Pygeum africanum 

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Cochrane Database Syst Rev. 1998 Jan; 1998(1): CD001044.Published online 1998 Jan 26

Pygeum africanum, an extract from the bark of the African prune tree, has been utilized in Europe since 1969 for the treatment of mild to moderate symptomatic benign prostatic hyperplasia. The mechanism of action of Pygeum africanum remains unclear.

Abstract

Background

Benign prostatic hyperplasia (BPH), nonmalignant enlargement of the prostate, can lead to obstructive and irritative lower urinary tract symptoms (LUTS). The pharmacologic use of plants and herbs (phytotherapy) for the treatment of LUTS associated with BPH has been growing steadily. The extract of the African prune tree, Pygeum africanum, is one of the several phytotherapeutic agents available for the treatment of BPH.

Objectives

To investigate the evidence whether extracts of Pygeum africanum (1) are more effective than placebo in the treatment of Benign Prostatic Hyperplasia (BPH), (2) are as effective as standard pharmacologic BPH treatments, and (3) have less side effects compared to standard BPH drugs.

Search methods

Trials were searched in computerized general and specialized databases (MEDLINE (1966 to 2000), EMBASE, Cochrane Library, Phytodok), by checking bibliographies, and by contacting relevant manufacturers and researchers.

Selection criteria

Trials were eligible if they (1) were randomized (2) included men with BPH (3) compared preparations of Pygeum africanum (alone or in combination) with placebo or other BPH medications (4) included clinical outcomes such as urologic symptom scales, symptoms, or urodynamic measurements. Eligibility was assessed by at least two independent observers.

Data collection and analysis

Information on patients, interventions, and outcomes were extracted by at least two independent reviewers using a standard form. The main outcome measure for comparing the effectiveness of Pygeum africanum with placebo and standard BPH medications was the change in urologic symptoms scale scores. Secondary outcomes included change in urologic symptoms including nocturia and urodynamic measures (peak and mean urine flow, prostate size). The main outcome measure for adverse effects was the number of men reporting adverse effects.

Main results

A total of 18 randomized controlled trials involving 1562 men met inclusion criteria and were analyzed. Only one of the studies reported a method of treatment allocation concealment, though 17 were double blinded. There were no studies comparing Pygeum africanum to standard pharmacologic interventions such as alpha‐adrenergic blockers or 5‐alpha reductase inhibitors. The mean study duration was 64 days (range, 30 to 122 days). Many studies did not report results in a method that permitted meta‐analysis. Compared to men receiving placebo, Pygeum africanum provided a moderately large improvement in the combined outcome of urologic symptoms and flow measures as assessed by an effect size defined by the difference of the mean change for each outcome divided by the pooled standard deviation for each outcome (‐0.8 SD [95% confidence interval (CI), ‐1.4 to ‐0.3 (n = 6 studies)]). Men using Pygeum africanum were more than twice as likely to report an improvement in overall symptoms (RR=2.1, 95% CI = 1.4 to 3.1). Nocturia was reduced by 19%, residual urine volume by 24% and peak urine flow was increased by 23%. Adverse effects due to Pygeum Africanum were mild and comparable to placebo. The overall dropout rate was 12% and was similar between Pygeum Africanum (13%), placebo (11%) and other controls (8%).

A standardized preparation of Pygeum africanum may be a useful treatment option for men with lower urinary symptoms consistent with benign prostatic hyperplasia. However, the reviewed studies were small in size, were of short duration, used varied doses and preparations and rarely reported outcomes using standardized validated measures of efficacy. Additional placebo‐controlled trials are needed as well as studies that compare Pygeum africanum to active controls that have been convincingly demonstrated to have beneficial effects on lower urinary tract symptoms related to BPH. These trials should be of sufficient size and duration to detect important differences in clinically relevant endpoints and use standardized urologic symptom scale scores.

Plain language summary

Extracts from the African prune tree (Pygeum africanum) may be able to help relieve urinary symptoms caused by enlarged prostate (benign prostatic hyperplasia)

Benign prostatic hyperplasia (BPH), enlargement of the prostate gland, is common in older men. An enlarged prostate can interfere with urination, increasing the frequency and urge, or causing problems emptying the bladder. Both surgery and drugs are used to try to treat BPH. However, using herbal medicines to try to relieve the symptoms of BPH is becoming common. Pygeum africanum is one of several popular herbal remedies for BPH. The review found that pygeum africanum is well tolerated, cheaper than many prescription medicines used for BPH, and provides moderate relief from the urinary problems caused by an enlarged prostate.

