Exploring the Impact of the Microbiome on Neuroactive Steroid Levels in Germ-Free Animals

Steroid hormones are essential biomolecules for human physiology as they modulate the endocrine system, nervous function and behaviour. Recent studies have shown that the gut microbiota is directly involved in the production and metabolism of steroid hormones in the periphery. However, the influence of the gut microbiota on levels of steroids acting and present in the brain (i.e., neuroactive steroids) is not fully understood. Therefore, using liquid chromatography–tandem mass spectrometry, we assessed the levels of several neuroactive steroids in various brain areas and the plasma of germ-free (GF) male mice and conventionally colonized controls. The data obtained indicate an increase in allopregnanolone levels associated with a decrease in those of 5α-androstane-3α, 17β-diol (3α-diol) in the plasma of GF mice. Moreover, an increase of dihydroprogesterone and isoallopregnanolone in the hippocampus, cerebellum, and cerebral cortex was also reported. Changes in dihydrotestosterone and 3α-diol levels were also observed in the hippocampus of GF mice. In addition, an increase in dehydroepiandrosterone was associated with a decrease in testosterone levels in the hypothalamus of GF mice. Our findings suggest that the absence of microbes affects the neuroactive steroids in the periphery and the brain, supporting the evidence of a microbiota-mediated modulation of neuroendocrine pathways involved in preserving host brain functioning.

Interaction of sex steroid hormones and obesity on insulin resistance and type 2 diabetes in men: the Third National Health and Nutrition Examination Survey

AIMS

We examined interaction of sex steroid hormones and obesity with regard to insulin resistance (IR) and type 2 diabetes (T2D) by using nationally representative data from the US.

METHODS

Data of 1461 men aged ≥20years who participated in the Third National Health and Nutrition Examination Survey were analyzed. Multiplicative interaction was calculated by cross-product interaction terms in multivariable logistic regression models. Additive interaction was assessed by the relative excess risk due to interaction (RERI).

RESULTS

After adjusting for demographic and lifestyle covariates, the odds of IR were greatest among obese men with low free testosterone and high androstanediol glucuronide. Multiplicative interactions for total testosterone, free testosterone, and free estradiol index (FEI) were statistically significant with central obesity but not with overweight and obesity regarding to T2D (P<0.05). Significant additive interactions with obesity or central obesity were detected for total testosterone (RERI=2.75, 95% CI=0.92,4.59), SHBG (RERI=5.71, 95% CI=0.77,10.64), and FEI (RERI=-9.96, 95% CI=-19.18,-0.74) with regard to IR, beta-cell dysfunction, and T2D.

CONCLUSIONS

Our findings add to the evidence suggesting that low testosterone and high estradiol may be associated greater risks of IR and T2D by interacting with overall and central obesity in adult men.

Profiling Neuroactive Steroid Levels After Traumatic Brain Injury in Male Mice

The incidence of traumatic brain injuries (TBIs) in humans has rapidly increased in the last ten years. The most common causes are falls and car accidents. Approximately 80 000-90 000 persons per year will suffer some permanent disability as a result of the lesion, and one of the most common symptoms is the decline of hormone levels, also known as post-TBI hormonal deficiency syndrome. This issue has become more and more important, and many studies have focused on shedding some light on it. The hormonal decline affects not only gonadal steroid hormones but also neuroactive steroids, which play an important role in TBI recovery by neuroprotective and neurotrophic actions. The present work used an adolescent close-head murine model to analyze brain and plasma neurosteroid level changes after TBI and to establish correlations with edema and neurological impairments, 2 of the hallmarks of TBI. Our results showed changes in brain pregnenolone, testosterone, dihydrotestosterone (DHT), and 3α-diol levels whereas in plasma, the changes were present in progesterone, DHT, 3α-diol, and 3β-diol. Within them, pregnenolone, progesterone, DHT, and 3α-diol levels positively correlated with edema formation and neurological score, whereas testosterone inversely correlated with these 2 variables. These findings suggest that changes in the brain levels of some neuroactive steroids may contribute to the alterations in brain function caused by the lesion and that plasma levels of some neuroactive steroids could be good candidates of blood markers to predict TBI outcome.

Synthesis of 5α-androstane-3α,17β-diol 17-O-glucuronide histaminyl conjugate for immunoassays

Simple method of preparation of 5α-androstane-3α,17β-diol 17-O-glucuronide N-histaminyl amide was developed for the construction of immunoanalytical kit. Improved method of glucuronide derivative synthesis was used, followed by hydroxybenzotriazole-dicyclohexylcarbodiimide coupling with histamine.

