Fruit Extract of Black Pepper (Piper Nigrum L.) Ameliorates Male Reproductive Dysfunction in Alloxan-Induced Diabetic...

Diabetes mellitus is a chronic hyperglycemic condition leading to metabolic problems that cause organ damage and result in serious complications. Long-term complications of diabetes can cause serious health problems, such as sexual and reproductive dysfunction in men and women. Black pepper (Piper nigrum L.) is a medicinal plant proven to increase testosterone hormone levels, sexual function (libido), and spermatogenesis parameters in male rats. In this study, the effect of black pepper fruit extract on sexual function and reproductive function (fertility) in alloxan-induced diabetic male rats was evaluated.

A total of 30 male Sprague Dawley rats (Rattus norvegicus), aged 2.5 to 3 months and weighing 100-150 g, were divided into five groups of 6 individuals each. Group I consisted of rats given only standard feed. Group II consisted of alloxan-induced hyperglycemic rats given standard feed. Groups III and IV were alloxan-induced hyperglycemic rats given black pepper extract at 122.5 and 245 mg/kg BW, respectively, for 8 days. Group V consisted of alloxan-induced hyperglycemic rats given sildenafil therapy or zinc plus ascorbic acid. After 8 days of treatment, the erectile function and libido of the rats were assessed, followed by an evaluation of spermatozoa and testicular histology. Data were analyzed using ANOVA with significance set at p < 0.05.

Alloxan-induced diabetic rats showed significant impairment in erectile function, libido, sperm quality, and testicular histology (p < 0.001 vs. control). Administration of black pepper extract at a dose of 122.5 mg/kg BW increased total penile reflexes (9.33 ± 1.03 vs. 6.00 ± 1.26 in the diabetes group, p = 0.002) and improved libido, with a decrease in courtship latency (5.50 ± 0.55 s vs. 21.00 ± 9.47 s, p = 0.013) and an increase in mounting frequency (18.05 ± 5.99 vs. 7.17 ± 1.83, p = 0.009). The extract dose of 245 mg/kg BW increased sperm concentration (158.16 ± 29.80 vs. 12.6 ± 1.3 ×10⁶, p < 0.001), progressive sperm motility (65.0 ± 35% vs. 27.0 ± 30%, p = 0.006), and normal sperm morphology (82.9 ± 5.7% vs. 35.0 ± 10.8%, p < 0.001). The number of Leydig cells increased significantly in the 122.5 mg/kg BW extract group (59.33 ± 4.08 vs. 30.50 ± 3.86; p < 0.001) compared to the diabetes group. There was no significant difference in spermatogonia count (640 ± 86.5 vs. 491 ± 37.0; p = 0.119).

Piper nigrum fruit extract ameliorates sexual dysfunction and reproductive impairment in alloxan-induced diabetic rats, particularly at 122.5 mg/kg BW, with significant improvements in erectile function, libido, sperm quality, and testicular histology. These findings suggest its potential as a natural therapeutic agent for diabetes-related male reproductive dysfunction.