Potential of the zebrafish model for the forensic toxicology screening of NPS: A comparative study of the effects of APINAC and methiopropamine on the behavior of zebrafish larvae and mice.

The increased diffusion of the so-called novel psychoactive substances (NPS) and their continuous change in structure andconceivably activity has led to the need of a rapid screening method to detect their biological effects as early as possible after their appearance in the market. This problem is very felt in forensic pathology and toxicology, so the preclinical study is fundamental in the approach to clinical and autopsy cases of difficult interpretation intoxication. Zebrafish is a high-throughput suitable model to rapidly hypothesize potential aversive or beneficial effects of novel molecules. In the present study, we measured and compared the behavioral responses to two novel neuroactive drugs, namely APINAC, a new cannabimimetic drug, and methiopropamine (MPA), a methamphetamine-like compound, on zebrafish larvae (ZL) and adult mice. By using an innovative statistical approach (general additive models), it was found that the spontaneous locomotor activity was impaired by the two drugs in both species: the disruption extent varied in a dose-dependent and time-dependent manner. Sensorimotor function was also altered: i) the visual object response was reduced in mice treated with APINAC, whereas it was not after exposure to MPA; ii) the visual placing responses were reduced after treatment with both NPS in mice. Furthermore, the visual motor response detected in ZL showed a reduction after treatment with APINAC during light-dark and dark-light transition. The same pattern was found in the MPA exposed groups only at the dark-light transition, while at the transition from light to dark, the individuals showed an increased response. In conclusion, the present study highlighted the impairment of spontaneous motor and sensorimotor behavior induced by MPA and APINAC administration in both species, thus confirming the usefulness of ZL as a model for a rapid behavioural-based drug screening.

Discovery of Indazoles as Potent, Orally Active Dual Neurokinin 1 Receptor Antagonists and Serotonin Transporter Inhibitors for the Treatment of Depression.

Combination studies of neurokinin 1 (NK1) receptor antagonists and serotonin-selective reuptake inhibitors (SSRIs) have shown promise in preclinical models of depression. Such a combination may offer important advantages over the current standard of care. Herein we describe the discovery and optimization of an indazole-based chemotype to provide a series of potent dual NK1 receptor antagonists/serotonin transporter (SERT) inhibitors to overcome issues of ion channel blockade. This effort culminated in the identification of compound 9, an analogue that demonstrated favorable oral bioavailability, excellent brain uptake, and robust in vivo efficacy in a validated depression model. Over the course of this work, a novel heterocycle-directed asymmetric hydrogenation was developed to facilitate installation of the key stereogenic center.

Effect of whole-body hyperthermia on lonidamine and doxorubicin pharmacokinetics and toxicity in dogs.

Six cycles of the maximum tolerable intravenous doses of lonidamine (400 mg/m2) and doxorubicin (30 mg/m2) were administered to three normothermic dogs and three dogs undergoing whole-body hyperthermia (WBH) (42 degrees C X 90 min), at 3-week intervals. Lonidamine pharmacokinetics was unaltered by WBH. WBH increased doxorubicin clearance 1.6-fold, however this trend was not statistically significant. WBH resulted in a 2.4-fold increase in the volume of distribution (Vdss) of doxorubicin relative to dogs treated under euthermic conditions (p < 0.001). This finding suggests tissue extraction of doxorubicin was increased by WBH. The specific tissues in which this occurred is unknown, but myelosuppression and cardiotoxicity were only minimally increased. Therefore, doxorubicin uptake in critical normal tissues was probably unaffected. The biochemical and haematologic toxicities observed 6 h and 1 week after each treatment did not appear to differ in character or severity from that reported in dogs receiving lonidamine +/- WBH or doxorubicin +/- WBH. These results suggest WBH did not decrease the maximum tolerable dose of doxorubicin when given with lonidamine, and that the antitumour activity of this combination should be assessed.

Effect of whole-body hyperthermia on the pharmacokinetics and toxicity of lonidamine in dogs.

The pharmacokinetics and toxicity of intravenous lonidamine were investigated in dogs receiving four cycles of lonidamine (400 or 800 mg/m2) +/- whole-body hyperthermia (WBH). Clearance and volume of distribution in dogs receiving lonidamine during WBH increased 1.6-2.3 and 1.9-3.5-fold respectively, relative to dogs receiving lonidamine under euthermic conditions (p < 0.02). In dogs receiving lonidamine under euthermic conditions or 400 mg/m2 + WBH, the area under the lonidamine concentration versus time curve (AUC) measured during the fourth treatment was 21-58% lower than the first treatment AUC. However, in dogs receiving 800 mg/m2 + WBH, the fourth treatment AUC was four-fold higher than the first treatment AUC (p < 0.02). This suggests repeated exposure to 800 mg/m2 lonidamine and WBH impairs lonidamine metabolism. Weakness, hypoglycaemia, and elevations in amylase, alanine aminotransferase, alkaline phosphatase and bilirubin were more severe or occurred exclusively in dogs receiving 800 mg/m2 + WBH. Since these changes were attributable to marked AUC increases, which occurred secondary to repeated exposure to 800 mg/m2 lonidamine during WBH, 400 mg/m2 was identified as the maximum tolerable dose to be administered intravenously to dogs during WBH.

1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxylic acid (DICA), an exfoliative antispermatogenic agent in the rat.

The oral administration of 50 mg DICA/kg at nine weekly or four monthly intervals produced partially reversible infertility in male rats as judged by the results of serial mating and testicular histology. Oral 500 mg DICA/kg doses administered at the same intervals produced permanent sterility. Single oral doses of 50 or 500 mg DICA/kg elevated mean FSH concentrations on days 2, 3, and 7 but did not affect LH or testosterone. Mean plasma concentration peaked at 74 micrograms/ml 4 hr after a 50 mg/kg dose of uniformly tritiated DICA; 24 hr later, it had declined rapidly to 5.5 micrograms/ml. The drug did not have a strong affinity for any tissue studied including the testis. DICA-induced exfoliation of immature germ cells was first observed 4 hr after administration and led to significantly reduced testis weights by day 2. Neither single doses of 10--250 mg DICA/kg nor five daily doses of 10--100 mg DICA/kg reduced seminal vesicle, ventral prostate, or body weights of male rats. Chronic weekly DICA administration did reduce mean seminal vesicle weight. These studies have shown that DICA is an effective, partially reversible antifertility agent that directly affects the rat testis.