UPLC-MS analysis and network pharmacology-based investigation into the active ingredients and molecular mechanisms of anti-fatigue of male flowers with Eucommia ulmoides Oliv.

The male flowers of Eucommia ulmoides Oliv. (MFEU) was a natural product that could alleviate fatigue and accelerate fatigue alleviation. Nonetheless, the active ingredients and underlying pharmacological mechanisms remain unknown. This study aimed to decode the active ingredients and potential action mechanisms of MFEU in the therapy of anti-fatigue using an integrated UPLC-MS analysis, network pharmacology approach, and cell experiments. Characterizations of chemical constituents of MFEU extract were identified by UPLC-Q-TOF-MS. The corresponding drug targets were retrieved from the drug target database and used to construct the "composite-target-pathway" network. The Cytoscape was used to identify potential protein targets of these MFEU components, indicating that 24 anti-fatigue compounds in MFEU regulate 18 anti-fatigue-related targets in 10 signaling pathways. The 16 components of MFEU were verified at the cellular level. The results of cell experiments showed that MFEU extract (0.361 mu g/ml), Caffeic acid, Deacetylasperulosidic acid, Naringenin, Acanthoside B, Geniposidic acid, Rutin, and Quercetin could promote testosterone secretion on Leydig cells at 50 mu M. The MFEU extract and seven compounds in MFEU might play a role in anti-fatigue by participating in the regulation of testosterone secretion. Finally, the results of PCR analysis showed that MFEU promotes the secretion of testosterone, which is related to CYPIIa1 and 17 beta-HSD, STAR in the signal pathway of testosterone synthesis. This study provides a basis for further exploring the anti-fatigue mechanism of MFEU, adopting the method of multi-compound and multi-target.