A randomized, double-blind, placebo-controlled trial to determine the effectiveness of botanically derived inhibitors of 5-α-reductase in the treatment of androgenetic alopecia

THE JOURNAL OF ALTERNATIVE AND COMPLEMENTARY MEDICINE
Volume 8, Number 2, 2002, pp. 143–152
Mary Ann Liebert, Inc.
A Randomized, Double-Blind, Placebo-Controlled Trial to Determine the Effectiveness of Botanically Derived Inhibitors of 5-a-Reductase in the Treatment of NELSON PRAGER, Ph.D.,1 KAREN BICKETT, R.N.,1 NITA FRENCH, Ph.D.,2 ABSTRACT
Background: Androgenetic alopecia (AGA) is characterized by the structural miniaturization
of androgen-sensitive hair follicles in susceptible individuals and is anatomically defined withina given pattern of the scalp. Biochemically, one contributing factor of this disorder is the con-version of testosterone (T) to dihydrotestosterone (DHT) via the enzyme 5-a reductase (5AR).
This metabolism is also key to the onset and progression of benign prostatic hyperplasia (BPH).
Furthermore, AGA has also been shown to be responsive to drugs and agents used to treat BPH.
Of note, certain botanical compounds have previously demonstrated efficacy against BPH. Here,we report the first example of a placebo-controlled, double-blind study undertaken in order toexamine the benefit of these botanical substances in the treatment of AGA.
Objectives: The goal of this study was to test botanically derived 5AR inhibitors, specifically
the liposterolic extract of Serenoa repens (LSESr) and b-sitosterol, in the treatment of AGA.
Subjects: Included in this study were males between the ages of 23 and 64 years of age, in
good health, with mild to moderate AGA.
Results: The results of this pilot study showed a highly positive response to treatment. The
blinded investigative staff assessment report showed that 60% of (6/10) study subjects dosedwith the active study formulation were rated as improved at the final visit.
Conclusions: This study establishes the effectiveness of naturally occurring 5AR inhibitors
against AGA for the first time, and justifies the expansion to larger trials.
INTRODUCTION
the parallel etiologies of these two disorders, itwas the central hypothesis of this pilot study Androgenetic alopecia (AGA) shares a num- to examine the putative benefit of botanicals in
nign prostatic hyperplasia (BPH). Certain AGA is characterized by a receding hairline botanical compounds, and specifically those and/or hair loss within a specific pattern on the under investigation herein, have previously scalp (Shapiro et al., 2000). This condition, demonstrated the ability to inhibit key meta- which affects men and women, is inherited as bolic processes associated with BPH. Based on a polygenic disorder likely involving several 1Clinical Research and Development Network, Aurora, CO.
2French and Associates, Atlanta, GA.
3Advanced Restoration Technologies, Denver, CO.
PRAGER ET AL.
genes and multiple pathways, although the pre- prostate gland is reduced by approximately cise mechanism(s) remain unknown. However, 20%, and the level of prostate-specific antigen one factor that has been demonstrated to con- (PSA) drops by approximately 50% (Mikola- tribute to the pathogenesis of this condition in- volves a genetically predetermined sensitivity to Interestingly, it has also been observed that the effects of the androgenic hormone dihy- eunuchs (males who have been castrated prior drotestosterone, or DHT, in certain scalp hair fol- to the onset of puberty) do not develop BPH, licles (Mowszowicz et al., 1993). DHT is believed nor do they develop AGA, and moreover, af- to shorten the growth, or anagen, phase of the ter castration BPH has been shown to regress hair cycle, causing miniaturization of the folli- (Wilson et al., 1999). Because normal testicu- cles, and producing progressively finer hairs.
lar function appears to be necessary for the de- velopment of BPH, it is believed that the hy- testosterone [T]) is catalyzed by the enzyme 5- a reductase (5AR). In the prostate gland and hormones differently than normal prostate in susceptible scalp hair follicles, androgen re- tissue. Progressive growth of the prostate may sponsive cells express the genes encoding the cause significant obstruction of the urethra and interfere with the normal flow of urine bound enzyme that catalyzes the irreversible (Wilt et al., 2000b). As with AGA, the inci- conversion of T to DHT (Itami et al., 1994).
dence of BPH increases with advancing age.
