Treatment of hirsutism with 5 alpha-reductase inhibitors

Synthesis and activity of 8-substituted benzo[c]quinolizin-3-ones as dual inhibitors of human 5alpha-reductases 1 and 2

Some potent dual inhibitors of 5alpha-reductases 1 and 2, based on the benzo[c]quinolizin-3-one structure and with IC(50) values ranging between 93 and 166nM for both isozymes, were found. The presence of the F atom on the ester moiety at the position 8 was crucial. This result can help in the design of other potent, dual inhibitors to be developed as drugs in the treatment of 5alpha-reductase related diseases.

Synthesis of 17beta-N-substituted 19-Nor-10-azasteroids as inhibitors of human 5alpha-reductases I and II

The synthesis of 17beta-[N-(phenyl)methyl/phenyl-amido] substituted 10-azasteroids has been accomplished by either the TiCl4- or TMSOTf-catalysed reaction of carbamates 11 and 12 with Danishefsky's diene. The reaction provided 5alpha-H isomers 3a-5a and 5beta-H isomers 3b-5b depending on the reaction conditions. Both epimers of each compound were tested against human 5alpha-reductase types I and II. Unexpectedly, 5beta-H compounds were found more active than their 5alpha-H counterparts, the best inhibitors being 3b (IC50=279 and 2000 nM toward isoenzyme I and II, respectively) and 5b (IC50=913 and 247 nM toward isoenzymes I and II, respectively).

Effect of C-ring modifications in benzo[c]quinolizin-3-ones, new selective inhibitors of human 5 alpha-reductase 1

The synthesis and the inhibition potency of octahydro- and decahydrobenzo[c]quinolizin-3-one derivatives 3--7, as new non-steroidal selective inhibitors of human enzyme 5 alpha-reductase type 1, are reported. These compounds differ from the recently reported benzo[c]quinolizin-3-one inhibitors 2 by the presence of a fully or partially saturated C-ring. Compounds 3 and 4, with a double bond in the C-ring, were prepared by sequential rearrangement-annulation of isoxazolines 19 and 20. C-ring saturated compounds 5--7 were prepared by the Lewis acid-promoted Mannich-Michael tandem reaction of Danishefsky diene with the appropriate N-t-Boc iminium ion. Inhibition experiments were carried out on 5 alpha R-1 and 5 alpha R-2 expressed by CHO cells. Among the prepared compounds, octahydrobenzo[c]quinolizin-3-one 3, with a double bond at the position 6a--10a, was a potent and selective inhibitor of human 5 alpha R-1 (IC(50)=58 nM). The introduction of a tert-butylcarboxyamide at the position 8 (compound 4) was deleterious for the inhibition activity. The lack of the double bond in the C-ring reduced strongly the inhibition activity of compounds 5--7. The extended planarity of the most potent benzo[c]quinolizin-3-ones as well as favorable interactions of the C-ring unsaturation with the enzyme active site could account for the inhibition activity of these compounds.

Inhibition of skin 5 alpha-reductase by oral contraceptive progestins in vitro

Androgenic disorders of female skin such as hirsutism, acne and alopecia are etiologically caused by androgen excess. Skin 5 alpha-reductase activity is a major factor influencing the manifestation of endogenous androgen excess in women. Oral contraceptives have proven useful for the treatment of androgen disorders of the skin. The mechanisms of action by which oral contraceptives correct skin androgen levels may include inhibition of 5 alpha-reductase and androgen receptor activity. We investigated the inhibitory effect of oral contraceptive progestins and ethinyl estradiol on skin 5 alpha-reductase and their influence on androgen receptor activity and affinity, using three different in vitro assay systems. It was shown that norgestimate blocked 5 alpha-reductase activity with an IC50 value of 10 microM, followed by levonorgestrel (IC50 52 microM), dienogest (IC50 55 microM), cyproterone acetate (IC50 87 microM) and gestodene (IC50 98 microM). To determine the full androgenic potential of the progestins, androgen receptor binding affinities and activation potentials were determined. The progestins norgestimate and dienogest in particular combined 5 alpha-reductase inhibition with minimal androgenic potential. These data demonstrate that the progestins norgestimate and dienogest might help in the treatment of clinical hyperandrogeny in women.

