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Interactions of Endocannabinoid Virodhamine and Related Analogs With Human Monoamine oxidase-A and -B

Pankaj Pandey, Narayan D Chaurasiya, Babu L Tekwani, Robert J Doerksen

Biochem Pharmacol. 2018 Sep;155:82-91.

PMID: 29958841

Abstract:

The endocannabinoid system plays an important role in the pathophysiology of various neurological disorders, such as anxiety, depression, neurodegenerative diseases, and schizophrenia; however, little information is available on the coupling of the endocannabinoid system with the monoaminergic systems in the brain. In the present study, we tested four endocannabinoids and two anandamide analogs for inhibition of recombinant human MAO-A and -B (monoamine oxidase). Virodhamine inhibited both MAO-A and -B (IC50 values of 38.70 and 0.71 μM, respectively) with ∼55-fold greater inhibition of MAO-B. Two other endocannabinoids (noladin ether and anandamide) also showed good inhibition of MAO-B with IC50 values of 18.18 and 39.98 μM, respectively. Virodhamine was further evaluated for kinetic characteristics and mechanism of inhibition of human MAO-B. Virodhamine inhibited MAO-B (Ki value of 0.258 ± 0.037 μM) through a mixed mechanism/irreversible binding and showed a time-dependent irreversible mechanism. Treatment of Neuroscreen-1 (NS-1) cells with virodhamine produced significant inhibition of MAO activity. This observation confirms potential uptake of virodhamine by neuronal cells. A molecular modeling study of virodhamine with MAO-B and its cofactor flavin adenine dinucleotide (FAD) predicted virodhamine's terminal -NH2 group to be positioned near the N5 position of FAD, but for docking to MAO-A, virodhamine's terminal -NH2 group was far away (∼6.52 Å) from the N5 position of FAD, and encountered bad contacts with nearby water molecules. This difference could explain virodhamine's higher potency and preference for MAO-B. The binding free energies for the computationally-predicted poses also showed that virodhamine was selective for MAO-B. These findings suggest potential therapeutic applications of virodhamine for the treatment of neurological disorders.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP304472 Kynuramine dihydrobromide Kynuramine dihydrobromide 304-47-2 Price
AP443129359 Virodhamine hydrochloride Virodhamine hydrochloride 443129-35-9 Price
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