Two isozymes exist: the type 1 enzyme, en- BPH is so common, that it is believed all men coded by the SRD5A1 gene, localized to chro- will develop BPH if they live long enough.
Some degree of BPH is present in 80% of all men over 40 years old and this figure increases chromosome 2p23 (Morissette et al., 1996). Im- munolocalization studies have shown that the type 1 enzyme is expressed primarily in new- born scalp, and in skin and liver, and the type and BPH, several lines of evidence have con- 2 isozyme protein is expressed primarily in verged to support the view that circulating T genital skin, liver, and the prostate (Negri- Cesi et al., 1999). In the prostate gland, the found effects on androgen metabolism, and provide insight into the role of these hormones strongly implicated in the pathogenesis of in hair loss. Specifically, the absence of circu- BPH. Of note, the endocrine dysfunction as- lating T and, therefore, its metabolite DHT, in sociated with BPH bears a striking similarity males castrated prior to puberty has been shown to prevent AGA in later life. These find- BPH affects almost all men to some degree ings demonstrate the importance of this me- as they age, and can cause a significant dis- tabolism in the pathogenesis of male pattern ruption of lifestyle because of urinary outflow obstruction and irritative symptoms. BPH is Of equal relevance, it has been observed that characterized clinically by large, discrete nod- in a group of male pseudohermaphrodites with ules formed in the periurethral region of the prostate. These nodules may narrow the ure- preservation of the juvenile hairline invariably thra sufficiently to cause full or partial ob- occurs (Imperato-McGinley et al., 1990). These struction. Increased conversion of T to its more examples demonstrate that whether the dis- active metabolite, DHT, has been shown to con- turbance in androgen metabolism results from tribute to BPH, however, the specific etiology either the absence of substrate (T), the active of BPH remains unknown. Nonetheless, stud- metabolite DHT, or dysfunction of the enzyme ies have demonstrated that by blocking the 5AR, at least one phenotypic consequence is conversion of T to DHT, with either pharma- consistent and reproducible: terminal hair den- ceuticals or natural compounds, the circulating sity as well as juvenile hairlines remain intact level of DHT is reduced by 80%, the size of the BOTANICALS IN THE TREATMENT OF AGA
In contrast, a third and critical observation bone density, and sexual function. As noted has been noted in bodybuilders who self-ad- minister anabolic steroids, in that excessive lev- miniaturized hair follicles and increased els of circulating T and therefore DHT had the opposite effect of the first two examples, that scalp, and finasteride treatment inhibit the of acceleration of hair loss in genetically sus- isozyme, resulting in a rapid reduction in scalp ceptible individuals because of upregulation of the hormonal processes that result in AGA pathways with BPH, it was previously recog- Collectively, these lines of evidence point to nized that the pharmaceutical agents useful against BPH may offer some potential bene- from dysregulation of the conversion of T to fit in the treatment of AGA. The modification DHT, and have led to the central hypothesis of of Proscar™ (finasteride, 5 mg; Merck; initially this research. Until now, the only treatments indicated for BPH), to Propecia (finasteride, 1 available for AGA have consisted essentially of mg, new indication, AGA) serves as a para- the topically administered drug Rogaine™ (mi- digm for this rationale (Kaufmann, 1999).