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Background

Benign prostatic hyperplasia (BPH) is a nonmalignant enlargement of the prostate. Symptoms related to BPH are one of the most common problems in older men. Histological evidence of BPH is found in more than 40% of men in their fifties and nearly 90% of men in their eighties (Berry 1984). The majority of men over the age of 60 are considered to have urinary symptoms attributable to BPH. In the United States treatment of BPH accounts for approximately 1.7 million physician office visits (Guess 1992) and results in more than 300,000 prostatectomies annually (McConnell 1994). The proliferative disorder resulting in BPH affects both the stromal and the epithelial portions of the prostate. The enlarging prostate results in the progressive occlusion of the proximal urethra and can result in both obstructive and irritative urinary tract symptoms. The obstructive symptoms of BPH include weak urinary stream, hesitancy, intermittency, incomplete bladder emptying, terminal urine dribbling and abdominal straining (Christensen 1990; Caine 1987). The irritative symptoms include urinary frequency, urgency and nocturia. The treatment goal in the vast majority of patients with BPH is to relieve these bothersome symptoms.

The use of plants and herbs for medicinal purposes (phytotherapy) including treatment of BPH symptoms has been growing steadily in most countries. Usage of plant extracts is common in Europe and is increasing in the United States. Phytotherapeutic agents represent nearly half of the medications dispensed for BPH in Italy, compared with 5% for alpha blockers and 5% for 5‐alpha reductase inhibitors (Di Silverio 1993). In Germany and Austria, phytotherapy is the first‐line treatment for mild to moderate urinary obstructive symptoms and represents > 90% of all drugs prescribed for the treatment of BPH (Buck 1996). In the United States their use has also markedly increased, they are readily available as nonprescription dietary supplements and are often recommended in "natural health food stores or books" for self treatment of BPH symptoms.

Pygeum africanum, an extract from the bark of the African prune tree, has been utilized in Europe since 1969 for the treatment of mild to moderate symptomatic benign prostatic hyperplasia. The mechanism of action of Pygeum africanum remains unclear. In animal models, Pygeum africanum has been shown to have pharmacologic properties that may be beneficial in the treatment of benign prostatic hyperplasia. These include modulation of bladder contractility, anti‐inflammatory activity, decreased production of leukotrienes and other 5‐lipoxygenase metabolites (Sidoti 1993; Paubert‐Braquet 1994), inhibition of fibroblast production (Yablonsky 1997; Paubert‐Braquet 1993) effects on adrenal androgens (Thieblot 1977), and restoration of secretory activity of prostate epithelium.

Despite the wide‐spread use of Pygeum africanum uncertainty remains regarding treatment effectiveness and tolerability. A previous qualitative summary did not meet criteria for a systematic review (Andro 1995). This review included results from open‐labelled uncontrolled studies, did not assess study quality nor conduct a quantitative meta‐analysis to estimate the magnitude or statistical significance of treatment efficacy and was sponsored by a manufacturer of Pygeum africanum extract. We conducted a systematic review including a quantitative meta‐analysis, where possible, of the evidence from randomized controlled trials to determine the therapeutic efficacy and tolerability of Pygeum africanum, alone or in combination with other herbal agents, for men with symptomatic benign prostatic hyperplasia.

Objectives

The aim of our review was to provide a comprehensive overview including a quantitative meta‐analysis of the existing evidence to determine the therapeutic efficacy and the adverse effects of the plant extract Pygeum africanum. Specifically, was Pygeum africanum more effective than placebo in improving the symptoms and/or urodynamics of BPH and as effective as current medical therapies.

Main comparison
Determine if Pygeum africanum was more efficacious than placebo in improving validated and standardized urologic symptom scores in men with symptomatic BPH.

Secondary comparisons
1. Determine if Pygeum africanum is more efficacious than placebo in improving urodynamic measurements and urinary symptoms including peak urine flow, mean urine flow, residual urine, prostate size, nocturia, dysuria, and urinary frequency.

