International Journal of Marine Science 2016, Vol.6, No.4, 1-12
1
ResearchArticle Open Access
Toxicity Effects of the Environmental Hormone 4-tert-octylphenol in Zebrafish
(
Danio rerio
)
Saputra F.
1, 2
, Yen C.H.
1
, Hsieh C.Y.
3
, Ou T.Y.
4
, Risjani Y.
2
, Cheah W.K.
5
, Hu S.Y.
1,
1 Department of Biological Science and Technology, National Pingtung University of Science and Technology, Pingtung, Taiwan
2 Department of Aquaculture, Faculty of Fisheries and Marine Science, University of Brawijaya, Indonesia
3 Department of Environmental Science and Engineering, National Pingtung University of Science and Technology, Pingtung, Taiwan
4 Department of Industrial Engineering and Management, National Quemoy University, Kinmen, Taiwan
5 School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia Engineering Campus, 14300 Nibong Tebal, Penang, Malaysia
Corresponding author email
International Journal of Marine Science, 2016, Vol.6, No.4 doi: 10.5376/ijms.2016.06.0004
Received: 17 Sep., 2015
Accepted: 22 Oct., 2015
Published: 21 Jan., 2016
Copyright
©
2016
Saputra et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Saputra F., Yen C.H., Hsieh C.Y., Ou T.Y., Risjani Y., Cheah W.K., and Hu S.Y., 2016, Toxicity effects of the environmental hormone 4-tert-octylphenol in
zebrafish (
Danio rerio
), International Journal of Marine Science, 6(4):1-12 (doi
)
Abstract
4-tert-octylphenol (4-t-OP), an environmental exogenous estrogen is produced by microbial degradation of alkylphenol
polyethoxylates (APEOs). Although it is well known that 4-t-OP can cause the feminization of male, sterility and deficiency of gonad
development of aquatic animals by disrupting the endocrine reproductive signaling, less is known about the effects of 4-t-OP on
embryonic development. Moreover, the presence of 4-t-OP were detected in umbilical cord blood samples of newborns suggesting
infants during development may expose to the risk of 4-t-OP contaminant, hence to investigate the effect of 4-t-OP on physiological
function during embryonic development is necessary. In the present study, zebrafish embryos exposed to 4-t-OP were used to
evaluate the toxicity of 4-t-OP. The 50% lethal dose (LD50) for wild type zebrafish embryos exposure to 4-t-OP for 3 days is
approximately 1.0
M, and a high ratio of cardiovascular defects were showed in survival embryos. To observe the cardiovascular
defects more efficiently, Tg (fil-1:EGFP) zebrafish embryos was used in 4-t-OP exposure treatment. Following exposure
Tg(fil-1:EGFP) zebrafish embryos to 4-t-OP at 1.0
M for 4 days, a highly proportion of defects revealed in cardiovascular system,
including pericardical edema, irregular shape or incomplete looping of ventricle and atrium, the absence of intersegmental vessel in
the tail of notochord, unformed parachordal vessel and kinks in the caudal vein. The phenotype of cardiovascular defects was
accompanied by reduced heart rate and impaired blood circulation. The mRNA expression levels of transcription factors, which are
critical for zebrafish heart chamber formation and blood vessel development, were analyzed by RT-PCR. The results showed that the
presence of 4-t-OP significantly induce expression level of ERα and ERβ2, and caused cardiovascular defects by suppressing
transcription factor Nkx2.7, Hand2, Tbx2a, Tbx2b, Tbx5a, FGF1a, GATA-4, -5 and -6 in zebrafish. The present study suggests that
4-t-OP affects the cardiovascular development in zebrafish and elucidated that early life exposure to 4-t-OP potentially may take a
risk of impaired cardiovascular function.
Keywords
4-tert-octylphenol; Toxicity; Zebrafish; Cardiovascular development
1 Introduction
Accompanying w ith the progress of human activity,
loads of industrial or agricultural chemicals
introduced into the aquatic environment and have
been found to elic it adverse health effects in human
and w ildlife. One kind of thes e chemicals is called
endocrine disrupting chemicals (EDCs) due to its
interfered effects on a phys iological function by
mimicking or antagonizing the action of the natural
hormone. The presence of environmental EDCs in
animals body may alter reproduction, secretion,
transport, binding and action of natural hormones that
are responsible for maintenance of homeostasis (Frye
et al., 2012; Kirkley, and Sargis, 2014; Meeker, 2012;
Orlando,
and
Ellestad,
2014).
Alkylphenol
polyethoxylates (APEOs) are considered as one sort of
EDCs, which belong to the group of nonionic
surfactants and are widely used in the manufacturing
of detergent, plastics, cosmetics, paint, and
agrochemicals (Kovarova et al., 2013; Ying et al.,
2002). Alkylphenolic contaminants, 4-tert-octylphenol
(4-t-OP), is one of microbial degradation products of
