Recent Progress in Discovering the Role of Carotenoids and Their Metabolites in Prostatic Physiology and Pathology with a Focus on Prostate Cancer—A Review—Part I: Molecular Mechanisms of Carotenoid Action

Abstract

Among the vast variety of plant-derived phytochemicals, the group of carotenoids has continuously been investigated in order to optimize their potential application in the area of dietary intervention and medicine. One organ which has been especially targeted in many of these studies and clinical trials is the human prostate. Without doubt, carotenoids (and their endogenous derivatives—retinoids and other apo-carotenoids) are involved in intra- and intercellular signaling, cell growth and differentiation of prostate tissue. Due to the accumulation of new data on the role of different carotenoids such as lycopene (LC) and β-carotene (BC) in prostatic physiology and pathology, the present review aims to cover the past ten years of research in this area. Data from experimental studies are presented in the first part of the review, while epidemiological studies are disclosed and discussed in the second part. The objective of this compilation is to emphasize the present state of knowledge regarding the most potent molecular targets of carotenoids and their main metabolites, as well as to propose promising carotenoid agents for the prevention and treatment of prostatic diseases.

What Is the Current Direction of the Research on Carotenoids and Human Health? An Overview of Registered Clinical Trials

“…Overall, they aim to increase the knowledge, research, and competitiveness of the European agro-food industry [ 12 , 13 , 14 , 15 , 16 ]. An additional important goal the EUROCAROTEN network is trying to promote is the enhancement of knowledge on the health-related effects of these compounds by collecting data and coordinating studies that will reveal the mechanisms of health impacts [ 17 ], provide evidence on health biomarkers [ 18 ], and indicate health-promoting nutritional recommendations [ 11 ].…”

Are We Sentenced to Pharmacotherapy? Promising Role of Lycopene and Vitamin A in Benign Urologic Conditions

“…Duli ńska-Litewska et al focused on molecular aspects of carotenoid action in their extensive review, studying the enzymes responsible for carotenoid metabolism pathways. In humans, there are two enzymes-BCO1 and β-carotene 9',10' dioxygenase-2 (BCO2)involved in converting carotenoids into bioactive compounds [7]. Genetically modified mice lacking BCO1, which are unable to synthesize retinol, present with multipoint disruptions in prostatic androgen receptor signaling and many other disorders, e.g., changes in steroid metabolism [8].…”

Synthetic Retinoids as Potential Therapeutics in Prostate Cancer—An Update of the Last Decade of Research: A Review

“…The scope of the importance and potential use of retinoids that can be identified in human serum under physiological conditions in PC has been thoroughly discussed in other reports [ 18 , 19 ]. However, recent research also covered new synthetic retinoids.…”

“…Interestingly, if there is no ligand, then the α-helix H11 becomes the β-strand S3, which binds the corepressors. RXR forms heterodimers with other receptors (including RAR), however, ligand-bound RXR could activate the heterodimer only if the RXR partner receptor is weakly associated with its co-repressors (i.e., peroxisome proliferator-activated receptors (PPAR)), while for most of the receptors, such a situation does not occur (e.g., RAR, vitamin D receptor (VDR), or thyroid receptor (TR); these are called non-permissive heterodimers of RXR) [ 18 ].…”

“…The effects are usually tissue-specific and also change in diseased tissues, such as cancer. Briefly, in PC, ATRA was shown to particularly influence apoptosis, cell cycle control, and synthesis of inflammatory factors [ 18 ]. It seems that among the universal effects (i.e., observed in multiple tissues) of activation of retinoid receptors is up-regulation of SOD, which was reported in some studies [ 36 , 37 ].…”