Qianlie Beixi Capsules Ameliorate Diabetes-Induced Erectile Dysfunction via Modulation of the HIF-1α/VEGF Signaling Pathway: Evidence From an in Vivo Study

Diabetic-induced erectile dysfunction (DIED) is a frequent complication of diabetes mellitus. Qianlie Beixi Capsules, a formulation of traditional Chinese medicine, have long been used for its management. The effectiveness of Qianlie Beixi Capsules in treating DIED was evaluated together with an exploration of their possible mechanism of action. Streptozotocin (STZ) was administered to rats to induce diabetes, with confirmation of erectile dysfunction using apomorphine (APO). The animals were allocated to six groups: the blank control (NC), model (M), Qianlie Beixi Capsules low-dose (QD), Qianlie Beixi Capsules medium-dose (QZ), Qianlie Beixi Capsules high-dose (QG), and HIF-1α inhibitor (YC) groups. After 2 weeks of treatment, serum levels of testosterone (T), Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), and Endothelial Microparticles (EMPs) were measured. Penile histology was analyzed for structural alterations. Furthermore, Western blotting and reverse transcription quantitative polymerase chain reaction (RT-qPCR) were utilized to assess levels of mammalian target of rapamycin(mTOR), p70 ribosomal protein S6 kinase(p70s6k), hypoxia-inducible factor 1-alpha(HIF-1α), vascular endothelial growth factor(VEGF), and endothelial nitric oxide synthase(eNOS ) in the corpus cavernosum. The QZ and QG groups demonstrated markedly increased penile erection frequency relative to the model rats (p < .05). Histological analyses revealed increased smooth muscle cell densities, reduced collagen deposition, and a decrease in erythrocytes within the blood sinuses in these groups. Expression of HIF-1α and VEGF proteins was significantly reduced (p < .05), while eNOS expression was elevated (p < .05). Moreover, serum levels of LOX-1 and EMPs were markedly reduced (p < .05) in the QZ and QG groups. Qianlie Beixi Capsules improve DIED by modifying the mTOR/HIF-1α/VEGF signaling axis, which additionally increases penile endothelial function and reduces endothelial fibrosis.