Er-Chen decoction alleviates spermatogenic dysfunction in obese mice by tuning the SIRT1/p53 axis

Er-Chen Decoction (ECD), a classic traditional Chinese medicine (TCM) formula, is clinically indicated for dispelling dampness and resolving phlegm. It has been widely used in the management of phlegm‒dampness syndrome, including obesity, with a long-standing clinical application history in improving obesity-related male infertility. Although its therapeutic efficacy has been validated through long-term clinical practice, the underlying molecular mechanisms remain incompletely understood.

This study aimed to investigate the molecular mechanisms by which ECD ameliorates obesity-related spermatogenic dysfunction (SD) through the SIRT1/p53 signaling axis.

A mouse model of diet-induced obesity was established by feeding a high-fat diet (HFD) for 8 weeks. Subsequently, obese mice were randomly assigned to receive interventions with ECD (low-, medium-, or high-dose) or L-carnitine (positive control) for 3 weeks. Sperm functional parameters were evaluated to assess obesity-related SD. A combination of network pharmacology analysis, molecular docking, biochemical assays, hematoxylin‒eosin (HE) staining, Oil Red O staining, transmission electron microscopy (TEM), quantitative real-time polymerase chain reaction (RT‒qPCR), immunofluorescence (IF) staining, immunohistochemical (IHC) staining, Western blotting (WB), and transcriptomic analysis was employed to dissect the molecular mechanisms underlying the protective effects of the ECD against obesity-related SD. Additionally, the bioactive components of ECD were characterized using extensive targeted mass spectrometry.

Medium-dose ECD (ECD-M) significantly reduced body weight and lipid accumulation in HFD-induced obese mice. Notably, compared with the HFD group, the ECD-M group presented a 50 % reduction in the abnormal sperm percentage (p < 0.01), along with a 60 % increase in sperm concentration (p < 0.01), and showed an upward trend in both sperm progressive motility and sperm motility. Furthermore, ECD-M significantly upregulated the expression of the tight junction (TJ) proteins Occludin (p < 0.001) and β-catenin (p < 0.05), thereby restoring the integrity of the blood‒testis barrier (BTB). Mechanistically, ECD not only reversed lipid-induced inhibition of SIRT1 but also suppressed p53 acetylation, leading to a significant decrease in the ratios of cleaved caspase-3/caspase-3 (p < 0.05) and Bax/Bcl-2 (p < 0.0001) in testicular tissues. These effects collectively alleviated mitochondria-mediated apoptosis in the testes of obese mice.

ECD alleviates mitochondria-mediated apoptosis in testicular tissues by regulating the SIRT1/p53 axis, thereby mitigating obesity-related SD. These findings highlight ECD as a potential therapeutic agent for the management of obesity-related male infertility.