Ivermectin (Synonyms: 22,23-dihydro Avermectin B1, L-640,471, MK-933)

Ivermectin (MK-933) is a broad-spectrum anti-parasite medication used in humans most commonly to treat nematode infections such as onchocerciasis, as well as scabies and lice. Ivermectin (MK-933) is a specific inhibitor of Impα/β1-mediated nuclear import and has potent antiviral activity towards both HIV-1 and dengue virus. It is a positive allosteric effector of P2X4 and the α7 neuronal nicotinic acetylcholine receptor (nAChRs).

In the submicromolar range (EC50=250 nM) the action of Ivermectin (MK-933) is rapid and reversible, resulting in increased amplitude and slowed deactivation of P2X4 channel currents evoked by ATP[1]. Ivermectin (MK-933) markedly increases the potency of ATP and that of the normally low-potency agonist a,b-methylene-ATP in a use- and voltage-independent manner without changing the ion selectivity of P2X4 channels[1].Ivermectin (MK-933) activates glutamate-gated chloride channels in the nerves and muscles of the parasite, leading to membrane hyperpolarization and muscle paralysis[2].Ivermectin (MK-933) strongly inhibits the binding of Impα/β1 to NS5 (IC50=17 μM), but not of Impβ1 alone to NS5[3].Ivermectin (MK-933) has potent antiviral activity towards both HIV-1 and dengue virus, both of which are strongly reliant on importin α/β nuclear import, with respect to the HIV-1 integrase and NS5 (non-structural protein 5) polymerase proteins respectively[3].

References:
[1]. Khakh BS, et al. Allosteric control of gating and kinetics at P2X(4) receptor channels. J Neurosci. 1999 Sep 1;19(17):7289-99.
[2]. Priel A, et al. Mechanism of ivermectin facilitation of human P2X4 receptor channels. J Gen Physiol. 2004 Mar;123(3):281-93.
[3]. Wagstaff KM, et al. Ivermectin is a specific inhibitor of importin α/β-mediated nuclear import able to inhibit replication of HIV-1 and dengue virus. Biochem J. 2012 May 1;443(3):851-6.