Serum androgens and prostate cancer risk: results from the placebo arm of the Prostate Cancer Prevention Trial

BACKGROUND

Compelling and long-standing data suggest that androgens play an important role in the development of both normal prostate epithelium and prostate cancer. Although testosterone administration can induce prostate cancer (PCA) in laboratory animals, serum-based epidemiologic studies examining androgens in humans have not consistently supported a role for androgens in prostate carcinogenesis. We examined whether pre-diagnostic serum androgens were associated with PCA risk in the placebo arm of the Prostate Cancer Prevention Trial.

METHODS

In this nested case-control study, cases (n = 1,032) were primarily local-stage, biopsy-detected cancers, and controls (n = 1,025) were biopsy-confirmed to be PCA-free. Pre-diagnostic serum androgens (total testosterone, 3α-androstanediol glucuronide, free testosterone), estrogen-to-testosterone ratio, and sex hormone-binding globulin (SHBG) concentrations were measured in pooled (baseline and year 3) blood samples.

RESULTS

We found no significant associations between serum androgens, estrogen-to-testosterone ratios, or SHBG and risk of total, low (Gleason <7) or high-grade (Gleason 7-10) PCA.

CONCLUSION

Much remains to be learned about the role of androgens in prostate carcinogenesis. Further research is needed to evaluate the role of androgens, timing of exposure, genetic modulators of androgen metabolism, or environmental exposures that may affect androgen influence on prostate carcinogenesis.

Neuroprotective Effect of Progesterone in MPTP-Treated Male Mice

BACKGROUND

Numerous studies have reported on the neuroprotective activity of estradiol, whereas the effect of the other ovarian steroid, progesterone, is much less documented.

METHODS

This study sought to investigate neuroprotection with a low dose of progesterone (1 µg) in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated male mice to model Parkinson's disease and compare it to the effect of this steroid in intact mice (experiment 1). We also investigated if high doses of progesterone could protect dopaminergic neurons already exposed to MPTP (experiment 2). We measured progesterone effects on various dopaminergic markers [dopamine and its metabolites, dopamine transporter (DAT) and vesicular monoamine transporter 2 (VMAT2)] and on neuroactive steroids in both plasma and the brain.

RESULTS

For experiment 1, our results showed that progesterone completely prevented the effect of MPTP toxicity on dopamine concentrations, on the increase in the 3-methoxytyramine/dopamine ratio, as well as on VMAT2-specific binding in the striatum and the substantia nigra. Progesterone decreased MPTP effects on 3,4-dihydroxyphenylacetic acid concentrations and DAT-specific binding in the lateral part of the anterior striatum and in the middle striatum (medial and lateral parts). Progesterone treatment of intact mice had no effect on the markers investigated. For experiment 2, measures of dopaminergic markers in the striatum showed that 8 mg/kg of progesterone was the most effective dose to reduce MPTP effects, and more limited effects were observed with 16 mg/kg. We found that progesterone treatment increases the levels of brain progesterone itself as well as of its metabolites.

CONCLUSION

Our result showed that progesterone has neuroprotective effects on dopaminergic neurons in MPTP-treated male mice.

Circulating total testosterone and PSA concentrations in a nationally representative sample of men without a diagnosis of prostate cancer

BACKGROUND

The association between serum sex steroid hormones and PSA in a general population has not been described.

METHODS

Included were 378 men aged 40-85 years who participated in the National Health and Nutrition Examination Survey in 2001-2004, who did not have a prostate cancer diagnosis, and had not had a recent biopsy, rectal examination, cystoscopy, or prostate infection or inflammation. Serum total PSA, total testosterone, androstanediol glucuronide (3α-diol-G), estradiol, and sex hormone binding globulin (SHBG) concentrations were previously measured. Free testosterone was estimated by mass action. We applied sampling weights and calculated geometric mean PSA concentration by hormone quintiles adjusting for age and race/ethnicity, and also for body mass index, waist circumference, smoking, diabetes, and mutually for hormones. We estimated the OR of PSA ≥2.5 ng/ml per hormone quintile using logistic regression.

RESULTS

Geometric mean PSA increased across testosterone quintiles after age and race/ethnicity (Q1: 0.80, Q5: 1.14 ng/ml; P-trend = 0.002) and multivariable (Q1: 0.79, Q5: 1.16 ng/ml; P-trend = 0.02) adjustment; patterns were similar for free testosterone and 3α-diol-G. SHBG was inversely associated with PSA only after multivariable adjustment (Q1: 1.32, Q5: 0.82 nmol/L; P-trend = 0.01). Estradiol and PSA were not associated. The OR of PSA ≥2.5 ng/ml was 1.54 (95% CI 1.18-2.01) per testosterone quintile after age and race/ethnicity adjustment, and 1.78 (95% CI 1.16-2.73) after multivariable adjustment.

CONCLUSIONS

In this nationally representative sample, men with higher testosterone had higher PSA even after taking into account other hormones and modifiable factors. Men with higher SHBG had lower PSA, but only after multivariable adjustment.

