A flavonoid derivative of icariside II (YS-10) improves erectile dysfunction in radiation-injured rats via oxidative stress pathway

Background: We explored the preventive effect and mechanism of YS-10, a novel synthesized flavonoid derivative based on the structure of icariside II (ICA II), on a rat model of radiation-induced erectile-dysfunction (Ri-ED). Methods: Eighteen 10-week-old male Sprague-Dawley (SD) rats were randomly divided into 3 groups. Six rats were used as the control group (Control), and the remaining 12 were given a single X-ray irradiation of 20 Gy in the prostate and then randomly divided into the radiation injury group (Ri-ED group) and YS-10 treatment group (Ri-ED+YS-10, 2.5 mg/kg/day). After 4 weeks of drug administration and a 2-week drug washout period in the YS-10 treatment group, the erectile function of the animals was evaluated, and the tissues were collected for histopathological analysis and detection of oxidative stress indicators. Results: After radiation injury, the ratio of maximum intracavernosal pressure (ICP) to mean arterial pressure (MAP), the number of neuronal nitric oxide synthase (n-NOS) positive nerve fibers in the penis cavernosa, endothelial cell content, and n-NOS and endothelial nitric oxide synthase (e-NOS) proteins in the Ri-ED group were significantly lower than those in control group. Compared with the control group, the Ri-ED group had lower superoxide dismutase (SOD) levels and higher malondialdehyde (MDA) levels. Compared with the Ri-ED group, the YS-10 group had a significant increase in the ratio of ICP/MAP in the corpus cavernosum (0.59 +/- 0.06 vs. 0.43 +/- 0.06, P<0.01), the number of n-NOS positive nerve fibers, and the content of endothelial cells. The protein content of n-NOS and e-NOS in the corpus cavemosum increased and could significantly reduce the level of MDA (2.67 +/- 0.27 vs. 3.25 +/- 0.21, P<0.05). Conclusions: As a novel ICA II derivative, YS-10 could significantly improve the erectile dysfunction and pathological damage in rats caused by radiation injury, and its mechanism may be related to the improvement of radiation-induced oxidative stress.