Aquatic Pollution and Risks to Biodiversity: The Example of Cocaine Effects on the Ovaries of Anguilla anguilla

Abstract

Pollution is one of the main causes of the loss of biodiversity, currently one of the most important environmental problems. Important sources of aquatic pollution are illicit drugs, whose presence in waters is closely related to human consumption; their psychoactive properties and biological activity suggest potential adverse effects on non-target organisms, such as aquatic biota. In this study, we evaluated the effect of an environmentally relevant concentration of cocaine (20 ng L−1), an illicit drug widely found in surface waters, on the ovaries of Anguilla anguilla, a species critically endangered and able to accumulate cocaine in its tissues following chronic exposure. The following parameters were evaluated: (1) the morphology of the ovaries; (2) the presence and distribution of enzymes involved in oogenesis; (3) serum cortisol, FSH, and LH levels. The eels exposed to cocaine showed a smaller follicular area and a higher percentage of connective tissue than controls (p < 0.05), as well as many previtellogenic oocytes compared with controls having numerous fully vitellogenic and early vitellogenic oocytes. In addition, the presence and location of 3β-hydroxysteroid dehydrogenase, 17β-hydroxysteroid dehydrogenase, and P450 aromatase differed in the two groups. Finally, cocaine exposure decreased FSH and LH levels, while it increased cortisol levels. These findings show that even a low environmental concentration of cocaine affects the ovarian morphology and activity of A. anguilla, suggesting a potential impact on reproduction in this species.

Illicit Drugs in Surface Waters: How to Get Fish off the Addictive Hook

“…COC and its metabolites have also been found to accumulate in fish, with studies demonstrating that European eels Anguilla anguilla L. can accumulate COC, leading to alterations in various organs and systems [19,85,[91][92][93][94]. Capaldo et al [85] documented the accumulation of COC in European eels after exposure to environmentally relevant COC concentrations of 20 ng/L for one month, finding the highest concentrations in the brain (30.5 ± 0.4 pg/g), muscle (20.2 ± 0.5 pg/g), liver (13.4 ± 2.2 pg/g), and kidney Pharmaceuticals 2024, 17, 537 9 of 25 (11.4 ± 1.2 pg/g).…”

Cocaine Effects on Reproductive Behavior and Fertility: An Overview

“…These findings are consistent with those of another study conducted both in vitro and in vivo in female rats [ 21 ], which confirmed that cocaine affects LH or FSH release, acting not directly on the pituitary gland, as gonadotropin secretion increases indirectly by increasing hypothalamic GnRH release. In contrast to studies in humans and mammals, chronic exposure to environmental cocaine concentrations decreased the serum levels of FSH and LH in teleost Anguilla anguilla [ 22 ], probably via the cocaine-stimulated increase in dopamine levels, that in teleost fish inhibits the synthesis and release of gonadotropins [ 23 ].…”

“…Compared to mammals, there are fewer studies concerning the effects of cocaine on the fertility of no mammalian species. Studies performed in European eels [ 22 ] showed that chronic exposure to an environmental cocaine concentration had a profound influence on the ovary, in which a smaller follicular area, a higher amount of connective tissue, and a greater number of previtellogenic oocytes were observed. Also, the presence and the localization of some key enzymes involved in eel oogenesis, 3β-hydroxysteroid dehydrogenase, 17 β-hydroxysteroid dehydrogenase, and P450 aromatase, were affected by cocaine, suggesting a lower maturation rate in ovarian follicles exposed to cocaine, and a potential risk to reproductive health of this species.…”

Environmental Pollution in Belgium and Implications for Aquatic Health

“…Besides industrial aquatic pollutants, illegal drugs are a relatively new category of contaminants identi ed and frequently found in aquatic environments globally. Their presence and metabolites are directly related to humans' consistent and growing use (Fontes et al 2022). Furthermore, the psychoactive properties of illegal drugs and their biological activity suggest their potential adverse effects on non-target aquatic organisms (Fontes et al 2022).…”

“…Their presence and metabolites are directly related to humans' consistent and growing use (Fontes et al 2022). Furthermore, the psychoactive properties of illegal drugs and their biological activity suggest their potential adverse effects on non-target aquatic organisms (Fontes et al 2022).…”