Testosterone regulates 3T3-L1 pre-adipocyte differentiation and epididymal fat accumulation in mice through modulating macrophage polarization

Low testosterone levels are strongly related to obesity in males. The balance between the classically M1 and alternatively M2 polarized macrophages also plays a critical role in obesity. It is not clear whether testosterone regulates macrophage polarization and then affects adipocyte differentiation. In this report, we demonstrate that testosterone strengthens interleukin (IL) -4-induced M2 polarization and inhibits lipopolysaccharide (LPS)-induced M1 polarization, but has no direct effect on adipocyte differentiation. Cellular signaling studies indicate that testosterone regulates macrophage polarization through the inhibitory regulative G-protein (Gαi) mainly, rather than via androgen receptors, and phosphorylation of Akt. Moreover, testosterone inhibits pre-adipocyte differentiation induced by M1 macrophage medium. Lowering of serum testosterone in mice by injecting a luteinizing hormone receptor (LHR) peptide increases epididymal white adipose tissue. Testosterone supplementation reverses this effect. Therefore, our findings indicate that testosterone inhibits pre-adipocyte differentiation by switching macrophages to M2 polarization through the Gαi and Akt signaling pathways.

Bioconversion of 6-(N-methyl-N-phenyl)aminomethyl androstane steroids by Nocardioides simplex

The newly synthesized (α/β)-diastereomers of 6-(N-methyl-N-phenyl)aminomethylandrost-4-ene-3,17-dione (5) and 6-(N-methyl-N-phenyl)aminomethylandrost-4-en-17β-ol-3-one (6) were firstly investigated as substrates for the whole cells of Nocardioides simplex VKM Ac-2033D in comparison with their unsubstituted analogs, - androst-4-ene-3,17-dione (1) and androst-4-en-17β-ol-3-one (2). 1(2)-Dehydroderivatives were identified as the major bioconversion products from all the substrates tested. When using the mixtures of (α/β)-stereoisomers of 5 and 6 as the substrates, only β-stereoisomers of the corresponding 1,4-diene-steroids were formed. Along with 1(2)-dehydrogenation, N. simplex VKM Ac-2033D promoted oxidation of the hydroxyl group at C-17 position of 6: both 6(α) and 6(β) were transformed to the corresponding 17-keto derivatives. No steroid core destruction was observed during the conversion of the 6-substituted androstanes 5 and 6, while it was significant when 1 or 2 was used as the substrate. The results suggested high potentials of N. simplex VKM Ac-2033D for the generation of novel 1(2)-dehydroanalogs.

Amelioration of testosterone induced benign prostatic hyperplasia by Prunus species

ETHNOPHARMACOLOGICAL RELEVANCE

Benign prostatic hyperplasia (BPH) is a common urological disorder of men. The ethnomedicinal use of an African plant Prunus africana (Hook.f.) Kalkman (Pygeum) in treating men's problems made it a popular remedy all over the globe for the treatment of BPH and related disorders. However, rampant collections made from the wild in Africa have pushed the plant to Appendix II of CITES demanding conservation of the species.

AIM OF THE STUDY

In the present study, the aim was to unearth the protective effect of bark of different species of Prunus against BPH. The five selected Indian plants of family Rosaceae viz. Prunus amygdalus Stokes, Prunus armeniaca L., Prunus cerasoides Buch.-Ham. ex D. Don, Prunus domestica L. and Prunus persica (L.) Batsch were evaluated against P. africana (Hook.f.) Kalkman for a suitable comparison of efficacy as antiBPH agents.

MATERIALS AND METHODS

The antiBPH activity was evaluated in testosterone (2mg/kg/day, s.c, 21 days) induced BPH in Wistar rats. The parameters studied were body weights; histopathological examination, immunohistochemistry (PCNA) and biochemical estimations of the prostate; supported by prostatic index, testicular index, creatinine, testosterone levels; antioxidant and anti-inflammatory evaluation. The study also included chemical profiling using three markers (β-sitosterol, docosyl ferulate and ursolic acid) and estimation of β-sitosterol content through GC.

RESULTS

The Prunus species showed the presence of all the three markers in their TLC fingerprint profile and maximum amount of β-sitosterol by GC was observed in P. domestica. Interestingly, all the species exhibited significant amelioration in testosterone induced parameters with P. domestica showing the most encouraging effect as indicated from histopathological examination, immunohistochemistry and biochemical studies. The Prunus species further showed remarkable anti-inflammatory and antioxidant activity signifying their role in interfering with various possible factors involved in BPH.

CONCLUSIONS

These findings are suggestive of a meaningful inhibitory effect of testosterone induced BPH by the bark of different species of Prunus in the order of P. domestica, P. persica, P. amygdalus, P. cerasoides and P. armeniaca with an efficacy of P. domestica comparable to P. africana and can be used as the potential backup of Pygeum for the management of BPH.

