Assessment of the therapeutic activity of a combination of almitrine and raubasine on functional rehabilitation following ischaemic stroke

Background and objectives: Stroke is a major cause of disability. Certain experimental studies have suggested that a combination of almitrine?+?raubasine (Duxil) increases the supply of oxygen to cerebral tissues and may be beneficial in post-stroke rehabilitation. This multicentre clinical study was carried out in order to assess the efficacy of this combination on post-stroke rehabilitation.

Methods: The trial was a randomised, double-blind, placebo-controlled study. Patients that had experienced an ischaemic cerebrovascular accident (confirmed by CT scan) were included 4-6 weeks after the acute onset and received randomised treatment of either almitrine?+?raubasine or placebo 2 tablets daily for 3 months. Before treatment, there was a 2-week washout period for stopping all other drugs, except for antihypertensive and antidiabetic drugs. We assessed the patients by Barthel Index (BI), Neurological Functional Deficit Scores (NFDS), and Hasagawa Dementia Scales (HDS) each month after treatment.

Results: A total of 83 patients were entered into the study and data were available for 74. Of these, 38 patients received almitrine?+?raubasine and 36 received placebo. The baseline characteristics were comparable between both groups. Almitrine?+?raubasine was significantly more effective than placebo at increasing BI at 1, 2 or 3 months (14.6?±?13.8 versus 3.3?±?13.2, p?=?0.01; 19.3?±?13.6 versus 8.8?±?14.0, p?=?0.02; 22.6?±?14.7 versus 10.7?±?17.0, p?=?0.02 respectively) and reducing NFDS at 1 month (3.6?±?3.2 versus 1.9?±?3.5, p?=?0.034) after treatment. More almitrine?+?raubasine-treated patients' NFDS had improved compared with placebo-treated patients at 2 and 3 months (97 versus 78%, p?=?0.013; 100 versus 86%, p?=?0.023 respectively). Compared with pre-treatment, there was a strong tendency towards an improvement of HDS with almitrine + raubasine. The number of adverse events reported was low for the almitrine + raubasine-treated group and the placebo group and all events were mild, of short duration and resolved without treatment. Almitrine + raubasine had no clinically significant effect on blood pressure, heart rate or other laboratory tests.

Conclusion:The results indicate that almitrine + raubasine can accelerate neurological function recovery after stroke to some degree and is well tolerated.     

Stability-indicating spectrophotometric methods for determination of tazarotene in the presence of its alkaline degradation product by derivative spectrophotometric techniques

The stability of tazarotene (TZ) was investigated and two stability‐indicating methods—namely, first derivative and a derivative ratio spectrophotometric method—were used to determine tazarotene in the presence of its alkaline degradation product (HD) using methanol as a solvent. A linear relationship was obtained in the range 1–10 µg ml⁻¹ for both methods. By applying the proposed methods, it was possible to determine tazarotene in its pure powdered from with accuracy 99.35 ± 1.410 (n = 10) for the first derivative method and 99.45 ± 1.053 (n = 10) for the derivative ratio method. First derivative and derivative ratio methods were used for the analysis of laboratory‐prepared mixtures containing different ratios of tazarotene and its degradation product and they were valid in the presence of up to 70% and 80% degradation product, respectively. The proposed methods were validated and found to be suitable as stability‐indicating assay methods for tazarotene in pharmaceutical formulations. Copyright © 2010 John Wiley & Sons, Ltd.     

Chromatographic determination of drugs of abuse in vitreous humor using solid‐phase extraction

A simple method is presented for the simultaneous determination of morphine, 6‐acetylmorphine, codeine, cocaine, benzoylecgonine, cocaethylene, methadone and 2‐ethylidene‐1,5‐dimethyl‐3,3‐diphenylpyrrolidine (EDDP) in vitreous humor by high‐performance liquid chromatography with photodiode array detector after solid‐phase extraction with Oasis® HLB cartridges and dichloromethane as eluent. The chromatographic process was carried out using an XTerra® RP8 column (250 × 4.6 mm i.d., 5 µm particle size) and a mobile phase composed of acetonitrile and pH 6.5 phosphate buffer in gradient mode. A linear response from the detector was obtained within the concentration range of 0.1–4 µg ml^?1, with correlation coefficients higher than 0.99. The limits of detection were lower than 30 ng ml^?1 for all the drugs studied, the coefficients of variation fluctuated between 0.1 and 12.4%, and the average recoveries were higher than 78% for all the drugs except for EDDP, with a value of 66.4%. Finally, the proposed method was applied to 15 vitreous humor samples coming from individuals who had died from opiate and/or cocaine overdose, showing consumption of cocaine in 14 cases, methadone in five cases and heroin in three cases. Average concentrations of 0.30 µg ml^?1 for morphine, 0.24 µg ml^?1 for 6‐acetylmorphine, 0.10 µg ml^?1 for codeine, 0.81 µg ml^?1 for cocaine, 1.26 µg ml^?1 for benzoylecgonine, 0.15 µg ml^?1 for cocaethylene, 0.11 µg ml^?1 for methadone and 0.68 µg ml^?1 for EDDP were obtained. Copyright © 2012 John Wiley & Sons, Ltd.     

