Neuroprotective effect of Hongjing I granules on erectile dysfunction in a rat model of bilateral cavernous nerve injury.

Neurogenic erectile dysfunction (NED) is an inevitable postoperative disease of cavernous nerve injury which will lead to various pathophysiological changes in the corpus cavernosum and dorsal penile nerve caused by radical prostatectomy (RP). Although serval years of clinical application of HJIG I granules (HJIG), an innovative formulation, has demonstrated its reliable clinical efficacy against NED, the mechanism of HJIG remains unclear. This study aimed to assess the neuroprotective effect of HJIG, to repair damaged nerves in a rat model of bilateral cavernous nerve injury (BCNI) in vivo and their effects on neurites of major pelvic ganglia (MPG) regeneration and Schwann cells (SCs) proliferation in vitro. Rats were divided into five groups randomly: normal control (NC), BCNI-induced ED model (M), M + low-dose HJIG (HL), M + medium-dose HJIG (HM), and M + high-dose HJIG (HH). All groups were treated with normal saline or the relevant drug for 28 consecutive days after a standard NED animal model. Our data revealed that administration of HJIG improved NED that was detected by intracavernous pressure (ICP) in a dose-dependent manner. The haematoxylin-eosin (HE) and Immunofluorescence (IF) staining demonstrated that HJIG ameliorate the shape of penis and induced the protein synthesis of GAP43, NF200, S100, and nNOS. NF200 and S100 level were also detected by western blotting. Moreover, HJIG (0.78 mg/mL) markedly increased SCs viability and promoted neurites regeneration of MPG. These findings provide new insights into the NED therapy by HJIG.