Gibberellic acid

CASRN 77

- 06

- 5 Tox21 Chemical QC: Pass, purity and mw confirmed ER QSAR Prediction: Inactive (EAS=8.13)

Gibberellic Acids are naturally occurring plant hormones. Gibberellic Acids are used in agriculture as plant regulators to stimulate both cell division and cell elongation that affect leaves as well as stems (eventually affecting fruit development and fruit set). Applications of Gibberellic Acids can also hasten plant maturation and seed germination. Because they are naturally occurring compounds and have a nontoxic mode of action in target plants, Gibberellic Acid and related isomers have been classified as biochemical pesticides ( http://www.epa.gov/oppsr rd1/REDs/factsheets/4110fact.pdf )

.

Two developmental toxicity studies for Gibberellic Acids were reviewed by the EPA. In the first study, rats were dosed at 0, 100, or 1,000 mg/kg/day for 8 weeks without significant chemical, hematological or pathologic evidence of toxicity. The maternal

to xicity NOEL was greater than 1,000 mg/kg/day (HTD). In the second study, rabbits were dosed at 0, 300, or 1,000 mg/kg/day; the highest concentration caused increased mortality, abortion rates, clinical signs of toxicity, and gross pathological observations

. The maternal and developmental NOELs were established at 300 mg/kg/day. ( http://www.epa.gov/oppsrrd1/REDs/factsheets/4110fact.pdf )

.

One published reference was considered guideline

- like ( PMID 7442448 ). This study

used the Ovx mouse model with sc dosing beginning at either postnatal day 70 or 110;

t he results are summarized in the table below. Gibberellic acid demonstrated a agonistic

effect after five consecutive days of treatment a t a dose of .0001 mg /day.PMID Result Model Species Route Duration LEL (mg/day)

7442448 POS Ovx _PND70 Mouse sc 5 d .0001

7442448 POS Ovx _PND 110 Mouse sc 5 d .0001

Giberellic acid was inactive in the ToxCast ER assays and the ER Pathway model.

Octamethylcyclotetrasiloxane (D4)

CASRN 556

- 67

- 2 Tox21 Chemical QC: Inconclusive, Analysis in progress ER QSAR Prediction: Inactive (EAS=3.73e

- 7)Octamethylcyclotetrasiloxane (D4) is used in the formulation of various hair care, skin

care, and deodorant products, as well as topical pharmaceutical s and as a component in breast implants

. Depending on the product type, the concentration of D4 in form ulations

varies between 0.1

- and 54%

. Certain food products are processed using silicone antifoam containing octamethyltetracyclosiloxane. I nhalation studies in Sprague Dawley rats and

New Zealand White rabbits revealed no evidence of developmental toxicity or teratogenicity up to the highes t dose levels tested, i.e. 700 ppm for rats and 500 ppm for rabbits. However, effects on female rat fertility were identified at 700 ppm characterized by reduced numbers of eggs ovulated and a decrease in implantation sites and litter size. ( http://ec.europa.eu/health/ph_risk/committees/04_sccp/docs/sccp_o_035.pdf )

Octamethylcyclotetrasiloxane (D4) showed positive uterotrophic results in two published

reference s that were considered guideline

- like (PMID 11509742 and 14575643) . One study used immature rats and started oral dosing at two different time points, PND 18 and PND21, and the other used ovariectomized mice and oral dosing; the results are

summarized in the tabl e below. Both studies observed a positive response at extremely high doses, which may result in plasma level concentrations that are above the concentration range tested in the HTS assays.