A rapid and sensitive UPLC-MS/MS method for the simultaneous quantification of serum androsterone glucuronide, etiocholanolone glucuronide, and androstan-3α, 17β diol 17-glucuronide in postmenopausal women

Quantification of steroidal glucuronide conjugates by the indirect methods of immunoassay and GC-MS/MS may underestimate some conjugates since hydrolysis is needed in sample processing. In the present work, a sensitive and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the simultaneous direct quantification of androsterone glucuronide, etiocholanolone glucuronide, and androstan-3α, 17β diol 17-glucuronide in postmenopausal women's serum. The quantification limits are 0.1ng/mL for 3α-diol-17G and 4ng/mL for both ADT-G and Etio-G, respectively, with an extraction from 200μL serum while the total run time is less than 6min for all three glucuronides. In this method, solid phase extraction is used for sample preparation. The assay has been validated in compliance with EndoCeutics SOPs and FDA guidelines for bioanalytical method development and validation. The recovery of glucuronides in stripped serum is consistent with that in unstripped serum, where the average difference in stripped and unstripped is less than 10%. A linear regression model fits well the standard curves of all three compounds with R≥0.99 where the weighting factor is 1/X. Interday accuracy and CV for all levels of QCs are within the range of 15% in both stripped and unstripped serum while all calibration curves are within the range of 6% except for LLOQs, which are within the range of 9%. Other parameters have also been assessed such as selectivity, matrix, lipemic and hemolysis effects as well as stabilities in solution and matrix. Incurred sample reanalysis has been performed with a result of over 93% within 20% of the original values. This reliable, sensitive and fast method is ready for large-scale clinical sample assays.

Neurosteroid 3α-androstanediol efficiently counteracts paclitaxel-induced peripheral neuropathy and painful symptoms

Painful peripheral neuropathy belongs to major side-effects limiting cancer chemotherapy. Paclitaxel, widely used to treat several cancers, induces neurological symptoms including burning pain, allodynia, hyperalgesia and numbness. Therefore, identification of drugs that may effectively counteract paclitaxel-induced neuropathic symptoms is crucial. Here, we combined histopathological, neurochemical, behavioral and electrophysiological methods to investigate the natural neurosteroid 3α-androstanediol (3α-DIOL) ability to counteract paclitaxel-evoked peripheral nerve tissue damages and neurological symptoms. Prophylactic or corrective 3α-DIOL treatment (4 mg/kg/2days) prevented or suppressed PAC-evoked heat-thermal hyperalgesia, cold-allodynia and mechanical allodynia/hyperalgesia, by reversing to normal, decreased thermal and mechanical pain thresholds of PAC-treated rats. Electrophysiological studies demonstrated that 3α-DIOL restored control values of nerve conduction velocity and action potential peak amplitude significantly altered by PAC-treatment. 3α-DIOL also repaired PAC-induced nerve damages by restoring normal neurofilament-200 level in peripheral axons and control amount of 2’,3’-cyclic-nucleotide-3’-phosphodiesterase in myelin sheaths. Decreased density of intraepidermal nerve fibers evoked by PAC-therapy was also counteracted by 3α-DIOL treatment. More importantly, 3α-DIOL beneficial effects were not sedation-dependent but resulted from its neuroprotective ability, nerve tissue repairing capacity and long-term analgesic action. Altogether, our results showing that 3α-DIOL efficiently counteracted PAC-evoked painful symptoms, also offer interesting possibilities to develop neurosteroid-based strategies against chemotherapy-induced peripheral neuropathy. This article shows that the prophylactic or corrective treatment with 3α-androstanediol prevents or suppresses PAC-evoked painful symptoms and peripheral nerve dysfunctions in rats. The data suggest that 3α-androstanediol-based therapy may constitute an efficient strategy to explore in humans for the eradication of chemotherapy-induced peripheral neuropathy.

Androgen activity and markers of inflammation among men in NHANES III

OBJECTIVES

Inflammation contributes to chronic diseases. Lower serum testosterone among men is associated with less inflammation, yet immune defense is thought to trade-off against reproduction with androgens adversely affecting immune function. Anti-androgens are effective at castrate levels of serum testosterone, suggesting serum testosterone may not capture all androgen activity. The association of two androgen biomarkers with key markers of inflammation was examined.

METHODS

The adjusted association of serum testosterone and androstanediol glucuronide with C-reactive protein, white blood cell, granulocyte and lymphocyte count, fibrinogen, and hemoglobin, as a control outcome because testosterone administration raises hemoglobin, were examined in a nationally representative sample of 1,490 US men from the National Health and Nutrition Examination Survey III phase 1 (1988-1991) using multivariable linear regression.

