"Niclosamide: A potential antipruritic agent by modulating serotonin pathway through metabotropic glutamate receptors...

Pruritus is an uncomfortable sensation induced by various pruritogens, including serotonin. Serotonin, acting as an inflammatory mediator, can activate a histamine-independent pathway. Consequently, many anti-pruritus medications, such as antihistamines, are not effective in adequately relieving patient symptoms. Niclosamide, an anthelmintic drug, has recently demonstrated an affinity for Metabotropic glutamate receptors (mGluRs). mGluRs are a group of receptors activated by glutamate, and they are involved in regulating neuronal excitability. In this study, we utilized mouse models of serotonergic itch and administered different doses of Niclosamide to examine the expression of mGluR1, mGluR5, and 5-HT2. The administration of 5 mg/kg Niclosamide successfully suppressed pruritus in the mice. Additionally, the levels of mGluR1, mGluR5, 5-HT2, and TRPV1 were significantly reduced. These findings suggest that Niclosamide holds promise as a potential antipruritic drug.