PMID Result Model Species Route Duration LEL (mg/kg/day)

11509742 POS Immature_PND21 Rat p.o. 4 d 3162

11509742 POS Immature_PND18 Rat p.o. 4 d 3162

14575643 POS Ovx _PND42

- 49 Mouse p.o. 3 d 250

Interestingly, this compound was active in the two transactivation assays from the Attagene platform run in HepG2 cells , as shown in the left panel of the plot below, and was therefore predicted by the model to act via technology

- specific assay

interference . The top tested concentration in these assays was 200 uM, twice that of any other assay, supporting the idea that this co mpound may need to be tested at higher concentrations to observe the potential estrogenic activity. These assays also have limited metabolic capacity, which may be necessary for the endocrine activity

of D4 in vivo.Triclosan

CASRN 3380

- 34

- 5

Tox21 Chemical QC: Pass, purity and mw confirmed ER QSAR Prediction: Borderline (EAS=14.6)

Triclosan is a diphenyl ether derivative used in cosmetics and to ilet soaps as an antiseptic, and has both bacteriostatic and fungistatic action. In rats, the Reproducti ve/Developmental LOAEL is 150 mg/kg/day , based on reduced viability of pups and reduced body weights , and in mice the developmental LOAEL is 75 mg/kg/day based on irregular ossification of the skull

. In a rabbit developmental toxicity study, no

treatment r elated effects were observed up to 150 mg/kg/day. ( http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=5564&loc=ec_rcs )

One published reference on Triclosan was considered guideline

- like ( PMID 22062131 ). This study used the immature rat model with oral dosing starting at PND 19; t he results

are summarized in the table belowPMID Result Model Species Route Duration LEL (mg/kg/day)

22062131 POS Immature_PND19 Rat p.o. 3 d 7.5

This compound was active in one of the transactivation assays from the Attagene platform run in HepG2 cells, as shown in the left panel of the plot below, and the

Tox21 ERa beta

- lactamase antagonist assay (orange line), but at concentrations concurrent with overt cytotoxicity (gray box) . The top tested concentration in these assays was 200 uM, twice that of any other assay, supporting the idea that this compound may need to be tested at higher concentrations to observe the potential estrogenic activity. The ATG assay also has limited metabolic capacity, which may be necessary for the endocrine activity of triclosan in vivo.

Methyl Paraben

CASRN 99

- 76

- 3
Tox21 Chemical QC: Pass, purity and mw confirmed ER QSAR Prediction: Positive (EAS=18.5)Methyl paraben is a stable, non

- volatile compound used as an inhibitor of yeasts and

molds, a n anti

- microbial preservative in foods, beverages, cosmetics, parenteral solutions, topi cal antibiotics, corticosteroid preparations, and galencials, and as a vehicle for ophthalmic solution . This widespread production and use may result in its release to the environment through various waste streams

. There is a tolerance of zero established for residues of methylpara ben in milk from dairy animals. Residues of methyl p

hydroxybenzoate are exempted from the requirement of a tolerance when used as a preservative (Limit: meets specifications of Food Chemical Codex; not to exceed 0.1% in

formulati ons)

. It is hydrolyzed to p

- hydro xybenzoic acid, conjugated, and rapidly

excreted in the urine ; t here is no evidence of accumulation. Acute and chronic toxicity studies in animals indicate that methyl paraben is non

- toxic by various dosing routes. Methyl p araben is not carcinogenic or mutagenic , nor is it teratogenic or embryotoxic

. ( http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=7456&loc=ec_rcs#x332 )

Methyl paraben showed conflicting uterotrophic results in two published references that were considered guideline

- like (PMID 9875295 and 15697177). One study used immature rats and with either oral or s.c. dosing and saw negative results in both protocols , and the other also used immature rats and s.c. dosing but saw a positive result at 55 mg/kg/day; the results are summarized in the table below.

PMID Result Model Species Route Duration LEL or HDT (mg/kg/day)

9875295 NEG Immature_PND21 Rat p.o. 3 d 800

9875295 NEG Immature_PND21 Rat s.c. 3 d 80

15697177 POS Immature_PND21 Rat s.c. 3 d 55

Methyl paraben was active at high concentrations in the two transactivation assays from the Attagene platform run in HepG2 cells (pink lines) and the ERa

- ERb proteincomplementation assay (green line) , as shown in the left panel of the plot below,

and was predicted by the model to act via technology

- specific assay interference, with a very small AUC score for ER agonism as well (R1=0.0077). This compound

may a lso need to be tested at higher concentrations or be metabolized to observe the potential estrogenic activity.