Enhanced spectrophotometric determination of two antihyperlipidemic mixtures containing ezetimibe in pharmaceutical preparations

Two spectrophotometric methods are presented for the simultaneous determination of ezetimibe/simvastatin and ezetimibe/atorvastatin binary mixtures in combined pharmaceutical dosage forms without prior separation. The first is the derivative ratio method where the amplitudes of the first derivative of the ratio spectra (¹DD) at 299.5 and 242.5 nm were found to be linear with ezetimibe and simvastatin concentrations in the ranges 0.5–20 µgml^?1 and 1–40 µgml^?1, respectively, whereas the amplitudes of the first derivative of the ratio spectra (¹DD) at 289.5 and 288 nm were selected to determine ezetimibe and atorvastatin in the concentration ranges 5–50 µgml^?1 and 1–40 µgml^?1, respectively. The second is the H‐point standard additions method; absorbances at the two pairs of wavelengths, 228 and 242 nm or 238 and 248 nm, were monitored while adding standard solutions of ezetimibe or simvastatin, respectively. For the analysis of ezetimibe/atorvastatin mixture, absorbance values at 226 and 248 nm or 212 and 272 nm were monitored while adding standard solutions of ezetimibe or atorvastatin, respectively. Moreover, differential spectrophotometry was applied for the determination of ezetimibe in the two mixtures without any interference from the co‐existing drug. This was performed by measurement of the difference absorptivities (ΔA) of ezetimibe in 0.07 M 30% methanolic NaOH relative to that of an equimolar solution in 0.07 M 30% methanolic HCl at 246 nm. The described methods are simple, rapid, precise and accurate for the determination of these combinations in synthetic mixtures and dosage forms. Copyright © 2010 John Wiley & Sons, Ltd.     

Stability‐indicating methods for the determination of famciclovir in the presence of its alkaline‐induced degradation product

Five sensitive, selective and precise stability‐indicating methods are presented for the determination of famciclovir (FCV) in the presence of its alkaline‐induced degradation product. Method A utilizes the first derivative spectrophotometry at 321 nm. Method B depends on using the first derivative of the ratio spectrophotometry (DD¹) by measurement of the amplitude at 256 nm. Method C is based on the reaction of FCV with hydroxylamine to form hydroxamic acid, causing the hydroxamic acid to react with triferric ion to form ferric hydroxamate that is measured at 503 nm. Method D is based on the separation of FCV from its degradation product followed by densitometric measurement of the bands at 304 nm. The separation was carried out on silica gel 60 F₂₅₄, using chloroform: methanol (70:30, v/v) as a mobile phase. Method E is based on a high performance liquid chromatographic (HPLC) separation of FCV from its degradation product using an ODS column with a mobile phase consisting of methanol–50 mM dipotassium hydrogen phosphate (25:75, v/v, pH 3.0)with UV detection at 304 nm. Regression analysis showed good correlation in the concentration ranges 16–72 µg/ml, 40–240 µg/ml, 40–240 µg/ml, 0.75–5.25 µg/band and 20–240 µg/ml with percentage recoveries of 99.65 ± 0.85, 100.27 ± 0.91, 99.72 ± 0.84, 100.65 ± 1.52 and 99.88 ± 0.50 for methods A, B, C, D and E, respectively. These methods are suitable as stability‐indicating methods for the determination of FCV in the presence of its degradation product either in bulk powder or in pharmaceutical formulation. Statistical analysis of the results has been carried out revealing high accuracy and good precision. Copyright © 2010 John Wiley & Sons, Ltd.     