noxidil, 2% and 5%; Upjohn-Pharmacia, Kala- Similar to finasteride, several botanically de- mazoo, MI) and the orally delivered pharma- rived substances have also demonstrated the ceutical Propecia™ (finasteride, 1 mg; Merck, ability to inhibit key hormonal processes as- sociated with BPH. Importantly, these botan- Rogaine (topically applied minoxidil, 2%–5%) icals have not been linked with the spectrum is the best-known drug in the category of med- of negative side-effects, adverse reactions, or ical AGA treatment. Minoxidil delivered via teratogenicity associated with the pharma- oral ingestion was initially indicated in the ceutically derived alternatives (Klepser and treatment of refractory hypertension. It was noted to cause hypertrichosis (increased non- Recently, several clinical trials have reported sexual hair growth), however, the mechanism the efficacy of botanical compounds in the by which it stimulates hair growth remains un- treatment of a number of androgen-dependent known. Clinical trials have shown that a 2% so- conditions, and specifically, BPH. For example, lution applied topically to the scalp can stimu- among 1098 BPH patients tested in one recent study, the general safety profile of the lips- terolic extract of Serenoa repens (LSESr, 320 mg/d), or saw palmetto berry extract, com- pared favorably to that of finasteride, and sex- ual side-effects were less common with the ex- male pattern hair loss (AGA) in men only.
tract than with the drug. In particular, the use Safety and efficacy were demonstrated in men of this extract has not been associated with between 18 and 41 years of age with mild to erectile dysfunction, ejaculatory disturbance, moderate hair loss of the vertex and anterior or altered libido (Wilt et al., 2000a). Remark- midscalp area. Efficacy in bitemporal recession ably, in another biochemical study, it was has not been established (Kaplan and Olsson, found that LSESr was a threefold more effec- 1996). Propecia is not approved for use in tive inhibitor than finasteride (5 mg/d) at con- women or children. Finasteride is a preferen- tial, competitive inhibitor of the intracellular, doses for BPH treatment. It should be noted type 2, 5AR isoenzyme that converts T into that finasteride as indicated for AGA is dosed DHT, the more potent androgen. In target or- significantly lower (1 mg/d), suggesting, a 15- gans, finasteride treatment is thought to result fold more potent level of inhibition at the rec- in selective androgen deprivation, affecting DHT without lowering circulating levels of testosterone, thus preserving the desired an- LSESr is the first line of BPH treatment in Eu- drogen-mediated effects on muscle strength, rope and elsewhere, and is believed to act by PRAGER ET AL.
inhibiting 5AR. Several in vitro experiments in mild-to-moderate AGA. Exclusion criteria con- sisted of (1) those who had been on prescrip- found LSESr to be a strong and specific in- tion or over-the-counter treatment for AGA or a prostate condition within the past 30 days Kopp, 1999). In vitro studies have also shown prior to initiation of the trial; (2) symptomatic that LSESr inhibits both isozymes, whereas fi- cardiac problems, uncontrolled hypertension, nasteride selectively inhibits only type 2 5AR symptomatic hypotension, autoimmune disor- (Iehle et al., 1995). Moreover, finasteride ders; (3) those who had participated in a clini- demonstrates a solely competitive inhibition, cal trial within 30 days prior to enrollment; (4) while LSESr has additionally been found to dis- those with any known allergy to any ingredi- play noncompetitive as well as uncompetitive ents in the test products; and (5) those with any inhibition of the type 1 as well as type 2 5AR other medical condition that could interfere with successful conclusion of the study. Sub- As with LSESr, the primary indication for jects enrolled in this study met guidelines es- treatment with the plant phytosterol b-sitos- tablished under the Hamilton/Norwood scale terol has been in the treatment of BPH. In ad- of hair loss. Study subjects presented with dition to a potential role in 5AR inhibition, as moderate to significant male pattern hair loss a minor component of LSESr, b-sitosterol in in the vertex area (grade II vertex through grade VI vertex). Baseline characteristics of bioavailability of cholesterol in the local envi- study subjects were reasonably well matched ronment in animal models, thereby suggesting and fell within the desired study protocol in- it may inhibit downstream steriod hormone biosynthesis, specifically testosterone (Wang proved by the Western Institutional Review and Ng, 1999). One potential mechanism of ac- Board, Olympia, WA, and all investigations tion of b-sitosterol in the prostate and the hair were performed following written informed follicle, therefore, may involve a local reduc- consent in accordance with these guidelines.
tion of T (substrate) in the microenvironment All investigative staff members participating in this study were trained to evaluate and report In one large clinical study, a total of 519 men the parameters described in the study protocol.
undertook a 26-week double-blind controlledstudy testing b-sitosterol against placebo in as- sessing urinary flow as the operative criterion.
