4-Quinolinylhydrazone analogues kill Leishmania (Leishmania) amazonensis by inducing apoptosis and mitochondria-dependent pathway cell death.

Despite efforts, available alternatives for the treatment of leishmaniasis are still scarce. In this work we tested a class of 15 quinolinylhydrazone analogues and presented data that support the use of the most active compound in cutaneous leishmaniasis caused by Leishmania amazonensis. In general, the compounds showed activity at low concentrations for both parasitic forms (5.33-37.04 µM to promastigotes, and 14.31-61.98 µM to amastigotes). In addition, the best compound (MHZ15) is highly selective for the parasite. Biochemical studies indicate that the treatment of promastigotes with MHZ15 leads the loss of mitochondrial potential and increase in ROS levels as the primary effects, which triggers accumulation of lipid droplets, loss of plasma membrane integrity and apoptosis hallmarks, including DNA fragmentation and phosphatidylserine exposure. These effects were similar in the intracellular form of the parasite. However, in this parasitic form there is no change in plasma membrane integrity in the observed treatment time, which can be attributed to metabolic differences and the resilience of the amastigote. Also, ultrastructural changes such as vacuolization suggesting autophagy were observed. The in vivo effectiveness of MHZ15 in the experimental model of cutaneous leishmaniasis was carried out in mice of the BALB/c strain infected with L. amazonensis. The treatment by intralesional route showed that MHZ15 acted with great efficiency with significantly reduction in the parasite load in the injured paws and draining lymph nodes, without clinical signs of distress or compromise of animal welfare. In vivo toxicity was also evaluated and null alterations in the levels of hepatic enzymes aspartate aminotransferase, and alanine aminotransferase was observed. The data presented herein demonstrates that MHZ15 exhibits a range of favorable characteristics conducive to the development of an antileishmanial agent.

Pharmacological profiling of JME-173, a novel mexiletine derivative combining dual anti-inflammatory/anti-spasmodic functions and limited action in Na+ channels.

Existing evidence suggests that the local anaesthetic mexiletine can be beneficial for patients with asthma. However, caution is required since anaesthesia of the airways inhibits protective bronchodilator neuronal reflexes, limiting applications in conditions of hyperirritable airways. Here, we describe the synthesis of a new series of mexiletine analogues, which were screened for reduced activity in Na+ channels and improved smooth muscle relaxant effects, that were evaluated using the patch-clamp technique and an isolated tracheal organ bath, respectively. JME-173 (1-(4-bromo-3,5-dimethylphenoxy)propan-2-amine) was the most effective among the four mexiletine analogues investigated. JME-173 was then studied in vivo using a murine model of lung inflammation induced by cigarette smoke (CS) and in vitro using neutrophil chemotaxis and mast cell degranulation assays. Finally, the JME-173 pharmacokinetic profile was assessed using HPLC-MS/MS bioanalytical method. JME-173 directly inhibited IL-8 (CXCL8)- and FMLP-induced human neutrophil chemotaxis and allergen-induced mast cell degranulation. After oral administration 1 h before CS exposure, JME-173 (50 mg/kg) strongly reduced the increased number of macrophages and neutrophils recovered in the bronchoalveolar effluent without altering lymphocyte counts. Pharmacokinetic experiments of JME-173 (10 mg/kg, orally) showed values of maximum concentration (Cmax), maximum time (Tmax), area under the blood concentration-time curve (AUC0-t) and area under the blood concentration-time curve from 0-Inf (AUC0-inf) of 163.3 ± 38.3 ng/mL, 1.2 ± 0.3 h, 729.4 ± 118.3 ng*h/ml and 868.9 ± 117.1 ng*h/ml (means ± S.E.M.), respectively. Collectively, these findings suggest that JME-173 has the potential to be an effective oral treatment for diseases associated with bronchoconstriction and inflammation.