RESULTS

Serum testosterone and androstanediol glucuronide were weakly correlated (0.13). Serum testosterone was associated with lower white blood cell count [-0.26 × 10(-9) per standard deviation, 95% confidence interval (CI) -0.37 to -0.14] and granulocyte count (-0.21 × 10(-9) , 95% CI -0.29 to -0.13) but not with hemoglobin (0.02 g/l, 95% CI -0.89 to 0.92), adjusted for age, education, race/ethnicity, smoking, and alcohol. Similarly adjusted, androstanediol glucuronide was not associated with white blood cell count (0.10 × 10(-9) , 95% CI -0.05 to -0.25), granulocyte count (0.12 × 10(-9) , 95% CI -0.02 to 0.25), or fibrinogen (0.05 g/l, 95% CI -0.004 to 0.11), but was with hemoglobin (0.70 g/l, 95% CI 0.07 to 1.32).

CONCLUSIONS

Different androgen biomarkers had different associations with inflammatory markers, highlighting the need to consider several androgen biomarkers. The possibility remains that androgens may generate inflammatory processes with implications for chronic diseases.

[The antiepileptic role of 3α-androstanediol on the epileptic rats induced by pentylenetetrazole]

The influence of 3α-androstanediol (3α-diol) on twitch and electroencephalogram (EEG) of the epileptic rats induced by pentylenetetrazole (PTZ) has been observed in this experiment in order to comprehensively explore the role of 3α-diol on epileptic attack from the aspects of behavior and EEG. Thirty-two male Sprague-Dawley rats were evenly and randomly divided into 4 groups: the normal and supplied with oil epileptic (N+oil+PTZ) group, the normal and supplied with 3α-diol epileptic (N+3α-diol+PTZ) group, the gonadectomized and supplied with oil epileptic (GDX+oil+PTZ) group and the gonadectomized and supplied with 3α-diol epileptic (GDX+3α-diol+PTZ) group. The changes of the behavior and EEG of epileptic rats in every group were recorded and analyzed. The results of behavior observation showed that the latency to clonic seizure and tonic-clonic seizure was shortened and the number of tonic-clonic seizure was increased significantly in the GDX+oil+PTZ group in comparison with N+oil+PTZ group (P < 0.05); comparing GDX+3α-diol+PTZ group with GDX+oil+PTZ group, or N+3α-diol+PTZ group with N+oil+PTZ group, we found that the latency to clonic seizure and tonic-clonic seizure became prolonged significantly, and the number of clonic seizure and tonic-clonic seizure was decreased significantly (P < 0.05). The results of EEG showed that the latency to epileptic waves was cut and the number of epileptic waves was augmented significantly in the GDX+oil+PTZ group in comparison with N+oil+PTZ group (P < 0.05); comparing GDX+3α-diol+PTZ group with GDX+oil+PTZ group, or N+3α-diol+PTZ group with N+oil+PTZ group, we found that the latency to epileptic waves became lengthened significantly, the number of epileptic waves was reduced significantly and the percentage of change of TP (total power of spectrum) was lessened significantly (P < 0.05). These results indicate that 3α-diol has an antiepileptic activity in the gonadectomized and normal epileptic rats.

Testosterone responses to intensive interval versus steady-state endurance exercise

Free testosterone (FT) hormonal responses were compared between high-intensity interval exercise (IE) and steadystate endurance exercise (SSE) in endurance trained males (no.=15). IE session was repeated periods of 90-sec treadmill running at 100-110% maximal oxygen uptake (VO2max) and 90-sec active recovery at 40% VO2max for 42-47 min. The SSE session consisted of a continuous 45-min run at 60-65% VO2max. Total work output was equal for each exercise session. A 45-min supine rest control session (CON) was also performed. All three sessions were on separate days. Pre-session (PRE), immediate post-session (POST), and 12-h post-session (12POST) blood samples were collected and used to determine FT, SHBG, LH, 3- α-androstanediol glucuronide (3-α Diol G) and cortisol. Analysis of variance compared IE and SSE biomarker responses to the reference CON session. IE and SSE each caused an increase (p<0.01) in FT, but IE more so than SSE (p<0.05). The 5α-reductase marker 3-α Diol G response at 12POST IE was elevated while FT was reduced (p<0.05); no such change occurred following SSE. These findings suggest IE might produce a more pronounced turnover of FT by androgen sensitive tissue than the SSE form of exercise.

