Project Summary/Abstract from active award number R16GM149204 Chronic pain is the primary cause of disability worldwide. According to the National Institutes of Health, nearly 25.3 million Americans suffer from daily pain, and another 23.4 million Americans report significant pain. Approximately 1 in 5 adults worldwide suffer from pain, and another 1 in 10 adults are diagnosed with chronic pain each year. We aim to develop dual inhibitors, single small molecules that will simultaneously inhibit two enzymes: soluble epoxide hydrolase (sEH) and fatty acid amide hydrolase (FAAH). The most original and mechanistically distinct aspect of these compounds is their ability to simultaneously inhibit two different enzymes that play significant roles in pain and inflammation. Dual sEH/FAAH inhibitors described here have the potential to be used as a promising novel non-opioid therapeutic strategy in pain management. In our previous NIH SC2 grant (GM135020), we identified several very potent dual inhibitors, and one was tested in a rat model of acute inflammatory pain. Demonstrating antinociception of this dual inhibitor provided the first evidence that a dual sEH/FAAH inhibitor alleviates acute inflammatory pain induced by intraplantar injection of dilute formalin. We also observed that this dual inhibitor produces antinociception at lower doses than the traditional nonsteroidal anti-inflammatory drug ketoprofen. In the proposed studies, we will synthesize and evaluate novel libraries of ligands that are designed to interact simultaneously with both target enzymes, assess and improve the drug-like properties of these molecules, and evaluate whether two previously identified dual inhibitors together with the new compounds (identified in this proposal) produce pain relief against chronic inflammatory pain in vivo in a rat model of chronic inflammatory pain. The compounds we propose to study represent a much-needed, completely novel non-opioid starting point in pain management research. Because this class has different biological targets from existing analgesics, it represents an opportunity to solve long-standing problems that have been linked to the existing opioid and non- opioid therapies in pain management. To our knowledge, this proposal is the first attempt to use the strategy of dual sEH/FAAH inhibitors as a rational therapeutic strategy for pain management. In addition, the design principles and synthetic and in vivo tools behind these dual inhibitors are rigorous, comprehensive, and innovative. This multipronged plan is a forte in our dual inhibition generation/optimization program. Our studies may provide a foundation for the future investigation of the benefits of using the dual ligand strategy in analgesia. This proposal represents a collaborative work between two Hispanic-serving institutions, California State University, Fullerton and California State University, East Bay, with a strong collaborative partnership with the University of California...