A Combination of Cuscuta chinensis and Lycium barbarum Ameliorates Spermatogenic Impairment in Mice and Is Associated With Modulation of the miR-21/PTEN/PI3K/AKT/mTOR Signaling Axis.

SC-FL is a traditional Chinese herbal formula that has been used for kidney tonification and the clinical treatment of oligospermia and asthenospermia. This medicinal compound comprises dodder seed (Cuscuta chinensis Lam.) and wolfberry fruit (Lycium barbarum L.). However, the precise mechanisms of SC-FL remain undetermined. Therefore, this study aimed to identify potential therapeutic targets of SC-FL in oligoasthenozoospermia and validate these targets in vivo. To establish a spermatogenic dysfunction model, male BALB/c mice were administered glucosides of Tripterygium wilfordii Hook. f. (GTW) and then treated with SC-FL. Furthermore, the expression of microRNA-21 (miR-21), key PI3K/AKT/mTOR signaling pathway-related proteins and mRNAs, as well as molecular markers of cell proliferation and apoptosis, was evaluated. The results indicated that the mouse body weight did not significantly differ across SC-FL-treated groups compared to the GTW group (non-treated model group); however, the high-dose SC-FL mice showed significantly higher testicular weight (p < 0.05). Both medium- and high-dose SC-FL mice showed significantly increased sperm concentration and motility relative to the GTW group (p < 0.01). Histological analysis by hematoxylin and eosin staining revealed that SC-FL treatment alleviated GTW-induced testicular tissue damage and preserved testicular structure. SC-FL treatment reduced serum IL-6 and TNF-α levels and decreased PTEN mRNA and protein expression. It also increased miR-21, PI3K, AKT, and mTOR mRNA expression and increased the phosphorylated protein levels of PI3K, AKT, and mTOR, whereas total PI3K, AKT, and mTOR protein abundance remained relatively unchanged. In conclusion, SC-FL increased sperm concentration and motility and reduced serum inflammatory cytokine levels in mice. These beneficial effects were accompanied by increased miR-21 expression, decreased PTEN expression, and increased phosphorylation of PI3K, AKT, and mTOR. These findings indicate an association between the protective effects of SC-FL and alterations in the miR-21/PTEN/PI3K/AKT/mTOR signaling axis, but do not establish causal mediation by this pathway.