A systematic review of herbal medicine in the clinical treatment of benign prostatic hyperplasia

The use of herbal medicine and alternative medicine is reported to be in up to 50% of prescriptions for benign prostate hyperplasia (BPH) in Europe, along with an increased global interest for holistic medicinal approaches. This study aimed to systematically review the published evidence investigating the use of herbal medicines as a treatment for BPH in clinical trials based on PRISMA guidelines. A literature search was conducted using PubMed, Cochrane, Medline, and Scopus databases, including English language clinical trials (Jadad score of ≥ 4) that investigated herbal medicine as a sole intervention, reporting at least one of the following outcomes: International Prostate Symptom Score (IPSS); American Urological Association Symptom Index (AUASI); Maximum Urinary Flow Rate (Qmax); Post-void residual volume (PRV); Prostate volume (PV); Serum Prostatic Specific Antigen (PSA); Quality of Life (QoL) Scores. Following article screening, 28 articles were included. The most frequently studied herbs in isolation or in combination were Serenoa repens (54%), Urtica dioica (14%), Cucurbita pepo (14%), lycopene (14%), Pygeum africanum (14%) and Linum usitatissimum (7%). These herbal-based formulations mostly improved the symptoms associated with BPH (IPSS/AUASI, Qmax, PSA, QoL scores, PRV and PV). This review further discusses these herbs and the outcomes, with a focus on the potential mechanisms of action. There are limited high quality clinical trials investigating herbal medicine on BPH, where S. repens is significantly more represented than other popular herbs for BPH, such as C. pepo, U. dioica, P. africanum, and lycopene. Although the included studies broadly found positive positive results for standardised outcomes for LUTS and urinary flow, there was great variability in the study designs requires caution in interpretation. As these herbs are supported by in vivo and in vitro studies on potential mechanisms of actions, comparison of efficacy of mono-herbal and poly-herbal approaches, standardized extracts based on identification of active constituents, as well as dosage and long-term safety studies are warrented.