Compared with placebo, b-sitosterol signifi- cantly improved urinary symptom scores and male subjects ages 23 to 64 with AGA were ini- flow measures (Bracher, 1997). Based on the tially evaluated and randomly assigned, in a success of b-sitosterol in the treatment of BPH, double-blind manner, to one of the following as well as other factors, it was incorporated as groups: either active oral softgel supplement, 1 an active component of the AGA trial study for- softgel twice daily or matching oral placebo, 1 mulation. In recognition of the efficacy that The composition of the softgels, a Good Man- demonstrated in the treatment of BPH, it was ufacturing Practices–compliant product manu- the central hypothesis of this study to test them factured by Softgel Technologies Inc., Los An- geles, California, encased in an inert carob-colored soluble shell, was as follows. The activesoftgel components consisted of b-sitosterol, 50 SUBJECTS AND METHODS
mg, and saw palmetto extract (standardized to85%–95% liposterolic content) 200mg. Systemic absorption of the active softgel components’ Included in this study were males between bioavailability was enhanced by the use of 23 and 64 years of age, in good health, with lecithin, 50 mg; inositol, 100 mg; phosphatidyl BOTANICALS IN THE TREATMENT OF AGA
choline, 25 mg; niacin, 15 mg; biotin, 100 mg. The gena™ T/Gel (Los Angeles, CA) or similar historic experience of other investigators testing these botanicals against BPH was an important might otherwise occur by the use of differing factor in determination of the recommended Written informed consent was obtained from all study subjects prior to entry, with a copy support the safety, efficacy, and dosage for given to each subject. A brief medical history these botanical agents (Schilcher, 1999); how- was obtained including vital signs (weight, ever, no animal research was undertaken as a blood pressure, heart rate). Overall hair as- part of this proof-of-concept trial. The placebo sessment was made using a standardized scale soft gels, encased in an inert carob colored sol- uble shell, were composed as follows: soybean Subjects were asked to rate their current level of satisfaction with their hair. Subjects were Test product and placebo were prepared by then assigned to treatment in sequential order Softgel Technologies Inc. to be identical in ap- and given instructions regarding study agent.
pearance. Product was randomly assigned code Study supplies were then dispensed and sub- numbers. Codes were not available to involved jects were sent home to begin the study.
personnel until after completion of the trial andfinal data review. Study participation encom- passed a duration of approximately 4.6 months, As with the enrollment visit, a brief medical with a maximum duration of approximately 5.4 history was obtained including vital signs months. There were three scheduled clinic (weight, blood pressure, heart rate). Overall visits: baseline/randomization (approximately hair assessment was made using a standard- week 0), enrollment (approximately week 0), ized seven-point scale (Table 1). Subjects were and conclusion (approximately week 21). The asked to evaluate any change with respect to enrollment visit (visit 1) was also the random- their current level of satisfaction with their hair.
ization visit. During this visit subjects were ran-domized, study medication was dispensed, and baseline investigative staff evaluationswere made. The block size for this study was 30 with a treatment versus control ratio of 1:1.
baseline, and final visit. These were: (1) inves- All subjects were instructed to use Neutro- tigative staff assessed hair growth (Fig. 1) and SUBJECT SELF-ASSESSMENT QUESTIONS AND RATING OF SUBJECT CURRENT SATISFACTION Self Assessment Questions
1. Since the start of the study, I can see my bald spot getting smaller. Choice of answers: strongly agree, agree,
no opinion either way, disagree, strongly disagree.
2. Because of the treatment I have received since the start of the study, the appearance of my hair is: Choice of
answers: a lot better, somewhat better, a little better, same, a little worse, somewhat worse, a lot worse.
