Investigational New Drug‐Directed Toxicology and Pharmacokinetic Study of 4‐[3‐(2‐Nitro‐1‐Imidazolyl)‐Propylamino]‐7‐Chloroquinoline Hydrochloride (NLCQ‐1, NSC 709257) in Beagle Dogs

Abstract: 4‐[3‐(2‐Nitro‐1‐imidazolyl)‐propylamino]‐7‐chloroquinoline hydrochloride (NLCQ‐1), a 2‐nitroimidazole‐based hypoxia‐selective cytotoxin has been shown to target hypoxic regions of solid tumours. The present study is one of several pre‐clinical toxicology studies conducted in support of an ‘investigational new drug’ (IND) application to test this agent as an adjuvant to radio/chemotherapy for the treatment of cancer in humans. Twenty‐four dogs were each assigned to one vehicle control group or to one of three test article‐treated groups (three dogs/sex/treatment group). Intravenous (i.v.) doses of 0, 2.74, 5.48 and 10.95 mg/kg/day (54.8, 109.6 or 219 mg/m²/day) were administered on a per day × 5 days (qd × 5) schedule. NLCQ‐1 was formulated as a solution in sterile saline at 1.5 mg/ml. None of the dogs died during this 33‐day study. With few exceptions, most of the clinical signs of toxicity were noted within 2 hr following dosing in the 10.95 mg/kg/day dose group. These observations included aggressive behaviour, ataxia, tachypnea, emesis, hypoactivity, excessive salivation, tremors, and involuntary urination and defecation. Aggressive behaviour was judged to be dose‐limiting. No clinical signs of toxicity were noted during the 28‐day observation period that followed the 5‐day dose period. Findings in a functional observation battery examination were consistent with the clinical observations. No drug‐related effects were noted on the body weight or food consumption values, and no drug‐related changes were noted during ocular examinations made on these animals prior to scheduled necropsy or during examination of electrocardiogram recordings made at 15 min. and 2 hr after dosing on days 1 and 5. No definitive changes in haematology, clinical chemistry or coagulation values were noted in dogs treated with NLCQ‐1. NLCQ‐1 was detected in the plasma of treated dogs on days 1 and 5, up to 60 min. after dosing (2.74 and 5.48 mg/kg/day) and up to 8 hr after dosing (10.95 mg/kg/day). There was a dose‐related increase in maximum plasma concentration of NLCQ‐1 at 5 min. after dosing; comparable concentrations were noted on days 1 and 5. No definitive test article‐related lesions were noted during microscopic evaluation of tissues from dogs in this study, although lesions noted at the injection site and in the vascular tissue, lungs, thymus, prostate gland, muscle, adrenal cortex and tongue may have resulted from treatment with this drug. Any drug‐related toxicity noted was readily reversible and not cumulative. No sex difference was detected in the susceptibility to NLCQ‐1‐induced toxicity.     

Preclinical efficacy and safety assessment of nano-oxaliplatin oral formulation prepared by novel Fat Employing Supercritical Nano System,the FESNS®

Background: It is expected that oral cancer drug will provide ease of administration with decreased unwanted events to the patients. The purpose of this study is to prepare oral formulation of nano-oxaliplatin and examine the anticancer efficacy and safety. Nano-oxaliplatin was prepared utilizing our proprietary technology, the Fat Employing Supercritical Nano System (FESNS^®).

Result: It showed regular nanoparticles with a mean diameter of around 212?nm. When nano-oxaliplatin was orally administered in rats, the relative bioavailability of nano-oxaliplatin oral formulations was about 25–31% compared to the Eloxatin^® administered intravenously (i.v.). For antitumor activity in xenograft model, nano-oxaliplatin oral formulation (20?mg/kg, once daily) presented superior inhibition of tumor growth against Eloxatin^® (5?mg/kg, i.v. once a week). In single-dose toxicity, dead animals were observed at or above 1000?mg/kg (LD₅₀: 888.38?mg/kg for male; 725.43?mg/kg for female rats). In repeated dose toxicity, there were hematological changes observed in rats, which is a common finding in the class of cancer drugs. It was thought that the expected dose level that has cytotoxic effect without death would be 30?mg/kg in rats, which is double the dose level of Eloxatin^®.

Conclusion: Nano-oxaliplatin oral formulation changed the pharmacokinetic behavior of crude oxaliplatin, thus increasing oral bioavailability as well as its anticancer activity. In addition, single and repeated dose toxicity studies indicated that oral nano-oxaliplatin is superior in toxicity at the pharmacologically active doses compared to Eloxatin^® in rats. Nano-oxaliplatin oral formulation has potential as a novel anticancer therapy.     