Validation of a sequential extraction and liquid chromatography-tandem mass spectrometric method for determination of dihydrotestosterone, androstanediol and androstanediol-glucuronide in prostate tissues

Androgens are key mediators of prostate development and function, a role that extends to the development of prostate diseases such as benign prostatic hyperplasia (BPH) and prostate cancer. In prostate, DHT is the major androgen and reduction and glucuronidation are the major metabolic pathways for DHT elimination. A streamlined method for quantitation of dihydrotestosterone (DHT), 5α-androstan-3α,17β-diol (3α-diol), and 3α-diol glucuronide (diol-gluc) was established and validated for use with archived prostate tissue specimens to facilitate examination of the roles of the underlying metabolism. This involved a sequential 70/30 hexane/ethyl acetate (hex/EtOAc) extraction of steroids, followed by an ethyl acetate extraction for diol-gluc. Derivatization of the hex/EtOAc fraction with2-fluoro-1-methylpyridinium p-toluene-4-sulfonate (FMP) was used to enhance sensitivity for hydroxyl steroids and liquid chromatography-tandem mass spectrometry (LC-MS/MS) was utilized for analysis of both fractions. The method was validated with calibration standards followed by recovery assessment from spiked samples of BPH and normal prostate. Lower limits of quantitation (LLOQ) were 50 pg/g, 20 pg/g and 100 pg/g for DHT, 3α-diol and diol-gluc, respectively for extracts from 50mg equivalents of tissue. Prepared samples were stable for up to three weeks at 4 °C and 37 °C. The method provides excellent sensitivity and selectivity for determination of tissue levels of DHT, 3α-diol, and diol-gluc. Furthermore, this protocol can easily be extended to other hydroxyl steroids, is relatively straightforward to perform and is an effective tool for assessing steroid levels in archived clinical prostate samples.

Sex steroids and personality traits in the middle luteal phase of healthy normally menstruating young professional women

OBJECTIVE

Sex steroids affect human behavior. The aim of the present study was to determine the associations, if any, between the circulating levels of gonadal and adrenal sex steroids in the mid luteal phase (21st day of a normal menstrual cycle, MC) of young professional women and psychometric parameters as assessed by the Minnesota Multiphasic Personality Inventory (MMPI).

RESULTS

Our results are as follows: (a) The metabolic product of activated adrenal and gonadal androgens, 3alpha-diolG, was modestly but significantly associated with the social introversion scale (10-SI) (r=0.36, p<0.05), independently accounting for 13% of its variation across participants (R²=0.13, F(1,45)=6.58, p=0.014). (b) Total testosterone was significantly associated with the paranoia scale (6-Pa) (r=0.27, p<0.05). Multiple regression analyses indicated that 10% of the variability in paranoia scores could be independently explained by total testosterone levels (R²=0.10, F(1,57)=6.23, p=0.016). We were unable to find any association between the circulating androgens and scores on the masculinity-femininity scale (Mf). We were also unable to document any association between the weak adrenal androgens DHEA and DHEA-S and depression in contrast to several published reports. (c) Our data suggest a marginally significant association between progesterone and scores on the 7-Pt (obsessive/compulsive/psychasthenia) scale (r=0.27, p<0.05). However, only 7% of the 7-Pt variance was explained by progesterone (R²=0.071, F(1,50)=3.81, p=0.057).

CONCLUSIONS

We have found that total testosterone was associated with the paranoia score, the metabolic product of activated androgens, 3alpha-diolG, to social introversion and, finally, progesterone to obsessive-compulsive behavior.

Impact of electro-acupuncture and physical exercise on hyperandrogenism and oligo/amenorrhea in women with polycystic ovary syndrome: a randomized controlled trial

Polycystic ovary syndrome (PCOS), the most common endocrine disorder in women of reproductive age, is characterized by hyperandrogenism, oligo/amenorrhea, and polycystic ovaries. We aimed to determine whether low-frequency electro-acupuncture (EA) would decrease hyperandrogenism and improve oligo/amenorrhea more effectively than physical exercise or no intervention. We randomized 84 women with PCOS, aged 18-37 yr, to 16 wk of low-frequency EA, physical exercise, or no intervention. The primary outcome measure changes in the concentration of total testosterone (T) at week 16 determined by gas and liquid chromatography-mass spectrometry was analyzed by intention to treat. Secondary outcome measures were changes in menstrual frequency; concentrations of androgens, estrogens, androgen precursors, and glucuronidated androgen metabolites; and acne and hirsutism. Outcomes were assessed at baseline, after 16 wk of intervention, and after a 16-wk follow-up. After 16 wk of intervention, circulating T decreased by -25%, androsterone glucuronide by -30%, and androstane-3α,17β-diol-3-glucuronide by -28% in the EA group (P = 0.038, 0.030, and 0.047, respectively vs. exercise); menstrual frequency increased to 0.69/month from 0.28 at baseline in the EA group (P = 0.018 vs. exercise). After the 16-wk follow-up, the acne score decreased by -32% in the EA group (P = 0.006 vs. exercise). Both EA and exercise improved menstrual frequency and decreased the levels of several sex steroids at week 16 and at the 16-wk follow-up compared with no intervention. Low-frequency EA and physical exercise improved hyperandrogenism and menstrual frequency more effectively than no intervention in women with PCOS. Low-frequency EA was superior to physical exercise and may be useful for treating hyperandrogenism and oligo/amenorrhea.