2. Determine if Pygeum africanum is as efficacious as active controls in improving urologic symptom scores and urodynamic measures.

3. Determine the adverse effects of Pygeum africanum.

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Methods

Criteria for considering studies for this review

Types of studies

Randomized controlled clinical trials.

Types of participants

Men with symptomatic benign prostatic hyperplasia

Types of interventions

Comparison of preparations of Pygeum africanum with placebo or medical therapies for BPH with a treatment duration of at least 30 days.

Types of outcome measures

Urologic symptom scores (Boyarsky, American Urologic Association Score, International Prostate Symptom Score:IPSS); Urodynamic measures (defined as change in peak urine flow (PUF), mean urine flow (MUF), residual urine volume; changes in prostate size (measured in cc); urinary frequency, nocturia (times/per evening); quality of life score (QOL); and overall physician/patient health assessment.

Search methods for identification of studies

We searched MEDLINE for 1966 to 2000 using a combination of the March 1996 update of the optimally sensitive search strategy for trials from the Cochrane Collaboration with the MeSH headings "prostatic hyperplasia," "phytotherapy," "plant extracts," "Pygeum africanum," "Tadenan", "Docosonal", and "Pigenil" including all subheadings (Dickersin 1994). A search of EMBASE, years 1974 to 1999 was done by using a similar approach to that for Medline. We also searched the private database Phytodok, Munich Germany, and the Cochrane Library, including the database of the Cochrane Prostate Diseases and Urologic Malignancies Review Group and the Cochrane Field for Complementary Medicine. Reference lists of all identified trials and previous reviews were searched for additional trials. The manufacturer and authors were contacted for missing data or additional trials. There were no language restrictions.

Data collection and analysis

Eligibility:
Two investigators (AI and RM) independently determined if identified studies met inclusion criteria.

Extraction:
The following data were extracted from each included study: study characteristics, demographics of patients, enrollment criteria, outcomes, adverse effects, and number and reasons for dropout. Missing or additional information was sought from authors/sponsors. Included and excluded studies as well as extracted data were reviewed and discrepancies resolved by discussion and consensus.

Assessment of methodological quality:
Study quality was assessed using the method outlined by Schulz and colleagues (Schulz 1995) assigning 1 to poorest quality and 3 to best quality: 1 = trials in which concealment was inadequate (e.g. alteration or reference to case record numbers or to dates of birth); 2 = trials in which the authors either did not report an allocation concealment approach at all or reported an approach that did not fall into one of the other categories; and 3 = trials deemed to have adequate measures to conceal allocations (e.g. central randomization; numbered or coded bottles or containers; drugs prepared by the pharmacy; serially numbered, opaque, sealed envelopes etc. that contained elements convincing of concealment).

Summarizing results of primary studies:
Outcomes:
The mean urologic symptom score (points), peak and mean urine flow (mL/sec), residual urine volume (mL), prostate size (cc), frequency (% men reporting), urgency (% men reporting), dysuria (% men reporting) and nocturia (# times). The number and percent of men reporting specific side effects and/or withdrawing from the study.

Meta‐analysis:
Because no common outcome measure was available from all eighteen studies we utilized two methods for combining data. One method, reported by Saint 1995, assesses treatment effect size for continuous variables by the difference of the mean change for each outcome divided by the pooled standard deviation for each outcome when trials report different outcome measures of effectiveness (e.g. symptom scale scores, nocturia, peak urine flow rate). The second method calculates a summary measure for individual outcomes using studies that provide similar outcome measures and utilizes standard meta‐analytic techniques described below.

For determining effect size we utilized the outcome that was determined a priori to be most clinically significant (order of clinical importance: symptom scale score > nocturia > peak urine flow > residual urine volume). One outcome from each study was then transformed into units of standard deviations (SD), giving a comparable effect size for each study. The study‐specific overall effect size was the difference in mean outcome for the Pygeum africanum and placebo groups, divided by the pooled SD of the outcome measure. The summary effect size across studies was calculated as the weighted average of the study‐specific effect size, with weights equal to the inverse of the estimated variance of each using standard meta‐analytic methodology as developed by DerSimonian and Laird (DerSimonian 1986; Laird 1990). We used the same definition of standardized effect sizes to look at individual and comparable continuous outcomes when available (nocturia and peak urine flow). The statistical significance of the summary effect size was assessed by comparing it with the standard normal distribution. A scale for effect size suggested by Cohen 1988 was used with 0.8 reflecting a large effect, 0.5 a moderate effect, and 0.2 a small effect.

