[Icariin improves erectile function in spontaneously hypertensive rats by up-regulating Nrf2].

Objective: To investigate whether icariin improves erectile function in spontaneously hypertensive rats (SHR) by regulating the NRF2 pathway.

Methods: We equally randomized 24 ten-week-old healthy male Wistar-Kyoto rats (WKR) and healthy male SHR rats into four groups: WKR control, WKR + icariin, SHR control and SHR + icariin, the controls treated intragastrically with normal saline, and the animals in the WKR + icariin and SHR + icariin groups with icariin, all at 10 mg/kg/d for 4 weeks. Then we obtained the body weight and serum T level of the rats and measured the maximum intracorporeal pressure / mean arterial pressure (ICPmax/MAP) and the contents of nuclear factor-erythroid 2-related factor-2 (Nrf2), memeoxygenase-1 (HO-1), endothellial nitric oxide synthase (eNOS), peroxisome proliferator activated receptor gamma (PPAR-γ) , dimethylarginine dimethylaminohydrolase (DDAH), nitric oxide (NO), cyclic guanosine monophosphate (cGMP) and asymmetric dimethylarginine (ADMA) in the corpora cavernosa tissue.

Results: There were no statistically significant differences in the body weight or serum T level among the four groups of rats. The ratios of ICPmax/MAP and P-eNOS/eNOS and the expressions of Nrf2, HO-1, PPAR-γ, DDAH, NO and cGMP in the corpora cavernosa tissue were significantly higher in the SHR + icariin group than in the SHR control (P < 0.05) but lower than in the WKR control. The ADMA level in the corpora cavernosa tissue was remarkably reduced in the SHR + icariin group compared with that in the SHR control (P < 0.05).

Conclusions: By up-regulating the expression of Nrf2, icariin increases the HO-1, DDAH and PPAR-γ levels and the P-eNOS/eNOS ratio in the corpora cavernosa and improves the erectile function of spontaneously hypertensive rats.