5Alpha-androstane-3beta,7alpha,17beta-triol and 5alpha-androstane-3beta,7beta,17beta-triol as substrates for the human 11beta-hydroxysteroid dehydrogenase type 1

Several studies have shown that the native 7alpha-hydroxy-dehydroepiandrosterone (7alpha-hydroxy-DHEA) is a substrate for the human 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) which converts the 7alpha- into the 7beta-epimer through an oxido-reduction process. Research on the 11beta-HSD1 has investigated its function and structure through using native glucocorticoid substrates and known inhibitors. Other steroid substrates are also of interest. Among testosterone metabolites, 5alpha-androstane-3beta,17beta-diol (Adiol) is a substrate for the cytochrome P450 7B1 which produces 5alpha-androstane-3beta,7alpha,17beta-triol (7alpha-Adiol). This steroid may be a substrate for the 11beta-HSD1. We used recombinant yeast-expressed 11beta-HSD1 with NADP(H)-regenerating systems for examining the products obtained after incubation with 7alpha-Adiol, 7beta-Adiol or 7-oxo-Adiol. Oxidative conditions for the 11beta-HSD1 provided no trace of 7-oxo-Adiol but the inter-conversion of 7alpha- and 7beta-hydroxy-Adiol with V(max)/K(M) (pmol min(-1) microg(-1)/microM) values of 2 and 0.5, respectively. This state was maintained under reductive conditions. The use of a 7-oxo-Adiol substrate under reductive conditions led to the production of both 7alpha- and 7beta-hydroxy-Adiol with V(max)/K(M) values of 3.43 and 0.22, respectively. These findings support the hypothesis that the oxido-reductase and epimerase activities of 11beta-HSD1 depend on the positioning of the steroid substrates within the active site and may provide insight into its fine structure and mechanism of action.

Androgens and prostate cancer risk: a prospective study

BACKGROUND

Androgens have been implicated in prostate tumorigenesis, but prospective studies have overall reported no association between circulating levels of androgens and risk of prostate cancer. However, some recent studies have shown that a high level of testosterone increase the risk of non-aggressive tumors but is associated with a decreased risk of aggressive tumors.

METHODS

We prospectively measured plasma levels of total testosterone, androstanediol glucuronide (A-diol-g) and sex hormone binding globuline (SHBG) and calculated estimated levels of free testosterone, in a nested case-control study of 392 cases and 392 matched controls.

RESULTS

None of the studied hormones were significantly associated with prostate cancer risk in the full study group or in subgroups according to tumor aggressiveness. Odds ratios in the full study group, for top versus bottom quartile, was for total testosterone 1.25 (95% CI = 0.79-2.00; P(trend) = 0.51); free testosterone, 1.31 (95% CI = 0.82-2.07; P(trend) = 0.35); A-diol-g, 0.88 (95% CI = 0.59-1.33; P(trend) = 0.77); and for SHBG, 1.01 (95% CI = 0.64-1.58; P(trend) = 0.94).

CONCLUSIONS

We found no significant associations between androgen levels and risk of prostate cancer in this population-based, non-screened cohort.

Mass spectrometric assay and physiological-pharmacological activity of androgenic neurosteroids

Steroid hormones play a key role in the pathophysiology of several brain disorders. Testosterone modulates neuronal excitability, but the underlying mechanisms are obscure. There is emerging evidence that testosterone-derived "androgenic neurosteroids", 3alpha-androstanediol and 17beta-estradiol, mediate the testosterone effects on neural excitability and seizure susceptibility. Testosterone undergoes metabolism to neurosteroids via two distinct pathways. Aromatization of the A-ring converts testosterone into 17beta-estradiol. Reduction of testosterone by 5alpha-reductase generates 5alpha-dihydrotestosterone, which is then converted to 3alpha-androstanediol, a powerful GABA(A) receptor-modulating neurosteroid with anticonvulsant properties. Although the 3alpha-androstanediol is an emerging neurosteroid in the brain, there is no specific and sensitive assay for determination of 3alpha-androstanediol in biological samples. This article describes the development and validation of mass spectrometric assay of 3alpha-androstanediol, and the molecular mechanisms underlying the testosterone modulation of seizure susceptibility. A liquid chromatography-tandem mass spectrometry assay to measure 3alpha-androstanediol is validated with excellent linearity, specificity, sensitivity, and reproducibility. Testosterone modulation of seizure susceptibility is demonstrated to occur through its conversion to neurosteroids with "anticonvulsant" and "proconvulsant" actions and hence the net effect of testosterone on neural excitability and seizure activity depends on the levels of distinct testosterone metabolites. The proconvulsant effect of testosterone is associated with increases in plasma 17beta-estradiol concentrations. The 5alpha-reduced metabolites of testosterone, 5alpha-dihydrotestosterone and 3alpha-androstanediol, had powerful anticonvulsant activity. Overall, the testosterone-derived neurosteroids 3alpha-androstanediol and 17beta-estradiol could contribute to the net cellular actions of testosterone in the brain. Because 3alpha-androstanediol is a potent positive allosteric modulator of GABA(A) receptors, it could serve as an endogenous neuromodulator of neuronal excitability in men. The 3alpha-androstanediol assay is an important tool in this area because of the growing interest in the potential to use adjuvant aromatase inhibitor therapy to improve treatment of epilepsy.