Additional meta‐analyses considered the difference between Pygeum africanum treatment and the control treatment in the mean change from baseline to end of follow‐up for each separate continuous outcome. For those studies not reporting mean change scores and the corresponding standard errors, the standard errors for the mean change scores were approximated using the standard errors of the outcomes at baseline and followup. The approximation used the methodology reported by Laird 1990 and Lau 1996 based on the correlation between outcomes. Analyses were conducted for three different assumed values for this correlation (0.25, 0.50, 0.75). This approach was taken to examine the sensitivity of the results to the value of this unknown parameter. Weighted mean differences were calculated using the methodology outlined above. There were no qualitative differences between the meta‐analysis results for the three assumed correlation values; we present here the results for the assumed correlation of 0.50. For categorical outcome measures weighted relative risks and 95% CI were calculated using standard meta‐analytic techniques.

Chi squared tests were used for analysis of bivariate comparisons (adverse events and dropouts) using simple pooling of data. To assess the percentage of patients having improvement in urologic symptoms, a modified intention‐to‐treat analysis was performed (i.e., men who dropped out or were lost to follow‐up were considered to have had worsening symptoms) (Lavori 1992). The denominator for the modified intention‐to‐treat analysis included the number randomized to treatment at baseline, and the numerator included the number completing the trial and showing improvement. A test for heterogeneity was calculated according to standard formulas (DerSimonian 1986; Saint 1995) and a random effects model utilized for all summary estimates.

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Results

Description of studies

The combined search strategies identified 31 trials; 18 met inclusion criteria. None were conducted in the United States and 12 were reported in a non‐English language [German (1), Italian (10), French (2)]. Fourteen trials were excluded because they did not include a control group (Anonymous 1973; Breza 1998; Diz 1973; Grasset 1974; Greiner 1970; Grévy 1970; Guilland‐Vallée 1970; Guillemin 1970; Huet 1970; Lange 1970; Lhez 1970; Martínez‐Piñeiro '73; Robineau 1976; Rometti 1970). The majority of studies examined Pygeum Africanum alone versus placebo alone (n = 11) (Barlet 1990; Bassi 1987; Blitz 1985; Bongi 1972; Donkervoort 1977; Dufour 1984; Frasseto 1986; Maver 1972; Ranno 1986; Rizzo 1985). Two trials comparing Pygeum africanum against an anti‐inflammatory drug (Gagliardi 1983; Rigatti 1983). One study comparing Pygeum Africanum to placebo included an additional treatment arm of Pygeum africanum in combination with a steroid (Giacobini 1986). Two studies compared Pygeum africanum alone to one or more herbal agents and versus placebo (Barth 1981; Mandressi 1983), one trial compared Pygeum africanum to another herbal agent (Dutkiewicz 1996), one trial compared different daily dosage forms of Pygeum africanum (Chatelain 1999), and one trial compared two different doses of Pygeum africanum in combination with another herbal extract (Krzeski 1993). None of the "active comparison" arms have been conclusively demonstrated to be effective in treating symptomatic benign prostatic hyperplasia.

A total of 1562 participants were randomized in the 18 trials. The mean treatment duration was 64 ± 21.1 days and ranged from 30 to 122 days. The majority of the studies (n = 14; participants = 1103) utilized a standardized extract of Pygeum africanum. The doses of Pygeum africanum ranged between 75 to 200 mg per day. Of the placebo controlled trials 1 utilized a dose of Pygeum africanum equal to 75 mg per day, 7 utilized a dose of 100 mg per day, 4 utilized a dose of 200 mg/day and one did not report the dosage (Dutkiewicz 1996). For studies that provided baseline data, results did not vary between treatment arms and were consistent with men typically presenting with moderate benign prostatic hyperplasia. The mean age was 66.± 6.9 years (9 studies, n = 845, range 42 to 89); nocturia = 3 ± 0.7 times per evening (4 studies, n = 413); peak urine flow = 12 ± 3.6 mL/sec (5 studies, n = 416); residual urine volume = 40 ± 25.6 mL (2 studies, n = 284). Not all studies could be pooled because of differences in reporting methods. Of the 13 trials of Pygeum africanum versus placebo identified, 12 reported a beneficial effect of Pygeum africanum on at least one measure of effectiveness: overall symptoms, nocturia, peak urine flow or residual volume. Only one trial demonstrated no difference between Pygeum africanum and placebo (Rizzo 1985). This trial assessed the effect of Pygeum africanum on nocturia, peak urine flow and overall symptom change in 20 men over 12 weeks. None of the trials showed an effect of Pygeum africanum worse then placebo or "active control."