Antitumor efficacy of solid dispersion of paclitaxel prepared by supercritical antisolvent process in human mammary tumor xenografts

The efficacy of intravenous chemotherapy for breast cancer has been improving with newer agents. However, the fractional improvements in breast cancer progression-free survival were quite modest and these small gains are obtained at the cost of significant toxicity. To address this problem, paclitaxel solid dispersion (PSD), a Cremophor EL-free formulation prepared by supercritical antisolvent process using hydrophilic polymers as carrier, was developed to avoid Cremophor EL-associated toxicities in Taxol^®. In this study, we investigated the antitumor activity of PSD as a function of dose from 12 to 24 mg/kg (dose–effect) and compared antitumor activity of 18 mg/kg dose of PSD to that of Taxol^® (relative efficacy) in female athymic mice bearing mammary tumor xenografts. In dose–effect study, PSD showed excellent activity and good tolerance at all doses tested with a significant increase in tumor growth inhibition, recurrence time, survival percent, and number of tumor free survivors compared to control (P < 0.01). In all of the four doses tested in this study, the magnitude of the increase in effectiveness of PSD was quite substantial and statistically significant with similar degrees of weight loss. In relative efficacy study of PSD and Taxol^®, PSD demonstrated a greater degree of tumor growth inhibition with 10 complete tumor regressions (100%) and eight tumor-free survivors (80% cure). Besides, mice treated with PSD regained their initial body weight by day 27 following initial acute weight reductions, whereas mice treated with Taxol^® required more than 40 days to regain their initial weight. In conclusion, PSD prepared by supercritical process was very effective and safe, without Cremophor EL-associated toxicities of Taxol^®, in human mammary tumor xenografts with possibilities of dose escalation.     

Unravelling the cardiovascular effects induced by α‐terpineol: A role for the nitric oxide–cGMP pathway

1. α‐Terpineol is a monoterpene found in the essential oils of several aromatic plant species. In the present study, we investigated the mechanisms underlying the cardiovascular changes induced by α‐terpineol in rats. 2. In normotensive rats, administration of α‐terpineol (1, 5, 10, 20 and 30 mg/kg, i.v.) produced a dose‐dependent hypotension (?10 ± 3, ?20 ± 8, ?39 ± 16, ?52 ± 21 and ?57 ± 23 mmHg, respectively; n = 5) followed by tachycardia. The hypotensive responses to 1, 5, 10, 20 and 30 mg/kg, i.v., α‐terpineol were significantly attenuated following the administration of N^G‐nitro‐l‐ arginine methyl ester (l ‐NAME; 20 mg/kg, i.v.; ?2 ± 1, ?5 ± 2, ?7 ± 3, ?22 ± 9 and ?22 ± 10 mmHg, respectively; P < 0.05; n = 5). 3. In 10 μmol/L phenylephrine (PE)‐precontracted mesenteric artery rings, α‐terpineol (10^?12 to 10^?5 mol/L) caused a concentration‐dependent relaxation (maximum relaxation 61 ± 6%; n = 7). After removal of the endothelium, the vasorelaxation elicited by α‐terpineol was attenuated (maximum relaxation 20 ± 1%; P < 0.05; n = 7). In addition, vasorelaxation induced by α‐terpineol in rings pretreated with 100 or 300 μmol/L l ‐NAME, 30 μmol/L hydroxocobalamin or 10 μmol/L 1H‐[1,2,4]oxadiazolo[4,3‐a]quinoxalin‐1‐one was attenuated (maximum relaxation 18 ± 3, 23 ± 3, 24 ± 7 and 21 ± 1%, respectively; n = 6; P < 0.05). 4. Furthermore, in a rabbit aortic endothelial cell line, 10^?6, 10^?5 and 10^?4 mol/L α‐terpineol induced concentration‐dependent increases in nitric oxide (NO) levels (12 ± 6, 18 ± 9 and 34 ± 12%Δ fluorescence, respectively; n = 3). 5. In conclusion, using combined functional and biochemical approaches in the present study, we were able to demonstrate that α‐terpineol‐induced hypotension and vasorelaxation are mediated, at least in part, by the endothelium, most likely via NO release and activation of the NO–cGMP pathway.     