Serum sex steroid hormones and lower urinary tract symptoms in Third National Health and Nutrition Examination Survey (NHANES III)

OBJECTIVES

To evaluate the association of circulating sex steroid hormones and sex hormone binding globulin (SHBG) with lower urinary tract symptoms (LUTS).

METHODS

We included 260 men, 60 years old or older, who participated in Phase 1 (1988 to 1991) of the Third National Health and Nutrition Examination Survey and for whom surplus serum was available. We measured the serum concentrations of testosterone, androstanediol glucuronide (AAG), estradiol, and SHBG. Free testosterone was calculated from the circulating testosterone, SHBG, and albumin. The cases (n = 128) were men with two to four symptoms (nocturia, hesitancy, incomplete emptying, and weak stream), but who had never undergone noncancer prostate surgery. The controls (n = 132) were men who neither had symptoms nor had undergone noncancer prostate surgery. We adjusted for age, race/ethnicity, waist circumference, cigarette smoking, alcohol consumption, and physical activity in logistic regression models and used sampling weights.

RESULTS

The cases had statistically significantly greater AAG and estradiol concentrations than did the controls. After multivariate adjustment, the men in the top tertile of AAG (odds ratio 2.62, 95% confidence interval 1.12 to 6.14) had a greater risk of LUTS compared with men in the bottom two tertiles. Also, men with a greater estradiol concentration (odds ratio 1.78, 95% confidence interval 0.91 to 3.49) and a greater estradiol/SHBG molar ratio (odds ratio 2.41, 95% confidence interval 1.39 to 4.17) had a greater risk of LUTS than did men with lower concentrations. No consistent associations were seen for circulating testosterone, free testosterone, or SHBG.

CONCLUSIONS

In this cross-sectional study representative of older U.S. men, circulating AAG, a metabolite of dihydrotestosterone, and estradiol were associated with an increased risk of having LUTS.

Serum levels of 3α-androstanediol glucuronide in young women with polycystic ovary syndrome, idiopathic hirsutism and in normal subjects

OBJECTIVE

The study objective was to assess the role of 3alpha-androstanediol glucuronide (3alpha-diolG) as the marker of peripheral androgen action in the young women with hirsutism diagnosed as polycystic ovary syndrome (PCOS), in patients with idiopathic hirsutism (IH) and in normal non-hirsute women.

STUDY DESIGN

Fifty-nine young women with mean age 21.90+/-3.52 years suffered from hirsutism were included in the study. Among these 59 hirsute women 31 women with mean age 21.60+/-3.56 years were diagnosed as PCOS and 28 women with mean age 22.20+/-3.59 years were classified as idiopathic hirsutism patients. Twenty-seven normal women, age-matched (mean age 22.60+/-2.90 years), without signs of hirsutism and with normal menstrual cycle served as control for this study. Serum was collected from women with hirsutism (due to PCOS or idiopathic hirsutism) and from non-hirsute women. Serum levels of 3alpha-androstanediol glucuronide (3alpha-diolG), main androgens such as: testosterone, free testosterone, dehydroepiandrosterone (DHEAS) and also others hormones such as follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2) and sex hormone-binding globuline (SHBG) were measured using radioimmunoassay (RIA) method in the study and control group. Hirutism was assessed using modified Ferriman-Gallwey method. Serum 3alpha-diolG levels in PCOS women were significantly higher than in controls.

RESULTS

There were no significant differences between serum 3alpha-diolG levels in PCOS group and IH group. Similarly, there were significant differences between serum 3alpha-diolG levels in IH group and control subjects.

CONCLUSION

We conclude that 3alpha-diolG is not useful as the marker for peripheral androgen metabolism and for differentiation between idiopathic hirsutism and PCO-related hirsutism.