2009
Pygeum africanum may suppress the oxidative stress in diabetic bladder and may slow the process of diabetic cystopathy.
Abstract Title:
Pygeum africanum: effect on oxidative stress in early diabetes-induced bladder.
Abstract Source:
Int Urol Nephrol. 2009 Jul 16. PMID: 19609708
Abstract Author(s):
Dan Wang, Yongzhi Li, Guihua Hou, Ping Wang, Jianping Zhang, Vincent Laudon, Benkang Shi
Abstract:
OBJECTIVE: To evaluate the effect of Pygeum africanum on oxidative stress and functional changes of the bladder after diabetes induction. MATERIALS AND METHODS: Thirty-two adult Wistar male rats were treated daily for 8 weeks and grouped as follows: Control group (n = 6), Streptozotocin-induced diabetic group (n = 10), diabetes plus P. africanum group (n = 10), and control plus P. africanum group (n = 6). After diabetes induction for 4 weeks, the diabetes plus P. africanum and control plus P. africanum groups were fed with P. africanum (100 mg/kg, orally) in peanut oil for another 4 weeks. The catalase, superoxide dismutase activity, and malondialdehyde levels were measured as a marker of lipid peroxidation. The levels of inducible nitric oxide synthase were also evaluated. Urodynamic studies were performed to evaluate the functional changes of diabetic bladders after P. africanum treatment. RESULTS: The catalase and superoxide dismutase activities significantly increased (P < 0.05) and maleic dialdehyde levels significantly decreased from diabetic plus P. africanum group compared with diabetic group (P < 0.05). Immunohistochemical studies showed a significantly decreased number of inducible nitric oxide synthase-positive cells in diabetic plus P. africanum group compared with diabetic group (P < 0.05). In diabetic plus P. africanum group, maximal bladder volume significantly decreased, while bladder pressure and maximal bladder pressure significantly increased compared with diabetic group (P < 0.05). CONCLUSIONS: Early treatment with P. africanum could effectively suppress the oxidative stress status in diabetic bladder and may slow down the process of diabetic cystopathy.
Article Published Date : Jul 16, 2009
Study Type : Animal Study
Additional Links
Substances : Pygeum Bark : CK(15) : AC(5)
Diseases : Diabetic: Bladder Dysfunction : CK(2) : AC(1), Diabetic Cystopathy : CK(2) : AC(1)

