Background and Aim : Introduction: Medicinal plants are considered as an important source of natural medicines for the treatment of depression. One of the native plants of Iran is Khosharizeh (Echinophora platyloba), which has many uses in traditional medicine. Previous studies have shown that this plant has antidepressant properties. One of the mechanisms through which antidepressants exert their properties is through the inhibition of monoamine oxidase B. The aim of this study was to investigate the molecular docking of the compounds of this plant with monoamine oxidase B to find possible inhibitory compounds of this enzyme in this plant. Methods : The compounds of E. platyloba were extracted by studying previous articles about the extract and essential oil of this plant. The protein structure of monoamine oxidase B was obtained from the PDB database with the code 2v5z. After preparation of the protein using pymol software, molecular docking of obtained plant compounds and monoamine oxidase B was done with PyRx software package. Results : The results of the docking study showed that the two compounds isoverbanol acetate and (E)-sesquilavandulol had the highest binding affinity with the active site of the enzyme with the binding affinity of -7.2 and -7.8 kcal/mol, respectively. These results look good compared with the control drug, rasagiline, with binding affinity of -7.8 kcal/mol. Despite this, toxicity study with the ProTox-II web server showed the relative toxicity of these substances in some tests. Conclusion : In spite of the fact that some beneficial compounds in the plant extract can probably inhibit the monoamine oxidase enzyme, but due to toxicity, they cannot be introduced as drug candidates.
