STRUCTURE-BASED VIRTUAL SCREENING IDENTIFIES NOVOBIOCIN, MONTELUKAST, AND CINNARIZINE AS TRPV1 MODULATORS WITH ANTICONVULSANT ACTIVITY IN-VIVO

MARTÍN, P; LLANOS, M; ENRIQUE, N; SBARAGLINI, ML; GAROFALO, F; TALEVI, A; GAVERNET, L

Mar del Plata

Congreso; Reunión anual de Sociedades de Biociencias; 2022

SAIC - SAI - SAFIS

Epilepsy is a disease characterized by the recurrent presence of seizures. It affects more than 50 million people worldwide. Pharmacotherapy is the first-line treatment for this pathology. However, approximately 30% of patients do not respond to existing pharmacological therapies. Transient Receptor Potential Vanilloid 1 (TRPV1) is a nonselective cation channel modulated by ligands, pH, temperature, and voltage. It has been proposed as a promising target to develop novel anticonvulsant drugs (ACDs). However, thermoregulatory side effects associated with channel inhibition have hindered the way toward TRPV1 antagonists becoming marketed drugs. In this work, we conducted a virtual screening (VS) campaign to repurpose TRPV1 inhibitors among approved drugs, which are known to be thermally-neutral. To this end, three homology models of the hTRPV1 were constructed and refined with Rosetta. The experimental structures of the Rattus norvegicus channel (rTRPV1) were used as templates (PDB IDs: 5IRZ, 5IRX, and 5IS0 for the apo, fully-open, and closed conformation, respectively). Two different docking programs were evaluated, QuickVina-2 and Autodock4-GPU. All docking complexes were re-scored using three functions, Vina, Vinardo, and AD4_scoring. The performance of the docking protocols was evaluated in terms of sampling power and scoring power, in order to find the best docking modeable to identify compounds interacting with the capsaicin (CAP) binding site. The best protocol was applied in a prospective VS over the DrugBank database, and three hits were selected for biological testing. Novobiocin, Montelukast, and Cinnarizine were evaluated in vitro by the patch-clamp technique and in vivo on the maximal electroshock seizure (MES), the 6 Hz psychomotor (6 Hz), and pentylenetetrazole (PTZ) mice tests. The interaction between the selected compounds and the molecular target was evaluated by their ability to reduce TRPV1 currents induced by 250 nM CAP using the patch-clamp technique on HEK293 cells expressing the channel. All tested compounds (100 nM) showed inhibitory effects on CAP-induced TRPV1 currents measured at -100 mV (% inhibition: 53,4±7,1 (n=7), 56,3±6,7 (n=9), and 50,4±9,2 (n=7) for Montelukast, Novobiocin, and Cinnarizine, respectively). Finally, their in vivo anticonvulsant profile was completed, showing good activity mainly in the MES test. Our results further support the modulation of TRPV1 channels as a promising strategy to develop novel ACDs.