3. Since the start of the study, how would you describe the growth of your hair? Choice of answers: greatly
increased, moderately increased, slightly increased, no change, slightly decreased, moderately decreased,greatly decreased.
4. Since the start of the study, how effective do you think the treatment has been in slowing your hair loss?
Choice of answers: very effective, somewhat effective, not very effective, not effective at all.
5. Compared to the beginning of the study, which statement best describes your satisfaction with the
appearance of: (1) The hairline at the front of your head? (2) The hair on top of your head? (3) Your hair
overall? Choice of answers: very satisfied, satisfied, neutral, dissatisfied, very dissatisfied.
Subject Current Satisfaction
1. What is your current level of satisfaction with your hair condition? Choice of answers: 23 very dissatisfied,
22 moderately dissatisfied, 21 slightly dissatisfied, 11 slightly satisfied, 12 moderately satisfied, 13 verysatisfied.
PRAGER ET AL.
Investigative Staff Assessment
Graphic representation of the results of the Investigative Staff Assessment of the study group. The upper bar represents subjects treated with active formulation, versus the lower bar representing subjects in the placebogroup. The x-axis represents numbers of subjects (1–10). The results demonstrated that 6 of 10 subjects (60%) wererated as improved in the group taking the active formulation, compared to 1 of 9 subjects (11%) in the placebo con-trol group.
(2) patient self-assessment of treatment efficacy tutional Review Board (IRB) guidelines. The and satisfaction with appearance (Fig. 2).
causality of adverse events was based on afour-point scale with 1 5 great probability that the adverse event was likely to be related to useof the study drug and 4 5 great probability that The parameters assessed by study subjects in the adverse event was not likely to be related this analysis were the following questions: size of bald spot; appearance of hair; growth of hair; The adverse events noted during the course rate of hair loss; and satisfaction with appear- of this study included nausea, constipation, and diarrhea. However, no adverse events occurringwithin this pilot study were determined as likely to be related to the use of the active compound.
As recorded in the Study Protocol Case Re- The data are presented in accordance with the port Forms, the primary measure utilized by CONSORT clinical study reporting guidelines the investigative staff in determination of for- as described by Moher et al. (2001).
mulation efficacy was a seven point scale start-ing with (23) denoting greatly decreased hairdensity, ranging to (13) marking greatly in- Our primary goal in this initial pilot study Risk of toxicity in this study was considered was to assess if the study formulation was ef- minimal inasmuch as the median lethal dose ficacious in arresting scalp hair loss as well as (LD50) for the botanicals under investigation improving hair quality. Based on anecdotal and was far greater than the highest dosages likely open-label data, we anticipated being able to show a positive trend demonstrating a re- studies evaluating similar formulations sup- sponse to therapy. The two measurements uti- port this observation (Carraro et al., 1996; Ger- ber et al., 1998; Wilt et al., 1998, 1999, 2000a).
Adverse events were recorded in the Study 1. Investigative staff assessment using a stan- Protocol Case Report Form Manual per Insti- BOTANICALS IN THE TREATMENT OF AGA
Deterioration
2. Subject self-assessment of hair condition The study participant’s self-assessment cri- terion reflected a time-dependent analysis of any change noted in the thinning areas of the scalp. Subject assessment of the “appearance of the bald spot” at the final visit compared tobaseline were as follows. In the treatment group [0], 0% deteriorated versus the placebogroup where [3] 33% deteriorated (Fig. 2).