Labedipinedilol‐A: A vanilloid‐based α/β‐adrenoceptor blocker with calcium entry blocking and long‐acting antihypertensive properties

The combination of β‐adrenoceptor blockade and vasodilator action have proved highly useful in antihypertensive therapy. Studies of the mechanisms of action of labedipinedilol‐A that combine these effects within a single molecule are described in this report. Intravenous labedipinedilol‐A (0.1–1.0 mg/kg) produced dose‐dependent hypotensive and bradycardia responses for above 1.0 h, significantly different from nifedipine (0.5 mg/kg, i.v.)‐induced hypotensive and reflex tachycardia activities in pentobarbital‐anesthetized Wistar rats. Pretreatment with labedipinedilol‐A also inhibited phenylephrine (20 μg/kg, i.v.)‐induced hypertensive and (‐)isoprenaline (0.5 μg/kg, i.v.)‐induced tachycardia effects. Oral administration of labedipinedilol‐A (5–50 mg/kg) in spontaneously hypertensive rats (SHR) reduced the blood pressure and heart rate for 24 h but did not increase heart rate. Labedipinedilol‐A (10^–7–10^–5 M) competitively antagonized (‐)isoprenaline (10^–10–10^–4M)‐induced positive chronotropic and inotropic effects of the isolated rat atria and tracheal relaxation responses of the isolated guinea pig tissues. Labedipinedilol‐A also prevented the rate‐increasing effects of increased extracellular Ca²⁺ (3.0–9.0 mM) in a concentration‐dependent manner. In the isolated rat aorta, labedipinedilol‐A competitively antagonized CaCl₂ and norepinephrine‐induced contractions with pKCa^–1 and pA₂ values of 8.46 ± 0.05 and 8.28 ± 0.03 and had a potent effect of inhibiting high K⁺‐induced vasocontraction. Furthermore, labedipinedilol‐A, in an equal antagonist activity, inhibited norepinephrine‐induced phasic and tonic contraction. In the cultured blood vessel smooth muscle cell (A7r5 cell line), KCl, norepinephrine, and Bay K 8644‐induced intracellular calcium changes were decreased after application of labedipinedilol‐A (10^–9–10^–6 M). The binding characteristics of labedipinedilol‐A were evaluated in [³H]CGP‐12177 binding to ventricle and lung and [³H]nitrendipine and [³H]prazosin binding to brain membranes in rats. The ‐logIC₅₀ values of labedipinedilol‐A for β₁‐, β₂‐, and α₁‐adrenoceptor and calcium channel, were 8.17 × 10^–7 M, 8.20 × 10^–7 M, 2.20 × 10^–8 M, and 2.46 × 10^–8 M, respectively. Labedipinedilol‐A‐induced sustained depressor effect was mainly attributed to its calcium entry and α‐adrenoceptor blocking activities in the blood vessel. Sustained bradycardia effect resulted from β‐adrenoceptor and calcium entry blocking, which deleted the sympathetic activation‐associated reflex tachycardia in the heart. Drug Dev. Res. 49:94–108, 2000. © 2000 Wiley‐Liss, Inc.     

Radiosynthesis of 2‐exo‐(2′‐[18F]Fluoro‐3′‐(4‐fluorophenyl)‐pyridin‐5′‐yl)‐7‐azabicyclo[2.2.1]heptane ([18F]F2PhEP), a potent epibatidine‐based radioligand for nicotinic acetylcholine receptor PET imaging

2‐exo‐(2′‐Fluoro‐3′‐(4‐fluorophenyl)‐pyridin‐5′‐yl)‐7‐azabicyclo[2.2.1]heptane (F₂PhEP), a novel, epibatidine‐based, α4β2‐selective nicotinic acetylcholine receptor antagonist of low toxicity, as well as the corresponding N‐Boc‐protected chloro‐ and bromo derivatives as precursors for labelling with fluorine‐18 were synthesized from 7‐tert‐butoxycarbonyl‐7‐azabicyclo[2.2.1]hept‐2‐ene in 13, 19 and 8% overall yield, respectively. [¹⁸F]F₂PhEP was prepared in 8–9% overall yield (non‐decay‐corrected) using 1 mg of the bromo derivative in the following two‐step radiochemical process: (1) no‐carrier‐added nucleophilic heteroaromatic ortho‐radiofluorination with the activated K[¹⁸F]F‐Kryptofix^®₂₂₂ complex in DMSO using microwave activation at 250 W for 90 s, followed by (2) quantitative TFA‐induced removal of the N‐Boc protective group. Radiochemically pure (>95%) [¹⁸F]F₂PhEP (1.48–1.66 GBq, 74–148 GBq/µmol) was obtained after semi‐preparative HPLC (Symmetry^® C18, eluent aqueous 0.05 M NaH₂PO₄ CH₃CN: 78/22 (v:v)) in 75–80 min starting from an 18.5 GBq aliquot of a cyclotron‐produced [¹⁸F]fluoride production batch. Copyright © 2006 John Wiley & Sons, Ltd.     