Simultaneous determination of metformin hydrochloride and pioglitazone hydrochloride in binary mixture and in their ternary mixture with pioglitazone acid degradate using spectrophotometric and chemometric methods

In this work two well known oral hypoglycemic drugs that are administered in combination for patients with type‐II diabetes were simultaneously determined. Several spectrophotometric methods were developed and validated for the determination of metformin hydrochloride (MET), pioglitazone hydrochloride (PIO) and pioglitazone acid degradate (PIO Deg). Derivative, ratio derivative, isosbestic and chemometric‐assisted spectrophotometric methods were developed. The first derivative (D₁) method was used for the determination of MET in the range of 5–30 µg.mL^?1 and PIO in the range of 10–90 µg.mL^?1 by measuring the peak amplitude at 247 nm and 280 nm, respectively. The concentration of PIO was calculated directly at 268 nm. The first derivative of ratio spectra (DD₁) method used the peak amplitudes at 238 nm and 248.6 nm for the determination of MET in the range of 5–30 µg.mL^?1. In the isosbestic point method (ISO), the total mixture concentration was calculated by measuring the absorbance at 254.6 nm. Classical least squares (CLS), principal component regression (PCR) and partial least squares (PLS‐2) were used for the quantitative determination of MET, PIO and PIO Deg. The methods developed have the advantage of simultaneous determination of the cited components without any pre‐treatment. Resolution and quantitative determination of PIO degradate with a minimum concentration of 3 µg.mL^?1 in drug samples was done. The proposed methods were successfully used to determine each drug and the acid degradate in a laboratory‐prepared mixture and pharmaceutical preparations. The results were statistically compared using one‐way analysis of variance (ANOVA). The methods developed were satisfactorily applied to the analysis of the two drugs in pharmaceutical formulations. Copyright © 2009 John Wiley & Sons, Ltd.     

Electrochemical study of spiramycin and its determination in pharmaceutical preparation

Spiramycin (SPY) is a medium‐spectrum antibiotic with high effectiveness against Gram‐positive bacteria. The voltammetric behaviour of spiramycin was studied using differential pulse polarography (DPP) and square wave polarography (SWP). The drug in Britton‐Robinson buffer (pH 11.5) is reduced at ? 1.45 V, giving rise to a well‐defined cathodic peak using hanging mercury drop electrode (HMDE) versus Ag/AgCl electrode. This peak is attributed to the reduction of the aldehyde group. The results proved that the reduction of SPY is an irreversible diffusion‐controlled process. The diffusion current‐concentration relationship was shown to be rectilinear over the range of 20–80 and 0.8–80 µg ml^?1 using DPP and SWP modes, respectively, with detection limit of 8.5 µg ml^?1 (1.01 × 10^?5 M) and 0.46 µg ml^?1 (5.46 × 10^?7 M) for DPP and SWP modes, respectively. A mechanism is postulated for the reduction of SPY. The proposed techniques were successfully applied to the determination of the studied compound either in pure form or in its formulation. Copyright © 2010 John Wiley & Sons, Ltd.     

In vitro evaluation of the effects of perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) on IL‐2 production in human T‐cells

Perfluorinated compounds, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), have been shown to alter various immune functions suggesting they are immunotoxic. This study assessed the effects of PFOS and PFOA on interleukin (IL)‐2 production in the human Jurkat T‐cell line and PFOS in healthy human primary T cells. Jurkat cells were stimulated with phytohemagglutinin (PHA)/phorbol myristate acetate (PMA), anti CD‐3/anti CD‐28, or anti CD‐3, and dosed with 0, 0.05, 0.1, 0.5, 1, 5, 10, 50, 75, or 100 µg ml^?1 PFOS or 0, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 5, or 10 µg ml^?1 PFOA. Jurkat cells stimulated with PHA/PMA or anti CD‐3 exhibited decreased IL‐2 production beginning at 50 µg PFOS ml^?1 and 5 µg PFOS ml^?1 respectively, but stimulation with anti‐CD3/anti‐CD28 resulted in no changes compared with the control. Addition of the PPAR‐alpha antagonist GW6471 to PFOS‐dosed cells stimulated with PHA/PMA resulted in decreases in IL‐2 production starting at 50 µg PFOS ml^?1, which suggests PFOS affected T‐cell IL‐2 production via PPAR‐alpha‐independent mechanisms. Exposure to PFOA, PFOA + GW6471, or PFOS + PFOA in Jurkat cells resulted in no significant differences in IL‐2 production. In vitro dosing studies using healthy primary human CD4+ T cells were consistent with the Jurkat results. These data demonstrated that PFOA did not impact IL‐2 production, but PFOS suppressed IL‐2 production in both a human cell line and human primary cells at dose levels within the high end of the human exposure range. A decrease in IL‐2 production is characteristic of autoimmune diseases such as systemic lupus erythematosus and should be further investigated. Copyright © 2014 John Wiley & Sons, Ltd.     

