Molecular Docking of the Terpenes in Gorgonian Corals to COX-2 and iNOS Enzymes as Anti-Inflammatory

Background: Because the inflammatory pathway is triggered by the enzymes cyclooxygenase- 2 (COX-2) and inducible nitric oxide synthase (iNOS), inhibitors, such as nonsteroidal anti-inflammatory drugs (NSAIDs), are needed, although these have side effects. Therefore, the discovery and development of natural medicine as a lead compound are needed. The gorgonian corals have been reported to contain cyclic diterpenes with anti-inflammatory activities. The specific anti-inflammatory inhibitor potential has not been reported regarding these secondary metabolites, whether in COX-2 or iNOS. Thus, the in silico method is the right alternative. Objective: This study aimed to determine the potency of fifteen terpenes of the various gorgonian corals to COX-2 and iNOS enzymes as an anti-inflammatory. Methods: Molecular docking was performed using ChemDraw Ultra 12.0, Chem3D Pro 12.0, Biovia Discovery Studio 2016 Client®, Autodock Tools 4.2, prediction pharmacokinetics (Pre-ADMET), and oral administration (Lipinski rule of five). Results: Potential terpenes based on ΔG (kcal/mol) and Ki (nM) to COX-2 were gyrosanol B (-10,32; 27,15), gyrosanol A (-10,20; 33,57), echinolabdane A (-9,81; 64,76). Only nine terpenes were specific to COX-2 active sites, while for iNOS were palmonine F (-7.76; 2070), briarenol C (-7.55; 2910), and all test compounds binding to the iNOS active sites. Pre-ADMET prediction obtained that HIA was very excellent (70–100%), Caco-2 had moderate permeability (4-70 nm sec-1), and PPB had strong binding (> 90%). Eight terpenes qualified for the Lipinski rule of five. Conclusion: iNOS was a specific target for terpenes based on the free energy of binding (ΔG).