Safety against nephrotoxicity in paclitaxel treatment: Oral nanocarrier as an effective tool in preclinical evaluation with marked in vivo antitumor activity

Oral paclitaxel (PTXL) formulations freed from cremophor^® EL (CrEL) is always in utmost demand by the cancerous patients due to toxicities associated with the currently marketed formulation. In our previous investigation [Int. J. Pharm. 2014; 460:131], we have developed an oral oil based nanocarrier for the lipophilic drug, PTXL to target bioavailability issue and patient compliance. Here, we report in vivo antitumor activity and 28-day sub-chronic toxicity of the developed PTXL nanoemulsion. It was observed that the apoptotic potential of oral PTXL nanoemulsion significantly inhibited the growth of solid tumor (59.2 ± 7.17%; p < 0.001) without causing any explicit toxicity. The 6.5 mg/kg and 3 mg/kg oral PTXL nanoemulsion dose did not cause any notable alteration in haematological, biochemical/structural characteristics during 28-day sub-chronic toxicity studies in the experimental mice. Whereas, the toxicity of 12.8 mg/kg body weight dose showed decrease in RBC, haemoglobin and neutrophil counts. In contrast, marketed PTXL (Taxol^®) was found to be comparatively more toxic to the experimental animals. Taxol^® treatment resulted glomerulonephritis in histopathological examination, which could be correlated with increased level of creatinine and associated nephrotoxicity. This investigations conclude that the developed oral nanoemulsion presents a viable therapeutics bio-system to step towards clinical application as well as substitute CrEL based PTXL formulations.     

Safety evaluation of AB-LIFE® (Lactobacillus plantarum CECT 7527, 7528 and 7529): Antibiotic resistance and 90-day repeated-dose study in rats

AB-LIFE^® is a probiotic product consisting of equal parts of three strains of Lactobacillus plantarum (CECT 7527, 7528, and 7529) blended with inert excipients. Whole genome sequencing was performed on each of the three strains. Antibiotic resistance was evaluated by genomic mining for resistance genes, and assessment for transferability. No risk of transfer potential was identified for any antibiotic resistance genes in the three strains. AB-LIFE^® was evaluated for potential subchronic oral toxicity in rats, with dosages of 300 and 1000 mg/kg BW/day (equivalent to 5.55 × 10¹⁰ and 1.85 × 10¹¹ CFU/kg BW/day). Survival of the three test strains through the gastrointestinal tract was supported by fecal analysis. No adverse effects were identified with respect to in-life parameters, clinical or anatomic pathology, translocation, or fecal chemical analyses. The no-observed-adverse-effect level (NOAEL) for AB-LIFE^® in male and female rats was 1000 mg/kg BW/day (1.85 × 10¹¹ CFU of AB-LIFE^®/kg BW/day), the highest dose level evaluated. These results, in conjunction with a previous acute toxicity study in rats, support the conclusion that AB-LIFE^® is safe for human consumption.     

Curcumin,Silybin Phytosome® and α‐R‐Lipoic Acid Mitigate Chronic Hepatitis in Rat by Inhibiting Oxidative Stress and Inflammatory Cytokines Production

Chronic hepatitis is recognized as a worldwide health problem that gradually progresses towards cirrhosis and hepatocellular carcinoma. Despite the large number of experiments using animal models for allergic hepatitis, it is still difficult to produce a picture of chronic hepatitis. Therefore, this study was conducted to introduce an animal model approximating to the mechanism of chronicity in human hepatitis. The study also aimed to examine the hepatoprotective effects of curcumin, silybin phytosome^® and α‐R‐lipoic acid against thioacetamide (TAA)‐induced chronic hepatitis in rat model. TAA was administered intraperitoneally at a dose of 200 mg/kg three times weekly for 4 weeks. At the end of this period, a group of rats was killed to assess the development of chronic hepatitis in comparison with their respective control group. TAA administration was then discontinued, and the remaining animals were subsequently allocated into four groups. Group 1 was left untreated, whereas groups 2–4 were allowed to receive daily oral doses of curcumin, silybin phytosome^® or α‐R‐lipoic acid, respectively, for 7 weeks. Increases in hepatic levels of malondialdehyde associated with TAA administration were inhibited in groups receiving supplements. Furthermore, glutathione depletion, collagen deposition, macrophage activation and nuclear factor κappa‐B expression as well as tumour necrosis factor‐α and interleukin‐6 levels were significantly decreased in response to supplements administration. Serological analysis of liver function and liver histopathological examination reinforced the results. The above evidence collectively indicates that the antioxidant and anti‐inflammatory activities of curcumin, silybin phytosome^® and α‐R‐lipoic acid may confer therapeutic efficacy against chronic hepatitis.     

