Atorvastatin attenuates testosterone-induced benign prostatic hyperplasia in rats: role of peroxisome proliferator-activated receptor-γ and cyclo-oxygenase-2

The role of autophagy in prostate cancer and prostatic diseases: a new therapeutic strategy

BACKGROUND

Autophagy is a well-conserved catabolic process that plays a key role in cell homeostasis. In the prostate, defective autophagy has been implicated in the genesis and progression of several pathological conditions.

AIM

The present review explored the autophagy pathway in prostate-related dysfunctions, focusing on prostate cancer (PCa), benign prostatic hyperplasia (BPH) and prostatitis.

RESULTS

Impaired autophagy activity has been shown in animal models of BPH and prostatitis. Moreover, autophagy activation by specific and non-specific drugs improved both conditions in pre-clinical studies. Conversely, the efficacy of autophagy inducers in PCa remains controversial, depending on intrinsic PCa characteristics and stage of progression. Intriguingly, autophagy inhibitors have shown beneficial effects in PCa suppression or even to overcome chemotherapy resistance. However, there are still open questions regarding the upstream mechanisms by which autophagy is deregulated in the prostate and the exact role of autophagy in PCa. The lack of specificity and increased toxicity associated with the currently autophagy inhibitors limits its use clinically, reflecting in reduced number of clinical data.

CONCLUSION

New therapeutic strategies to treat prostatic diseases involving new autophagy modulators, combination therapy and new drug formulations should be explored. Understanding the autophagy signaling in each prostatic disease is crucial to determine the best pharmacological approach.

Peroxisome Proliferator-Activated Receptors (PPARs) and Oxidative Stress in Physiological Conditions and in Cancer

Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear hormone receptor superfamily. Originally described as “orphan nuclear receptors”, they can bind both natural and synthetic ligands acting as agonists or antagonists. In humans three subtypes, PPARα, β/δ, γ, are encoded by different genes, show tissue-specific expression patterns, and contribute to the regulation of lipid and carbohydrate metabolisms, of different cell functions, including proliferation, death, differentiation, and of processes, as inflammation, angiogenesis, immune response. The PPAR ability in increasing the expression of various antioxidant genes and decreasing the synthesis of pro-inflammatory mediators, makes them be considered among the most important regulators of the cellular response to oxidative stress conditions. Based on the multiplicity of physiological effects, PPAR involvement in cancer development and progression has attracted great scientific interest with the aim to describe changes occurring in their expression in cancer cells, and to investigate the correlation with some characteristics of cancer phenotype, including increased proliferation, decreased susceptibility to apoptosis, malignancy degree and onset of resistance to anticancer drugs. This review focuses on mechanisms underlying the antioxidant and anti-inflammatory properties of PPARs in physiological conditions, and on the reported beneficial effects of PPAR activation in cancer.

Effect of atorvastatin on testosterone levels

BACKGROUND

Statins are one of the most prescribed classes of drugs worldwide. Atorvastatin, the most prescribed statin, is currently used to treat conditions such as hypercholesterolaemia and dyslipidaemia. By reducing the level of cholesterol, which is the precursor of the steroidogenesis pathway, atorvastatin may cause a reduction in levels of testosterone and other androgens. Testosterone and other androgens play important roles in biological functions. A potential reduction in androgen levels, caused by atorvastatin might cause negative effects in most settings. In contrast, in the setting of polycystic ovary syndrome (PCOS), reducing excessive levels of androgens with atorvastatin could be beneficial.

OBJECTIVES

Primary objective To quantify the magnitude of the effect of atorvastatin on total testosterone in both males and females, compared to placebo or no treatment. Secondary objectives To quantify the magnitude of the effects of atorvastatin on free testosterone, sex hormone binding globin (SHBG), androstenedione, dehydroepiandrosterone sulphate (DHEAS) concentrations, free androgen index (FAI), and withdrawal due to adverse effects (WDAEs) in both males and females, compared to placebo or no treatment.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials (RCTs) up to 9 November 2020: the Cochrane Hypertension Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; Embase; ;two international trials registries, and the websites of the US Food and Drug Administration, the European Patent Office and the Pfizer pharmaceutical corporation. These searches had no language restrictions. We also contacted authors of relevant articles regarding further published and unpublished work.

SELECTION CRITERIA

RCTs of daily atorvastatin for at least three weeks, compared with placebo or no treatment, and assessing change in testosterone levels in males or females.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the citations, extracted the data and assessed the risk of bias of the included studies. We used the mean difference (MD) with associated 95% confidence intervals (CI) to report the effect size of continuous outcomes,and the risk ratio (RR) to report effect sizes of the sole dichotomous outcome (WDAEs). We used a fixed-effect meta-analytic model to combine effect estimates across studies, and risk ratio to report effect size of the dichotomous outcomes. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included six RCTs involving 265 participants who completed the study and their data was reported. Participants in two of the studies were male with normal lipid profile or mild dyslipidaemia (N = 140); the mean age of participants was 68 years. Participants in four of the studies were female with PCOS (N = 125); the mean age of participants was 32 years. We found no significant difference in testosterone levels in males between atorvastatin and placebo, MD -0.20 nmol/L (95% CI -0.77 to 0.37). In females, atorvastatin may reduce total testosterone by -0.27 nmol/L (95% CI -0.50 to -0.04), FAI by -2.59 nmol/L (95% CI -3.62 to -1.57), androstenedione by -1.37 nmol/L (95% CI -2.26 to -0.49), and DHEAS by -0.63 μmol/l (95% CI -1.12 to -0.15). Furthermore, compared to placebo, atorvastatin increased SHBG concentrations in females by 3.11 nmol/L (95% CI 0.23 to 5.99). We identified no studies in healthy females (i.e. females with normal testosterone levels) or children (under age 18). Importantly, no study reported on free testosterone levels.

