The effects of oral administration of the novel muscarinic receptor antagonist DA-8010 on overactive bladder in rat with bladder outlet obstruction.

BACKGROUND: DA-8010 is a novel compound developed for the treatment of overactive bladder (OAB) and urinary incontinence. The aims of this study were to investigate the effects of DA-8010 on OAB in a rat model. METHODS: Study animals were divided into the following five groups of seven animals each: a sham-operated control group, a control group with partial bladder outlet obstruction (BOO) (OAB group), and three DA-8010 (doses of 0.3 mg/kg/day, 1 mg/kg/day, and 3 mg/kg/day, respectively) with partial BOO groups. Oral administration of the drugs was continued for 14 days after 2 weeks of partial BOO. After 4 weeks of partial BOO, cystometrography was performed in all groups. Additionally, pro-inflammatory cytokines, Rho-kinases, and histology of the bladder were analyzed. RESULTS: There was a significant increase in the contraction interval and a decrease in contraction pressure in the 3 mg/kg/day DA-8010 group versus those in the OAB group. Rho kinase was also significantly decreased in the DA-8010 3 mg/kg/day dosage treatment group. The increased ratio of collagen to smooth muscle after partial BOO was significantly attenuated in the DA-8010 3 mg/kg/day dosage group. CONCLUSIONS: Oral administration of DA-8010 at 3 mg/kg/day improved findings in an OAB rat model induced by partial BOO. Our results suggest that the novel muscarinic receptor antagonist DA-8010 may be a promising drug for treating patients with OAB.

An observational analysis of the impact of indoor residual spraying with non-pyrethroid insecticides on the incidence of malaria in Ségou Region, Mali: 2012-2015.

BACKGROUND: Ségou Region in Central Mali is an area of high malaria burden with seasonal transmission, high access to and use of long-lasting insecticidal nets (LLINs), and resistance to pyrethroids and DDT well documented in Anopheles gambiae s.l. (the principal vector of malaria in Mali). Ségou has recently received indoor residual spraying (IRS) supported by Mali's collaboration with the US President's Malaria Initiative/Africa Indoor Residual Spraying programme. From 2012 to 2015, two different non-pyrethroid insecticides: bendiocarb in 2012 and 2013 and pirimiphos-methyl in 2014 and 2015, were used for IRS in two districts. This report summarizes the results of observational analyses carried out to assess the impact of these IRS campaigns on malaria incidence rates reported through local and district health systems before and after spraying. METHODS: A series of retrospective time series analyses were performed on 1,382,202 rapid diagnostic test-confirmed cases of malaria reported by district routine health systems in Ségou Region from January 2012 to January 2016. Malaria testing, treatment, surveillance and reporting activities remained consistent across districts and years during the study period, as did LLIN access and use estimates as well as An. gambiae s.l. insecticide resistance patterns. Districts were stratified by IRS implementation status and all-age monthly incidence rates were calculated and compared across strata from 2012 to 2014. In 2015 a regional but variable scale-up of seasonal malaria chemoprevention complicated the region-wide analysis; however IRS operations were suspended in Bla District that year so a difference in differences approach was used to compare 2014 to 2015 changes in malaria incidence at the health facility level in children under 5-years-old from Bla relative to changes observed in Barouéli, where IRS operations were consistent. RESULTS: During 2012-2014, rapid reductions in malaria incidence were observed during the 6 months following each IRS campaign, though most of the reduction in cases (70% of the total) was concentrated in the first 2 months after each campaign was completed. Compared to non-IRS districts, in which normal seasonal patterns of malaria incidence were observed, an estimated 286,745 total fewer cases of all-age malaria were observed in IRS districts. The total cost of IRS in Ségou was around 9.68 million USD, or roughly 33.75 USD per case averted. Further analysis suggests that the timing of the 2012-2014 IRS campaigns (spraying in July and August) was well positioned to maximize public health impact. Suspension of IRS in Bla District after the 2014 campaign resulted in a 70% increase in under-5-years-old malaria incidence rates from 2014 to 2015, significantly greater (p = 0.0003) than the change reported from Barouéli District, where incidence rates remained the same. CONCLUSIONS: From 2012 to 2015, the annual IRS campaigns in Ségou are associated with several hundred thousand fewer cases of malaria. This work supports the growing evidence that shows that IRS with non-pyrethroid insecticides is a wise public health investment in areas with documented pyrethroid resistance, high rates of LLIN coverage, and where house structures and population densities are appropriate. Additionally, this work highlights the utility of quality-assured and validated routine surveillance and well defined observational analyses to rapidly assess the impact of malaria control interventions in operational settings, helping to empower evidence-based decision making and to further grow the evidence base needed to better understand when and where to utilize new vector control tools as they become available.