Evaluation of cytotoxic concentration–time response in A549 cells exposed to respirable α‐quartz

A causal pathway between quartz, silicosis and lung cancer has been postulated. The aim of our study was to assess cytotoxic effects induced in a human lung epithelial cell line (A549) by exposure to α‐quartz. Cells were exposed to respirable α‐quartz (SRM1878a, NIST) at 25, 50 or 100 µg ml^?1 for 24 h and at 50 or 100 µg ml^?1 for 48 h. Cytotoxic effects were analyzed by scanning electron microscopy (SEM), apoptotic morphology analysis with Hoechst staining and lactate dehydrogenase (LDH) release assay. In cells exposed to α‐quartz for 24 h, a concentration‐dependent bleb development and in particular the localization of blebs at the cell edge at higher concentrations were observed. The blebbing phenomenon was more evident after 48 h of exposure to 50 or to 100 µg ml^?1 of α‐quartz and large blebs were localized at the cell edge. At the same concentrations surface smoothing was also observed. Moreover the presence of holes and tears was detected at the highest concentration both at 24 and 48 h. Results of morphological analysis with Hoechst stain evidenced an increase concentration–time dependent of apoptotic cell percentage that was more marked after 48 h exposure to 100 µg ml^?1 and a prevalence of late apoptosis stage with the increase of exposure time and concentration. Cells exposed to 50 or 100 µg ml^?1 of α‐quartz for 24 and 48 h produced a significant increase in LDH release. The concentration–time‐dependent bleb induction evidenced by SEM correlates with the increase of apoptotic cells and LDH activity release, demonstrating the onset of cytotoxic effects in human lung cells exposed to α‐quartz. Copyright © 2009 John Wiley & Sons, Ltd.     

A validated HPLC method for the simultaneous determination of naftidrofuryl oxalate and its degradation product (metabolite), naftidrofuryl acid: applications to pharmaceutical tablets and biological samples

A simple, sensitive, and selective reverse phase‐high performance liquid chromatography (RP‐HPLC) method was developed and validated for the simultaneous determination of naftidrofuryl oxalate (NF) and its hydrolytic degradation product (metabolite), naftidrofuryl acid (NFA). Chromatographic separation was achieved on Spheri‐5 RP‐C8 (5 µm) (220 × 4.6 mm i.d.) column using a mobile phase composed of acetonitrile, 0.05 M sodium acetate and triethylamine (40 : 60 : 0.1, by volume) adjusted to pH 5.5 using glacial acetic acid. The mobile phase was pumped at flow rate 1.5 ml/min. The UV detector was set at 225 nm and quantification of the analytes was based on measuring the peak areas. The method was proved to be accurate and precise with linearity ranges of 0.1–25 and 0.2–25 µg ml^‐1 for NF and NFA, respectively. The limits of detection were 0.03 and 0.04 µg ml^‐1 for NF and NFA, respectively. The method was applied to serve three goals: (1) stability‐indicating assay of the parent drug NF in its pharmaceutical formulation, (2) determination of the degradation product NFA down to a level of 0.005% in the presence of large excess of the parent drug, and (3) drug monitoring of naftidrofuryl and its metabolite, naftidrofuryl acid, in human plasma/urine samples taken from a healthy volunteer treated with 200 mg oral dose of naftidrofuryl oxalate. The proposed method proved to be accurate, precise, and reliable in all these application fields. Copyright © 2012 John Wiley & Sons, Ltd.     