AUTHORS' CONCLUSIONS

We found no significant difference between atorvastatin and placebo on the levels of total testosterone in males. In females with PCOS, atorvastatin lowered the total testosterone, FAI, androstenedione, and DHEAS. The certainty of evidence ranged from low to very low for both comparisons. More RCTs studying the effect of atorvastatin on testosterone are needed.

Pharmacological Effects and Potential Clinical Usefulness of Polyphenols in Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH) is arguably the most common benign disease among men. This disease is often associated with lower urinary tract symptoms (LUTS) in men and significantly decreases the quality of life. Polyphenol consumption reportedly plays an important role in the prevention of many diseases, including BPH. In recent years, in addition to disease prevention, many studies have reported the efficacy and safety of polyphenol treatment against various pathological conditions in vivo and in vitro. Furthermore, numerous studies have also revealed the molecular mechanisms of the antioxidant and anti-inflammatory effects of polyphenols. We believe that an improved understanding of the detailed pharmacological roles of polyphenol-induced activities at a molecular level is important for the prevention and treatment of BPH. Polyphenols are composed of many members, and their biological roles differ. In this review, we first provide information regarding the pathological roles of oxidative stress and inflammation in BPH. Next, the antioxidant and anti-inflammatory effects of polyphenols, including those of flavonoids and non-flavonoids, are discussed. Finally, we talk about the results and limitations of previous clinical trials that have used polyphenols in BPH, with particular focus on their molecular mechanisms of action.

Chronic inflammation promotes proliferation in the prostatic stroma in rats with experimental autoimmune prostatitis: study for a novel method of inducing benign prostatic hyperplasia in a rat model

Objective

Inflammation plays an important role in the development of benign prostatic hyperplasia (BPH). The aim of the present study was to reference the study of the pathological changes in the prostate gland of rats with experimental autoimmune prostatitis (EAP), for the development of experimental models of BPH.

Methods

Experimental autoimmune prostatitis was induced in rats by the intradermal injection of rat prostate antigen with immunoadjuvants. In case of the positive BPH group, BPH was induced by the subcutaneous injection of testosterone propionate. At the end of the 45-day model period, prostate weights were measured, and the histopathological analysis of the prostate glands was performed. The levels of cytokines, TGF-β1/RhoA/ROCK signals, and the oxidative stress status were also examined.

Results

Rats from the EAP group had a higher histological score than those from the control group. Compared to the samples from rats in the hormone-induced group, those from the EAP group showed a more pronounced increase in the size of the stromal compartment; this was characterized by the formation of reactive stroma and the deposition of a greater amount of extracellular matrix (ECM). Significant increases in the numbers of CD3-positive cells and CD68-positive cells, as well as a significant upregulation in the cytokine levels, and an increase in the TGF-β1 levels and activation of RhoA/ROCK signaling, were observed in the samples from rats in the EAP group.

Conclusion

Chronic inflammation can induce BPH in rats via EAP model method. When performing drug experiments on the stroma compartments of BPH, the use of the EAP model is a recommendation of the authors based on this study.

Statin use and longitudinal changes in prostate volume; results from the REduction by DUtasteride of prostate Cancer Events (REDUCE) trial

OBJECTIVE

To test the association between statin use and prostate volume (PV) change over time using data from the REduction by DUtasteride of prostate Cancer Events (REDUCE) trial, a 4-year randomised controlled trial testing dutasteride for prostate cancer chemoprevention.

SUBJECTS/PATIENTS AND METHODS

We identified men with a baseline negative prostate biopsy from REDUCE who did not undergo prostate surgery or develop prostate cancer over the trial period. Men reported statin use at baseline. PV was determined from transrectal ultrasonography performed to guide prostate biopsy at baseline, and 2- and 4-years after randomisation. Multivariable generalised estimating equations tested differences in PV change over time by statin use, overall and stratified by treatment arm. We tested for interactions between statins and time in association with PV using the Wald test.

RESULTS

Of 4106 men, 17% used statins at baseline. Baseline PV did not differ by statin use. Relative to non-users, statin users had decreasing PVs over the trial period (P = 0.027). Similar patterns were seen in the dutasteride and placebo arms, although neither reached statistical significance. The mean estimated PV was modestly but significantly lower in statin users relative to non-users in the dutasteride arm at 2-years (4.5%, P = 0.032) and 4-years (4.0%, P = 0.033), with similar (3-3.3%) but non-significant effects in the placebo arm.

CONCLUSION

If confirmed, our present findings support a role for statins in modestly attenuating PV growth, with a magnitude of effect in line with previously reported prostate-specific antigen-lowering effects of statins (~4%). Future studies are needed to assess whether this putative role for statins in PV growth could impact lower urinary tract symptom development or progression.