Potential mechanism prediction of indole-3-propionic acid against diminished ovarian reserve via network pharmacology, molecular docking and experimental verification.

Background: Oxidative stress (OS) is one of the major causes of ovarian aging and dysfunction. Indole-3-propionic acid (IPA) is an indole compound derived from tryptophan with free radical scavenging and antioxidant properties, and thus may have potential applications in protecting ovarian function, although the exact mechanisms are unknown. This study aims to preliminarily elucidate the potential mechanisms of IPA that benefit ovarian reserve function through network pharmacology, molecular docking, and experimental verification.

Methods: The related protein targets of IPA were searched on SwissTargetPrediction, TargetNet, BATMAN-TCM, and PharmMapper databases. The potential targets of diminished ovarian reserve (DOR) were identified from OMIM, GeneCards, DrugBank, and DisGeNET databases. The common targets were uploaded directly to the STRING database to construct PPI networks. We then performed GO and KEGG enrichment analysis on the targets. Subsequently, molecular docking and molecular dynamics simulation were used to validate the binding conformation of IPA to candidate targets. Furthermore, we carried out in vitro experiments to validate the prediction results of network pharmacology.

Results: We identified a total of 61 potential targets for the interaction of IPA with DOR. The PPI network topological parameter analysis yielded 13 hub genes for DOR treatment. The GO biological process enrichment analysis identified 293 entries, mainly enriched in aging, signal transduction, response to hypoxia, negative regulation of apoptotic process, and positive regulation of cell proliferation. The KEGG enrichment analysis mainly included lipid and atherosclerosis, progesterone-mediated oocyte maturation, AGE-RAGE, relaxin, estrogen, and other signaling pathways. The molecular docking further revealed the direct binding of IPA with six hub proteins including NOS3, AKT1, EGFR, PPARA, SRC, and TNF. In vitro experiments showed that IPA pretreatment attenuated H₂O₂-induced cellular oxidative stress damage, while IPA exerted cytoprotective and antioxidant damage effects by regulating the six hub genes and antioxidant proteins.

Conclusion: We systematically illustrated the potential protective effects of IPA against DOR through multiple targets and pathways using network pharmacology, and further verified the cytoprotective effect and antioxidant properties of IPA through in vitro experiments. These findings provide new insights into the targets and molecular mechanisms whereby IPA improves DOR.