In vitro evaluation of the cytotoxic and genotoxic effects of artemether,an antimalarial drug,in a gastric cancer cell line (PG100)

Artemisinin is a sesquiterpene lactone endoperoxide, obtained from Artemisia annua, and extensively used as an antimalarial drug. Many studies have reported the genotoxic and cytotoxic effects of artemisinins; however, there are no studies that compare such effects between cancer cell lines and normal human cells after treatment with artemether, an artemisinin derivative. Gastric cancer is the fourth most frequent type of cancer and the second highest cause of cancer mortality worldwide. Thus, the aim of this study was to evaluate the in vitro genotoxic and cytotoxic effects induced by artemether in gastric cancer cell line (PG100) and compare them with the results obtained in human lymphocytes exposed to the same conditions. We used MTT (3‐(4,5‐methylthiazol‐2‐yl)‐2, 5‐diphenyl‐tetrazolium bromide) assay, comet assay and ethidium bromide/acridine orange viability staining to evaluate the cytotoxic and genotoxic effects of artemether in PG100. MTT assay showed a decrease in the survival percentages for both cell types treated with different concentrations of artemether (P < 0.05). PG100 also showed a significant dose‐dependent increase in DNA damage index at concentrations of 119.4 and 238.8 µg ml^?1 (P < 0.05). Our results showed that artemether induced necrosis in PG100 at concentrations of 238.8 and 477.6 µg ml^?1, for all the tested harvest times (P < 0.05). In lymphocytes, artemether induced both apoptosis and necrosis at concentrations of 238.8 and 477.6 µg ml^?1, for all the tested harvest times (P < 0.05). In conclusion, human lymphocytes were more sensitive to the cytotoxic effects of the antimalarial drug than the gastric cancer cell line PG100. Copyright © 2011 John Wiley & Sons, Ltd.     

Comparison of in vitro cytotoxicity,estrogenicity and anti‐estrogenicity of triclosan,perfluorooctane sulfonate and perfluorooctanoic acid

Concern with increasing levels of emerging contaminants exists on a global scale. Three commonly observed emerging environmental contaminants: triclosan (2,4,4‐trichloro‐2′‐hydroxydiphenyl ether), a synthetic, broad‐spectrum antibacterial agent, and perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), used in stain‐ and water‐resistant treatments, have become distributed ubiquitously across ecosystems and have been detected in wildlife and humans. MCF‐7 BOS human breast cancer cells were used to investigate the potential for cytotoxicity, estrogenicity and anti‐estrogenicity of these three compounds at environmentally relevant concentrations using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐5‐(3‐carboxymethoxyphenyl)‐2‐(4‐sulfophenyl)‐2H‐tetrazolium, inner salt assay (MTS) and the E‐SCREEN bioassay. The doses used were 0.002–200 µg ml^?1 for triclosan and 0.03–30 µg ml^?1 for PFOS and PFOA. Quantitative results from the MTS assay revealed no significant cytotoxicity at lower concentrations for any of the test compounds; however, both triclosan and PFOA were cytotoxic at the highest concentrations examined (100–200 and 30 µg ml^?1, respectively), while PFOS showed no significant cytotoxicity at any of the concentrations tested. Positive estrogenic responses (P < 0.05) were elicited from the E‐SCREEN at all concentrations examined for triclosan and PFOA and at 30 µg ml^?1 for PFOS. Further, significant anti‐estrogenic activity (P < 0.05) was detected for all compounds tested at all concentrations when cells were co‐exposed with 10^?9 m 17‐β estradiol (E₂). The overall results demonstrated that triclosan, PFOS and PFOA have estrogenic activities and that co‐exposure to contaminants and E₂ produced anti‐estrogenic effects. Each of these compounds could provide a source of xenoestrogens to humans and wildlife in the environment. Published 2011. This article is a US Government work and is in the public domain in the USA.     

Hypothesis testing for the validation of the kinetic spectrophotometric methods for the determination of lansoprazole in bulk and drug formulations via Fe(III) and Zn(II) chelates

Point and interval hypothesis tests performed to validate two simple and economical, kinetic spectrophotometric methods for the assay of lansoprazole are described. The methods are based on the formation of chelate complex of the drug with Fe(III) and Zn(II). The reaction is followed spectrophotometrically by measuring the rate of change of absorbance of coloured chelates of the drug with Fe(III) and Zn(II) at 445 and 510 nm, respectively. The stoichiometric ratio of lansoprazole to Fe(III) and Zn(II) complexes were found to be 1:1 and 2:1, respectively. The initial‐rate and fixed‐time methods are adopted for determination of drug concentrations. The calibration graphs are linear in the range 50–200 µg ml⁻¹ (initial‐rate method), 20–180 µg ml⁻¹ (fixed‐time method) for lansoprazole‐Fe(III) complex and 120–300 (initial‐rate method), and 90–210 µg ml⁻¹ (fixed‐time method) for lansoprazole‐Zn(II) complex. The inter‐day and intra‐day precision data showed good accuracy and precision of the proposed procedure for analysis of lansoprazole. The point and interval hypothesis tests indicate that the proposed procedures are not biased. Copyright © 2010 John Wiley & Sons, Ltd.     

