International Journal of Marine Science 2016, Vol.6, No.4, 1-12
2
APEOs and predominant existed in various mediums
of water environment, such as sewage sludge,
sediments and waste water treatment plants. Several
investigations
have
reported
that
4-t-OP
contamination occurred in rivers and estuaries of
Asian, European, Australia, Africa and South
American rivers (Jiang et al., 2012; Watanabe et al.,
2007; Brix et al., 2010; Ying et al., 2009;
Salgueiro-Gonzalez et al., 2015; Oketola, and
Fagbemigun, 2013; Mayer et al., 2007). However,
although several reports showed that limited level of
4-t-OP were detected in the worldwide river, the
presence of 4-t-OP in aquatic environment was
potentially suggesting the release of 4-t-OP from
industrial activities. The releasing of 4-t-OP into
aquatic environment from manufacturing industries
increase the probability of living organism exposure to
4-t-OP and led to the bioaccumulation of 4-t-OP in
living organism through direct or indirect uptake
process. In recent year global concern regarding
4-t-OP contamination in the environment potentially
resulted in toxicity and damage to health due to its
xenoestrogen role to disrupt endocrine function
through competitive bidding to the nature estrogen
receptors, consequently, investigators using diverse
animal model to evaluate the effects of 4-t-OP on live
organism.
Studies have shown that the harmful effects of 4-t-OP
on reproductive function and endocrine action of
diverse fish species, for examples, the adult female of
zebrafish exposed to 4-t-OP higher than 25
g/L for 3
weeks resulted in declined ovary somatic index (OSI)
in zebrafish (Van den Belt et al., 2001); a regress in
testicular growth and vitellogenin (VTG) level
induction was observed respectively in male and
juvenile rainbow trout after a 3-week exposure to 30
g/L 4-t-OP (Jobling et al., 1996; Van den Belt et al.,
2003); exposure to 4-t-OP induced VTG synthesis and
disrupts testis morphology in South American
freshwater fish (Cichlasoma dimerus) (Rey Vazquez
et al., 2009); diet supplement of 4-t-OP in Sparus
aurata induced alteration of liver morphology and
degeneration and mediated induction of heat shock
protein 70 (Hsp 70) and cathepsin genes, which are
bioindicators of endocrine disruption (Traversi et al.,
2014). In addition to fish model, 4-t-OP also has been
proved to alter cyp19a1 expression profiles involving
in gonadal differentiation of male American bullfrog
(Wolff et al., 2015), and susceptible to vascular
function and led to the reduction of vascular
contractile in rats (Hsieh et al., 2009). Due to the
toxicity of 4-t-OP and harmful effects over diverse
species, many countries including European Union
members have legislated to restrict the use of APEOs
in domestic application. However, in spite of that,
human still have many other pathways exposure to
4-t-OP. Recently, clinical reports showed that 4-t-OP
was detected in urine samples from a 57.4%
population of the 2517 subjects, and the concentration
range of 4-t-OP in subjects is between 0.2 ng/mL and
20.6 ng/mL (Calafat et al., 2008). This result
potentially indicated that human already have
exhibited high risk exposure to 4-t-OP from living
environment including drinking water or food. This
view point also can be supported by reports which
showed that 4-t-OP was detected in human milk
samples which is the main nourishment for newborn,
and correlated finding with dietary factors (Ademollo
et al., 2008; Chen et al., 2010). The presence of
4-t-OP contaminant in human milk may increase
health risks in newborn or infant. Moreover, report
also showed that 4-t-OPwas detected in 31 samples in
concentrations from < 0.05 to 1.15 ng/ml from 180
umbilical cord blood samples of newborns, suggesting
that expectant mothers exposed to 4-t-OP and leading
to contamination of fetus through blood delivery (Tan
and Ali Mohd, 2003). It is widely believed that
embryos and infants during development are highly
sensitive to chemicals that cause serious damage to
development and growth, however the effect of 4-t-OP
on embryonic development and physiological function
of fetus so far is still unclear.
Zebrafish possess discrete organs and tissue that are
similar to their human counterparts at the anatomical,
physiological, and molecular level. It has become a
common
experimental
model
for
studying
developmental toxic ity due to the advantage of rapid
development, transparent body for observation, most
genes have been characterized from genome databases
and a larger number of offspring for providing
sufficient experimental material. In the present study,
the influences of 4-t-OP on embryonic development
