Endocannabinoids and Human Sperm Cells

Annarina Ambrosini,Giovanna Zolese,Rosamaria Fiorini

doi:10.3390/ph3103200

Abstract

N-acylethanolamides (NAEs) are naturally occurring signaling lipids consisting of amides and esters of long-chain polyunsaturated fatty acids. Usually they are present in a very small amounts in many mammalian tissues and cells, including human reproductive tracts and fluids. Recently, the presence of N-arachidonoylethanolamide (anandamide, AEA), the most characterised member of endocannabinoids, and its congeners palmitoylethanolamide (PEA) and oleylethanolamide (OEA) in seminal plasma, oviductal fluid, and follicular fluids was demonstrated. AEA has been shown to bind not only type-1 (CB1) and type-2 (CB2) cannabinoid receptors, but also type-1 vanilloid receptor (TRPV1), while PEA and OEA are inactive with respect to classical cannabinoid CB1 and CB2 but activate TRPV1 or peroxisome proliferator activate receptors (PPARs). This review concerns the most recent experimental data on PEA and OEA, endocannabinoid-like molecules which appear to exert their action exclusively on sperm cells with altered features, such as membrane characteristics and kinematic parameters. Their beneficial effects on these cells could suggest a possible pharmacological use of PEA and OEA on patients affected by some forms of idiopathic infertility.

Highlights

Cannabinoids are a large number of different active compounds found in the marijuana plant (Cannabis sativa)
A family of unsaturated fatty acid derivatives, biologically synthesised by many tissues, has been termed “endocannabinoids” (EC), because they exert their effects acting as endogenous ligands for cannabinoid receptors
We suggest that patients with idiopathic infertility, who suffer oxidative stress by increased levels of ROS [79] and need assisted reproduction procedures, could benefit from OEA in vitro supplementation during the preparation of their sperm cells for fertilization

Summary

Introduction

Cannabinoids are a large number of different active compounds found in the marijuana plant (Cannabis sativa). PEA and OEA present some endocannabinoid-like effects, likely by the so-called “entourage effect” [14]. It is used to indicate the effects of PEA and OEA to potentiate the AEA actions at TRPV1 receptors [16]. Can be performed by different mechanisms, such as the modulation of AEA target receptor [17], or the inhibition of endocannabinoids catabolism, increasing their levels to potentiate their biological actions [16,18]. Increasing evidence indicates that OEA and PEA can themseles activate other receptors that are potential targets of endocannabinoids, such as TRPV1 Vanilloid type (1) [14,19] or PPARs (Peroxisome Proliferator-Activated Receptors) [14]

Endocannabinoid System

Endocannabinoids and Sperm Cells

Conclusions