Black pepper (Piper nigrum L.) fruit extract ameliorates erectile dysfunction in alloxan-induced diabetic rats

Background Diabetes mellitus (DM) is a chronic metabolic disorder frequently associated with male sexual and reproductive dysfunction, including erectile dysfunction (ED), reduced libido, and impaired spermatogenesis. Black pepper ( Piper nigrum L.) fruit extract has been reported to possess antidiabetic and reproductive benefits, yet its effect on DM-related ED remains underexplored. Objective To evaluate the effects of Piper nigrum fruit extract on erectile function, libido, sperm parameters, and testicular histology in alloxan-induced diabetic male rats. Methods Thirty male Sprague Dawley rats were divided into five groups: normal control, diabetic control, diabetic rats treated with black pepper extract (122.5 or 245 mg/kg BW), and diabetic rats treated with sildenafil citrate. Erectile function was assessed via penile reflexes, libido by mating behavior, sperm quality by concentration, motility, and morphology, and testicular histology by Leydig cell and spermatogonia counts. Data were analyzed using ANOVA with significance at p