Mechanisms Associated with Ginkgo biloba and Future Research Directions: Implication of the Hypothalamic Pituitary-testicular Axis

Ginkgo biloba (GB) is a widely used herbal medicine purported to possess various therapeutic effects. While some research suggests beneficial impacts on cognitive function and circulation, the mechanisms underlying potential effects on the male reproductive system, specifically via the hypothalamic-pituitary-testicular (HPT) axis, remain poorly understood. This review aims to consolidate existing knowledge regarding the potential interaction between Ginkgo biloba and the HPT axis to identify gaps in the literature and propose future research directions. A search was conducted using databases including PubMed, Scopus, and Web of Science. Search terms included "Ginkgo biloba," "testosterone," "HPT axis," "male reproduction," "spermatogenesis," "luteinizing hormone (LH)", "follicle-stimulating hormone (FSH)", and related terms. Studies included were those investigating the effects of Ginkgo biloba or its extracts on male reproductive hormones, testicular function, and related physiological parameters in animal models or human subjects. The available evidence suggests that Ginkgo biloba may influence the HPT axis through multiple mechanisms, possibly involving enhanced circulation, antioxidant activity, and modulation of neurotransmitter systems. Some studies demonstrate alterations in testosterone levels, LH, and FSH following Ginkgo biloba administration. However, the results are inconsistent, and the specific pathways involved, potential dose-dependent effects, and influence of Ginkgo biloba constituents on different components of the HPT axis (hypothalamus, pituitary, and testes) requires further investigation. Furthermore, potential interactions with other medications or pre-existing conditions need clarification. In conclusion, Ginkgo biloba exhibits the potential to modulate the HPT axis, but the precise mechanisms and clinical significance necessitate further research. Future studies should focus on elucidating the specific molecular targets of Ginkgo biloba within the HPT axis, determining optimal dosages and treatment durations, and assessing the potential impact on fertility parameters and overall male reproductive health.