Puerarin alleviates oxidative stress, mitochondrial dysfunction, and apoptosis in corpus cavernosum smooth muscle cells through AKT/Nrf2/HO-1 pathway activation.

Background: Although functional abnormalities may precede structural alterations in early erectile dysfunction (ED), progressive corpus cavernosum smooth muscle cells (CCSMCs) apoptosis is a key trigger of corporal tissue damage, indicating the potential significance of improving CCSMCs anti-apoptotic activity for organic ED treatment. Aim: To evaluate the effects and mechanisms of puerarin (PUR) in improving the anti-apoptotic characteristics of CCSMCs. Methods: Rat CCSMCs were extracted and stimulated with transforming growth factor-β1 (TGF-β1) for establishing an in vitro apoptotic model. The cells were pretreated with PUR. The involvement of AKT and nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling cascades was assessed using corresponding inhibitors. Protein kinase B (AKT) silencing was performed to evaluate whether AKT functions upstream of Nrf2/HO-1. Outcomes: Cell viability, proliferation, apoptosis, oxidative stress, mitochondrial function, and protein expression were assessed using Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine, terminal deoxynucleotidyl transferase dUTP nick end labeling, flow cytometry, reactive oxygen species, malondialdehyde, superoxide dismutase, mitochondrial superoxide (MitoSOX), mitochondrial membrane potential, mitochondrial permeability transition pore assays, and Western blotting, respectively. Results: alpha‑smooth muscle actin (α‑SMA) and desmin were positively expressed in the isolated CCSMCs. PUR was nontoxic at ≤80 μM/L. TGF-β1 exposure significantly impaired CCSMCs' viability and proliferation, induced apoptosis, triggered oxidative stress and mitochondrial dysfunction, and suppressed AKT and Nrf2/HO-1 signaling. PUR pretreatment significantly alleviated these effects. Pharmacological inhibition of the AKT or Nrf2/HO-1 signaling partially reversed this protection, whereas AKT silencing abolished PUR-induced Nrf2/HO-1 activation. Clinical Translation: This study provides in vitro evidence that PUR alleviated CCSMCs damage through AKT/Nrf2/HO-1 pathway activation, highlighting the necessity for further in vivo studies to explore its potential role in ED. Strengths and Limitations: These findings provide preliminary evidence that PUR protects CCSMCs from oxidative stress, mitochondrial dysfunction, and apoptosis through AKT/Nrf2/HO-1 pathway modulation. However, further in vivo studies are warranted to validate these findings at the cellular level. Conclusion: Puerarin might attenuate TGF-β1-elicited oxidative stress, mitochondrial injury, and apoptosis via AKT/Nrf2/HO-1 pathway activation, indicating its therapeutic potential for ED.