Abstract
BACKGROUND: The kidney and spleen are associated with erectile dysfunction (ED) in traditional Chinese medicine (TCM) understanding. Zhenyuan granule (ZYKL) is a Chinese herbal formula with the function of tonifying kidney and spleen and promoting blood circulation. This study aims to evaluate the effects of ZYKL on improving ED and fatigue. METHODS: A rat model of orchiectomy (ORX) was developed by removing bilateral testicles. Male Sprague-Dawley rats were divided into Sham, ORX, testosterone (T) propionate (2 mg/kg), ZYKL low-dose (0.94 g/kg), ZYKL middle-dose (3.76 g/kg), and ZYKL high-dose (7.52 g/kg) group. Rats in ZYKL groups were given ZYKL by gavage for 21 days. Sexual behavior parameters, including erection latency (EL), mount latency (ML), and mount frequency (MF), as well as T levels, histological morphology of the penis, and nitric oxide synthase (NOS)-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) signaling pathway were analyzed to assess sexual function. The weight-loaded forced swimming (WLFS) test was conducted, and the concentrations of blood lactic acid (BLA) and blood urea nitrogen (BUN) were measured to evaluate the anti-fatigue effects. RESULTS: ZYKL significantly elevated T levels, shortened EL and ML, and increased MF in orchiectomized rats, and ameliorated the pathological alterations of the penis induced by ORX. In addition, ZYKL significantly increases NOS activity, NO and cGMP concentrations. Lower BLA and BUN levels were observed in the ZYKL-treated groups after swimming. CONCLUSIONS: These results indicate that ZYKL ameliorates ED and fatigue. The mechanism for improving ED might be associated with activating the NOS-NO-cGMP signaling pathway and elevating T levels.