Evaluation of Bacopa monniera for its synergistic activity with rivastigmine in reversing aluminum-induced memory loss and learning deficit in rats.

The objective of this study was to evaluate the synergistic activity of Bacopa monniera with Rivastigmine against aluminum-chloride (AlCl3)-induced cognitive impairment in rats. Adult male Wistar rats were divided into ten groups (n = 10) and subjected to their assigned treatments for 42 days. On the 20(th) day of the respective drug treatments, all the animals were trained in the Morris water maze (retention latency) and the elevated plus maze (transfer latency). After the initial training, the retention latency (RL) and the transfer latency (TL) were evaluated on the 21(st) and the 42(nd) days of the study. Chronic administration of AlCl3 caused significant memory impairment associated with increased RL in the Morris water maze task and increased TL in the elevated plus maze test. Interestingly, animals treated with oral administration of B. monniera (100 and 200 mg/kg), Rivastigmine (5 mg/kg) or a combination of B. monniera (100 mg/kg) with Rivastigmine (5 mg/kg) showed significant protection against AlCl3-induced memory impairment compared to animal treated with AlCl3per se. Additionally, the neuroprotective effect of B. monniera (100 and 200 mg/kg) was significantly improved when supplemented with Rivastigmine (5 mg/kg). These findings suggest that treatment with a combination of B. monniera with Rivastigmine may be highly beneficial compared to their per-se treatment.

The effect of rivastigmine on the LPS-induced suppression of GnRH/LH secretion during the follicular phase of the estrous cycle in ewes.

This study was designed to determine the effect of a potent subcutaneously injected acetylcholinesterase inhibitor, rivastigmine (6mg/animal), on the gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) release during inflammation induced by an intravenous lipopolysaccharide (LPS) (400ng/kg) injection in ewes during the follicular phase of the estrous cycle. The results are expressed as the mean values from -2 to -0.5h before and +1 to +3h after treatment. Rivastigmine decreased the acetylcholinesterase concentration in the blood plasma from 176.9±9.5 to 99.3±15.1µmol/min/ml. Endotoxin suppressed LH (5.4±0.6ng/ml) and GnRH (4.6±0.4pg/ml) release; however, the rivastigmine injection restored the LH concentration (7.8±0.8ng/ml) to the control value (7.8±0.7ng/ml) and stimulated GnRH release (7.6±0.8pg/ml) compared to the control (5.9±0.4pg/ml). Immune stress decreased expression of the GnRH gene and its receptor (GnRH-R) in the median eminence as well as LHß and GnRH-R in the pituitary. In the case of the GnRH and LHß genes, the suppressive effect of inflammation was negated by rivastigmine. LPS stimulated cortisol and prolactin release (71.1±14.7 and 217.1±8.0ng/ml) compared to the control group (9.0±5.4 and 21.3±3.5ng/ml). Rivastigmine also showed a moderating effect on cortisol and prolactin secretion (43.1±13.1 and 169.7±29.5ng/ml). The present study shows that LPS-induced decreases in GnRH and LH can be reduced by the AChE inhibitor. This action of the AChE inhibitor could result from the suppression of pro-inflammatory cytokine release and the attenuation of the stress response. However, a direct stimulatory effect of ACh on GnRH/LH secretion should also be considered.

Potential therapeutic effect of nanobased formulation of rivastigmine on rat model of Alzheimer's disease.

