Strong Inhibitory Effect, Low Cytotoxicity and High Plasma Stability of Steroidal Inhibitors of N-Methyl-D-Aspartate Receptors With C-3 Amide Structural Motif

Abstract

Herein, we report the synthesis, structure-activity relationship study, and biological evaluation of neurosteroid inhibitors of N-methyl-D-aspartate receptors (NMDARs) receptors that employ an amide structural motif, relative to pregnanolone glutamate (PAG) – a compound with neuroprotective properties. All compounds were found to be more potent NMDAR inhibitors (IC50 values varying from 1.4 to 21.7 μM) than PAG (IC50 = 51.7 μM). Selected compound 6 was evaluated for its NMDAR subtype selectivity and its ability to inhibit AMPAR/GABAR responses. Compound 6 inhibits the NMDARs (8.3 receptors (8.3 ± 2.1 μM) more strongly than it does at the GABAR and AMPARs (17.0 receptors (17.0 ± 0.2 μM and 276.4 ± 178.7 μM, respectively). In addition, compound 6 (10 μM) decreases the frequency of action potentials recorded in cultured hippocampal neurons. Next, compounds 3, 5–7, 9, and 10 were not associated with mitotoxicity, hepatotoxicity nor ROS induction. Lastly, we were able to show that all compounds have improved rat and human plasma stability over PAG.

Pharmacokinetic, pharmacodynamic, and behavioural studies of deschloroketamine in Wistar rats

“…ECS contained (in mM) 160 NaCl, 2.5 KCl, 10 HEPES, 10 glucose, 2 CaCl 2 , 1 MgCl 2 , and 0.03 glycine (pH‐adjusted to 7.3 with NaOH). Compound stock solutions were prepared fresh before each experiment, and measurements were performed at room temperature (21°C–25°C) (Adla et al, 2018).…”

“…Cells were dissociated in papain, washed, and plated in a Neurobasal A medium supplemented with B27 (Gibco) at a density of 50,000 cellsÁcm À2 on top of a confluent layer of cortical astrocytes grown on collagen/poly-D-lysine-covered glass coverslips. (Adla et al, 2018).…”

Neurosteroids: Structure-Uptake Relationships and Computational Modeling of Organic Anion Transporting Polypeptides (OATP)1A2

“…Cellular uptake of synthetic neurosteroids 1 – 11 (syntheses have been reported in our earlier publications [ 32 , 33 ]) was evaluated by using the MCF-7 (human breast adenocarcinoma; Michigan Cancer Foundation-7) cell line, which is known to express several OATPs and efflux transporters [ 34 , 35 ]. More detailed transport mechanisms were investigated by performing Eadie-Hofstee plot analysis, which revealed that almost all synthesized neurosteroids 1–11 had two distinct transport mechanisms.…”