Indole and benzimidazole derivatives as steroid 5alpha-reductase inhibitors in the rat prostate

A novel series of indole and benzimidazole derivatives were synthesized and evaluated for their inhibitory activity of rat prostatic 5alpha-reductase. Among these compounds, 4-¿2-[1-(4,4'-dipropylbenzhydryl)indole-5-carboxamido]phenoxy¿buty ric acid (15) and its benzimidazole analogue 25 showed potent inhibitory activities for rat prostatic 5alpha-reductase (IC50 values of 9.6+/-1.0 and 13+/-1.5 nM, respectively), with the potency very close to that of finasteride. Compound 30, in which the moiety between the benzene ring and amide bond was replaced by quinolin-4-one ring, showed almost equipotent activity (IC50= 19+/-6.2nM) with the correspondent amide derivative 13. This result was consistent with the previous observation that the coplanarity of this moiety might contribute to the potent inhibitory activity.

Comparison of Diane 35 and Diane 35 plus spironolactone in the treatment of hirsutism

OBJECTIVE

To compare the clinical efficacy and safety of Diane 35 (cyproterone acetate [2] mg and ethinyl estradiol [35 microg]) plus spironolactone [100 mg] combination and Diane 35 alone in the treatment of hirsutism.

DESIGN

Prospective clinical study.

SETTING

Outpatients in Erciyes University Medical School.

PATIENT(S)

Fifty women with hirsutism.

INTERVENTION(S)

Group I patients (n = 22) were treated with Diane 35 alone and group II patients (n = 28) with Diane 35 plus spironolactone [100 mg].

MAIN OUTCOME MEASURE(S)

The basal hormone levels total and free T, androstenedione, DHEAS, sex hormone-binding globulin (SHBG), and prolactin (PRL) were measured by RIA before the study. Free T, SHBG, and DHEAS were also measured at 6-month intervals for 12 months. Hirsutism was graded at 6-month intervals.

RESULT(S)

The basal hormone levels were similar between the groups. Hirsutism score significantly decreased at the end of the therapy in both groups. The reduction in hirsutism score in group II at 12 months was greater than in group I. But the scores before the treatment, at 6 and 12 months were similar between the groups.

CONCLUSION(S)

Although the actual hirsutism score and free T concentration are not significantly different between the two groups at 12 months, percentage change in the hirsutism score at 12 months was higher in the Diane 35 plus spironolactone group. Therefore, the addition of spironolactone to Diane 35 may have a synergistic effect on hirsutism score.

19-nor-10-azasteroids: a novel class of inhibitors for human steroid 5alpha-reductases 1 and 2

Steroid 5alpha-reductase is a system of two isozymes (5alphaR-1 and 5alphaR-2) which catalyzes the NADPH-dependent reduction of testosterone to dihydrotestosterone in many androgen sensitive tissues and which is related to several human endocrine diseases such as benign prostatic hyperplasia (BPH), prostatic cancer, acne, alopecia, pattern baldness in men and hirsutism in women. The discovery of new potent and selective 5alphaR inhibitors is thus of great interest for pharmaceutical treatment of these diseases. The synthesis of a novel class of inhibitors for human 5alphaR-1 and 5alphaR-2, having the 19-nor-10-azasteroid skeleton, is described. The inhibitory potency of the 19-nor-10-azasteroids was determined in homogenates of human hypertrophic prostates toward 5alphaR-2 and in DU-145 human prostatic adenocarcinoma cells toward 5alphaR-1, in comparison with finasteride (IC50 = 3 nM for 5alphaR-2 and approximately 42 nM for 5alphaR-1), a drug which is currently used for BPH treatment. The inhibition potency was dependent on the type of substituent at position 17 and on the presence and position of the unsaturation in the A and C rings. delta9(11)-19-Nor-10-azaandrost-4-ene-3,17-dione (or 10-azaestra-4,9(11)-diene-3,17-dione) (4a) and 19-nor-10-azaandrost-4-ene-3,17-dione (5) were weak inhibitors of 5alphaR-2 (IC50 = 4.6 and 4.4 microM, respectively) but more potent inhibitors of 5alphaR-1 (IC50 = 263 and 299 nM, respectively), whereas 19-nor-10-aza-5alpha-androstane-3,17-dione (7) was inactive for both the isoenzymes. The best result was achieved with the 9:1 mixture of delta9(11)- and delta8(9)-17beta-(N-tert-butylcarbamoyl)-19-nor-10-aza-4- androsten-3-one (10a,b) which was a good inhibitor of 5alphaR-1 and 5alphaR-2 (IC50 = 127 and 122 nM, respectively), with a potency very close to that of finasteride. The results of ab initio calculations suggest that the inhibition potency of 19-nor-10-azasteroids could be directly related to the nucleophilicity of the carbonyl group in the 3-position.