New insights into the androgen biotransformation in prostate cancer: A regulatory network among androgen, androgen receptors and UGTs

Androgen, as one kind of steroid hormones, is pivotal in the hormone-sensitive cancer, such as prostate cancer (PCa). The synthesis, elimination, and bioavailability of androgen in prostate cells have been proved to be a main cause of the carcinogenesis, maintenance and deterioration of PCa. This review illustrates the outlines of androgen biotransformation, and further discusses the different enzymes, especially UDP-glucuronyltransferases (UGTs) embedded in both benign and malignant prostate cells, which catalyze the reactions. Although many inhibitors of the enzymes responsible for the synthesis of androgens have been developed into drugs to fight against PCa, the elimination procedures metabolized by the UGTs are less emphasized. Thus the regulatory network among androgen, androgen receptors (AR) and UGTs is carefully reviewed in this article, indicating the determinant effects of UGTs on prostatic androgens and the regulation of AR. Finally, the hypothesis is also put forward that the regulators of UGTs may be developed to accelerate the androgen elimination and benefit PCa therapy.

Meclizine, a pregnane X receptor agonist, is a direct inhibitor and mechanism-based inactivator of human cytochrome P450 3A

Meclizine is an agonist of human pregnane X receptor (PXR). It increases CYP3A4 mRNA expression, but decreases CYP3A-catalyzed testosterone 6β-hydroxylation in primary cultures of human hepatocytes, as assessed at 24h after the last dose of meclizine. Therefore, the hypothesis to be tested is that meclizine inactivates human CYP3A enzymes. Our findings indicated that meclizine directly inhibited testosterone 6β-hydroxylation catalyzed by human liver microsomes, recombinant CYP3A4, and recombinant CYP3A5. The inhibition of human liver microsomal testosterone 6β-hydroxylation by meclizine occurred by a mixed mode and with an apparent Ki of 31±6μM. Preincubation of meclizine with human liver microsomes and NADPH resulted in a time- and concentration-dependent decrease in testosterone 6β-hydroxylation. The extent of inactivation required the presence of NADPH, was unaffected by nucleophilic trapping agents or reactive oxygen species scavengers, attenuated by a CYP3A substrate, and not reversed by dialysis. Meclizine selectively inactivated CYP3A4, but not CYP3A5. In contrast to meclizine, which has a di-substituted piperazine ring, norchlorcyclizine, which is a N-debenzylated meclizine metabolite with a mono-substituted piperazine ring, did not inactivate but directly inhibited hepatic microsomal CYP3A activity. In conclusion, meclizine inhibited human CYP3A enzymes by both direct inhibition and mechanism-based inactivation. In contrast, norchlorcyclizine is a direct inhibitor but not a mechanism-based inactivator. Furthermore, a PXR agonist may also be an inhibitor of a PXR-regulated enzyme, thereby giving rise to opposing effects on the functional activity of the enzyme and indicating the importance of measuring the catalytic activity of nuclear receptor-regulated enzymes.

Effects of crude kerosene on testosterone levels, aggression and toxicity in rat

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Kerosene supplementation increases serum testosterone levels in rat.

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Increased testosterone levels were associated with increased aggression.

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Kerosene supplementation had varied effects on blood parameters, notably, increased WBC counts.

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Supplementation resulted in active/chronic gastritis in the stomach of our rat model.

The use of crude kerosene as a dietary supplement in boarding schools has been a common practice in east Africa and other countries for many years, with the belief of it reducing the sex drive (libido) at the pubertal stage. There is however no scientific basis for this belief. The present study aimed at using a rat animal model to investigate the effects of crude kerosene on serum testosterone levels, aggression and its possible toxic effects. Fifteen male albino rats of approximately similar age and average weights were put into three groups of five animals each; the control group (placebo), low kerosene dose (10 μl/day) group and high kerosene dose (300 μl/day) group. ELISA was used to determine the serum testosterone levels. During treatment, changes in aggression were observed and noted. Liver toxicity was determined using enzyme assays, total protein and albumin while renal toxicity was monitored using serum creatinine levels. A full hemogram was conducted to determine hematological effects. Various tissue biopsies were obtained and examined using histopathological techniques for evidence of toxicity. Contrary to the common belief, our findings showed an overall increase of serum testosterone levels of up to 66% in the low dose and 75% in the high dose groups, with an increasing trend by the end of the study. The high dose group showed significantly increased levels of white blood cells (WBC) (p = 0.036), red blood cells (RBC) (p = 0.025), hematocrit (HCT) (p = 0.03), red cell distribution width (p = 0.028) and platelets (p = 0.017). The histological results of the stomach indicated chronic gastritis.