induced the apoptosis of swine AM with evidence of DNA laddering and nuclear fragmentation. However, both FmB1 and AFB1 exposure induced the expression of apoptosis-related heat shock protein 72 (HSP 72) in AM. Swine AM treated with 50 ng/ml of FmB1 and 100 ng/ml of AFB1 for 24 h led to a reduction in phagocytic ability to approximately 55 and 36% of the control levels, respectively. Incubation of AM with FmB1 (2 and 10 microg/ml) for 24 h dramatically decreased the mRNA levels of interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha). However, AFB1 treatment did not affect the expression of IL-1beta and TNF-alpha mRNA. The results suggest that both FmB1 and AFB1 are immunotoxic to swine AM but that they exert their toxic effects via different biochemical mechanisms.     

Simultaneous determination and pharmacokinetics of five bufadienolides in rat plasma after oral administration of Chansu extract by SPE-HPLC method

A sensitive and rapid solid-phase extraction-high performance liquid chromatography (SPE-HPLC) method has been developed for the determination of five bufadienolides, arenobufagin, teliocinobufagin, cinobufotalin, cinobufagin and resibufogenin in rat plasma and applied to a pharmacokinetic study in rats after oral administration of Chansu extract (Venenum Bufonis). Plasma samples were pretreated with solid-phase extraction using Extract-Clean cartridges, and the extracts were analyzed by a reversed-phase C(18) column on a HPLC system with photodiode array detection (DAD). The calibration curves were linear over the range of 0.10-1.66 microg/ml for arenobufagin, 0.03-1.20 microg/ml for telocinobufagin, 0.01-0.62 microg/ml for cinobufotalin, 0.03-0.70 microg/ml for cinobufagin and 0.02-2.57 microg/ml for resibufogenin, respectively. The limit of quantification was 1.1 ng/ml for arenobufagin, 0.3 ng/ml for telocinobufagin, 9.7 ng/ml for cinobufotalin, 8.8 ng/ml for cinobufagin, 7.7 ng/ml for resibufogenin, respectively. The established method could be easily applied to the determination and pharmacokinetic studies of five bufadienolides in rat plasma after oral administration of Chansu extract.     

Neutralization of the pharmacological effects of Cobra and Krait venoms by chicken egg yolk antibodies

Five-month-old white leghorn chickens were immunized with 50 microg of Common Cobra (Naja naja) and 30 microg of Krait venoms (Bungarus caeruleus) to generate antivenom antibodies against the venom antigen. Chickens received booster doses of increasing concentrations of venom at 14 days time intervals to raise the antivenom level in egg yolk. The antivenom from immunized chicken egg yolk was extracted by polyethylene glycol (PEG) and ammonium sulphate precipitation method which was further purified by DEAE cellulose ion exchange column chromatography. A high molecular weight protein of 180 kDa was detected by electrophoretic analysis which shows the purity of antivenom generated in chicken. Antibodies generated were specific and sensitive to the venom antigen. Various pharmacological activities of Cobra and Krait venoms were carried out by both in-vivo and in-vitro methods. The neutralization of lethality, hemorrhagic, edema, PLA(2) and procoagulant activity was evaluated in assays involving pre-incubation of venom and antivenom prior to testing. The antivenom was effective in neutralizing the toxic and enzymatic activities of venom. The LD(50) of venom for 18 g of mice was found to be 10 microg for Cobra and 3 microg for Krait venoms. The median effective dose (ED(50)) of anti-Cobra venom was 4.48 mg/5LD(50) and 1.0 ml neutralized 0.127 mg of Cobra venom and the median effective dose (ED(50)) of anti-Krait venom was 3.18 mg/5LD(50) and 1.0 ml neutralized 0.051 mg of Krait venom. The results indicate that antivenom generated in chicken could be used for therapeutic purposes in case of snakebite envenomation.     

Purification and renal effects of phospholipase A(2) isolated from Bothrops insularis venom.

Bothrops insularis venom contains a variety of substances presumably responsible for several pharmacological effects. We investigated the biochemical and biological effects of phospholipase A(2) protein isolated from B. insularis venom and the chromatographic profile showed 7 main fractions and the main phospholipase A(2) (PLA(2)) enzymatic activity was detected in fractions IV and V. Fraction IV was submitted to a new chromatographic procedure on ion exchange chromatography, which allowed the elution of 5 main fractions designated as IV-1 to IV-5, from which IV-4 constituted the main fraction. The molecular homogeneity of this fraction was characterized by high-performance liquid chromatography (HPLC) and demonstrated by mass spectrometry (MS), which showed a molecular mass of 13984.20 Da; its N-terminal sequence presented a high amino acid identity (up to 95%) with the PLA(2) of Bothrops jararaca and Bothrops asper. Phospholipase A(2) isolated from B. insularis (Bi PLA(2) ) venom (10 microg/mL) was also studied as to its effect on the renal function of isolated perfused kidneys of Wistar rats (n=6). Bi PLA(2) increased perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (UF) and glomerular filtration rate (GFR). Sodium (%TNa(+)) and chloride tubular reabsorption (%TCl(-)) decreased at 120 min, without alteration in potassium transport. In conclusion, PLA(2) isolated from B. insularis venom promoted renal alterations in the isolated perfused rat kidney.     

