Serenoa repens extracts: In vitro study of the 5α-reductase activity in a co-culture model for Benign Prostatic Hyperplasia

Abstract

Objectives. Benign Prostatic Hyperplasia (BPH) is a form of benign tumor that occurs in humans mainly with ageing. It affects more than 50% of over 50 years old males and it is characterized by an increased synthesis of dihydrotestosterone (DHT), due to the 5α-reductase activity. The BPH therapeutic approach mainly uses 5α-reductase inhibitors, such as the active compounds present in the extracts deriving from species Serenoa repens. Many lipidosterolic extracts are available on the market, which are obtained with different solvents, among them ethanol is recognized as non-toxic and has less handling risks than hexane. The purpose of the present experimental study was to investigate in-vitro the potency of an ethanol extract of S. repens comparing it with an n-hexane one. Materials and methods. Two different lipido-sterolic extracts of S. repens have been tested: ethanol extract and n-hexane extract, two batches for each one. The inhibitory action of the extract was evaluated estimating in-vitro the activity of enzyme 5α-reductase type I (5α-RI), which was mainly active under the experimental condition of pH 7.5. DHT amount, synthesized from testosterone (1 μM), was evaluated in a co-culture model of epithelial cells and fibroblasts resulting from prostatic biopsy of a patient with BPH.Results. The analysis of the resulting dose-response curves showed that the entire S. repens extracts inhibited the 5α-RI showing no difference between the two kinds of extract or between the batches. The resulting IC50 values were the following: 8.809 (95% CI = 5.133-15.56) and 9.464 (95% CI = 5.094- 18.27) for ethanol extracts; 11.08 (95% CI = 6.389-19.98) and 12.72 (95% CI = 7.758-21.53) for n-hexane extracts. Conclusions. The potency of ethanol extracts of S. repens was comparable with the one of n-hexane extracts.

A Prospective, Open-Label Comparison of Tamsulosin plus <b><i>Serenoa repens</i></b> and Bovine Colostrum versus Tamsulosin Alone in the Treatment of Benign Prostatic Hyperplasia

“…Although the exact action of SR is not yet completely understood, several mechanisms have been proposed [8]. In particular, the presence of fatty acids and phytosterols has been hypothesized to confer upon SR an anti-inflammatory and antiproliferative action on prostatic tissue [9]. However, the heterogeneity of the previous reports and the different ways of SR extraction have still restrained any accurate understanding of the effectiveness of SR itself as well as compared with alpha-blockers [10].…”

Rethinking the Role of Saw Palmetto Extract for Men with Lower Urinary Tract Symptoms in North America

“…The potential mechanisms by which LSESr affects these cellular processes and mitigates LUTS continue to be studied [22]. Studies have provided evidence that prostate cells preferentially take up free fatty acids, including those contained within LSESr [23][24][25].…”

“…Studies have provided evidence that prostate cells preferentially take up free fatty acids, including those contained within LSESr [23][24][25]. Once fatty acids are incorporated into the nuclear membrane, they can alter membrane fluidity, inducing temporary conformational changes to the 5-AR protein structure that can disrupt the conversion of testosterone to DHT [22,23,[26][27][28][29]. This form of non-competitive, reversible inhibition is hypothesized to reduce DHT-dependent androgen signaling, resulting in increased prostate cell apoptosis and decreased prostate cell proliferation and, subsequently, slowed prostate growth [15,22,26,27,29].…”

“…Once fatty acids are incorporated into the nuclear membrane, they can alter membrane fluidity, inducing temporary conformational changes to the 5-AR protein structure that can disrupt the conversion of testosterone to DHT [22,23,[26][27][28][29]. This form of non-competitive, reversible inhibition is hypothesized to reduce DHT-dependent androgen signaling, resulting in increased prostate cell apoptosis and decreased prostate cell proliferation and, subsequently, slowed prostate growth [15,22,26,27,29]. These effects have been observed in in vitro experiments using rat liver cells, pig prostate cells, biopsied human prostate cells, and PC3 prostate cancer cells [22,[26][27][28][29].…”

A Randomized, Double-Blind, Placebo-Controlled Study of a Nutraceutical Supplement for Promoting Hair Growth in Perimenopausal, Menopausal, and Postmenopausal Women With Thinning Hair

“…11 In addition to declining estrogen levels in relationship to androgens, 11 other significant changes which affect the hair follicle specifically through and after menopause include: increased oxidative stress and inflammation, 19 stress-related increases in cortisol, 20,21 metabolic changes, 22 and changes in nutritional status. 23 One key ingredient is saw palmetto, which has shown efficacy in hair loss, 24,25 and is known for its well-documented antiandrogenic and DHT-inhibiting 26 properties. The dosage was optimized and increased in this formula.…”