Glucagon Produced by Recombinant DNA Technology: Repeated Dose Toxicity Studies,Intravenous Administration to CD Rats and Beagle Dogs for Four Weeks

The toxicity of glucagon produced by recombinant DNA technology (Glucagon (ge)^®) was studied by daily intravenous administration to rats and dogs for 4 weeks. Pancreatic glucagon of bovine or porcine origin (Glucagon Novo^®) was used as a reference control in the dogs. Glucagon (ge)^® has the same sequence of the 29 animo acids as pancreatic glucagon of humans, cows, pigs, rats and dogs. The dosages were 0 (control), 0.2, 1.0 and 5.0 mg Glucagon (ge)^®/kg/day in the rats, and 0 (control), 1.0 and 5.0 mg Glucagon (ge)^® and 5.0 mg Glucagon (Novo)^®/kg/day in the dogs. The studies complied with current EEC, US and Japanese guidelines for 4 week toxicity studies of drugs. All dose levels were well tolerated. The plasma glucose and cardiovascular responses to dosing were monitored in the dogs and found to be in agreement with well-known effects of pancreatic glucagon. The most consistent finding in both species was an increase in liver weight. This change was without concomitant pathological deviations in the other parameters examined. There were no differences in the reaction of dogs following treatment with Glucagon (ge)^® or Glucagon (Novo)^®. A dose of 1 mg Glucagon (ge)^®/kg/day was regarded as a clear no-toxic-effect-level in both species.     

Hyaline droplet accumulation in kidney of rats treated with hexachloro‐1:3‐butadiene: influence of age,dose and time‐course

The present research investigates the occurrence of hyaline droplet (HD) accumulation related to age, dose and time after treatment in male Wistar rats given a single i.p. injection of hexachloro‐1:3‐butadiene (HCBD). In the study on age, rats from 1 to 12 months of age were treated with 100 mg kg^?1 body weight (b.w.) HCBD dose. Rats treated at 2 months of age showed a greater accumulation of HD than the other age groups; HD accumulation was not observed in 1‐month‐old rats. In the dose–response study, the treatment with 25, 50 and 100 mg kg^?1 b.w. at 2 months of age caused HD accumulation in the proximal convoluted tubule at all doses, with the 100 mg kg^?1 b.w. group slightly more affected. Finally, in the time‐course study, rats treated with a 100 mg kg^?1 b.w. dose at 2 months of age and sacrificed at 6, 12, 24, 48, 72 and 96 h post‐dosing showed a time‐related HD accumulation in terms of incidence and severity, after 6 h, with a peak at 24 and 48 h and decreasing at 72 and 96 h. The present results show that HD accumulation is an early finding, and is unrelated to dose level and particularly evident in rats of 2 month of age. These findings in male rats treated with HCBD emphasize the importance of considering the age of rats at the start of a study. The more sensitive model was used in the detection of nephrotoxic effects of chemicals. Copyright © 2011 John Wiley & Sons, Ltd.     

High doses of 2,2′‐dithienyl diselenide cause systemic toxicity in rats: an in vitro and in vivo study

Organoselenium compounds have important pharmacological properties. However, these compounds can cause toxicity, typically related to oxidation of endogenous thiols. The aim of this study was to investigate whether 2,2′‐dithienyl diselenide (DTDS) has potential toxicity in vitro and in vivo. Therefore, sulfhydryl‐containing enzyme activities, δ‐aminolevulinic acid dehydratase (δ‐ALA‐D) and Na⁺–K⁺‐ATPase were used to predict DTDS toxicity in rat brain homogenate in vitro. In in vivo experiments, a DTDS administration (50 or 100 mg kg^?1, p.o.) to rats was performed and toxicological parameters were determined. DTDS inhibited δ‐ALA‐D (IC₅₀ 2 µm ) and Na⁺–K⁺‐ATPase (IC₅₀ 17 µm ) activities in vitro. The inhibitory effect of DTDS on δ‐ALA‐D and Na⁺–K⁺‐ATPase activities was restored by dithiothreitol. DTDS (5–25 µm ) elicited a thiol oxidase‐like activity. In vivo, DTDS (50 and 100 mg kg^?1) caused systemic toxicity, evidenced by a decrease in water and food intakes and body weight gain, as well as the death of rats. DTDS at the dose of 100 mg kg^?1 increased plasma alanine and aspartate aminotransferase activities and decreased urea levels. At 50 and 100 mg kg^?1, it increased lipid peroxidation levels. At the highest dose, DTDS inhibited δ‐ALA‐D activity. By contrast, Na⁺–K⁺‐ATPase activity and antioxidant defense were not altered in the brains of rats exposed to DTDS. In conclusion, interaction with the cisteinyl residues seems to mediate the inhibitory effect of DTDS on sulfhydryl‐containing enzymes in vitro. In addition, high oral doses of DTDS induce toxicity in rats. Copyright © 2011 John Wiley & Sons, Ltd.     

