論文の公開元へBioconcentration and Behavioral Interference Effect of Diazepam on Adult Japanese Medaka (Oryzias latipes)
概要
九州大学学術情報リポジトリ
Kyushu University Institutional Repository
Bioconcentration and Behavioral Interference
Effect of Diazepam on Adult Japanese Medaka
(Oryzias latipes)
WANG, Sijing
Institute of Environmental Health and Ecological Security, School of the Environment and
Safety Engineering, Jiangsu University
ZHUO, Mengcheng
Institute of Environmental Health and Ecological Security, School of the Environment and
Safety Engineering, Jiangsu University
CHEN, Kun
Institute of Environmental Health and Ecological Security, School of the Environment and
Safety Engineering, Jiangsu University
SHI, Yanhong
Institute of Environmental Health and Ecological Security, School of the Environment and
Safety Engineering, Jiangsu University
他
https://doi.org/10.5109/6796256
出版情報：九州大学大学院農学研究院紀要. 68 (2), pp.135-141, 2023-09. 九州大学大学院農学研究院
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権利関係：
J. Fac. Agr., Kyushu Univ., 68 (2), 135–141 (2023)
Bioconcentration and Behavioral Interference Effect of Diazepam on Adult Japanese
Medaka (Oryzias latipes)
Sijing WANG1, Mengcheng ZHUO1, Kun CHEN1, Yanhong SHI1, Xuchun QIU1,2*,
Yuki TAKAI3, Yohei SHIMASAKI3 and Yuji OSHIMA3,4
Laboratory of Marine Environmental Science, Division of Animal & Marine Bioresource Science,
Department of Bioresource Sciences, Faculty of Agriculture,
Kyushu University, Fukuoka 819–0395, Japan
(Received May 9, 2023 and accepted May 18, 2023)
As one of the most commonly detected polluting drugs in the environment, diazepam (DZP) has been
widely detected in rivers, soil, and organisms. To better understand the bioconcentration of DZP in fish and
its impact on fish behaviors, we exposed both female and male medaka to a DZP (120 µg/L) for 7 days, and
then transformed them to clean dechlorinated water for 3 days of depuration. Regardless of gender, DZP
can rapidly accumulate in the brain and liver tissue and reach a stable phase within 24 hours of exposure.
When the fish was transferred to purified water for purification, the concentration of DZP in the tissue was
rapidly discharged, decreasing by one order of magnitude within 24 hours. The bioconcentration factors
(BCF) of DZP in the brain and liver of males were calculated to be 10.47 and 19.58 L/kg, respectively, and
those in females were calculated to be 6.12 and 6.03 L/kg. Compared with females, DZP accumulated more
in the tissue of male fish, which exhibited a higher mortality rate during exposure. In addition, DZP can be
significantly enriched in the ovaries of females, with a BCF of 10.54 L/kg. Furthermore, DZP exposure could
significantly interfere with the interactive behaviors between males and females during the courtship, as
indicated by the reduced duration of body contact and increased inter–individual distance. These findings
highlight the need to study the transgenerational toxicity of DZP in Japanese medaka to assess its potential
risk to fish populations accurately.
Key words: Behavior, Bioconcentration coefficient (BCF), Diazepam, Sex-dependent impacts, Japanese
medaka
drugs (Puia, 2001). Moreover, its metabolites (e.g., oxazepam, temazepam, and nordiazepam) can still inhibit the
activity of the central nervous system, also as a common
benzodiazepine drug used in clinical practice (Eghbali et
al., 1997). The pollution of DZP and its metabolites has
become very severe in various water ecosystems. For
example, Yuan et al. (2012) detected the residues of
oxazepam in medical and municipal wastewater in Beijing,
China, and found that the highest concentrations
detected in the inlet and outlet were 942 ng/L and
752 ng/L, respectively. John et al. (2022) collected surface water samples from 1052 regions along 258 rivers in
104 countries to detect pharmaceutical pollution and
found that the highest concentration of DZP was 851 ng/L.
Previous studies have demonstrated that DZP
belongs to the highly persistent drug pollutants, with a
half–life in natural ecosystems of 311 ± 26 days (West
and Rowland, 2012). According to its Log–Kow value
(=2.86), the bioconcentration coefficient (BCF) of DZP
in aquatic organisms can be estimated to be approximately 33, i.e., it has a moderate bioaccumulation ability
(Overturf et al., 2016; Wang et al., 2019). Overturf et al.
(2016) reported that DZP could enrich in various tissues
of channel catfish (Ictalurus punctatus) with kinetic
BCFs of 146, 45, 15, 9.8, and 2.1 in plasma, gonads,
brain, liver, and muscle, respectively. The investigation
of wild fish and aquatic products also indirectly proves
the bioaccumulation of DZP. For example, Kwon et al.
