The drug consists of the dried bark of the trunk of Prunus africana.
An evergreen tree, usually 10-25 m high, with straight, cylindrical trunk and dense, rounded crown. Leaves alternate, 8-12 cm long, long-stalked, simple, elliptic, bluntly pointed at apex, with shallow crenate margins; leathery, deep green, and glossy, with midrib sharply impressed or channelled on upper surface and strongly prominent on underside; smell of almonds when bruised. Leafstalks and young branchlets often reddish. Flowers small, white or cream, fragrant, in axillary racemes 3-8 cm long; corolla lobes up to 2 mm long. Fruits cherry-shaped, red to purplish-brown, 8-12 mm in diameter; very bitter flesh and bony stone. Wood pale red, with strong cyanide smell when freshly cut, darkening to rich dark red or mahogany-brown on exposure to air; straight-grained and even textured, strong and elastic, very hard and very heavy.
The tree occurs in tropical and subtropical parts of Africa, including Angola, Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Malawi, Mozambique, Republic of Congo, South Africa, Uganda, United Republic of Tanzania, Zambia and Zimbabwe, Burundi, Equatorial Guinea (Bioko, Sao Tome and Principe), Rwanda, Sudan, and Swaziland.
Wild-crafted. Wild-harvesting of bark is very destructive and some attempts have been made to establish plantations for sustainable bark production. Fresh bark is harvested, dried, crushed, and extract obtained from which a drug is segregated. Bark harvesting occurs year-round.
African plum tree, African prune tree, alumty, iluo, kirah, Natal tree, prunier d'afrique, vla, wotangue, armaatet, chati, inkhokhokho, inyangazoma-elimnyama, kiburabura, lemalan migambo, mueri, muiru, murugutu, mutimailu, mweria, mwiritsa, nuwehout, ol-koijuk, oromoti, red stinkwood, rooistinkhout, tenduet, tendwet, twendet, umdumizulu, umkakase, umkhakhazi, umlalume; mwiluti, mfila, mpembati, mdundulu, ligambo, mufubia, gwaami, kondekonde, olkonjuku, mkonde-konde.
Actions & Pharmacology
Docosanol (0.6%) and β-sitosterol (15.7%). Other major constituents include alkanols: tetracosanol (0.5%) and trans-ferulic acid esters of docosanol and tetracosanol, fatty acids (62.3%, comprising myristic, palmitic, linoleic, oleic, stearic, arachidic, behenic and lignoceric acids); sterols: sitosterone (2.0%) and daucosterol and triterpenes: ursolic acid (2.9%), friedelin (1.4%), 2-a-hydroxyursolic acid (0.5%), epimaslinic acid (0.8%) and maslinic acid.
Multiple mechanisms have been proposed for the genitourinary effects of prunus, including 5α-reductase inhibition, estrogenic effects, and anti-inflammatory properties. Genitourinary effects: P. africana extract appears to inhibit human prostatic 5α-reductase (IC50 63,000 ng/mL), but much less powerfully than finasteride (IC50 1.0 ng/mL). Reduction of urethral obstruction and improvement of bladder function have been observed. Most studies of P. africana extract have addressed outcomes related to the obstructive component. In rats, prunus inhibits dihydrotestosterone-induced prostate hyperplasia, with a mechanism that appears unrelated to androgen receptor blockade. In rats and humans, P. africana extract has been found to stimulate secretory activity of the prostate and seminal vesicles. Reduction of contractile dysfunction of the bladder caused by partial outlet obstruction has been observed with pre-treatment of rabbits with P. africana extract (Tadenan®, 1-100mg/kg/day oral).
In vitro studies report P. africana extract to inhibit production of 5-lipoxygenase metabolites at concentrations of 3mcg/mL when dissolved in DMSO, and 10mcg/mL when dissolved in NaOH/HCl (p<0.01). P. africana inhibits fibroblast proliferation induced by epidermal growth factor (EGF; IC50=4.5mcg/mL), insulin-like growth factor type I (IGF-I; IC50=7.7mcg/mL), and basic fibroblast growth factor (bFGF; IC50=12.6mcg/mL) in vitro. P. africana extract appears to possess phytoestrogenic properties.
Benign prostatic hypertrophy/BPH symptoms
In 2002, Wilt et al conducted a systematic review and meta-analysis to investigate the evidence surrounding the use of prunus in the treatment of BPH. The authors searched for trials in multiple databases, including Medline, Embase, the Cochrane Library, Phytodok, by checking bibliographies, and by contacting relevant manufacturers and researchers. Trials were eligible if they were randomized, included men with BPH, compared preparations of Prunus africana (alone or in combination) with placebo or other BPH medications, and if they included clinical outcomes such as urologic symptom scales, symptoms, or urodynamic measurements. The main outcome measure for adverse effects was the number of men reporting adverse effects. 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, although 17 were double-blinded. There were no studies comparing Prunus africana to standard pharmacologic interventions such as alpha-adrenergic blockers or 5-alpha reductase inhibitors. The mean study duration was 64 days (range, 30-122 days). According to the authors, most studies did not report results in a method that permitted meta-analysis. Compared to men receiving placebo, prunus 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, -0.3 (n=6 studies)]). Men using prunus were more than twice as likely to report an improvement in overall symptoms (RR=2.1, 95% CI = 1.4, 3.1). Nocturia was reduced by 19%, residual urine volume by 24%, and peak urine flow was increased by 23%. Adverse effects due to prunus were mild and comparable to placebo.
