Structure-based virtual screening identifies Novobiocin, Montelukast and Cinnarizine as TRPV1 modulators with anticonvulsant activity in-vivo.

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

Congreso; 20th IUPAB Congress; 2021

International Union for Pure and Applied Biophysics (IUPAB)

Introduction: Transient Receptor Potential Vanilloid 1 (TRPV1) is a nonselective cation channel modulated by endogenous and exogenous ligands, pH, temperature, and voltage. In the last few years, it has been proposed as a promising target to develop novel anticonvulsant compounds. However, thermoregulatory effects associated with channel inhibition have hindered the way towards TRPV1 antagonists becoming marketed drugs. Objective: we conducted a structure-based virtual screening (VS) campaign to repurpose TRPV1 inhibitors among approved drugs, which are known to be safe and thermally-neutral. Materials & Methods: Initially, three homology models of the hTRPV1 were constructed and refined with Rosetta, representing biologically relevant states of the channel: unliganded, open agonist-bound, and closed antagonist-bound. Then, several docking conditions were evaluated to find the best docking model, in terms of pose and score accuracy, able to identify compounds interacting with the capsaicin binding site. Top scoring hits were evaluated in vitro using the patch-clamp technique and, in vivo on the maximal electroshock seizure (MES), the 6 Hz psychomotor (6 Hz) and pentylenetetrazole (PTZ) mice tests. Discussion & Results: Among top scoring hits from the VS campaign, Novobiocin, Montelukast, and Cinnarizine were selected for biological testing. The interaction between the selected compounds and the TRPV1 channel heterologously expressed in HEK293 cells was evaluated by their ability to reduce currents induced by 250 nM capsaicin using the patch-clamp technique. All tested compounds showed inhibitory effects on capsaicin-induced TRPV1 currents measured at -100 mV (% inhibition: 60±7 (n=10), 62±8 (n=8) and 40±6 (n=6) for 0,1 µM Novobiocin, 0,1 µM Montelukast and 1 µM Cinnarizine, respectively). Finally, their in vivo anticonvulsant profile was completed, showing promising anticonvulsant activity mainly against maximal electroshock seizure (MES) test. Conclusions: Our results further support the modulation of TRPV1 channels as a promising strategy to develop novel antiepileptic drugs.