Effects of Jatropha oil on rats following 28‐day oral treatment

Jatropha oil is an emerging feedstock for the production of biodiesels. The increasing use of this nonedible, toxic oil will result in higher potential for accidental exposures. A repeated‐dose 28‐day oral toxicity study was conducted to provide data for risk assessment. Jatropha oil diluted in corn oil was administered by gavage to male and female rats at 0.5, 5, 50 and 500 mg kg^?1 body weight per day for 28 consecutive days. Control rats were administered corn oil only. The growth rates and consumption of food and water were monitored. At necropsy, organs were weighed and hematological parameters assessed. Serum clinical chemistry and C‐reactive protein were measured and histological examinations of organs and tissues were performed. Markedly depressed growth rate was observed in males and females receiving Jatropha oil at 500 mg kg^?1 per day. Decreased white blood cell and lymphocyte counts were detected in females at 50 and 500 mg kg^?1 per day and in males at 500 mg kg^?1 per day. These changes were correlated to mild and reversible histological changes in male and female spleens. In the liver, a mild increase in portal hepatocytes cytoplasm density was observed in males and females, while periportal vacuolation was observed exclusively in females. Mild acinar proliferation was observed in the female mammary glands at all dose levels. It is concluded that Jatropha oil produces adverse effects on female rats starting at 50 mg kg^?1 per day with decreased white blood cell and lymphocyte counts and at 500 mg kg^?1 per day in both genders in term of depressed growth rates. Copyright © 2011 John Wiley & Sons, Ltd.     

Lithium attenuates peripheral neuropathy induced by paclitaxel in rats

Abstract: As a cancer chemotherapeutic agent, paclitaxel (Taxol^®) causes dose‐related peripheral neuropathy in human beings. The mechanisms underlying this toxicity are currently unknown, and there are no validated treatments for its prevention or control. To assess whether lithium as a pre‐treatment and at subtherapeutic dose could prevent the peripheral neuropathy produced by it, rats were treated with paclitaxel (2 mg/kg i.p. every other day for a total of 16 times) and/or lithium chloride (300 mg/l) via water supply. General toxicity and body‐weight were measured regularly during the experiment. To evaluate the sensory and motor neuropathy hot‐plate, open‐field test and nerve conduction velocity were used. In rats treated with only paclitaxel, there was behavioural, electrophysiological and histological evidence of a mixed sensorimotor neuropathy after 16 injections. Lithium robustly reduced the rate of mortality and general toxicity. Paclitaxel‐induced sensorimotor neuropathy was significantly improved as indicated by changes in hotplate latency, total distance moved and a significant increase in sciatic, sural and tail sensory or motor nerve conduction velocity. The same results were observed in histopathological examinations; however, dorsal root ganglion neurons did not significantly change in the paclitaxel‐treated groups. These results suggest that lithium, at subtherapeutic doses, can prevent both motor and sensory components of paclitaxel neuropathy in rats. Thus, lithium at these doses, as an inexpensive and relatively safe salt, may be useful clinically in preventing the neuropathy induced by paclitaxel treatment.     

Physiologically based modeling of p‐tert‐octylphenol kinetics following intravenous,oral or subcutaneous exposure in male and female Sprague–Dawley rats

The objective of this study was to develop a physiologically based pharmacokinetic (PBPK) model for p‐tert‐octylphenol (OP) for understanding the qualitative and quantitative determinants of its kinetics in Sprague–Dawley rats. Compartments of the PBPK model included the liver, richly perfused tissues, poorly perfused tissues, reproductive tissues, adipose tissue and subcutaneous space, in which OP uptake was described as a blood flow‐ or a membrane diffusion‐limited process. The PBPK model successfully simulated previously published data on blood and tissue OP concentrations in Sprague–Dawley rats following oral, intravenous (i.v.) or subcutaneous (s.c.) routes. The model predicted that OP concentrations would reach 6.8, 13.8 and 27.9 ng ml^?1 (male) and 7.2, 14.7 and 31.4 ng ml^?1 (female), 4 h after a single i.v. dose of 2, 4 and 8 mg kg^?1, respectively. The model also predicted that OP concentrations would reach 53.3, 134.8 and 271.2 ng ml^?1 (male) and 87.4, 221.4 and 449.7 ng ml^?1 (female) 4 h after a single oral dose (50, 125 and 250 mg kg^?1) and that, 4 h after a single s.c. dose (125 mg kg^?1), OP concentrations would reach 111.3 ng ml^?1 (male) and 121.6 ng ml^?1. A marked sex difference was seen in blood and tissue OP concentrations. This was reflected in the model by a gender‐specific maximal velocity of metabolism (V_max) that was higher (1.77×) in male than in female rats. Further studies are required to elucidate the mechanism underlying the gender differences and to evaluate whether that is also observed in humans. Copyright © 2010 John Wiley & Sons, Ltd.     