DISCUSSION
As previously noted, both LSESr and b-sitos- Graphic representation of the results of the sub- jects’ self-assessment of the study group. The criterion terol represent, among other indications, first- represented here was the perceived deterioration of the line BPH treatments in Europe and elsewhere.
bald spot. The left-hand bar represents subjects in the This is meaningful in light of the previously treatment group, versus the right-hand bar representingsubjects in the placebo group. The y-axis represents per- noted etiologic similarities between BPH and cent deterioration. The results demonstrated that 0 of 10 AGA. However, to the best of our knowledge, subjects (0%) in the group taking active formulation re- prior to the small trial described in this study, ported any deterioration of the bald spot, compared to 3of 9 subjects (33%) in the placebo control group.
no controlled and blinded clinical research hadpreviously been conducted on a formula, eitheroral or topical, combining LSESr and b-sitos- Twenty-six (26) male subjects, ages 23 to 64 were enrolled in the trial between July 1999 and October 1999. Of these 26, 19 completed the signed on the basis of the excellent safety and trial. Seven dropped out prior to study com- efficacy previously demonstrated by each com- pletion; two of these because of a perceived ad- ponent alone. However, the published studies verse event (Table 3). Five of the seven patients were performed on each substance tested sep- who withdrew did not report an adverse event, arately, but never together. Nonetheless, both but dropped out for reasons unrelated to the LSESr and b-sitosterol alone have established research study. A total of 19 patients were eval- uated after study completion. Duration of par- For example, in a meta-analysis of 18 ran- ticipation in this study ranged from 18 to 24.7 domized controlled trials comparing LSESr to fi- nasteride, involving 2939 men, both magnitude On the basis of the investigative staff assess- of improvement and confidence interval, all ment of change in the patient’s scalp hair growth tend to favor the efficacy of LSESr with less erec- from baseline (Fig. 1), treatment with the active tile dysfunction that that associated with finas- study formula demonstrated 60% (6/10) sub-jects rated as “improved” at the final visit ascompared to baseline. In contrast, only 11% TABLE 2. INVESTIGATOR RATING SCALE FOR SUBJECT (1/9) in the placebo group were rated as “im- proved.” These findings show a markedly pos- itive response to treatment as denoted by theproportion of responders. Because of the small sample size, statistical significance and/or con- fidence intervals were not endpoint goals of this pilot study (n 5 19) nor were they achieved; however, future large-scale studies will be de- signed with these definable endpoints in mind.
PRAGER ET AL.
PERCEIVED ADVERSE EVENTS ARISING IN THE COURSE OF THE STUDY In total, there were eight perceived adverse events reported by seven subjects in the course of this study. One sub- ject in the treatment group reported acne that was present at baseline and worsened during the course of the study.
Three subjects in the treatment group reported GI symptoms, including loss of appetite, flatulence, and diarrhea. Onesubject in the placebo group reported lightheadedness with a bowel movement. One subject in the placebo group re-ported frequent urination, and one subject in the placebo group reported heightened sensations and awareness ofheartbeat.
GI, gastrointestinal; GU, genitourinary.
teride (Millon et al., 1999). Also, in a random- temic absorption, which may result in risk of ized, double-blind trial, BPH patients treated feminizing birth defect to a male fetus (Wolf with b-sitosterol showed a significant improve- ment in lower tract urinary symptoms as com- In contrast, these warnings and contraindica- pared to placebo recipients (Wilt et al., 1998).