2β-(N-Substituted Piperazino)-5α-Androstane-3α,17β-Diols: Parallel Solid-Phase Synthesis and Antiproliferative Activity on Human Leukemia HL-60 Cells

Leukemia is the most common cancer affecting children. A steroid possessing a methylpiperazine nucleus was recently reported to inhibit the proliferation of HL-60 leukemia cells. To speed up the development of this promising potential new drug, we generated libraries of analogues using parallel solid-phase organic synthesis (SPOS). A 6-step sequence of reactions, starting from dihydrotestosterone, afforded a steroidal 2,3alpha-epoxide, which was selectively opened to give, after N-Fmoc protection, a diol with suitable stereochemistry. The difference of reactivity between 3alpha-OH and 17beta-OH was then used to allow the regioselective coupling of 17beta-OH to chloro-activated butyldiethylsilane polystyrene. We next generated three libraries of 2beta-piperazinyl-5alpha-androstane-3alpha,17beta-diol N-derivatives with 1, 2, or 3 levels of molecular diversity in acceptable yields and purities for our biological screening assay. Several members of these libraries were more potent than the lead compound, especially five members with a proline as the first level of diversity and a cyclohexylcarbonyl, methylbutyryl, cyclohexylacetyl, cyclopentylpropionyl, or hexanoyl as the second level of diversity. They efficiently inhibited HL-60 cell proliferation with IC50 values of 0.58, 0.66, 1.78, 1.98, and 2.57 microM, respectively. The present work demonstrates the potential of our SPOS approach for the optimization of a new class of cytotoxic agents.

Consumption of Lactobacillus acidophilus and Bifidobacterium longum does not alter phytoestrogen metabolism and plasma hormones in men: a pilot study

OBJECTIVE

The aim of this study was to determine whether equol excretion status and plasma hormone and leptin concentrations can be influenced by consumption of a probiotic supplement. A secondary focus was to investigate whether male equol excretors have a hormone profile consistent with reduced prostate cancer risk.

DESIGN

The design was a randomized, single-blinded, placebo-controlled, parallel-arm trial.

SUBJECTS

Thirty-one (31) of the initially enrolled 39 subjects, 18 to 37 years old, completed all study requirements.

INTERVENTION

Subjects consumed either probiotic capsules (containing Lactobacillus acidophilus and Bifidobacterium longum) or placebo capsules for 2 months. Fasting plasma concentrations of testosterone (T), dihydrotestosterone (DHT), androstanediol glucuronide (AAG), androstenedione (A), dehydroepiandrosterone sulfate (DHEAS), sex hormone-binding globulin (SHBG), and leptin were measured on days 1 and 57. Urinary excretion of genistein, glycitein, daidzein, O-desmethylangolensin (O-Dma), and equol was measured on days 4 and 61 following a 4-day soy challenge.

RESULTS

Probiotic consumption did not significantly alter equol excretor status, plasma hormone, or leptin concentrations in these subjects. At baseline, there were no differences in plasma hormone concentrations between equol excretors and nonexcretors; however, the low number of equol excretors included in this study limits the strength of this finding.

CONCLUSIONS

The 2-month intervention with probiotic capsules did not significantly alter equol excretion, plasma hormone, or leptin concentrations in these subjects. A secondary finding was that male equol excretors in this study did not exhibit a hormone profile consistent with reduced prostate cancer risk, although this result should be interpreted with caution.

Polymorphisms in the CYP19 gene may affect the positive correlations between serum and urine phytoestrogen metabolites and plasma androgen concentrations in men

Phytoestrogens have been hypothesized to protect against prostate cancer via modulation of circulating androgen concentrations. We conducted a cross-sectional study of 267 men in the Norfolk arm of the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort with 2 aims: first, to investigate the association between phytoestrogen exposure (measured from diet, urine, and serum) and plasma concentrations of sex hormone-binding globulin (SHBG), androstanediol glucuronide, testosterone and Free Androgen Index (FAI); and second, whether the association may be modified by polymorphisms in CYP19 and SHBG genes. Dietary daidzein and genistein intakes were obtained from food diaries and computed using an in-house food composition database. Urinary and serum concentrations of 3 isoflavones (daidzein, genistein, glycitein), 2 daidzein metabolites O-desmethylangolensin (O-DMA) and 2 lignan metabolites (enterodiol and enterolactone) were measured using mass spectrometry. There was no association between dietary, urinary, and serum phytoestrogens and plasma SHBG concentrations. Enterolactone was positively associated with plasma androstanediol glucuronide concentrations (urinary enterolactone: r = 0.127, P = 0.043; serum enterolactone: r = 0.172, P = 0.006) and FAI (urinary enterolactone: r = 0.115, P = 0.067; serum enterolactone: r = 0.158, P = 0.011). Both urinary and serum equol were associated with plasma testosterone (urinary equol: r = 0.332, P = 0.013; serum equol: r = 0.318, P = 0.018) and FAI (urinary equol: r = 0.297, P = 0.027; serum equol: r = 0.380, P = 0.004) among men with the TT genotype but not the CC or CT genotypes (r = -0.029 to -0.134, P = 0.091-0.717) for the CYP19 3'untranslated region (UTR) T-C polymorphism. Urinary and serum enterolactone showed similar genotype-dependent associations with testosterone but not with FAI. In this first study on phytoestrogen-gene associations in men, we conclude that enterolactone and equol are positively associated with plasma androgen concentrations, and interactions with CYP19 gene may be involved.