Fermented Morinda citrifolia extract improves late-onset hypogonadism in aged rats

Late-onset hypogonadism (LOH) is an age-associated condition characterized by a progressive decline in testosterone levels. It manifests as reduced libido, infertility, muscle loss, and cognitive impairment in middle-aged men. Although testosterone replacement therapy is effective, its associated side effects highlight the need for safer alternatives. Previously, we have demonstrated the efficacy of the fermented Morinda citrifolia extract (FME) in ameliorating LOH symptoms in vitro. The present study aimed to assess the in vivo efficacy of FME in mitigating LOH symptoms using an aged rat model.

Thirty-three-week-old male Sprague-Dawley rats were administered either Testofen or FME daily for four weeks. Serum levels of total and free testosterone, sex hormone-binding globulin (SHBG), dihydrotestosterone, and metabolic hormones were measured. Testicular gene expression and protein expression related to steroidogenesis were also assessed. Muscle mass, physical performance (evaluated using treadmill test), and sperm quality were also assessed.

FME treatment significantly increased serum testosterone levels, reduced SHBG and dihydrotestosterone concentrations, and enhanced the expression of testosterone biosynthesis-related proteins. FME downregulated degradation enzymes such as 5α-reductase and aromatase. FME also improved sperm production, progressive motility, muscle mass, and treadmill running capacity. Histological analyses confirmed tissue recovery in the testes and muscles.

FME alleviated LOH-related symptoms in aged rats by modulating testosterone metabolism, enhancing reproductive and physical health, and maintaining a favorable safety profile. These findings validate the in vivo efficacy of FME and highlight its potential as a natural therapeutic candidate for managing LOH and related conditions.