tions have never been associated with the botan- Furthermore, a 26-week LSESr versus finas- ically based substances tested in this study, and teride trial involved 1098 men led to a remark- in fact LSESr has been safely and widely used able finding that highlights an important safety in women for the treatment of dysmenorrhea, aspect of these two therapies. It was found that genital/urinary problems, and difficulty associ- finasteride lowers the level of prostate-specific ated with lactation (Lee et al., 2000). In recogni- antigen (PSA) by 30% to 50%. This test is rou- tion of the safe and potentially efficacious na- tinely used to screen for prostate cancer and ture of the substances under examination, this monitor prostate cancer therapy (Gerber et al., small proof of principle trial was conducted 1998). This study showed that although finas- with the goal of demonstrating a positive re- teride does not affect the sequelae of prostate sponse for the active formula as measured process, because PSA values must be approxi- In summary, Investigative Staff Assessment mately doubled. In the same study, however, showed that 60% (6/10) subjects were rated as LSESr demonstrated no impact on PSA levels, “improved” by the investigator at the final visit suggesting the absence of this potentially dan- compared to baseline. This compares to 11% (1/9) in the placebo group (Fig. 1). Further- more, the subject assessment analysis of the ap- where negative side-effects are virtually nonex- pearance of the bald spot at the final visit com- istent, finasteride has been implicated with the pared to baseline showed that in the treatment following adverse reactions; decreased libido group, no subjects deteriorated. In contrast, the (1.8%), erectile dysfunction (1.3%), and ejacu- placebo group reported three subjects as dete- lation disorder (1.2%) (Carraro et al., 1996). Res- riorated. Inasmuch as maintenance of hair den- olution did occur in all men who discontinued sity and hair quality is a goal for many patients, therapy with finasteride because of these side- this finding is in itself noteworthy. Based on effects. Finally, finasteride treatment is con- the small number of subjects (n 5 19) our data traindicated in females as a result of its terato- justify the design of a larger scale study of these genic potential. In fact, even the handling of crushed finasteride tablets by pregnant females In conclusion, we have observed objective is discouraged because of the possibility of sys- evidence of efficacy using orally administered BOTANICALS IN THE TREATMENT OF AGA
botanical therapy in the treatment of AGA, for dose for the treatment of men with male pattern hair the first time. The implementation of larger loss. Arch Dermatol 1999;135:989–990.
gender-specific clinical trials, incorporating lo- Klepser TB, Klepser ME. Unsafe and potentially safe herbal therapies. Am J Health Syst Pharm 1999;56:125–138.
cal delivery concomitant with oral administra- Lee MM, Lin SS, Wrensch MR, Adler SR, Eisenberg D. Al- tion is planned as an appropriate next step. Re- ternative therapies used by women with breast cancer search is also underway to identify additional in four ethnic populations. J Natl Cancer Inst 2000; botanical compounds that may offer useful ac- Lise ML, da Gama e Silva TS, Ferigolo M, Barros HM.
Abuse of anabolic-androgenic steroids in sports. RevAssoc Med Bras 1999;45:364–370.
Mikolajczyk SD, Millar LS, Wang TJ, Rittenhouse HG, REFERENCES
Marks LS, Song W, Wheeler TM, Slawin KM. “BPSA,”a specific molecular form of free prostate-specific anti- Bracher F. Phytotherapy of benign prostatic hyperplasia.
gen, is found predominantly in the transition zone of patients with nodular benign prostatic hyperplasia.
Carraro JC, Raynaud JP, Koch G, Chisholm GD, Di Sil- verio F, Teillac P, Da Silva FC, Cauquil J, Chopin DK, Millon R, Jacqmin D, Muller D, Guillot J, Eber M, Abecas- Hamdy FC, Hanus M, Hauri D, Kalinteris A, Marencak sis J. Detection of prostate-specific antigen- or prostate- J, Perier A, Perrin P. Comparison of phytotherapy (Per- specific membrane antigen-positive circulating cells in mixon®) with finasteride in the treatment of benign prostatic cancer patients: Clinical implications. Eur Urol prostate hyperplasia: A randomized international study of 1,098 patients. Prostate 1996;29:231–240.
Moher D, Schulz KF, Altman DG, The CONSORT state- Delos S, Iehle C, Martin PM, Raynaud J. Inhibition of the ment: Revised recommendations for improving the activity of “basic” alpha-reductase (Type 1) detected in quality of reports of parallel-group randomised trials.
DU 145 cells and expressed in insect cells. Steroid Biochem Molec Biol 1994;48:347–352.