Physiological Effects of a Novel Immune Stimulator Drug, (1,4)‐α‐d‐Glucan,in Rats

Abstract: The (1,4)‐α‐d ‐glucan (α‐d ‐glucan), derived from medicinal plant, Tinospora cordifolia, activates human lymphocytes with downstream synthesis of the pro‐ and anti‐inflammatory cytokines, in vitro. We investigated physiological and immunological effects of a low and a high dose of α‐d ‐glucan (0.5 and 10 mg/kg), in vivo, testing the hypothesis that intravenous administration of α‐d ‐glucan does not affect haemodynamic, respiratory, haematological, and immune responses in normal rats. Male rats (300–400 g) were anaesthetized, tracheostomized, and catheterized in one femoral artery and vein. The mean arterial blood pressure and heart rate were continuously recorded. The baselines for gas exchange, differential blood cell count, and plasma concentration of TNF‐α, IL‐1β, IL‐4, IL‐6, and IFN‐γ were determined. Rats were then randomly assigned to controls (n = 7), a low dose (0.5 mg/kg; n = 10), and a high dose (10 mg/kg; n = 7) of α‐d ‐glucan for a six 6 hr study period. Gas exchange, differential cell count, plasma concentration of TNF‐α, IL‐1β, IL‐4, IL‐6, and IFN‐γ, and mean arterial blood pressure values remained within physiological range. Intravenous administration of 10 mg/kg α‐d ‐glucan created tachycardia, associated with hyperventilation, and significant reductions in the blood haemoglobin and haematocrit concentrations. We suggest that these in vivo effects of α‐d ‐glucan should be considered for future clinical and/or experimental trials.     

Radiosynthesis of 7‐chloro‐N,N‐dimethyl‐5‐[11C]methyl‐4‐oxo‐3‐phenyl‐3,5‐dihydro‐4H‐pyridazino[4,5‐b]indole‐1‐acetamide, [11C]SSR180575, a novel radioligand for imaging the TSPO (peripheral benzodiazepine receptor) with PET

SSR180575 (7‐chloro‐N,N,5‐trimethyl‐4‐oxo‐3‐phenyl‐3,5‐dihydro‐4H‐pyridazino[4,5‐b]indole‐1‐acetamide) is the lead compound of an original pyridazinoindole series of potent and highly selective TSPO (peripheral benzodiazepine receptor) ligands. Isotopic labeling of SSR180575 with the short‐lived positron‐emitter carbon‐11 (T_1/2: 20.38 min) at its 5‐methylpyridazino[4,5‐b]indole moiety as well as at its N,N‐dimethylacetamide function by methylation of the corresponding nor‐analogues was investigated. Best results in terms of radiochemical yields and purities were obtained for the preparation of [indole‐N‐methyl‐¹¹C]SSR180575, where routine production batches of 4.5–5.0 GBq of radiochemically pure (>99%) i.v. injectable solutions (specific radioactivities: 50–90 GBq/ µ mol) could be prepared within a total synthesis time of 25 min (HPLC purification included) starting from a 55 GBq [¹¹C]CO₂ cyclotron production batch (non‐decay‐corrected overall radiochemical yields: 8–9%). The process comprises (1) trapping at ?10°C of [¹¹C]methyl triflate in DMF (300 µ l) containing 0.2–0.3 mg of the indole precursor for labeling and 4 mg of K₂CO₃ (excess); (2) heating at 120°C for 3 min; (3) dilution of the residue with 0.5 ml of the HPLC mobile phase and (4) purification using semi‐preparative reversed‐phase HPLC (Zorbax^® SB‐C‐18). In vivo pharmacological properties of [indole‐N‐methyl‐¹¹C]SSR180575 as a candidate for imaging neuroinflammation with positron emission tomography are currently evaluated. Copyright © 2010 John Wiley & Sons, Ltd.     

Novel self-assembling PEG-p-(CL-co-TMC) polymeric micelles as safe and effective delivery system for Paclitaxel