Pharmacokinetic study of two acetylcholinesterase reactivators, trimedoxime and newly synthesized oxime K027, in rat plasma

K027 [1‐(4‐hydroxyiminomethylpyridinium)‐3‐(4‐carbamoylpyridinium)–propane dibromide] is a promising new reactivator of organophosphate‐ or organophosphonate‐inhibited acetylcholinesterase (AChE) with low acute toxicity and broad spectrum efficacy. The aim of the present study was to compare the pharmacokinetics of both compounds. Male Wistar rats (body weight = 320 ± 10 g) were administered a single intramuscular dose of K027 (22.07 mg kg^?1) and an equimolar dose of trimedoxime. Blood was collected at various time intervals until 180 min. Plasma samples were analyzed by reversed‐phase HPLC with ultraviolet (UV) detection. The recovery of both oximes from the plasma was approximately 90% and a linear relationship (R² > 0.998) was observed between the peak areas and concentrations of calibrated standards in the range 1–100 µg ml^?1. Near‐identical plasma profiles were obtained for both compounds. No differences were found in the mean ± SD values of C_max (18.6 ± 2.5 vs 20.0 ± 6.3 µg ml^?1, P = 0.72) and AUC_0–180min (2290 ± 304 vs 2269 ± 197 min µg ml^?1, P = 0.84). However, the percentage coefficient of variation of the first‐order rate constant of absorption (k_a) was 3‐fold higher (P < 0.01) providing evidence for more erratic absorption of intramuscular trimedoxime as compared with K027. In conclusion, oxime K027 might have superior pK properties that may be translated in its faster absorption and subsequent tissue distribution. Copyright © 2011 John Wiley & Sons, Ltd.     

Investigation on cobalt‐oxide nanoparticles cyto‐genotoxicity and inflammatory response in two types of respiratory cells

The increasing use of cobalt oxide (Co₃O₄) nanoparticles (NPs) in several applications and the suggested genotoxic potential of Co‐oxide highlight the importance of evaluating Co₃O₄ NPs toxicity. Cyto‐genotoxic and inflammatory effects induced by Co₃O₄ NPs were investigated in human alveolar (A549), and bronchial (BEAS‐2B) cells exposed to 1–40 µg ml^–1. The physicochemical properties of tested NPs were analysed by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Cytotoxicity was studied to analyze cell viability (WST1 test) and membrane damage (LDH assay), direct/oxidative DNA damage was assessed by the Formamido‐pyrimidine glycosylase (Fpg)‐modified comet assay and inflammation by interleukin (IL)‐6, IL‐8 and tumor necrosis factor‐alpha (TNF‐α) release (ELISA). In A549 cells, no cytotoxicity was found, whereas BEAS‐2B cells showed a viability reduction at 40 µg ml^–1 and early membrane damage at 1, 5 and 40 µg ml–1. In A549 cells, direct and oxidative DNA damage at 20 and 40 µg ml^–1 were detected without any effects on cytokine release. In BEAS‐2B cells, significant direct DNA damage at 40 µg ml^–1 and significant oxidative DNA damage with a peak at 5 µg ml^–1, that was associated with increased TNF‐α release at 1 µg ml^–1 after 2 h and increased IL‐8 release at 20 µg ml^–1 after 24 h, were detected. The findings show in the transformed alveolar cells no cytotoxicity and genotoxic/oxidative effects at 20 and 40 µg ml^–1. In normal bronchial cells, moderate cytotoxicity, direct DNA damage only at the highest concentration and significant oxidative‐inflammatory effects at lower concentrations were detected. The findings confirm the genotoxic‐oxidative potential of Co₃O₄ NPs and show greater sensitivity of BEAS‐2B cells to cytotoxic and oxidative‐inflammatory effects suggesting the use of different cell lines and multiple end‐points to elucidate Co₃O₄ NPs toxicity. Copyright © 2015 John Wiley & Sons, Ltd.     

