*Review* **Spotlight on Nociceptin/Orphanin FQ Receptor in the Treatment of Pain**

**Amal El Daibani <sup>1</sup> and Tao Che 1,2,\***


**Abstract:** In our society today, pain has become a main source of strain on most individuals. It is crucial to develop novel treatments against pain while focusing on decreasing their adverse effects. Throughout the extent of development for new pain therapies, the nociceptin/orphanin FQ receptor (NOP receptor) has appeared to be an encouraging focal point. Concentrating on NOP receptor to treat chronic pain with limited range of unwanted effects serves as a suitable alternative to prototypical opioid morphine that could potentially lead to life-threatening effects caused by respiratory depression in overdose, as well as generate abuse and addiction. In addition to these harmful effects, the uprising opioid epidemic is responsible for becoming one of the most disastrous public health issues in the US. In this article, the contributing molecular and cellular structure in controlling the cellular trafficking of NOP receptor and studies that support the role of NOP receptor and its ligands in pain management are reviewed.

**Keywords:** nociceptin/orphanin FQ receptor; NOP receptor; ligands; opioid receptor; nociceptin; N/OFQ; analgesia

**Citation:** El Daibani, A.; Che, T. Spotlight on Nociceptin/Orphanin FQ Receptor in the Treatment of Pain. *Molecules* **2022**, *27*, 595. https:// doi.org/10.3390/molecules27030595

Academic Editors: Mariana Spetea and Richard M. van Rijn

Received: 1 December 2021 Accepted: 12 January 2022 Published: 18 January 2022

**Publisher's Note:** MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).