The overall dropout rate was 12% and was similar between prunus (13%), placebo (11%) and other controls (8%). Although the authors concluded that standardized preparations of prunus may be a useful treatment option for men with lower urinary symptoms consistent with BPH, they noted that further research is necessary, as the reviewed studies overall were small in size, short in duration, used varied doses/preparations, and rarely reported outcomes using standardized validated measures of efficacy (Wilt et al, 2002).
In 2000, Ishani et al. conducted a systematic review and meta-analysis of 18 randomized controlled trials to evaluate the efficacy of prunus extract in the treatment of symptomatic BPH. Out of 31 randomized trials with a duration of 30 days or greater, 18 matched the inclusion criteria for this analysis. All 18 trials were conducted in Europe and included a total of 1562 subjects. Ten trials compared P. africana to placebo, two trials evaluated P. africana versus an anti-inflammatory drug, one study compared P. africana to both placebo and P. africana plus medroxyprogesterone, one trial compared once daily versus twice daily dosing of P. africana, two trials compared P. africana combined with another herbal vs. placebo, one trial compared P. africana to another herbal agent, and one trial compared two different doses of P. africana plus Urtica dioica. The doses of P. africana extract used in trials varied from 75mg to 200mg per day. The data were pooled using two methods: First, for summarizing trials with various outcome measures, treatment effect size for continuous variables was assessed by dividing the difference of the mean change for each outcome by the pooled standard deviation for that outcome. Second, effect size was estimated using the most clinically important outcome per study, according to the following preference scale: symptom score > nocturia > peak urine flow > residual urine volume. The summary effect size (difference in mean outcome divided by the pooled standard deviation for that outcome) was then assessed using the following key: 0.8 = large effect, 0.5 = moderate effect, 0.2 = small effect. Among 474 men from six trials comparing P. africana to placebo, summary effect size was calculated to be -0.8 (95%CI -1.4 to -0.3), which suggests a large, statistically significant improvement in symptomatic BPH with P. africana compared to placebo.
Furthermore, men taking P. africana were 2.1 (95%CI 1.4 to 3.4) times more likely experience an overall improvement of symptoms than those taking placebo, and also experienced a 19% reduction in nocturia as compared with those taking placebo (weighted mean difference of -0.9). The latter two results, however, were not statistically significant (95%CI -2.0 to 0.1). Peak urine flow, as analyzed from four trials (363 subjects), was significantly increased by 23% as compared to placebo (95% CI 0.3 to 4.7). For none of the effect measures, in none of the analyzed studies, was control treatment superior to P. africana extract (Ishani et al, 2000).
Aphrodisiac, bladder sphincter disorders, fever, impotence, inflammation, kidney disease, malaria, male baldness, partial bladder outlet obstruction, prostate cancer, prostatic adenoma, prostatitis, psychosis, sexual performance, stomach upset, urinary tract health. Prunus africana is traditional medicine in Africa used to treat chest pain, malaria, and fevers (Cunningham and Mbenkum 1993). The fresh bark, leaf, and fruits contain amygalin, yielding hydrocyanic acid when crushed; hence, they have an almond flavor. The bark was traditionally powdered and drunk as tea for genitourinary complaints, allergies, inflammation, kidney disease, malaria, stomach ache, and fever, among other uses.
Treatment of lower urinary tract symptoms of benign prostatic hyperplasia (BPH) stages I and II, as defined by Aiken (e.g. nocturia, polyuria and urinary retention), where diagnosis of prostate cancer is negative.
There is not sufficient scientific information to recommend prunus for use in children.
Prunus cannot be recommended during pregnancy or breast-feeding because of a lack of scientific information and possible hormonal effects.
Precautions & Adverse Reactions
Caution in taking 5 α-reductase inhibitors or saw palmetto
Prunus extract appears to inhibit human prostatic 5α-reductase. In theory, prostate specific antigen (PSA) values in serum may be reduced with the use of 5α-reductase inhibitors, masking otherwise elevated levels. Prunus may interact with estrogen or other hormones. Prunus may interact with herbs/supplements containing chemicals with estrogen-like constituents.
Lipophilic extract of the crude drug.
75-200mg lipidosterolic extract of the crude drug, in divided doses. To minimize gastrointestinal disturbances, take with food or milk.