Morissette J, Durocher F, Leblanc JF, Normand T, Labrie Gerber G. What is saw palmetto used for, and does it in- F, Simard J. Genetic linkage mapping of the human teract with any medications? Health News 2000;6:10.
steroid 5 alpha-reductase type 2 gene (SRD5A2) close Gerber GS, Zagaja GP, Bales GT, Chodak GW, Contreras to D2S352 on chromosome region 2p23 R p22. Cyto- BA. Saw palmetto (Serenoa repens) in men with lower urinary tract symptoms: Effects on urodynamic pa- Mowszowicz I, Melanitou E, Doukani A, Wright F, Kut- rameters and voiding symptoms. Urology 1998;51: tenn F, Mauvais-Jarvis P. Androgen binding capacity and 5 alpha-reductase activity in pubic skin fibroblasts Giltay EJ, Gooren LJ. Effects of sex steroid depriva- from hirsute patients. J Clin Endocrinol Metab tion/administration on hair growth and skin sebum production in transsexual males and females. Clin En- Negri-Cesi P, Colciago A, Poletti A, Motta M. 5alpha-re- ductase isozymes and aromatase are differentially ex- Guthrie RM, Siegel RL. A multicenter, community-based pressed and active in the androgen-independent hu- study of doxazosin in the treatment of concomitant hy- man prostate cancer cell lines DU145 and PC3. Prostate pertension and symptomatic benign prostatic hyper- plasia: The Hypertension and BPH Intervention. Trial Rushton DH, Unger WP, Cotterill PC, Kingsley P, James KC. Quantitative assessment of 2% topical minoxidil in Iehle C, Delos S, Guirou O, Tate R, Raynaud JP, Martin the treatment of male pattern baldness. Clin Exp Der- PM. Human prostatic steroid 5 alpha-reductase iso- forms—A comparative study of selective inhibitors. J Shapiro J, Wiseman M , Lui H. Practical management of Steroid Biochem Mol Biol 1995;54:273–279.
hair loss. Can Fam Phys 2000;46:1469–1477.
Imperato-McGinley J, Shackleton C, Orlic S, Stoner E. C19 Schilcher H. Is there a rational therapy for symptomatic and C21 5 beta/5 alpha metabolite ratios in subjects treatment of benign prostatic hyperplasia with phyto- treated with the 5 alpha-reductase inhibitor: Compari- genic drugs? Illustrated with the example of the son of male pseudohermaphrodites with inherited 5 al- prostate agent from Serenoa repens. Wien Med pha-reductase deficiency. J Clin Endocrinol Metab Swoboda H, Kopp B. Serenoa repens—The saw palmetto Itami S, Sonoda T, Kurata S, Takayasu S. Mechanism of or dwarf palm. Wien Med Wochenschr 1999;149:235.
action of androgen in hair follicles. J Dermatol Sci Wang HX, Ng TB. Natural products with hypoglycemic, hypotensive, hypocholesterolemic, antiatherosclerotic Kaplan SA, Olsson CA. Patient satisfaction with finas- and antithrombotic activities. Life Sci 1999;65:2663– teride in the treatment of symptomatic benign prosta- tic hyperplasia. Clin Ther 1996;18:73–83.
Wilson JD, Roehrborn C. Long-term consequences of cas- Kaufman KD. Finasteride, 1 mg (Propecia), is the optimal tration in men: Lessons from the Skoptzy and the eu- PRAGER ET AL.
nuchs of the Chinese and Ottoman courts. J Clin En- static hyperplasia: A systematic review. JAMA 1998; Wilt T, Ishani A, Stark G, MacDonald R, Mulrow C, Lau Wolff H, Kunte C. Therapy of androgenetic alopecia with J. Serenoa repens for benign prostatic hyperplasia.
finasteride. What must be considered in consultation Cochrane Database Syst Rev 2000a;2:CD001423.
and drug prescribing. MMW Fortschr Med 1999;141: Wilt T, Mac Donald R, Ishani A, Rutks I, Stark G. Cernil- ton for benign prostatic hyperplasia. Cochrane Data- Wilt TJ, MacDonald R, Ishani A. Beta-sitosterol for the treatment of benign prostatic hyperplasia. BJU Int Wilt TJ, Ishani A, Stark G, MacDonald R, Lau J, Mulrow C. Saw palmetto extracts for treatment of benign pro- E-mail: [email protected]

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