Paclitaxel (PTX) is an effective anti-cancer drug currently used to treat a wide variety of cancers. Unfortunately, nonaqueous vehicle containing Cremophor^® EL is associated with serious clinical side effects. This work aimed to evaluate the ability of polymeric micelles to (i) solubilize PTX without Cremophor^® EL and to be used as a (ii) safe and (iii) effective delivery system for PTX. Hence, we developed novel self-assembling poly(ethyleneglycol)₇₅₀-block-poly(ε-caprolactone-co-trimethylenecarbonate) (PEG-p-(CL-co-TMC)) polymeric micelles which form micelles spontaneously in aqueous solution. The solubility of PTX increased up to three orders of magnitude. The PTX-loaded micelles showed a slow release of PTX with no burst effect. The HeLa cells viability assessed by the MTT test was lower for PTX-loaded micelles than for Taxol^® (IC₅₀ 10.6 vs. 17.6 μg/ml). When solubilized in micelles, PTX induced apoptosis comparable with Taxol^®. The maximum tolerated doses (MTD) of PTX-loaded micelles and Taxol^® in mice were 80 mg/kg and 13.5 mg/kg, respectively, after intraperitoneal administration; and 45 mg/kg and 13.5 mg/kg, respectively, after intravenous administration. Similar anti-tumor efficacy of PTX-loaded micelles and Taxol^® was observed at the dose of 13.5 mg/kg on TLT-tumor-bearing mice, while the body weight loss was only observed in Taxol^® group. However, as higher dose was tolerated (80 mg/kg – IP), a higher growth delay was induced with PTX-loaded micelles. These results demonstrated that PTX-loaded self-assembling micelles present a similar anti-tumor efficacy as Taxol^®, but significantly reduced the toxicity allowing the increase in the dose for better therapeutic response.     

Practical Synthesis,Antidepressant, and Anticonvulsant Activity of 3‐Phenyliminoindolin‐2‐one Derivatives

Herein, a series of 3‐phenyliminoindolin‐2‐one derivatives were designed, synthesized, and screened for their antidepressant and anticonvulsant activities. The IR spectra of the compounds afforded NH stretching (3340–3346 cm^?1) bands and C=O stretching (1731–1746 cm^?1). In the ¹H‐NMR spectra of the compounds, N‐H protons of indoline ring were observed at 10.65–10.89 ppm generally as broad bands, and ¹³C‐NMR spectra of the compounds C=O were seen at 161.72–169.27 ppm. Interestingly, compounds 3o , 3p and 3r significantly shortened immobility time in the The forced swimming test (FST) and The tail suspension test (TST) at 50 mg/kg dose levels. In addition, compound 3r exhibited higher levels of efficacy than the reference standard fluoxetine but had no effect on locomotor activity in the open‐field test. Compound 3r significantly increased serotonin and norepinephrine and the metabolite 5‐hydroxyindoleacetic acid in mouse brain, suggesting that the effects of compound 3r may be mediated through these neurotransmitters. In the seizure screen, 15 compounds showed some degree against PTZ‐induced seizure at a dose of 100 mg/kg, and the tested compounds did not show any neurotoxicity at a dose of 300 mg/kg in the rotarod test.     

Pharmacological evidence that 5‐HT1D activation induces renal vasodilation by NO pathway in rats

5‐HT is a powerful vasoconstrictor substance in renal vasculature (mainly by 5‐HT₂ activation). Nevertheless, 5‐HT is notable for its dual cardiovascular effects, producing both vasodilator and vasoconstrictor actions. This study aimed to investigate whether, behind the predominant serotonergic vasoconstrictor action, THE 5‐HT system may exert renal vasodilator actions, and, if so, characterize the 5‐HT receptors and possible indirect pathways. Renal perfusion pressure (PP), systemic blood pressure (SBP) and heart rate (HR) measurement in in situ autoperfused rat kidney was determined in phenylephrine infused rats. Intra arterial (i.a.) bolus administration of 5‐HT (0.00000125–0.1 μg/kg) decreased renal PP in the presence of a phenylephrine continuous infusion (phenylephrine‐infusion group), without modifying SBP or HR. These vasodilator responses were potentiated by 5‐HT₂ antagonism (ritanserin, 1 mg/kg i.v.), whereas the responses were abolished by 5‐HT_1/7 antagonist (methiothepin, 100 μg/kg i.v.) or 5‐HT_1D antagonist (LY310762, 1 mg/kg i.v.). The i.a. administration (0.00000125 to 0.1 μg/kg) of 5‐CT or L‐694,247 (5‐HT_1D agonist) mimicked 5‐HT vasodilator effect, while other agonists (1‐PBG, α‐methyl‐5‐HT, AS‐19 (5‐HT₇), 8‐OH‐DPAT (5‐HT_1A) or CGS‐12066B (5‐HT_1B)) did not alter baseline haemodynamic variables. L‐694,247 vasodilation was abolished by i.v. bolus of antagonists LY310762 (5‐HT_1D, 1 mg/kg) or L‐NAME (nitric oxide, 10 mg/kg), but not by i.v. bolus of indomethacin (cyclooxygenase, 2 mg/kg) or glibenclamide (ATP‐dependent K⁺ channel, 20 mg/kg). These outcomes suggest that 5‐HT_1D activation produces a vasodilator effect in the in situ autoperfused kidney of phenylephrine‐infusion rats mediated by the NO pathway.