BACKGROUND: To sustain the effect of rivastigmine, a hydrophilic cholinesterase inhibitor, nanobased formulations were prepared. The efficacy of the prepared rivastigmine liposomes (RLs) in comparison to rivastigmine solution (RS) was assessed in an aluminium chloride (AlCl(3))-induced Alzheimer's model. METHODS: Liposomes were prepared by lipid hydration (F1) and heating (F2) methods. Rats were treated with either RS or RLs (1 mg/kg/day) concomitantly with AlCl(3) (50 mg/kg/day). RESULTS: The study showed that the F1 method produced smaller liposomes (67.51 ± 14.2 nm) than F2 (528.7 ± 15.5 nm), but both entrapped the same amount of the drug (92.1% ± 1.4%). After 6 hours, 74.2% ± 1.5% and 60.8% ± 2.3% of rivastigmine were released from F1 and F2, respectively. Both RLs and RS improved the deterioration of spatial memory induced by AlCl(3), with RLs having a superior effect. Further biochemical measurements proved that RS and RLs were able to lower plasma C-reactive protein, homocysteine and asymmetric dimethy-larginine levels. RS significantly attenuated acetylcholinesterase (AChE) activity, whereas Na(+)/K(+)-adenosine triphosphatase (ATPase) activity was enhanced compared to the AlCl(3)-treated animals; however, RLs succeeded in normalization of AChE and Na(+)/K(+) ATPase activities. Gene-expression profile showed that cotreatment with RS to AlCl(3)-treated rats succeeded in exerting significant decreases in BACE1, AChE, and IL1B gene expression. Normalization of the expression of the aforementioned genes was achieved by coadministration of RLs to AlCl(3)-treated rats. The profound therapeutic effect of RLs over RS was evidenced by nearly preventing amyloid plaque formation, as shown in the histopathological examination of rat brain. CONCLUSION: RLs could be a potential drug-delivery system for ameliorating Alzheimer's disease.

Amphiphilic polyaspartamide copolymer-based micelles for rivastigmine delivery to neuronal cells.

A novel polysorbate-80 (PS(80))-attached amphiphilic copolymer comprising a hydrophilic α,ß-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA) backbone and hydrophobic squalenyl-C(17) (Sq(17)) portions was synthesized and characterized; the formation of polymeric micelles was also evaluated. Rivastigmine free-base (Riv), a hydrophobic drug employed to treat Alzheimer's disease, was chosen as model drug to investigate micelle's ability to incorporate hydrophobic molecules and target them to neuronal cells. Micelle formation was studied through analyses including fluorescence spectroscopy and 2D (1)H-NMR NOESY experiments. Finally, the capacity of Riv-loaded micelles, versus free drug, to penetrate mouse neuroblastoma cells (Neuro2a) was evaluated. 2D (1)H-NMR NOESY experiments demonstrated that the PHEA-EDA-Sq(17)-PS(80) copolymer self-assembles into micelle structures in water, with a micelle core formed by hydrophobic interaction between Sq(17) alkyl chains. Fluorescence probe studies revealed the CAC of PHEA-EDA-Sq(17)-PS(80) micelles, which was 0.25 mg mL(-1). The micelles obtained had a nanometric hydrodynamic diameter with narrow size distribution and negative surface charge. The PHEA-EDA-Sq(17)-PS(80) micelles incorporated a large amount of Riv, and the system maintained the stability of Riv after incubation in human plasma. An in vitro biological assay evidenced no cytotoxic effects of either empty or loaded micelles on the neuronal cell lines tested. Moreover, the micelles are internalized by neuroblastoma cell lines with drug uptake depending on the micelles concentration.

Alterations in the rabbit lymphoid tissue after bendiocarb administration.

Various pesticides have immuno-suppressive effects, and thus the organisms become responsive to viral, bacterial and parasitic diseases and neoplasm. The aim of the study was to observe the structure of the small intestine (height of enterocytes and crypts), mucosal lymphoid tissue (Payer's patches, lymphocytes in lamina propria) and a lymph node after administration of bendiocarb (2,2-dimethyl-1,3-benzodioxol-4-yl-methylcarbamate) on days 3, 10, 20, 30 and 60 of the experiment. The height of the observed enterocytes showed an increasing tendency. On days 20, 30 and 60 we also observed an increase in diameter of crypts located in intestinal epithelium. The number of cells in lamina propria mucosae was significantly reduced on days 20 and 30 after administration of bendiocarb. Observations of the lymph node showed that on days 10 and 20 there was a significant increase in relative volume of medulla at the expense of the relative volume of the cortex and a decrease in the number of lymphocytes. However, we recorded an increase in diameter of lymphocytes. The intracellular parasite Toxoplasma gondii (T. gondii) belongs to the most common pathogenic parasites in the world and it can cause serious health complications in pregnant and immunodeficient individuals. DNA isolation, standard polymerase chain reaction (PCR) and visualization in a 2.5 % agarose gel, the presence of DNA T. gondii was detected in no examined rabbit brain samples. Using real time PCR T. gondii DNA was detected and quantified in the three rabbit brain samples (10 %).

Rivastigmine reduces tobacco craving in alcohol-dependent smokers.

