Potential Developmental and Reproductive Impacts of Triclocarban: A Scoping Review
Table 3
Animal studies evaluating the endocrine/reproductive and developmental effects of triclocarban.
Study
Model
Strain
Exposure duration
Age at exposure
Route of exposure
Doses
LOEL
Summary
Reproductive/endocrine
Ankley et al., 2010
Fish
Fathead minnow (Pimephales promelas)
21 d
Adult
Submersion
5, 10 µg/L
5.00 µg/L
TCC alone did not masculinize females (measured by induction of tubercles), but TCC + trenbolone increased tubercle scores, enhancing the effects of TRB alone. TCC had no effect on VTG levels.
Barros et al., 2017
Crustacean
Gammarus locusta
60 d
Juvenile, adult
Submersion
100, 500, 2500 ng/L
NA
TCC disrupted biochemical responses in Gammarus locusta exposed to environmentally relevant levels for 60 d but had no effect on ecological responses (survival, body length, or reproduction).
Chen et al., 2008
Rat
Sprague Dawley
10 d
Adult
Oral (food)
0.25%
NA
Rats exposed to T + TCC showed increased weights of seminal vesicles, ventral prostate, glans penis, Cowper’s gland, and LABC muscle compared to T treatment alone. TCC treatment alone increased ventral prostate weight.
Chung et al., 2011
Fish
Zebrafish (Danio rerio)
24 h
Embryonic
Submersion
0.25 µM
NA
TCC alone did not induce AroB expression (which is estrogen-responsive), but it enhanced E2-induced AroB expression. TCC also inhibited BPA-induced AroB expression.
Duleba et al., 2011
Rat
Sprague Dawley
10 d
Adult
Oral (food)
0.25%
NA
TCC treatment induced changes in the wet weight of the liver, seminal vesicle, ventral prostate, LABC, and glans penis. The dry weight of the seminal vesicle, LABC, and glans penis was increased by TCC exposure. TCC also increased the protein and DNA content of the ventral prostate, LABC, and glans penis. LH and T levels were not affected.
Geiss et al., 2016
Mollusk
Mud snail (Potamopyrgus antipodarum)
28 d
Embryonic
Submersion
0.1, 0.3, 1, 3, 10 µg/L (NC)
0.3 µg/L
Chronic exposure to environmentally relevant levels of TCC for 28 days altered the number of embryos in the brood pouch of mud snails in a nonmonotonic fashion.
Giudice et al., 2010
Mollusk
Mud snail (Potamopyrgus antipodarum)
2, 4 w
Adult
Submersion
0, 0.045, 0.14, 0.45, 1.4, 4.5, 14.0 µg/L
0.14 µg/L
After 4 weeks (but not before), TCC-exposed snails had significantly increased unshelled, shelled, and total embryos (there were some nonmonotonic results with shelled and total embryos).
Kennedy et al., 2014
Rat
Sprague Dawley
35 d
Embryonic, adult
Oral (food)
0.2, 0.5% w/w TCC
0.2% w/w TCC
TCC decreased maternal body weight gain and circulating T3 during gestation. There was no effect on implantation number, maternal organ weights, or hormone profile (E2, P, T, T4, and TSH). Exposure to pups from gestation through lactation did not affect number of pups born or birth weight. However, pups exposed to TCC from gestation through lactation did not survive past PND8 and there was evidence of mammary gland involution in the dams. Body weight and survival were decreased in pups nursed by TCC exposed dams.
Schultz et al., 2012
Fish
Fathead minnow (Pimephales promelas)
12 d
Larval, adult
Submersion
550, 1600 ng/L
1600 ng/L
In adults, TCC exposure had no effect on GSI, SSC, gonad histology, or VTG.
Villeneuve et al., 2017
Fish
Fathead minnow (Pimephales promelas)
22 d
Adult
Submersion
1, 5 µg/L
1 µg/L
Fecundity was decreased by greater than 50% in fathead minnows exposed to 5 µg/L TCC but not in those exposed to 1 µg/L. Fecundity was further decreased with coexposure to 5 µg/L TCC and 0.5 µg/L 17b-trenbolone. Chronic exposure to TCC for 22 d did not affect GSI or male secondary sex characteristics and did not cause masculinization of female fish. This exposure also did not alter plasma VTG concentrations or circulating E2 or T concentrations. In contrast, ex vivo assessment of steroid production from the reproductive organs was altered by TCC. Fish exposed to 5 µg/L TCC had more preovulatory atretic follicles and other abnormalities. Gene expression changes in the ovary were also observed in fish exposed to 5 µg/L TCC.
