A review of Serenoa serrulata: A potential monotherapy medicinal plant for prostatic disease in combination with other therapies

Background: Prostatic diseases which include prostatitis, benign prostatic hyperplasia (BPH) and prostate cancer are the benign or malignant disorders that affect the prostate. Phytotherapies have been adopted as the alternative treatment/ management option especially for BPH since the current modern methods of treatment presents a lot of adverse effects. Methodology: The literature was searched using different databases including Medline/PubMed, Cochrane library, Scopus, Proquest library, Embase, EBooks and Google Scholar for relevant records for a period from 1988 to 2021 to identify all the published articles of S. serrulata regarding treatment of prostatic diseases. The key search terms were Serenoa serrulata, S. repens, Saw palmetto, Prostate cancer treatment with Serenoa serrulata, treatment of Benign Prostatic Hyperplasia with Serenoa serrulata, phytochemicals of Serenoa serrulata, ethnobotanical uses of Serenoa serrulata, toxicity of Serenoa serrulata, pharmacological activities of Serenoa serrulata and also traditional management and treatment of prostatic diseases using Serenoa serrulata and also clinical trials on treatment of prostatic diseases with Serenoa serrulata. The retrieved articles were reviewed, synthesized and analyzed qualitatively. The reference list of the retrieved articles was also reviewed and synthesized. The original research articles which reported an investigation of S. serrulata of any study design, original published research articles, any time of publication and grey literature (conference papers, reported articles, academic thesis) were included. The articles whose full texts were not freely available by the time of search and those without clear information about methodology and study design were excluded. Results: This review reported that Serenoa serrulata belonging to the Arecaceae family commonly known as saw palmetto is used traditionally for treating prostatic disease conditions and other infertility conditions in both men and women. Phytochemical screening of hexanic and ethanolic extracts of S. serrulata comprised of free fatty acids and phytosterols which together contribute to their antiprostatic activities. These extracts of S. serrulata exhibited antiandrogenic, anti-inflammatory and anti-proliferative activities through inhibition of both isoenzymes 5α- reductase and inhibition of binding of dihydrotestosterone (DHT) to the cytosolic androgen receptors. This is a similar mechanism exhibited by finasteride and Tamsulosin both antiprostatic conventional drugs though the plant phytochemicals do not interfere with PSA secretion. S. serrulata has also been reported to be non-toxic in both non-clinical and clinical trial studies. The medicinal plants reported by this review to be used in combination include; stinging nettle (Urtica dioca), Zingiber officinalis, Echinacea angustifolia and pumpkin (Cucurbita pepo). The antiprostatic conventional drugs reported include Finasteride and Tamsulosin. Conclusion and Recommendation: The results showed that S. serrulata is effective in treating prostatic diseases. The potency and safety are improved when used in combination with Urtica dioca, Cucurbita pepo, Zingiber officinalis and Echinacea angustifolia as compared with anti-prostatic conventional drugs Finasteride and Tamsulosin alone. The plant combination has also been shown to have improvement in the quality of life and as well enhancing the synergy of Finasteride and Tamsulon and their adverse effects. Effective medicinal plant combinations should be formulated into products and integrated into the usual treatment for prostatic diseases.