(2009) reported that the concentration of DZP in the livers of wild–caught hornyhead turbot (Pleuronichthys
verticalis) ranged from 23 to 110 ng/g, and Mottaleb et
I N T RODUCTION
Due to the long treatment time and applicability of
psychiatric diseases to patients of all ages, the production and consumption of psychotropic drugs are very
large (Calisto and Esteves, 2009). Correspondingly, the
environmental pollution caused by the widespread use of
psychotropic drugs has attracted widespread attention
(Argaluza et al., 2021). Among them, benzodiazepines
(BZDs) are typical antianxiety and sedative drugs that
can selectively act on the limbic system of the brain,
enhancing the efficacy of the main inhibitory neurotransmitter γ–aminobutyric acid (GABA) (Fraser, 1998). Due
to their fast efficacy, low adverse reactions and high
safety, BZDs have been widely used in clinical practice
and also be detected in wastewater, surface water, drinking waters, and tissues of organisms in many countries
(Ma et al., 2018).
As a typical long–acting BZD prescription, diazepam
(DZP; C16H13ClN2O) is one of the world’s largest sedative
Institute of Environmental Health and Ecological Security,
School of the Environment and Safety Engineering, Jiangsu
University, Zhenjiang, Jiangsu 212013, China
2
Jiangsu Collaborative Innovation Center of Technology and
Material of Water Treatment, Suzhou University of Science and
Technology, Suzhou 215009, China
3
Laboratory of Marine Environmental Science, Faculty of
Agriculture, Kyushu University, Fukuoka 819–0395, Japan
4
Institute of Nature and Environmental Technology, Kanazawa
University, Kanazawa 920–1192, Japan
* Corresponding author: e–mail: xuchunqiu@ujs.edu.cn (Xuchun
QIU)
1
135
136
S. WANG et al.
al. (2016) reported that the concentrations of DZP in
the muscles of several commercially available fish species ranged from 1.99 to 16.57 ng/g. Therefore, estimating the accumulation of DZP in aquatic species and its
ecological consequences is essential to assess the potential risk of DZP pollution.
As a typical psychotropic drug, DZP may directly
interfere with the function of fish brains and adversely
affect their behavioral traits, closely related to socializing, foraging, and survival (Brodin et al., 2014; Chen et
al., 2021a). For example, exposure to sublethal concentrations of DZP (1200, 120, 12 µg/L) for 4 days can disturb juvenile zebrafish’s swimming activity and social
behaviors by affecting their brain GABA levels (Wu et
al., 2020). The metabolite of DZP, oxazepam, has also
been shown to significantly alter the social behavior of
wild bass at environmental concentrations, thereby
increasing their risk of being preyed on by pike fish,
reducing their population size, and disrupting the ecological balance of the entire water body (Brodin et al.,
2013). Several studies have demonstrated that DZP and
its metabolites to aquatic organisms exhibited gender–
specific toxic effects on aquatic organisms. For example,
Chen et al. (2020) exposed adult zebrafish to a sublethal
dose of DZP for 21 days and found gender differences in
neurotoxicity and behavioral toxicity of DZP to zebrafish,
with females being more sensitive to DZP. On the contrary, Genario et al. (2020) found that only males showed
anxiolytic responses to diazepam exposure (16 µg/L for
24 h). In mammals, the sex difference in hormones and
pharmacokinetics and pharmacodynamics between
females and males may influence their sensitivity to the
activity of drugs (Lynch et al., 2002; Ravenelle et al.,
2014). However, the mechanisms underlying the sex–specific toxic effects of diazepam on fish are still unclear.
Japanese medaka (Oryzias latipes) is a model
organism for environmental monitoring and chemical
risk assessment (OECD, 2012; Shima and Mitani, 2004).
Due to the similarity in the nervous system development
to mammals, Japanese medaka has also been widely
used in studying the pathogenic mechanisms of neurological diseases (Matsui, 2017; Wittbrodt et al., 2002).
Furthermore, many studies also use the behavioral
changes in Japanese medaka to evaluate the ecological
risks associated with sublethal exposure to neurotoxic
pollutants (Chen et al., 2021b; Gerhardt, 2007; Qiu et
al., 2017; Qiu et al., 2020a; Qiu et al., 2020b). In this
study, we determined the biological concentration factors of DZP in different tissues in both male and female
Japanese medaka, according to the (OECD, 2012).
Moreover, time–series variations in the behavioral traits
of fish were also determined. This study aimed to investigate the tissue–specific and gender–specific differences
in the bioconcentration of DZP in Japanese medaka and
its impact on fish behaviors during the countship.
M AT ER I A LS A N D M ET HODS
Chemicals
Diazepam (CAS No. 439–14–5) was purchased from
the Laiyao Biotechnology Co., Ltd. (Beijing, China).
Methanol (analytical grade) was purchased from Kemei
Biotechnology Co., Ltd. (Zhenjiang, Jiangsu, China).
The enzyme–linked immunosorbent assay (ELISA) kit
for assaying diazepam was purchased from Yanjin
Biotechnology Co., Ltd (Shanghai, China).
Organisms
Japanese medaka (nine–month–old, body length:
2.3–3.1 cm) used in this study was obtained from bloodstock maintained in our laboratory, Jiangsu University
(Zhenjiang, Jiangsu, China). ...
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