Wang et al., 2016
Fish
Zebrafish (Danio rerio)
21 d
Adult
Submersion
2.5, 5 µg/L (NC)
2.5 µg/L
The effects on reproduction of TCC alone or in combination with mercury were examined following 21 days of exposure. TCC exposure reduced spermatogenesis in males and delayed maturation of oocytes in females. Serum T and E2 were decreased in fish of both sexes and the expression of 3β-HSD, CYP17, 17-β-HSD, and CYP19a was decreased in the testes and disrupted in the ovaries of exposed fish. Liver VTG expression was also altered in males.
Yueh et al., 2012
Mouse
and CAR-null
2 d
Adult
Intraperitoneal
16, 20 mg/kg
16 mg/kg
TCC exposure in transgenic mice resulted in increased hUGT and CYP gene expression via the CAR.
Zenobio et al., 2014
Fish
Fathead minnow (Pimephales promelas)
48 h
Adult
Submersion
1.40 µg/L
NA
TCC exposure did not impact mortality, condition factor, or GSIs in adults. TCC exposure resulted in increased expression of liver VTG in both males and females, decreased testis AR and StAR, increased liver LPL in males, and decreased ovarian AR expression. There were no changes in CYP19a, ERα, THRα, or PGES.
TCC caused complete lethality of developing clam eggs larvae at 0.05 ppm and 0.1 ppm, respectively.
Enright et al., 2017
Mouse
CD-1
GD1–18; PND0–10
Embryonic; neonate; adult
Oral (water)
100 nM
NA
TCC-exposed offspring had increased bodyweight compared to controls, which persisted to PND56 (after cessation of treatment at PND10). Brain (both sexes) and uterine weights (females) were reduced in offspring. Fat pad and thymus weights were increased in female offspring. Also, in females, gene expressions of several lipid metabolism genes including leptin, adiponectin, and PPARα were downregulated in adipose and liver tissues.
Han et al., 2016
Rotifer
Brachionus koreanus
3, 6, 12, 24 h and 1–10 d
Neonate
Submersion
50, 100, 200 µg/L
100 µg/L
TCC retarded population growth and reduced cumulative offspring and lifespan of Brachionus koreanus. TCC also altered the expression of xenobiotic metabolizing genes.
Kennedy et al., 2014
Rat
Sprague Dawley
35 d
Embryonic, adult
Oral (food)
0.2, 0.5% w/w TCC
0.2% w/w TCC
TCC exposure to pups from gestation through lactation did not affect number of pups born or birth weight. However, pups exposed to TCC from gestation through lactation did not survive past PND8. Body weight and survival were decreased in pups nursed by TCC-exposed dams.
Schultz et al., 2012
Fish
Fathead minnow (Pimephales promelas)
12 d
Adult; larval
Submersion
550, 1600 ng/L
1600 ng/L
In the larva, TCC treatment did not have any effect on body weight, time to response, escape velocity, or total escape response.
On a population level, TCC reduced population density of daphnia immediately following exposure. Mortality was size- and age-dependent with neonates being more sensitive than adults. Mortality was decreased when multiwalled carbon nanotubules were present in the growth medium. Exposure to TCC or TCC + multiwalled carbon nanotubules increased the ratio of juveniles to adults in the population but had no effect on minimal or maximal body length.
TCC and other chemicals were tested in two embryo bioassays. TCC increased mortality rates at exposures greater than 350 µg/L but did not have effects on other developmental parameters. The NOEC for zebrafish was 100 µg/L. In Paracentrotus lividus, TCC decreased larval length and increased abnormalities at 0.64 and 1.6 µg/L, respectively.
Villeneuve et al., 2017
Fish
Fathead minnow (Pimephales promelas)
22 d
Adult
Submersion
1, 5 µg/L
1 µg/L
Chronic exposure to TCC for 22 days did not affect adult body mass.
Xu et al., 2015
Crustacean
Artemia salina
6, 12, 24 h
Larval
Submersion
18.0 µg/L
NA
TCC caused dose-dependent mortality in Artemia salina and was an order of magnitude more potent than TCS. DNA damage and apoptosis of Artemia salina nauplii coelomocytes were apparent as early as 12 and 24 hours after exposure