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2008
A compound isolated from Pygeum Bark has anti-androgenic actions which may be useful in the treatment of prostate cancer cell growth.
Abstract Title:
The natural compound atraric acid is an antagonist of the human androgen receptor inhibiting cellular invasiveness and prostate cancer cell growth.
Abstract Source:
J Cell Mol Med. 2008 Jul 4. PMID: 18627423
Abstract Author(s):
Maria Papaioannou, Sonja Schleich, Ina Prade, Stephanie Degen, Daniela Roell, Undine Schubert, Tamzin Tanner, Frank Claessens, Rudolf Matusch, Aria Baniahmad
Abstract:
Extracts from Pygeum africanum are used in the treatment of prostatitis, benign prostatic hyperplasia (BPH) and prostate cancer (PCa), major health problems of men in Western countries. The ligand-activated human androgen receptor (AR) supports the growth of the prostate gland. Inhibition of human AR by androgen ablation therapy and by applying synthetic antiandrogens is therefore the primary goal in treatment of patients. Here, we show that atraric acid (AA) isolated from bark material of Pygeum africanum has antiandrogenic activity, inhibiting the transactivation mediated by the ligand-activated human AR. This androgen antagonistic activity is receptor specific and does not inhibit the closely related glucocorticoid or progesterone receptors. Mechanistically, AA inhibits nuclear transport of AR. Importantly, AA is able to efficiently repress the growth of both the androgen-dependent LNCaP and also the androgen-independent C4-2 prostate cancer cells but not that of PC3 or CV1 cells lacking AR. In line with this, AA inhibits the expression of the endogenous prostate specific antigen (PSA) gene in both LNCaP und C4-2 cells. Analyses of cell invasion revealed that AA inhibits the invasiveness of LNCaP cells through extracellular matrix. Thus, this study provides a molecular insight for AA as a natural anti-androgenic compound and may serve as a basis for AA derivatives as a new chemical lead structure for novel therapeutic compounds as AR antagonists, that can be used for prophylaxis or treatment of prostatic diseases.
Article Published Date : Jul 04, 2008
Study Type : Animal Study
Additional Links
Substances : Pygeum Bark : CK(15) : AC(5)
Diseases : Prostate Cancer : CK(1586) : AC(463)
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1998
Pygeum Africanum reduces prostatic hyperplasia effectively and safely. - Article 1
Abstract Title:
Efficacy and acceptability of tadenan (Pygeum africanum extract) in the treatment of benign prostatic hyperplasia (BPH): a multicentre trial in central Europe.
Abstract Source:
Curr Med Res Opin. 1998;14(3):127-39. PMID: 9787978
Abstract Author(s):
J Breza, O Dzurny, A Borowka, T Hanus, R Petrik, G Blane, H Chadha-Boreham
Abstract:
Pygeum africanum extract is available as Tadenan in many countries, including those in central and eastern Europe, for the treatment of mild to moderate BPH. Its efficacy and acceptability have been demonstrated in numerous open and placebo-controlled studies in large populations. The present open three-centre efficacy and safety study was conducted according to common protocol at urology clinics in the Czech and Slovak Republics and in Poland, in order to confirm the therapeutic profile of Pygeum africanum in conditions of daily practice, using International Prostate Symptom Score (IPSS) and flowmetry assessments. Men aged 50-75 years and in compliance with the selection criteria (including IPSS > or = 12, quality of life (QoL) score > or = 3, and maximum urinary flow < or = 15 ml/s) were first examined then recalled after two weeks during which no treatment was provided (washout and check of stability). If still compliant, they were entered at this point into a two-month period of treatment with Pygeum africanum extract 50 mg twice daily. There followed a further one-month period without treatment, the objective being to evaluate the persistence of any effects observed during the previous two months of Pygeum africanum administration. The primary efficacy parameter investigated was IPSS; the other efficacy parameters were QoL, nocturnal frequency, maximum urinary flow, average urinary flow, post-voiding residual volume and prostatic volume, after one and two months of Pygeum africanum treatment and one month after stopping treatment. A total of 85 patients were evenly distributed between the three centres and completed the entire study. At inclusion their mean IPSS was 16.17, QoL was 3.60 and nocturia was 2.6 times per night. The changes in subjective scores, IPSS and QoL after the two-month treatment period were highly statistically significant with mean improvements of 40% and 31%, respectively. Nocturnal frequency was reduced by 32% and the mean reduction was again highly statistically significant. Mean maximum urinary flow, average urinary flow and urine volume were also statistically significantly improved, but the modest improvement in post-voiding volume did not reach statistical significance. The improvements, which exceeded those observed with placebo in earlier studies, were maintained after one month without treatment indicating an interesting persistence of clinically useful activity. Prostatic volume and quality of sexual life remained unchanged throughout. No treatment-related adverse effects were observed. In conclusion, under conditions of daily practice, Pygeum africanum extract induces significant improvement in IPSS and uroflowmetry parameters. These positive effects are accompanied by a very satisfactory safety profile with the overall result of a substantial improvement in QoL.
Article Published Date : Jan 01, 1998
Study Type : Human Study
Additional Links
Substances : Pygeum Bark : CK(15) : AC(5)
Diseases : Nocturia : CK(42) : AC(5), Prostatic Hyperplasia: Benign : CK(256) : AC(59), Urination Disorders : CK(10) : AC(1)

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