Context: Therapeutic effects of Qiangjing tablets (QJT) on sperm vitality and asthenozoospermia (AZS) have been confirmed. However, the mechanism of action remains unclear.
Objective: This study investigates the effects of QJT on AZS and the underlying mechanism of action.
Materials and methods: Sixty Sprague-Dawley rats were randomly divided into six groups: Control, ORN (ornidazole; 200 mg/kg), ORN + QJT-low (0.17 g/mL), ORN + QJT-middle (0.33 g/mL), ORN + QJT-high (0.67 g/mL), and ORN + QJT + Radicicol (0.67 g/mL QJT and 20 mg/kg radicicol) groups. Pathological evaluation and analysis of mitophagy were conducted by H&E staining and transmission electron microscopy, respectively. Reactive oxygen species were detected by flow cytometry. Protein expression was determined by Western blotting.
Results: QJT significantly improved ORN-treated sperm motility and kinematic parameters, as well as the pathological symptoms of testicular and epididymal tissues. In particular, QJT mitigated impaired mitochondrial morphology, and increased the PHB, Beclin-1, LC3-II protein, and ROS levels (p < 0.05), and reduced the protein expression levels of LC3-I and p62 (p < 0.05). Mechanistically, QJT antagonized the downregulation of SCF and Parkin protein levels (p < 0.05). Furthermore, QJT significantly increased the protein expressions levels of LKB1, AMPKα, p-AMPKα, ULK1 and p-ULK1 (p < 0.05). The ameliorative effect of QJT on pathological manifestations, mitochondrial morphology, and the expressions of mitophagy and mitochondrial ubiquitination-related proteins was counteracted by radicicol.
Discussion and conclusions: QJT improved AZS via mitochondrial ubiquitination and mitophagy mediated by the LKB1/AMPK/ULK1 signaling pathway. Our study provides a theoretical basis for the treatment of AZS and male infertility.
Keywords: LKB1/AMPK/ULK1; Mitophagy; mitochondria; sperm motility; traditional Chinese medicine.