Multi‐walled carbon nanotubes induce cytotoxicity and genotoxicity in human lung epithelial cells

The increasing use of nanomaterials in consumer products highlights the importance of understanding their potential toxic effects. We evaluated cytotoxic and genotoxic/oxidative effects induced by commercial multi‐walled carbon nanotubes (MWCNTs) on human lung epithelial (A549) cells treated with 5, 10, 40 and 100 µg ml^?1 for different exposure times. Scanning electron microscopy (SEM) analysis, MTT [3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide] and lactate dehydrogenase (LDH) assays were performed to evaluate cytotoxicity. Fpg‐modified comet assay was used to evaluate direct‐oxidative DNA damage. LDH leakage was detected after 2, 4 and 24 h of exposure and viability reduction was revealed after 24 h. SEM analysis, performed after 4 and 24 h exposure, showed cell surface changes such as lower microvilli density, microvilli structure modifications and the presence of holes in plasma membrane. We found an induction of direct DNA damage after each exposure time and at all concentrations, statistically significant at 10 and 40 µg ml^?1 after 2 h, at 5, 10, 100 µg ml^?1 after 4 h and at 10 µg ml^?1 after 24 h exposure. However, oxidative DNA damage was not found. The results showed an induction of early cytotoxic effects such as loss of membrane integrity, surface morphological changes and MWCNT agglomerate entrance at all concentrations. We also demonstrated the ability of MWCNTs to induce early genotoxicity. This study emphasizes the suitability of our approach to evaluating simultaneously the early response of the cell membrane and DNA to different MWCNT concentrations and exposure times in cells of target organ. The findings contribute to elucidation of the mechanism by which MWCNTs cause toxic effects in an in vitro experimental model. Copyright © 2012 John Wiley & Sons, Ltd.     

Potent enhancement of transdermal absorption and stability of human tyrosinase plasmid (pAH7/Tyr) by Tat peptide and an entrapment in elastic cationic niosomes

Abstract

Enhancement of transdermal absorption through rat skin and stability of the human tyrosinase plasmid (P) using Tat (T) and an entrapment in elastic cationic niosomes (E) were described. E (Tween61:cholesterol:DDAB at 1:1:0.5 molar ratio) were prepared by the freeze-dried empty liposomes (FDELs) method using 25% ethanol. TP was prepared by a simple mixing method. TPE was prepared by loading T and P in E at the T:P:E ratio of 0.5:1:160 w/w/w. For gel formulations, P, TP, PE and TPE were incorporated into Carbopol 980 gel (30?µg of plasmid per 1?g of gel). For the transdermal absorption studies, the highest cumulative amounts and fluxes of the plasmid in viable epidermis and dermis (VED) were observed from the TPE of 0.31?±?0.04?µg/cm² and 1.86?±?0.24?µg/cm²/h (TPE solution); and 4.29?±?0.40?µg/cm² and 25.73?±?2.40?µg/cm²/h (TPE gel), respectively. Only plasmid from the PE and TPE could be found in the receiving solution with the cumulative amounts and fluxes at 6?h of 0.07?±?0.01?µg/cm² and 0.40?±?0.08?µg/cm²/h (PE solution); 0.10?±?0.01?µg/cm² and 0.60?±?0.06?µg/cm²/h (TPE solution); 0.88?±?0.03?µg/cm² and 5.30?±?0.15?µg/cm²/h (PE gel); and 1.02?±?0.05?µg/cm² and 6.13?±?0.28?µg/cm²/h (TPE gel), respectively. In stability studies, the plasmid still remained at 4?±?2?°C and 25?±?2?°C of about 48.00–65.20% and 27.40–51.10% (solution); and 12.34–38.31% and 8.63–36.10% (gel), respectively, whereas at 45?±?2?°C, almost all the plasmid was degraded. These studies indicated the high potential application of Tat and an entrapment in elastic cationic niosomes for the development of transdermal gene delivery system.     