INTRODUCTION: Although alcohol-dependent smokers represent an important group for applying smoking interventions, a sufficient pharmacotherapy has not been established in this high-risk group so far. METHODS: In order to examine the effect of the acetylcholinesterase inhibitor rivastigmine on tobacco dependence, we performed a 12-week, randomized, placebo-controlled trial. 26 alcohol-dependent smokers were randomized to rivastigmine 6 mg/day (n=14) or placebo (n=12). Assessments on addictive behavior included carbon monoxide (CO), severity of tobacco dependence (FTND), daily smoked cigarettes (diaries), and craving for tobacco (QSU) and alcohol (AUQ). RESULTS: ANOVA revealed a significant treatment-by-time interaction for tobacco consumption and tobacco craving (each p<0.0001). The rivastigmine group showed a decrease in daily smoked cigarettes (-30%), in exhaled carbon monoxide (-32%) and in tobacco craving (-18%) whereas controls did not show significant changes. ANCOVA revealed rivastigmine effects to be more prominent in smokers suffering from more severe tobacco dependence. None of the patients developed an alcohol relapse or an increase in alcohol craving. DISCUSSION: Our preliminary data indicate an effect of rivastigmine on tobacco craving and consumption. This pilot study encourages further investigation of acetylcholinesterase-inhibitors as a promising treatment approach regarding tobacco dependence.

Rivastigmine for the prevention of postoperative delirium in elderly patients undergoing elective cardiac surgery--a randomized controlled trial.

OBJECTIVE: Cardiac surgery is frequently followed by postoperative delirium, which is associated with increased 1-year mortality, late cognitive deficits, and higher costs. Currently, there are no recommendations for pharmacologic prevention of postoperative delirium. Impaired cholinergic transmission is believed to play an important role in the development of delirium. We tested the hypothesis that prophylactic short-term administration of oral rivastigmine, a cholinesterase inhibitor, reduces the incidence of delirium in elderly patients during the first 6 days after elective cardiac surgery. DESIGN: : Double-blind, randomized, placebo-controlled trial. SETTING: One Swiss University Hospital. PATIENTS: One hundred twenty patients aged 65 or older undergoing elective cardiac surgery with cardiopulmonary bypass. INTERVENTION: Patients were randomly assigned to receive either placebo or 3 doses of 1.5 mg of oral rivastigmine per day starting the evening before surgery and continuing until the evening of the sixth postoperative day. MEASUREMENTS AND MAIN RESULTS: The primary predefined outcome was delirium diagnosed with the Confusion Assessment Method within 6 days postoperatively. Secondary outcome measures were the results of daily Mini-Mental State Examinations and clock drawing tests, and the use of a rescue treatment consisting of haloperidol and/or lorazepam in patients with delirium. Delirium developed in 17 of 57 (30%) and 18 of 56 (32%) patients in the placebo and rivastigmine groups, respectively (p = 0.8). There was no treatment effect on the time course of Mini-Mental State Examinations and clock drawing tests (p = 0.4 and p = 0.8, respectively). There was no significant difference in the number of patients receiving haloperidol (18 of 57 and 17 of 56, p = 0.9) or lorazepam (38 of 57 and 35 of 56, p = 0.6) in the placebo and rivastigmine groups, respectively. CONCLUSION: This negative or, because of methodologic issues, possibly failed trial does not support short-term prophylactic administration of oral rivastigmine to prevent postoperative delirium in elderly patients undergoing elective cardiac surgery with cardiopulmonary bypass.

In situ-forming oleogel implant for rivastigmine delivery.

PURPOSE: To provide a simplified dosing schedule and potentially reduce side effects associated to peak plasma concentrations, an in situ-forming oleogel implant was studied for the sustained-release of rivastigmine. MATERIALS AND METHODS: The gel was prepared by dissolving 5-10% (w/w) N-stearoyl L: -alanine methyl ester (SAM) organogelator in safflower oil containing either dissolved rivastigmine or its dispersed hydrogen tartrate salt. Rheological analysis, differential scanning calorimetry, and infrared spectroscopy were carried out to assess the impact of drug incorporation on the oleogel; this was followed by in vitro and in vivo release studies. RESULTS: A weakening of intermolecular interactions was suggested by gel-sol transition temperature drops of 10-15 degrees C upon incorporation of dissolved drug. Meanwhile, the dispersed drug salt induced minimal or no changes in transition temperature. Gels containing dispersed rivastigmine had the lowest burst in vitro (<15% in 24 h). In vivo, the 10% SAM formulation containing dispersed rivastigmine provided prolonged drug release within the therapeutic range for 11 days, with peak plasma levels well below the toxic threshold and up to five times lower than for the control formulation. CONCLUSIONS: This study established SAM gels to be a promising option for sustained-release formulations in the treatment of Alzheimer's Disease.