Is 3 alpha, 17 beta-androstanediol-glucuronide a diagnostic marker in women with androgenic manifestations?

3 alpha, 17 beta-androstanediol-glucuronide (Adiol-G) has been described as a marker of local androgen excess due to the increased activity of 5 alpha-reductase in the cells of the hair follicles. In order to test the diagnostic value of Adiol-G, the serum level was compared to that of testosterone, free testosterone, dehydroepiandrosterone sulfate (DHEA-S), androstenedione and to the body mass index in 44 women with androgenic symptoms (Group I), 27 women with menstrual disturbances but no androgenic symptoms (Group II), and 48 healthy women (Group III) who served as controls. Adiol-G was significantly higher (7.8 +/- 5.1 nmol/l) in women with androgenic symptoms than in the other groups, but there was a considerable overlap. Serum testosterone was also found to be higher in Group I than in Groups II and III, respectively. There was a significant correlation between Adiol-G and testosterone, and Adiol-G and DHEA-S. No significant correlation could be shown to exist between androstenedione and Adiol-G. When Adiol-G and testosterone were simply classified as 'normal' or 'increased' (Adiol-G 9.4 nmol/l; testosterone greater than 2.4 nmol/l), higher than normal values of the former were found in the presence of normal testosterone in only 4% of the cases. It is concluded that the level of Adiol-G generally parallels that of testosterone. Consequently, it does not seem to be an effective marker of peripheral androgen excess.

In vivo assay for conversion of testosterone to dihydrotestosterone by rat prostatic steroid 5 alpha-reductase and comparison of two inhibitors

An in vivo assay for steroid 5 alpha-reductase in rat ventral prostate has been developed and used to compare the inhibitory activity of N,N-diethyl-4-methyl-3-oxo-4-aza-5 alpha-androstane-17 beta-carboxamide (4-MA) and 6-methylene-4-pregnene-3,20-dione (LY207320). Immature rats (70-80 g) received test compounds 30 min prior to s.c. injection of [3H]-T. The rats were sacrificed 30 min later and the ventral prostates were analyzed for [3H]-T metabolites. Intraprostatic [3H]-T and [3H]-DHT reached peak levels within 5 min after injection of [3H]-T and declined to about 25% of peak levels after 2 hr. 4-MA was a very potent inhibitor of [3H]-DHT formation with an estimated IC50 of 0.2 mg/kg. LY207320, an inhibitor of 5 alpha-reductase in vitro, was weakly active in vivo and did not achieve greater than 45% inhibition at high doses (greater than 200 mg/kg, s.c.). Tissue uptake of [3H]-T was also inhibited by LY207320, which may contribute to its inhibitory activity on accessory sex organ growth in the rat.

Studies on the mechanism of steroid 5 alpha-reductase inhibition by 3-carboxy A-ring aryl steroids

The mechanism of interaction between two 3-carboxy A-ring aryl steroids, 17 beta-(N,N-diisopropylcarboxamide)-estra-1,3,5(10)-triene-3-carboxy lic acid (1) and 17 beta-(N-t-butylcarboxamide)-estra-1,3,5(10)-triene-3-carboxylic acid (2), with rat hepatic and human prostatic steroid 5 alpha-reductases has been investigated. Dead-end inhibition plots with 1 and 2 versus both substrates (testosterone and NADPH) were linear-uncompetitive using either enzyme, while double-inhibition analyses indicated cooperative binding to enzyme between NADP+ and 1 or 2. These results were interpreted within the ordered kinetic mechanism of steroid 5 alpha-reductase to result from the preferential association of 3-carboxy A-ring aryl steroids to the enzyme-NADP+ complex. The direct displacement by 2 of a radioligand known to associate to this same enzyme form provides further support for these conclusions.

