Combined treatment with extracorporeal shockwaves therapy and an herbal formulation for activation of penile progenitor cells and antioxidant activity in diabetic erectile dysfunction

Background: A Korean herbal formulation named KH-204 was reported to have an antioxidant effect in our previous study. We hypothesized that Low-intensity extracorporeal shockwave therapy (Li-ESWT) combined with KH-204 would accelerate the treatment of erectile dysfunction (ED) by enhancing antioxidant. We investigated the synergistic effect of Li-ESWT and KH-204 for ED and explored the mechanism. Methods: Human umbilical vein endothelial cells (HUVEC) were treated with KH-204 and LI-ESWT in vitro. Fifty 5-week-old male Sprague Dawley rats received an intraperitoneal injection of 5-ethynyl- 20-deoxyuridine (EdU) which can label live cells, and were randomly divided into five groups: (I) normal; (II) diabetes mellitus-associated erectile dysfunction (DMED); (III) DMED + KH-204; (IV) DMED + Li- ESWT; and (V) DMED + KH-204/Li-ESWT. Li-ESWT treatment was repeated three times a week every other day for four weeks in group 4 and 5. Meanwhile, rats in group 3 and 5 were orally fed 400 mg/kg of KH-204 daily for 1 month. Following a 1-week washout period, penile tissues were evaluated by immunostaining and Western blotting. Results: KH-204 combined with Li-ESWT improved intracavernosal pressure (ICP) in DMED rats. Li-ESWT/KH-204 stimulated HUVEC tube formation and promoted proliferation. Li-ESWT drove progenitor cells to migrate to penile tissue and KH-204 protected penile progenitor cells in the corpus cavernosum. Oxidative stress was relieved by KH-204/Li-ESWT. Treatment with KH-204/Li-ESWT protected penile progenitor cells, which were recruited to the corpus cavernosum by Li-ESWT, from apoptosis via its antioxidant activity. KH-204/Li-ESWT protected penile tissue from oxidative stress by improving the expression of nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1), increasing superoxide dismutase (SOD), decreasing 8-hydroxy-20-deoxyguanosine (8-OHdG), and reducing apoptosis. KH-204/Li-ESWT promoted stromal derived factor-1 (SDF-1) and platelet endothelial cell adhesion molecule-1 (PECAM-1) in DMED rats. Conclusions: KH-204 protected penile progenitor cells, which were recruited to the corpus cavernosum by Li-ESWT, from apoptosis via its antioxidant activity. The combination of Li-ESWT and KH-204 as a synergy therapy could be a potential and effective treatment for DMED.