4

- Hydroxybenzoic acid

CASRN 99

- 96

- 7 Tox21 Chemical QC: Pass, purity and mw confirmed ER QSAR Prediction: Positive (EAS=22.5)

4

- Hydroxybenzoic acid is used as a chemical intermediate, in synthetic dr ugs, and as a food preservative up to 0.1% (limits set by FDA). This may result in its release to the environment through various waste streams

. ( http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=135&loc=ec_rcs )4

- Hydroxybenzoic acid showed conflicting uterotrophic results in three published

references that we re considered guideline

- like (PMID 9417843, 15697177 and 17904329). All studies used s.c. dosing, the positive result was seen in ovariectomized mice, and both studies with immature rats yielded negative outcomes; the results are

summarized in the table be low.

PMID Result Model Species Route Duration LEL or HDT (mg/kg/day)

9417843 POS OVX_PND49 Mouse s.c. 3 d 5

15697177 NEG Immature_PND21 Rat s.c. 3 d 150

17904329 NEG Immature_PND20 Rat s.c. 3 d 1000

4

- Hydroxybenzoic acid was inactive in the ToxCast ER assays and the ER Pathway

model , as shown in the plot below

.

Permethrin

CASRN 52645

- 53

- 1 Tox21 Chemical QC: Inconclusive, Analysis in progress ER QSAR Prediction: Inactive (EAS=12.7)Permethrin is a pyrethroid insecticide commonly used as a topical treatment for scabies

and lice infestations. It m ediates the voltage

- dependent sodium ion permeability of

excitable membranes , and is known to interact with CYP2B6 and CYP3A4. ( http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=40326&loc=ec_rcs )

Permethrin showed conflicting uterotrophic results in two published references that were

consi dered guideline

- like (PMID 9875295 and 15697177). One study used

ovariectomized rats and oral dosing and saw a negative result at doses up to150 mg/kg/day, and the other study used immature rats and s.c. dosing and saw a positive

result at 800 mg/kg/day; t he results are summarized in the table below. The positive response was observed at an extremely high dose, which may result in plasma level concentrations that are well above the concentration range tested in the HTS assays

PMID Result Model Species Rou te Duration LEL or HDT (mg/kg/day)

12052007 NEG OVX_PND42 Rat p.o. 3 d 150

15599112 POS Immature_PND19 Rat s.c. 3 d 800Permethrin was active at high concentrations in the two transactivation assays from

the Attagene platform run in HepG2 cells, as shown in the left panel of the plot below, and was predicted by the model to act via technology

- specific assay interference. All of the aforementioned activity occurred in the same concentration range where cytotoxicity was also observed. This compound may also need to be tested at higher concentrations or be metabolized to observe the potential estrogenic activity.

Reserpine

CASRN 50

- 55

- 5 Tox21 Chemical QC: Pass, purity and mw confirmed
ER QSAR Prediction: Inactive (EAS= 3.34 )

Reserpine is an antipsychotic and antihypertensive drug that irreversibly blocks the uptake (and storage) of norepinephrine and dopamine into synaptic vesicles by inhibitingthe Vesicular Monoamine Transporters (VMAT). Dosing is typically up to 0.5 mg orally

once a day. Reserpine has been discontinued in some countries due to its many interactions and side effects. ( http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=5770&loc=ec_rcs )

Reserpine had conflicting result in the uterotrophic literature. One published reference

was cons idered guideline

- like ( PMID 23027998 ). This study used the Ovx mouse model with either po and sc dosing; t he results are summarized in the table below. Res erpine demonstrated a weak agonistic effect after seven consecutive days of treatment at the highest dose an d only by the sc route of expo sure.

PMID Result Model Species Route Duration LEL or Max tested (mg/kg/day)

23037998 NEG Ovx Mouse p.o. 7 d 1000

23037998 POS Ovx Mouse s.c. 7 d 3

Reserpine was active in the Tox21 ERa beta

- lactamase antagonist assay at concentrations approaching cytotoxic activity , as shown in the left

- hand plot, but had ER Pathway model scores of 0 for both agonism and antagonism.