A toxicokinetic comparison of norditerpenoid alkaloids from Delphinium barbeyi and D. glaucescens in cattle

Cattle are poisoned by N‐(methylsuccinimido) anthranoyllycoctonine type (MSAL‐type) and 7,8‐methylenedioxylycoctonine type (MDL‐type) norditerpenoid alkaloids in Delphinium spp. Alkaloids in D. glaucescens are primarily of the MSAL‐type, while D. barbeyi is a mixture of MSAL and MDL‐types. The objectives of this study were to determine and compare the toxicokinetics of selected alkaloids from D. glaucescens and D. barbeyi in cattle. The two species of larkspur were dosed to three groups of Angus steers via oral gavage at doses of 8 mg kg^?1 MSAL‐type alkaloids for D. barbeyi and either 8.0 or 17.0 mg kg^?1 MSAL‐type alkaloids for D. glaucescens. In cattle dosed with D. barbeyi, serum deltaline (MDL‐type) concentrations peaked at 488 ± 272 ng ml^?1 at 3 h and serum methyllycaconitine (MSAL‐type) concentrations peaked at 831 ± 369 ng ml^?1 at 6 h. Deltaline was not detected in the serum of cattle dosed with D. glaucescens. Serum methyllycaconitine concentrations peaked at 497 ± 164 ng ml^?1 at 18 h, and 1089 ± 649 ng ml^?1 at 24 h for the 8 mg kg^?1 and 17 mg kg^?1 doses of D. glaucescens respectively. There were significant differences between the maximum serum concentrations and the area under the curve for the two doses of D. glaucescens but not D. barbeyi. Results from this experiment support the recommendation that approximately 7 days are required to clear 99% of the toxic alkaloids from the serum of animals orally dosed with D. barbeyi or D. glaucescens, and that MDL‐type alkaloids play an important role in the toxicity of Delphinium spp. in cattle. Published in 2010 by John Wiley & Sons, Ltd.     

Urinary excretion of the main metabolites of methamphetamine,including p-hydroxymethamphetamine-sulfate and p-hydroxymethamphetamine-glucuronide,in humans and rats

The urinary concentrations of the main metabolites of methamphetamine (MA), specifically p-hydroxymethamphetamine-sulfate (?p-OHMA-Sul) and p-hydroxymethamphetamine-glucuronide (?p-OHMA-Glu), were directly measured in MA users and rats using an optimized LC-ESI MS method. The concentrations of the two conjugates in 50 MA human users’ urine ranged from 0.09 to 88.6?µM (0.02–21.7?µg?ml^?1) for p-OHMA-Sul and from <0.05 to 7.13?µM (<0.02–2.43?µg?ml^?1) for p-OHMA-Glu; the ratios of sulfate to glucuronide (S/G ratios) ranged from 2.2 to 37.1 (13.8?±?8.1). The results demonstrate that the sulfation is quantitatively more important than glucuronidation for the conjugation of p-OHMA in humans. The urinary concentration time-dependency in two MA users also revealed that the conjugates were mostly excreted in urine within 3 days post-intake. In contrast, in rat, almost all of the conjugated p-OHMA (>99%) was excreted as the glucuronide in urine. These findings confirm that a large species variation exists in the conjugation of p-OHMA between humans and rats.     

Phenanthrene decreases neutrophil function by disrupting intracellular redox balance

The aim of the present work was to evaluate whether the treatment of human neutrophils with phenanthrene (PHN) can alter the phagocytic and microbicidal capacity of these cells by causing a disruption in redox balance. Peripheral neutrophils from healthy subjects were treated for up to 24 h with increasing concentrations of phenanthrene. Phagocytic/microbicidal activities, antioxidant enzymes, oxidative lesions (thiobarbituric acid‐reactive substances and protein thiol and carbonyl groups) and redox signaling compounds (intracellular Ca²⁺, superoxide, hydrogen peroxide and nitric oxide) were monitored on neutrophils exposed to 10 µg PHN ml^?1. Cell viability decreased abruptly at PHN concentrations above 10 µg ml^?1 (LC50 = 20.86 ± 0.51 µg ml^?1 and p‐sigmoidal slope = 19.88 ± 10.11). Phagocytic and microbicidal capacities were decreased by 60 and 82%, respectively. Substantial increases in total‐/Mn‐SOD, catalase, glutathione peroxidase and glutathione reductase activities (by 61, 15, 87, 245 and 70%, respectively) matched the oxidative injury obtained in TBARS (2.5‐fold higher) and protein thiol (54% lower). Diminished productions of superoxide by 18% and hydrogen peroxide by 29% were observed in association to exacerbated calcium (27%) and nitric oxide (63%) levels. The data indicate that phenanthrene might be associated with substantial reduction in human neutrophil functions due to severe intracellular redox imbalances. Copyright © 2010 John Wiley & Sons, Ltd.