Spectrophotometric and fluorimetric methods for the determination of meloxicam in dosage forms

Four simple and accurate methods are presented for the determination of meloxicam in dosage forms. These methods are based on: the direct measurements of the differential spectra at 339.9-384.7 nm (A), the 1D-values at 322-368 nm and 2D-values at 343.2-385.6 nm (B), the formation of an ion-association complex between the drug and safranin T with subsequent absorption measurement at 518 nm (C) and fluorescence measurement at 582 nm (D). All variables were studied to optimize the formation of the ion-association complex. Beer's law was valid over the concentration range 2-10 microg ml(-1) (method A), 1-10 microg ml(-1) (method B), 4.0-12 microg ml(-1) (method C) and 0.4-1.2 microg ml(-1) (method D). The detection limits were 0.11, 0.07, 0.10, 0.33 and 8.74 x 10(-3) microg ml(-1) for methods A, B, C and D, respectively. The proposed methods were successfully applied to the assay of meloxicam in tablets and suppositories. The procedures were rapid, simple and suitable for quality control applications.     

小檗碱-四苯硼钠缔合纳米微粒体系的共振Rayleigh散射光谱及其分析应用小檗碱-四苯硼钠缔合纳米微粒体系的共振Rayleigh散射光谱及其分析应用

目的研究(小檗碱-四苯硼钠)_n缔合纳米微粒的形成与共振Rayleigh散射之间的关系，建立测定小檗碱的共振Rayleigh散射光谱分析新方法。方法采用共振Rayleigh散射光谱法、吸收光谱和透射电镜研究四苯硼钠(TPB)与盐酸小檗碱(BB)的缔合反应。结果在pH 5.0 NaAc-HAc缓冲溶液中，TPB与BB结合形成的(BB-TPB)_n缔合纳米微粒在470 nm处产生一个共振Rayleigh散射（RRS）峰。建立了测定0.06～5.28 mg·L^-1盐酸小檗碱的RRS新方法，检出限为26 μg·L^-1。 结论通过TPB－与BB⁺和Ag⁺反应形成可用透射电镜观测的(BB_jAg_p-TPBj+p)h复合缔合纳米微粒，证实了固液界面的形成是导致其共振Rayleigh散射光增强的充分必要条件。建立的RRS新方法可用于中成药中微量小檗碱的测定，具有灵敏度高，试样用量少等特点。     

Melittin inhibits inflammatory target gene expression and mediator generation via interaction with IkappaB kinase

We previously found that bee venom (BV) and melittin (a major component of BV) has anti-inflammatory effect by reacting with the sulfhydryl group of p50 of NF-kappaB. Since the sulfhydryl group is present in IkappaB kinase (IKKalpha and IKKbeta), anti-inflammatory effect of melittin via interaction with IKKs was investigated. We first examined binding of melittin to IKKs using surface plasmon resonance analyzer. Melittin binds to IKKalpha (K(d) = 1.34 x 10(-9) M) and IKKbeta (K(d) = 1.01 x 10(-9) M). Consistent with the high binding affinity, melittin (5 and 10 microg/ml) and BV (0.5, 1 and 5 microg/ml) suppressed sodium nitroprusside, TNF-alpha and LPS induced-IKKbeta and IKKbeta activities, IkappaB release, and NF-kappaB activity as well as the expressions of iNOS and COX-2, and the generation of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) in Raw 264.7 mouse macrophages and synoviocytes obtained from rheumatoid arthritis patients. The binding affinities of melittin to mutant IKKs, was reduced, and the inhibitory effect of melittin on IKK and NF-kappaB activities, and NO and PGE(2) generation were abrogated by the reducing agents or in Raw 264.7 transfected with mutant plasmid IKKalpha (C178A) or IKKbeta (C179A). These results suggest that melittin binding to the sulfhydryl group of IKKs resulted in reduced IKK activities, IkappaB release, NF-kappaB activity and generation of inflammatory mediators, indicating that IKKs may be also anti-inflammatory targets of BV.     

Study and analytical application of ion-pair formation in the system fluoxetine-pyrocatechol violet and fluvoxamine-pyrocatechol violet

Pyrocatechol violet (PCV) reacts in aqueous media with fluoxetine (FLX) and fluvoxamine (FLV) forming coloured ion-association complexes, which are insoluble in water but quantitatively extracted into chloroform-n-butanol mixture. The composition of the compounds, studied by spectrophotometric methods showed that the molar ratio PCV : FLX and PCV : FLV is 1 : 1. The compounds were characterized by UV-VIS, IR and NMR spectrometry. Under optimal experimental conditions fluoxetine and fluvoxamine were determined in the range 1.3-18.0 microg/ml and 2.6-39.1 microg/ml, respectively. The proposed methods have been succesfully applied to the determination of these drugs in pharmaceuticals and natural samples.