Table 2. Herbal remedies used for BPH.

IPSS: International Prostate Symptom Score; AUASI: American Urological Association Symptom Index; BPH: Benign prostatic hyperplasia; VEGF: Vascular endothelial growth factor; DHT: Dihydrotestosterone; TGFB: Transforming growth factor - beta; FGF: Fibroblast growth factor

Author (year)	Groups studied and interventions	Results and findings	Conclusions
Study 1: Carraro et al. [23]	1,908 patients were selected and divided into two groups via double-blind randomization. The first group received 320 mg of saw palmetto oil extract (Permixon) 320 mg once daily compared to the second group who received 5 mg of finasteride.	At the end of six months, both treatments provided comparable outcomes for IPSS score decrease and quality of life score increase. However, Finasteride was able to significantly decrease prostate volume and PSA levels, while Permixon had little to no effect. Patients on finasteride had increased complaints of sexual dysfunction.	According to “Comparison of phytotherapy (Permixon) with finasteride in the treatment of benign prostate hyperplasia: a randomized international study of 1,098 patients,” patients taking 320 mg Permixon and 5 mg finasteride had similar improvement in symptoms per IPSS score and quality of life.
Study 2: Bent et al. [24]	225 men aged >49 were assigned into two groups in a double-blind trial. The trial took place over twelve months. The intervention group took 160 mg twice daily, and the other group was a placebo group.	Results from this trial indicated that there was no improvement in symptoms or objective symptoms of benign prostate hyperplasia. There were no significant differences between mean change and AUASI scores over time between the two groups (difference in mean change 0.04 points). The saw palmetto group saw a decrease in the AUASI score by 0.68, and the placebo group had a decrease of 0.72.	This year-long trial proved that there were no significant differences between saw palmetto and placebo in treating BPH.
Study 3: Barry et al. [25]	Participants participated in a 27-week randomized, placebo-controlled, double-blind, multicenter trial. Participants were men aged at least 45 years old with a urinary peak flow rate greater than or equal to 4 ml/sec with an AUASI score greater than or equal to 8 but less than or equal to 24. Patients were divided into a placebo group and an intervention group. The intervention group received 320 mg daily until week 24. It was then increased to 320 mg twice daily at week 48, and 320 mg three times daily was continued to week 72.	Results indicated that mean AUASI scores decreased from 14.7 to 11.7 in placebo patients and 14.4 to 12.2 in saw palmetto patients with mean averages favoring the placebo treatment. When comparing secondary outcomes (nocturia, post-void residual volume, prostate-specific antigen, sexual function, and prostatitis symptoms), there were again no effective results seen in patients with saw palmetto treatment.	“Effect of increasing doses of saw palmetto extract on lower urinary tract symptoms: a randomized trial” indicated that even at increased dosage and dosing intervals there was still no significant evidence that saw palmetto had any improvement in treating BPH and patients with lower urinary tract symptoms.
Study 4: Sudeep et al. [26]	In this double-blind trial, participants were also exposed to b-sitosterol-enriched saw palmetto oil. Participants in this trial were aged 40-65 years old with symptomatic BPH. They were randomized into a 12-week double-blind treatment into three groups. Patients with 500 mg b-sitosterol enriched saw palmetto oil, conventional saw palmetto oil, and placebo with 33 participants in each group.	When comparing the IPSS score, for patients taking the b-sitosterol enriched saw palmetto oil it decreased from 20.00±4.41 to 16.82±4.03 by the conclusion of week 12 with a p-value of <0.0001. The decreases in value for the saw palmetto group and placebo group with not statistically significant.	“A double blind, placebo-controlled randomized comparative study on the efficacy of phytosterol-enriched and conventional saw palmetto oil in mitigating benign prostate hyperplasia and androgen deficiency” provided results that correlated in the two above studies that conventional saw palmetto and placebo provide patients with comparable results; however, when combined with phytosterol-enriched saw palmetto, there are significant improvements in outcomes.
Study 5: Gossell-Williams et al. [27]	A population of rats was collected and prostatic hyperplasia was induced with subcutaneous testosterone (0.3 mg/100g of body weight) for 20 days. The population was divided to receive pumpkin seed oil (2.0 mg/100g and 4.0 mg/100g of body weight) or corn oil (vehicle) was also given for 20 days.	On day 21, the prostates were removed and weight was calculated. Testosterone increased prostate size in the population significantly (p<0.05). Both pumpkin seed oils displayed a decrease in prostate size; however, the 4.0 mg/100g dosage led to a significantly higher effect of prostatic growth inhibition (p<0.02).	Pumpkin seed oil may provide protective effects against testosterone-induced hyperplasia of the prostate and may be beneficial in managing BPH given the statistically significant results of this study.
Study 6: Quiles et al. [34]	Primary prostate stromal cells were collected from BPH patients undergoing prostatectomy and patients without BPH undergoing cystectomy. Pyegeum africanum was introduced to both populations of cells and proliferation assays were collected after. Levels of apoptosis, transforming growth factor B1, fibroblast growth factor 2, vimentin, alpha-smooth muscle actin, and smoothelin levels were examined following the treatment with Pyegeum africanum.	Apoptosis and antiproliferation potency were increased in BPH versus non-BPH stromal cells. There was downregulation of transforming growth factor B1 in both populations. Fibroblast growth factor 2 presence increased the cell’s sensitivity to Pyegeum africanum. However, the presence of VEGF, DHT, or beta-estradiol decreased the antiproliferative activity of Pyegeum africanum.	Pyegeum africanum has antiproliferative and apoptotic effects on prostate fibroblasts and myofibroblasts but not on smooth muscle cells. The mechanisms of action include TGFB1 downregulation and inhibition of FGF2 signaling.