Effect of MK-906, a specific 5 alpha-reductase inhibitor, on serum androgens and androgen conjugates in normal men

To determine the hormonal effects of MK-906, an orally active 5 alpha-reductase inhibitor, on serum androgens and androgen conjugates, 12 healthy men were given 10, 20, 50, and 100 mg MK-906 2 weeks apart in randomized order in a 4-period crossover design. Serum testosterone (T), dihydrotestosterone (DHT), androstanediol glucuronide, and androsterone glucuronide were measured before and 24 hours after each dose. The effect of MK-906 on glucuronyl transferase activity, the enzyme responsible for androstanediol glucuronide and androsterone glucuronide formation, was assessed in vitro using rat prostate tissue. Serum T levels were unchanged after all doses. Serum DHT, androstanediol glucuronide, and androsterone glucuronide were suppressed by 70, 40, and 56%, respectively, after the 10-mg dose, and by 82, 52, and 66% after the 100-mg dose (P less than 0.02 for the comparison between the 10 and 100-mg doses for all three steroids), respectively. Baseline serum T and DHT levels were strongly correlated (R = 0.89, P = 0.0002), as were androstanediol glucuronide and androsterone glucuronide levels (R = 0.78, P = 0.003), but there was no correlation between DHT levels and the levels of either conjugated steroid. MK-906 had no effect on glucuronyl transferase activity in vitro. It was concluded that single doses of MK-906 suppress both conjugated and unconjugated 5 alpha-reduced androgens. While all three steroids appeared to be good markers of systemic 5 alpha-reductase inhibition, further research will be needed to determine which steroid best reflects tissue DHT levels in patients receiving these inhibitors.

Interaction between rat prostatic steroid 5 alpha-reductase and 3-carboxy-17 beta-substituted steroids: novel mechanism of enzyme inhibition

Efforts to identify novel compounds capable of blocking the steroid 5 alpha-reductase (SR) catalyzed conversion of testosterone (T) to 5 alpha-dihydrotestosterone have resulted in the development of 17 beta-substituted-3-androstene-3-carboxylic acids as potent inhibitors of the rat prostatic enzyme. The dead-end inhibition patterns of one of these steroidal acrylates, 17 beta-N-(2-methyl-2-propyl)-carbamoyl-androst-3,5-diene-3-carboxylic acid were best evaluated with a linear uncompetitive kinetic model vs both T (Kii = 11 +/- 1 nM) and NADPH (Kii = 22 +/- 2 nM). To interpret these observations, the kinetic mechanism of the rat prostatic SR was shown to involve the binding of NADPH prior to that of T through a series of dead-end and product inhibition experiments. Within the context of this preferentially ordered kinetic mechanism, it is proposed that the uncompetitive inhibition patterns result from the association of the steroidal acrylate to an enzyme complex containing NADP+ in formation of a dead-end ternary complex of enzyme, NADP+, and inhibitor.

Topical antiandrogens in the treatment of male-pattern baldness

Antiandrogen therapy for androgen-induced baldness is in its infancy. In men, because of side effects, topical antiandrogens appear to hold the most promise. Assessing changes in scalp hair growth may be difficult, however, and hirsutism provides a useful model for testing the efficacy of topical antiandrogens. Systemic administration of 5 alpha-reductase inhibitors may also eventually prove to be helpful in the treatment of male-pattern baldness, but side effects and long-term risks are unknown. In women, systemic antiandrogens appear to be a reasonable option for therapy and produce a good subjective response. Further research is needed, however, to document the long-term risks and efficacy of systemic antiandrogen therapy in women.